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# The underestimated potential of solar energy to mitigate climate change

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## Abstract and Figures

The Intergovernmental Panel on Climate Change's fifth assessment report emphasizes the importance of bioenergy and carbon capture and storage for achieving climate goals, but it does not identify solar energy as a strategically important technology option. That is surprising given the strong growth, large resource, and low environmental footprint of photovoltaics (PV). Here we explore how models have consistently underestimated PV deployment and identify the reasons for underlying bias in models. Our analysis reveals that rapid technological learning and technology-specific policy support were crucial to PV deployment in the past, but that future success will depend on adequate financing instruments and the management of system integration. We propose that with coordinated advances in multiple components of the energy system, PV could supply 30–50% of electricity in competitive markets.
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... Geometrisch lassen sie sich beschreiben als ein hexagonales Graphengitter, welches, wie in Abbildung 2.1 angedeutet, zu einem Zylinder aufgerollt wird. Dabei definiert der sogenannte Aufrollvektor die Struktur der SWNT, er stellt eine Linearkombination der beiden Einheitsvektoren ⃗ a 1 und ⃗ a 2 , die die hexagonale Einheitszelle aufspannen, dar: ⃗ C = n · ⃗ a 1 + m · ⃗ a 2 mit n, m ∈ N; n ≥ m. (2.1) Das Deskriptorenpaar n,m beschreibt die Geometrie der SWNT also eindeutig und damit auch die davon abhängigen Eigenschaften [37][38][39][40][41]. Für die in dieser Arbeit untersuchten (6,5) [30,92], aber auch Exzitonengrößen von 2 nm wurden vorhergesagt [88]. Das PSF und die experimentellen Parameter zur Bestimmung der Exzitonengröße werden in Kapitel 2. 1.3 näher erläutert. ...
... Es wurde eine Spektroelektrochemieküvette der Pfadlänge 0. 5 ...
... in dotierten (6,5)-SWNTs 5 ...
Thesis
Um den jahrtausendealten Weg der Menschheit vom Papyrus über Buchdruck und siliziumbasierte Halbleiter in Richtung noch leistungsfähigerer Technologien zu gehen und weiterhin Heureka-Momente zu schaffen, bieten Kohlenstoffnanoröhren ein weites Forschungsfeld. Besonders die halbleitenden Charakteristika von SWNTs sowie die Manipulation dieser durch Dotierung bergen viele Möglichkeiten für zukünftige Anwendungen in moderner Elektrotechnologie. Der Weg zu einer industriellen Implementierung von SWNTs in neuartigen optoelektronischen Bauteilen ließe sich durch eine Ausweitung des Wissens bezüglich SWNTs und der dotierungsbasierten Anpassung ihrer Eigenschaften ebnen. Mit dieser Erkenntniserweiterung als Zielsetzung wurden im Rahmen dieser Dissertation halbleitende, einwandige (6,5)-Kohlenstoffnanoröhren als chiralitätsreine, polymerstabilisierte Proben untersucht. Die ultrakurzzeitaufgelöste Spektroskopie der SWNTs erfolgte an organischen Suspensionen wie auch Dünnschichtfilmen, die je mittels eines gewissen Quantums an Gold(III)-chlorid dotiert worden waren. So konnten die ablaufenden Dynamiken auf einer ps-Zeitskala untersucht werden. In Kapitel 4 konnte mittels transienter Absorptionsexperimente an redoxchemisch p-dotierter SWNT-Suspensionen zunächst gezeigt werden, dass sich die bei optischer Anregung gebildeten Trionen nicht analog zu Exzitonen diffusiv entlang der Nanoröhre bewegen, sondern lokalisiert vorliegen. Die längere trionischen Zerfallsdauer nach X$_1$- verglichen mit X$_1^+$-resonanter Anregung zeugt außerdem davon, dass das Trion aus dem Exziton gespeist wird. Der Einfluss der Dotierung auf die Zerfallsdynamiken von X$_1$ und X$_1^+$ wurde an SWNT-Dünnschichtfilmen untersucht. Das Photobleichsignal des Exzitons verschiebt hypsochrom und zerfällt schneller mit zunehmender Ladungsträgerdichte durch höherer Gold(III)-chloridkonzentrationen. Dies resultiert aus dem verringerten Abstand zwischen den Ladungsträgern, welche als nichtstrahlende Löschstellen fungieren. Für das X$_1^+$-PB ist ein ähnliches Verhalten zu beobachten. Dabei wird dieses Signal mit weiter steigender Dotierung von einer der H-Bande zuzuordnenden Photoabsorption überlagert. Diese lässt sich in einer starken Sättigung der Dotierung wie auch einer hohen Bandkantenverschiebung begründen. In Kapitel 5 wurde die Größe der Exzitonen und Trionen in dotierten SWNT-Dünnschichtfilmen mittels des Phasenraumfüllmodells bestimmt. Dabei lag besonderes Augenmerk auf der Kompensation des PB/PA-Überlapps, dem schnellen Zerfall, einem Ausgleich von Differenzen zwischen Anrege- und Absorptionsspektrum sowie dem Anteil intrinsischer/dotierter Nanorohrsegmente, um korrigierte Größen $\xi_\mathrm{k}$ zu erhalten. Für die Trionengröße wurde zusätzlich der Überlapp der Absorptionsbanden einbezogen, um korrigierte Werte $\xi_{\mathrm{T,k}}$ zu bestimmen. $\xi_\mathrm{k}$ beträgt in der intrinsischen Form 6$\pm$2\,nm und bleibt bis zu einer Ladungsträgerdichte $n_{\mathrm{LT}}<0.10$\,nm$^{-1}$ etwa gleich, anschließend ist ein Absinken bis auf etwa 4\,nm bei $n_{\mathrm{LT}}\approx0.20$\,nm$^{-1}$ zu beobachten. Für diesen Trend ist die Überlagerung von Exziton- und H-Bande verantwortlich, da so der Faktor zur Bestimmung des Anteils intrinsischer Nanorohrsegmente an der SWNT verfälscht wird. Die Abweichung der intrinsischen Größe von den in der Literatur berichteten 13$\pm$3\,nm ist möglicherweise auf Unterschiede in der Probenpräparation zurückzuführen. Für die Trionengröße ergibt sich bei steigender Dotierung ein ähnliches Verhalten: Sie beträgt für $n_{\mathrm{LT}}<0.20$\,nm$^{-1}$ 1.83$\pm$0.47\,nm, was in der Größenordnung in guter Übereinstimmung mit der Literatur ist. Für höhere Dotierungen sinkt $\xi_{\mathrm{T,k}}$ bis auf 0.92$\pm$0.26nm ab. Dies erklärt sich dadurch, dass bei höherer $n_{\mathrm{LT}}$ die H-Bande das Spektrum dominiert, sodass der Einfluss der Absorptionsbandenüberlagerung nicht mehr vollständig durch den entsprechenden Korrekturfaktor kompensiert werden kann. Kapitel 6 beschäftigte sich anstelle redoxchemischer Dotierung der nanoskaligen Halbleiter mit der (spektro-)elektrochemischen Untersuchung von Vorläufern molekularer Radikale. SWV-Messungen weisen dabei darauf hin, dass die Pyrene Pyr1-Pyr3 entsprechend der Anzahl ihrer Substituenten bei Reduktion Mono-, Bi- beziehungsweise Tetraradikale bilden. Die strukturelle Ähnlichkeit der Moleküle äußert sich in gleichen Reduktionspotentialen wie auch ähnlichen potentialabhängigen Absorptionsspektren. Während nur marginale Unterschiede in den PL-Spektren der neutralen und reduzierten Spezies festgestellt werden konnte, lieferte das zeitkorrelierte Einzelphotonenzählen aufschlussreichere Ergebnisse: So wird die Fluoreszenzlebensdauer stark von der Polarität der Umgegbung beeinflusst - bereits die Zugabe des Leitsalzes führt hier zu Änderungen. Die durchschnittliche Fluoreszenzlebensdauer $\tau_{\mathrm{av}}$ sinkt außerdem mit Reduktion und Radikalbildung; für höhere Emissionswellenlängen ist $\tau_{\mathrm{av}}$ außerdem höher. Insgesamt verdeutlichten die Experimente die gute Abschirmung zwischen Pyrenkern und Naphthalimidsubstituenten der Moleküle sowie die Sensibilität gegenüber dem Medium durch TICT, das Vorhandensein von Bi- und Tetraradikalen kann allerdings nicht vollständig belegt werden, wofür EPR-Messugen notwendig wären.
... On the supply side, renewable electricity must replace generation from fossil fuels. Especially wind and photovoltaic (PV) power offer a great global technical potential ranging from 1,585 to 50,580 EJ, at least three times 2019's primary consumption, and declined in levelized costs by 70% and 90% in the last ten years, respectively [2,3]. Consequently, power generation from wind and PV is rising and in some countries already constitutes a major share: In 2020, wind and PV amounted to 60% of total generation in Denmark or 32% in Germany [4]. ...
... In transport, direct electrification involves battery electric vehicles (or electric overhead lines for heavy-duty vehicles), while fuel cell (FC) vehicles or combustion of synthetic fuels create an indirect demand for electricity. Non-electric options for decarbonization in these sectors are scarce since the sustainable potential of biomass (BM) as a primary source of energy is estimated between 100 and 300 EJ and far from sufficient to satisfy global demand [2]. Carbon capturing, if available, will be limited to industrial scale and not applicable in space heating or individual transport. ...
... In light of our research question, analysis of model results focuses on flexibility needs and provision rather than total quantities of supply and demand. 2 To quantify the provision of flexibility from different technologies, we extend the approach introduced in Heggarty et al. [9]. Its basic idea is to visualize the modulation of technology operation around its average, for instance by time of day as in Fig. 5. Positive values indicate total generation for a given hour is above the yearly average; negative values below. ...
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Supply and demand for electricity are central to the decarbonisation of the energy system. To replace fossil fuels, supply of electricity must shift to wind and solar, but due to their variability, fully renewable supply poses a challenge. On the other hand, additional demand for electricity arises to cut emissions in the heating, transport, or industry sector. We analyze how additional demand from these sectors can be flexible to support the integration of fluctuating renewables on the supply-side. The analysis builds on a macro-energy system model with an extensive scope to cover all sectors and high spatio-temporal detail to capture the variability of renewables. Results show that flexible electrification can efficiently provide a major share of system flexibility if incentivized by regulation. Especially electricity demand for the production of hydrogen is flexible, if hydrogen pipelines and storages are deployed to match production with final consumption.
... In grid-available locations, hybrid units are suggested to ensure contentious operations whereas in off-grid locations intermittent renewable desalination systems are suggested. According to a recent study, the IPCC (Intergovernmental Panel on Climatic Change) is oversighting the potential of solar energy (Creutzig et al. 2017). By 2050, solar PV would play a dominant role in electricity generation with a share of 30-50% (Creutzig et al. 2017). ...
... According to a recent study, the IPCC (Intergovernmental Panel on Climatic Change) is oversighting the potential of solar energy (Creutzig et al. 2017). By 2050, solar PV would play a dominant role in electricity generation with a share of 30-50% (Creutzig et al. 2017). The installed photovoltaic system capacity worldwide is projected to increase from 600 to 3000 GW between 2019 and 2030. ...
... IAM scenarios with low-or no-overshoot tend to have lower levels of wind and solar share in electricity generation in 2050 than do the IEA NZE, Shell Sky and BP Net Zero scenarios, as shown in Fig. 4a (~45% vs. 60%-65%), possibly reflecting a historical tendency of IAMs to underestimate the potential for higher shares of variable renewable energy [36][37][38][39][40] . All models tend to show similar characteristics for nuclear power by mid-century (Fig. 4b), with a share in electricity generation somewhat lower than at present, but higher in absolute terms due to the increasing contribution of electricity in the energy system (Fig. 4e). ...
... Our focus has been on institutional pathways, but similar limitations are valid for the growing literature of bottom-up energy modeling approaches that find the potential for 100% renewable energy-based systems by mid-century [52][53][54][55][56][57][58][59][60][61] , which tend to outpace estimates of renewable penetration rates compared to IAMs 36,62,63 . A claim of 100% renewable energy by 2050 may align with energy sector benchmarks for PA-compatibility, but it is not sufficient to guarantee these pathways meet the LTTG. ...
Article
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Scientifically rigorous guidance to policy makers on mitigation options for meeting the Paris Agreement long-term temperature goal requires an evaluation of long-term global-warming implications of greenhouse gas emissions pathways. Here we employ a uniform and transparent methodology to evaluate Paris Agreement compatibility of influential institutional emission scenarios from the grey literature, including those from Shell, BP, and the International Energy Agency. We compare a selection of these scenarios analysed with this methodology to the Integrated Assessment Model scenarios assessed by the Intergovernmental Panel on Climate Change. We harmonize emissions to a consistent base-year and account for all greenhouse gases and aerosol precursor emissions, ensuring a self-consistent comparison of climate variables. An evaluation of peak and end-of-century temperatures is made, with both being relevant to the Paris Agreement goal. Of the scenarios assessed, we find that only the IEA Net Zero 2050 scenario is aligned with the criteria for Paris Agreement consistency employed here. We investigate root causes for misalignment with these criteria based on the underlying energy system transformation.
... Historically, most energy-economy models have underestimated deployment rates for renewable energy technologies and overestimated their costs [2][3][4][5][6][7] , which has led to calls for alternative approaches and more reliable technology forecasting A B Figure 1. Historical costs and production of key energy supply technologies (A) Inflation-adjusted useful energy costs (or prices for oil, coal, and gas) as a function of time. ...
... (Note that IAM and IEA projections are better for mature incumbent technologies such as fossil fuels, but their projections for solar PV, wind, batteries, and electrolyzers have systematically underestimated deployment and overestimated costs.). 2,5,45 Wright's law is widely used to generate technology cost projections in IAMs. [46][47][48] However, it is typically used in conjunction with ad hoc constraints such as deployment rate limits and floor costs, i.e., fixed levels that costs are assumed to never fall below. ...
Article
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Rapidly decarbonizing the global energy system is critical for addressing climate change, but concerns about costs have been a barrier to implementation. Most energy-economy models have historically underestimated deployment rates for renewable energy technologies and overestimated their costs. These issues have driven calls for alternative approaches and more reliable technology forecasting methods. Here, we use an approach based on probabilistic cost forecasting methods that have been statistically validated by backtesting on more than 50 technologies. We generate probabilistic cost forecasts for solar energy, wind energy, batteries, and electrolyzers, conditional on deployment. We use these methods to estimate future energy system costs and explore how technology cost uncertainty propagates through to system costs in three different scenarios. Compared to continuing with a fossil fuel-based system, a rapid green energy transition will likely result in overall net savings of many trillions of dollars—even without accounting for climate damages or co-benefits of climate policy.
... In grid-available locations, hybrid units are suggested to ensure contentious operations whereas in off-grid locations intermittent renewable desalination systems are suggested. According to a recent study, the IPCC (Intergovernmental Panel on Climatic Change) is oversighting the potential of solar energy (Creutzig et al. 2017). By 2050, solar PV would play a dominant role in electricity generation with a share of 30-50% (Creutzig et al. 2017). ...
... According to a recent study, the IPCC (Intergovernmental Panel on Climatic Change) is oversighting the potential of solar energy (Creutzig et al. 2017). By 2050, solar PV would play a dominant role in electricity generation with a share of 30-50% (Creutzig et al. 2017). The installed photovoltaic system capacity worldwide is projected to increase from 600 to 3000 GW between 2019 and 2030. ...
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Due to current water stress, there is a problem with hygiene and sanitation in many parts of the world. According to predictions from the United Nations, more than 2.7 billion people will be challenged by water scarcity by the middle of the century. The water industry is increasingly interested in desalination of the sea, ocean, and brackish water. Desalination processes are widely classified as thermal or membrane technologies. In the Middle East, thermal desalination remains the primary technology of choice, but membrane processes, for example reverse osmosis (RO), have evolved rapidly and in many other parts of the world are currently even surpassing thermal processes. The purpose of this paper is to review the renewable energy source, the technology, desalination systems, and their possible integration with renewable energy resources and their cost. This article suggests that the most practical renewable desalination techniques to be used are the solar photovoltaic integrated RO desalination process, the hybrid solar photovoltaic-wind integrated RO desalination process, the hybrid solar photovoltaic-thermal (PVT) integrated RO desalination process, and the hybrid solar photovoltaic-thermal effect distillation (PVT-MED) desalination process. However, intensive research is still required to minimize the cost, reduce the heat loss, enhance the performance, and increase the productivity.
... A similar observation was achieved with the REMIND model, which has produced quite slow RE uptake [298], [299]. However, if realistic solar PV and VRE integration costs are applied, the model switches to VRE-dominated solutions [146], [295]. ...
... Similar to parts of the academic community at large, they resist the challenge of 100% RE scenarios based on the dogma that the world cannot do without fossil fuels and nuclear energy. Over the years, two influential organizations have attracted especially heavy criticism for underestimating VRE in general and solar PV specifically: the International Energy Agency, and the Intergovernmental Panel on Climate Change, as pointed out for instance by Philipps et al. [359], Breyer et al. [192], Creutzig et al. [295], and Breyer and Jefferson [360]. ...
Article
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Research on 100% renewable energy systems is a relatively recent phenomenon. It was initiated in the mid-1970s, catalyzed by skyrocketing oil prices. Since the mid-2000s, it has quickly evolved into a prominent research field encompassing an expansive and growing number of research groups and organizations across the world. The main conclusion of most of these studies is that 100% renewables is feasible worldwide at low cost. Advanced concepts and methods now enable the field to chart realistic as well as cost- or resource-optimized and efficient transition pathways to a future without the use of fossil fuels. Such proposed pathways in turn, have helped spur 100% renewable energy policy targets and actions, leading to more research. In most transition pathways, solar energy and wind power increasingly emerge as the central pillars of a sustainable energy system combined with energy efficiency measures. Cost-optimization modeling and greater resource availability tend to lead to higher solar photovoltaic shares, while emphasis on energy supply diversification tends to point to higher wind power contributions. Recent research has focused on the challenges and opportunities regarding grid congestion, energy storage, sector coupling, electrification of transport and industry implying power-to-X and hydrogen-to-X, and the inclusion of natural and technical carbon dioxide removal (CDR) approaches. The result is a holistic vision of the transition towards a net-negative greenhouse gas emissions economy that can limit global warming to 1.5°C with a clearly defined carbon budget in a sustainable and cost-effective manner based on 100% renewable energy-industry-CDR systems. Initially, the field encountered very strong skepticism. Therefore, this paper also includes a response to major critiques against 100% renewable energy systems, and also discusses the institutional inertia that hampers adoption by the International Energy Agency and the Intergovernmental Panel on Climate Change, as well as possible negative connections to community acceptance and energy justice. We conclude by discussing how this emergent research field can further progress to the benefit of society.
... III. Enjeux et perspectives de développement du solaire PV en Guyane D'après[28], le PV dispose d'atouts majeurs : une excellente fiabilité, une modularité sans pareille, un fonctionnement exempt de toute nuisance et une très bonne aptitude à l'intégration architecturale propice aux installations urbaines et rurales. Issu d'une ressource dont le potentiel pour limiter le changement climatique est encore sous-estimé[29], il peut, à de nombreux égards, contribuer à la transition énergétique du territoire.1) Analyse SWOT de la filière PVForces : Comme évoqué plus haut, la Guyane possède des conditions d'ensoleillement favorables au développement de l'énergie solaire. ...
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Du fait de sa situation géographique, la Guyane, région française d'Outre-mer, reste fortement dépendante des énergies fossiles importées. Avec un unique réseau électrique alimentant le littoral d'un territoire de 83 534 km 2 , les enjeux énergétiques sont nombreux et notamment liés à la diversification du mix électrique qui repose principalement sur des moyens thermiques et hydrauliques. La Guyane connaît un véritable paradoxe énergétique avec d'une part une abondance de ressources renouvelables et d'autre part une lente évolution des énergies qui en découlent. En France, la loi de transition énergétique pour la croissance verte (LTECV), a comme principal objectif de favoriser la valorisation des sources d'énergies locales pour atteindre l'autonomie énergétique à l'horizon 2030. Malgré un ensoleillement favorable et des opportunités offertes par mise en place de mécanismes de soutien, les investissements dans les projets photovoltaïques (PV) en Guyane n'émergent pas aussi vite qu'il le faudrait au regard de la croissance accrue de ses besoins électriques. Cet article fait un état des lieux en présentant, par une analyse SWOT, les enjeux et les perspectives de développement en Guyane. Il propose également une analyse économique d'un projet PV raccordé au réseau intégrant des analyses de sensibilité et simulations Monte Carlo. L'étude fournit aux porteurs de projets des informations importantes sur la rentabilité économique et financière des projets PV et met en exergue la baisse des coûts de production de la filière en Guyane.
... For example, most IAMs embed exogenous parameters about the population, economic growth, and technology costs without taking into account interactions between these factors [172]. In addition, it is undoubtedly a great challenge to reliably estimate changes in technology costs and innovation over the coming decades, and no models have yet done this [173,174]. Another key limitation is that most models explore and optimize the deployment routines of CCUS under the constraint of CO 2 emissions, as a result, the obtained results are goal-directed and may be far from the real world. ...
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With the proposal to achieve carbon neutrality by the mid-21st century, carbon capture, utilization, and storage (CCUS) as a critical negative carbon technology is receiving extensive attention and concerns around the world. Under this context, the development of CCUS and relevant literature both have been experiencing an upsurge. However, the actual scale of CCUS is still far behind our expectations, especially, the various risks and uncertainties associated with its deployment planning have not yet been addressed clearly. Therefore, this paper provides an overview of model-based CCUS deployment pathways toward carbon neutrality, as well as the associated risks of financial, technical, environmental, health and safety (EHS) aspects. On this basis, we scrutinize the potential challenges that could lead to the pace of CCUS deployment inconsistent with the need to achieve a carbon-neutral target. The results suggest that the "Golden Age" of CCUS deployment lies from 2040 to 2060 in the world, while 2030-2050 for China. Furthermore, we found that inadequate exploration in geologic storage capacity also creates a critical conundrum for CCUS deployment and optimization, apart from typical challenges including high failure rate of projects, the lack of financial support and market stimulus, as well as incomplete regulation framework and risk-sharing mechanism. Lastly, this paper points out the further potential research direction, followed by policy implications and recommendations.
... The development of the photovoltaic power generation industry has been paid more and more attention to actively dealing with climate change. The development and utilization of solar energy have been considered as an effective way to solve the energy crisis and climate problems (UNDP 2000;Sun 2011;Creutzig et al. 2017). At present, many countries in the world attach great importance to the development of the solar photovoltaic industry (Cui et al. 2013). ...
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In this study, the relationship of the surface shortwave radiation (SSR) with the daily precipitation intensity (DPREI), total cloud cover (TCC), and aerosol optical depth (AOD) is analyzed for the five northwestern provinces (Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi) of China. It reveals the influences of the different DPREI levels and different TCC and AOD levels on the SSR diurnal variation. The results show that the average SSR is stronger in Xinjiang and Qinghai, and the seasons with the stronger intensity of SSR and larger variation of diurnal SSR in the provinces of northwest China are summer and spring. Detailed analysis shows that the influence of DPREI, TCC, and AOD on SSR is greater in the eastern region of northwest China than that in the western region. In spring and summer, it is possible to select a factor among DPREI, TCC, and AOD which has the best-fitting relationship with SSR in each province of northwest China. When considering the DPREI, TCC, and AOD simultaneously, the fitting effect of SSR is better than that of the results fitted by the single factor. In particular, the fitting ability of SSR in Xinjiang and Qinghai has been significantly improved. According to the basic meteorological elements such as DPREI, TCC, and AOD, the variation characteristics of regional mean SSR under typical weather conditions can be obtained. It is helpful to assess the SSR simply just based on the weather information from the meteorological office.
... [7][8][9] The main reasons behind this are the use of outdated costs for wind and solar and the poor modeling of renewable balancing strategies in IAMs. 32,33,72,73 In our work, these limitations are overcome resulting in wind and solar becoming the cornerstone of the decarbonized system. This is in agreement with the recent analysis by Luderer et al. 10 We found that at least a small amount of CO 2 sequestration, in the order of 200 MtCO 2 /a, at a reasonable price, is needed to ease the operation of the fully decarbonized system. ...
Article
Europe’s contribution to global warming will be determined by the cumulative emissions until climate neutrality is achieved. Here, we investigate alternative transition paths under different carbon budgets. We use PyPSA-Eur-Sec, an open model of the sector-coupled European energy system with high spatial and temporal resolution. All the paths entail similar technological transformations, but the timing of the scale-up of important technologies like electrolysis, carbon capture, and hydrogen network differs. Solar PV and onshore and offshore wind become the cornerstone of a net-zero energy system, enabling the decarbonization of other sectors via direct electrification (heat pumps and electric vehicles) or indirect electrification (using synthetic fuels). For a social cost of carbon (SCC) of 120€/tCO2, transition paths under 1.5 and 1.6°C budgets are, respectively, 8% and 1% more expensive than the 2°C budget because building assets earlier costs more. The 1.5°C budget is cost optimal if a SCC of at least 300€/tCO2 is considered.
... During the transition to LCP, the external main factors that encourage innovation are precisely the other two risk drivers of the transition: government policies and society's change of preferences, according to institutional and stakeholder theories. Their demand-pull effect J o u r n a l P r e -p r o o f contributes to accelerating the adoption of low-carbon technologies (Creutzig et al., 2017). Other authors mention specific policies, such as regulation (Berrone et al., 2013), and the influence of specific agents, such as stakeholders, as the drivers of companies' adoption of greener practices (Cainelli et al., 2015;Liao, 2018). ...
Article
The transition to carbon neutrality by 2050 is a challenge for EU firms. The increasingly stringent regulation and required technological change in the context of environmental demands by firms' stakeholders and civil society may compromise the viability of high carbon emitters. This study analyzes the impact of environmental performance on default risk as firms advance to low-carbon production (LCP), considering the moderating effect of stranded assets and innovation. For a sample of listed firms from 16 European countries from 2005 to 2019, our results indicate a greater distance to default for better carbon performers that are more advanced in their transition to LCP. Furthermore, default risk is lower when tangibility decreases and a firm has an active role in innovation activities, these effects being amplified for good carbon performers. Our results are robust to the use of alternative proxies for default risk, stranded assets, and innovation.
... There has been a significant increase in the solar photovoltaic (PV) installed capacity worldwide, increasing from 41 GW in 2010 to 716 GW by the end of 2020 [1], with a continuous trend of exceeding expectations [2,3]. For example, China has increased capacity from 1 GW in 2010 to 254 GW by 2020, while the United States has progressed from 3 GW PV in 2010 to 74 GW by 2020 [4]. ...
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Solar photovoltaic (PV) deployments are growing rapidly to provide a sustainable source of electricity, but their output is strongly impacted by environmental phenomena such as soiling and low irradiance conditions induced by haze from urban sources, dust, and bushfire smoke. This review examines the effects of haze on PV performance, highlights significant results, and identifies apparent research gaps in the current literature. In addition to the severe health issues caused by industrial exhausted aerosol, dust storms particles, and bushfire smoke, reduction in irradiance (in some cases up to 80%) is the most dominant impact of these sources of haze. Haze also causes changes in the received solar spectrum, and higher bandgap PV materials are more affected by the presence of haze and aerosols in the atmosphere by 20-40% than low bandgap semiconductors. In many cities throughout the world, pollution-related haze causes substantial annual revenue loss to PV operators. In addition, haze imposes severe effects on direct irradiance; therefore, tracking systems and concentrated PV systems are most affected. These technical impacts of haze all indicate the need for careful customization of PV systems for specific locations. In addition, to increase global PV output, it is clear that air pollution control regulations such as China’s national policies against air pollution and eco-friendly international actions such as COP26 should be employed and executed. Further studies are needed including indoor experiments, forecasting future implications of aerosols on PV energy conversion, and performing energy policy analysis to identify associated challenges and propose practical strategies.
... Full dependence on such resources has been a global problem for the last three decades [5]. Hence finding alternatives for energy resources based on renewable energy is vital for reducing the effects of climate change [6]. ...
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The rising energy demand for school's buildings in Palestine is one of the problems facing the energy sector. This paper aims to provide estimation for the potential production of electricity from the installation of PV systems on the roof of schools' buildings, to produce its energy needs and to provide electricity to its surrounding buildings. The most used school building types were selected for the installation of the photovoltaic (PV) system. The produced electricity from the installation of PV systems was estimated using PVSOL software. The energy consumption for the selected type of the schools was simulated using design-builder thermal simulation software. A comparison between energy production and consumption was done for two climatic zones, with different tilt angles and different scenarios for the school's building envelope and indoor systems. The results show that the PV systems on schools' buildings can supply their estimated consumption, and provide a surplus in electricity production. This surplus can be a base for the transition to renewable energy in the residential areas surrounding school buildings. The study concluded that the installation of PV systems should be combined with building envelope thermal improvements or a combination of envelope improvements and heating and cooling systems.
... To achieve objectives of the Paris Climate Agreement and limit global warming, the energy system must undergo a major transformation and replace 86% of primary energy from fossil fuels as of 2019 with renewable resources (Ritchie & Roser, 2020). At the heart of this transformation is renewable electricity from wind and photovoltaic (PV) for two reasons: First, its technical potential exceeds other renewables and even demand projections (Creutzig et al., 2017). Estimates for the global potential of PV alone range from 1,585 to 50,580 EJ, at least three times 2019's primary consumption. ...
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This paper applies Benders decomposition to two-stage stochastic problems for energy planning with multiple climatic years, a key problem for the design of renewable energy systems. First, we implement Benders decomposition with existing enhancements suited for the characteristics of the problem, a simple continuous master-problem and few but large sub-problems. Next, we develop a novel trust-region method using a quadratic constraint that is continuously adapted to further improve the algorithm. In a quantitative case-study our method accelerates Benders decomposition by a factor of four to six slightly increasing solve time of the master-problem, but greatly reducing the number of iterations. With the computational resources at our disposal, Benders decomposition with quadratic trust-region outperforms closed optimization if planning covers more than six climatic years, because run-time does not increase with the number of scenarios thanks to distributed computing. Furthermore, results show that the quadratic trust-region approach benefits from a heuristic starting solution but does not depend on it to be performative. Finally, we suggest further improvements of the algorithm. First, heuristic methods to narrow the solution space of the master-problem. Second, approximations of the sub-problems to faster add inexact but valid cuts.
... Photovoltaic solar power system is a renewable energy system which converts sunlight energy into electricity [1,2]. Notably, solar energy has the potential to adequately provide the present and future global energy demands [2,3,4,5,6]. This can be realized through effective and sustained research and technological advancement which will help in boosting the harvesting and harnessing of the solar energy wherever there is sufficient sunlight. ...
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In this paper, PVSyst software-based comparative techn-economic analysis of photovoltaic (PV) power plant for two installation sites with different climatic conditions is presented. The installations sites are in Bayelsa State and Sokoto State. Bayelsa State has annual average Peak Sun Hour (PSH) of 4.12 hours whereas Sokoto State has annual average PSH of 6.24 hours. Also, the annual average temperature of Sokoto State is 27.1 °C which is higher than that of Bayelsa State (which is25.5 °C). In the analysis, a constant daily load demand that consists of 2000 W power that runs for 24 hours every day in the whole year is adopted. For the installation at Bayelsa State, a total of 310 batteries and 362 PV panels are required to meet the stringent load demand specifications of zero loss of load. On the other hand, at Sokoto , a total of 310 batteries and 362 PV panels are required to meet the same load demand and this is about 142 units (39.22%) reduction in the PV modules. This resulted in gives 25Naira/kWh (13.44 %) reduction in the unit cost of energy for the PV installation in Sokoto State. Furthermore, Bayelsa State has a total of 3082.3 kWh unused energy per year , performance ratio (PR) of 64.3 % and 0.0% loss of load probability (Pr LoL) while Sokoto State has a total of 3.274 kWh unused energy per year , performance ratio (PR) of 69.9 % and 0.0% loss of load probability (Pr LoL).. In all, the results showed that it is more expensive to install and run PV power system in Bayelsa State than in Sokoto State. The idea presented in this study can facilitate policy framework for optimal site for large scale PV installation across Nigeria.
... It is highly desirable to develop sustainable energy sources with the growing demand of energy requirements in recent times. 1 Since solar energy is a tremendously available source of renewable energy, solar-to-chemical conversion methods to generate renewable fuels have become more prudent. 2 Solar energy has been explored to mimic the natural photosynthesis process of plants to engender sustainable H 2 energy fuel. 3 H 2 is a potent renewable fuel (energy carrier) due to its high gravimetric energy density and environmentally benign nature. ...
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In the field of photocatalysis, metal−organic frameworks (MOFs) have emerged as potential photocatalysts owing to their well-defined and tailorable porous structures, high surface areas, and inherent semiconductor-like behavior. However, their photocatalytic H 2 evolution reaction is still limited due to the higher charge recombination rates. Precious metal cocatalysts, such as Pt and Au, are used to suppress electron−hole recombination effects by forming a Schottky junction, but the high cost and scarcity of these metals limit their large-scale applications. Herein, for the first time, we have developed novel ZnCo-MOF hollow rings at room temperature and loaded it with monodispersed transition-metal phosphide (TMPs; NiCoP, FeCoP, Ni 2 P, CoP) nanoparticles as non-noble-metal cocatalysts for efficient visible light driven H 2 evolution reaction. The as-obtained NiCoP@ZnCo-MOF composite displays significantly improved H 2 production rates as compared to the parent MOF and their physical mixture and offers similar photocatalytic H 2 evolution activity as compared to that of Pt@ZnCo-MOF. This is attributed to efficient n−n heterojunction charge separation and transfer, and rapid H 2 evolution reaction dynamics by the reduction of activation energy by NiCoP cocatalyst. The H 2 production rate of NiCoP@ZnCo-MOF is 8583.4 μmol h −1 g −1 , 16 times higher than parent ZCM, and the apparent quantum yield (AQY) is 20.1% at 590 nm, which remained constant for a minimum of 18 h of repeated cycling in the H 2 production without any degradation of the catalyst.
... Another prevalent critique in the literature is the bias of IAMs towards certain technological trajectories [92][93][94][95]. This section explores the justice implications of modelled technological change at two different levels. ...
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Integrated Assessment Models (IAMs) have become the dominant approach for envisioning different mitigation scenarios. While they are not intended to deal with justice, IAM assumptions and structure have justice implications that have not been explicitly discussed or clearly elucidated in critical accounts of modelling practices. Given their key influence in policy decisions and the increasing imperative for just transitions and climate action, a more explicit consideration of the justice dimensions of IAM-derived mitigation pathways is necessary. This paper reviews existing critiques to IAMs through a three-dimensional justice lens to examine the extent to which justice concerns emerge or remain unnoticed in the literature. This review helps substantiate how disciplinary and geographical assumptions and norms shape policy choices. Focusing mostly on the role of technoeconomic framings and processes of model-based knowledge production, and drawing from critical justice theorists, such as Nancy Fraser, the article shows how dominant approaches to justice have overlooked questions of recognition and their subsuming distributional and participational concerns. It also points to the need to engage with other knowledge systems and approaches through cognitive justice, for a more transformative critique of policy relevant climate knowledge, as well as to strive for more diverse, equitable and inclusive policy options.
... Some critiques implicitly targeted the (unrealistic) imaginative capacity of developers, like too optimistic regional GDP (Castles and Henderson, 2003a), global technology developments (Pielke et al., 2008), and some NETs critiques. However, historical non-OECD GDP and non-biomass renewable energy were within SRES ranges (Pedersen et al., 2021), and technology developments have been more rapid than expected (Creutzig et al., 2017). Despite this, such critiques play a role in 1) continuously challenging the modelers' perceptions, which shape assumptions, and 2) informing scenario users about plausible shortfalls. ...
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Long-term global emission scenarios enable the analysis of future climate change, impacts, and response strategies by providing insight into possible future developments and linking these different climate research elements. Such scenarios play a crucial role in the climate change literature informing the Intergovernmental Panel on Climate Change’s (IPCC) Assessment Reports (ARs) and support policymakers. This article reviews the evolution of emission scenarios, since 1990, by focusing on scenario critiques and responses as published in the literature. We focus on the issues raised in the critiques and the possible impact on scenario development. The critique (280) focuses on four areas: 1) key scenario assumptions (40%), 2) the emissions range covered by the scenarios and missing scenarios (25%), 3) methodological issues (24%), and 4) the policy relevance and handling of uncertainty (11%). Scenario critiques have become increasingly influential since 2000. Some areas of critique have decreased or become less prominent (probability, development process, convergence assumptions, and economic metrics). Other areas have become more dominant over time (e.g., policy relevance & implications of scenarios, transparency, Negative Emissions Technologies (NETs) assumptions, missing scenarios). Several changes have been made in developing scenarios and their content that respond to the critique.
... Lipton and Ravalion (1995) suggest a close relationship between paucity of energy services and indicators of poverty, including illiteracy, life expectancy, and infant mortality, among others (World Health Organization, 2016). Harnessing the potential of the Earth's solar energy for electricity generation is not only pivotal to poverty alleviation and economic development but a smart and costeffective alternative for climate mitigation and a low-carbon future economy (Creutzig et al., 2017). Solar energy provides people disconnected from the global economy and without access to power grids the opportunity to light their homes and businesses in places where grid power can either be extremely expensive or unreliable (International Trade Forum [ITF], 2011). ...
Article
Energy demand continues to drive sustainable development in all countries of the world. As Ghana is accelerating her transition to a low carbon economy, this paper aims to investigate the nature, opportunities and challenges of the solar energy market in the City of Accra. This paper used a qualitative inquiry approach to investigate the solar energy market development in Accra. The Ghana Government’s policy framework for achieving sustainable energy in the country as well as the emerging opportunities and barriers relating to market development of this energy sub-sector in Accra are analysed. The paper found that inadequate institutional and service-provider’s financial support, after-sales technical support, limited consumer credit facilities, a dearth of public education and general awareness among the public about solar energy technology remain important barriers to solar energy development in Accra. In addition, the Net Metering policy dissonance constitutes a critical barrier to solar energy transition and market development in the city. In conclusion, government programming and increasing industrial sector participation will provide a vital catalyst for the development of the solar energy sub-sector and market in Accra.
... Thus, renewables can easily serve as backup power supply for water treatment plant. Other studies show that renewable energy sources can provide enough energy to satisfy the annual energy demand of the integrated energy system on a global scale [20,21]. Thus, it seems that use of renewable energy sources as a back-up power supply is reasonable from environmental and economical perspectives [22,23]. ...
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The article is focused on the issue of blackouts in a water industry and the selection of a renewable energy source for a water treatment plant. In the case of power outage, it is necessary to constantly ensure the supply of a drinking water, if this requirement would not be met, it could cause of deterioration of hygiene and health of the population. To be able to convey drinking water during a blackout, it is mandatory to have a backup power supply. The state of the current water treatment plants in the Czech Republic is that they are using diesel generators as backup power supply, which causes air pollution. There are other options of power supply that can be used, such as renewable energy sources. By using a multi-criteria analysis method, renewable energy sources were analyzed for a water treatment plant in the selected region. Based on the results, it seems that the most suitable choice is a small hydro power plant at the entry points of water treatment plant. Other possibilities of renewable energy sources that may be suitable for a water treatment plant and the usage of a multi-criteria analysis method for a water treatment plant in other countries are also discussed.
... Solar thermal energy conversion technology has been considered as a promising method for efficient solar energy harvesting and utilization in recent years, which is getting more and more attention owing to its high energy conversion efficiency [1][2][3][4]. Usually it can be integrated with a thermal energy storage system, so it is expected to be popularized to realize large-scale and continuous solar energy utilization. As a critical equipment for the solar thermal utilization, many kinds of collectors contained in the solar thermal power generation systems have realized commercial application, the solar selective absorbing coatings (SSAC) in the collectors are important components for effective solar thermal conversion [5,6], which directly determines the overall efficiency of the collectors. ...
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Al 2 O 3 based solar selective absorbing coatings have been considered as a promising candidate for solar thermal conversions, but their properties are expected to be improved urgently. Herein, inspired by the composite materials design, an optimization method for optical performance and thermal stability of Al 2 O 3 was explored by us, the W-Al 2 O 3 based composite structures used for solar was developed, and its electronic structure and optical performance were investigated by the first-principles calculations. It was found that the band gap of the proposed composite structure can be successfully regulated and it decreases significantly with the increase of the mass fraction of W doped in Al 2 O 3 , which leads to the improvement of the thermal stability. The optical properties and solar thermal conversion properties of W-Al 2 O 3 based selective absorption coating are accurately predicted. The results show that W-Al 2 O 3 based solar selective absorption coating also has good absorption and reflection properties. The addition of W atom leads to the reduction of solar thermal efficiency. When the W mass fraction doped in W-Al 2 O 3 is 23.92% at the temperature of 273 K, compared with pure Al 2 O 3 , the solar thermal conversion efficiency is reduced by 6.56%, and the corresponding absorption rate and thermal radiation was reduced by 6.54% and 1.99%, respectively.
... Recently, the technology has experienced rapid cost reductions, which have been widely discussed in the media and consultancy reports [8][9][10], with some speculating that subsidy-free offshore wind was already achieved. As with the rapid cost reductions in solar photovoltaics [11] and energy storage [12], the pace of offshore wind cost reductions has proceeded more rapidly than was widely anticipated, in contrast to the increasing capital costs during the earlier stages of development [13][14][15][16]. For example, in 2016 Wiser et al. [17] used an expert survey to forecast the cost reductions for wind power, and the prices received in recent auctions have already fallen below the expectations for 2050. ...
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This dissertation is a compilation of four self-contained research articles that focus on selected subjects in the field of energy economics. The first article focuses on the competitiveness of offshore wind in mature markets. In this work, we harmonise auction results based on the auction design features. We show that offshore wind power generation can be considered commercially competitive in mature markets without subsidy. Furthermore, once auction results are harmonised, we observe similar expected revenue streams of wind farms across countries. This finding means that different auction designs can fairly reflect the actual costs of developing wind farms and thus translate cost reductions into lower bids. The second article explores the impacts of uncertainty in integrated electricity and gas system optimization models. We address the trade-off that the energy research community faces on a daily basis, i.e., whether to neglect uncertainty when constructing an energy system model and accept a suboptimal solution or to incorporate uncertainty and increase model complexity. Our research aims to bring a systematic understanding of which parametric uncertainties most substantially affect long-term planning decisions in energy system models. In the third article, we focus on seasonal flexibility in the European natural gas market. We develop a market optimization model to simulate the operation of the gas market over a long period. This allows us to explore structural trends in market development, which are driven by changing supply and demand fundamentals. Our work contributes to the methodological question of how to measure the contributions of different flexibility options. Finally, the fourth article investigates the value of Projects of Common Interest—gas infrastructure projects supported by EU public funds—in maintaining gas system resilience amid cold-winter demand spikes and supply shortages. For this purpose, we develop the first application of adaptive robust optimization to gas infrastructure expansion planning. The model endogenously identifies the unfortunate realizations of unknown parameters and suggests the optimal investments strategies to address them. We find that (i) robust solutions point to consistent preferences for specific infrastructure projects, (ii) the real-world construction efforts have been focused on the most promising projects, and (iii) most projects are unlikely to be realized without financial support.
... The social pain of confinement and the changes that accompany it could influence the future trajectory in unanticipated ways34, but social responses alone, as shown here, would not be sufficient to achieve the deep and long-term reductions required to achieve netzero emissions. Low-energy and/or material demand scenarios investigated for climate stabilization expressly aim to link lower demand with increased well-being (Creutzig et al., 2017;McCollum et al., 2020), an ambition that coercive confinements do not meet. Still, by applying economic stimulus that are linked with lowcarbon paths, there are potential to set structural changes in motion. ...
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Government initiatives during the COVID-19 outbreak had a significant impact on global energy consumption patterns. Many international borders were blocked, and individuals were confined to their homes, restricting mobility and changing social habits. The lockdowns introduced economic, physical, and social pastimes to a halt. However, as an advantage, the world had a good effect on air quality, the environment, and greenhouse gases (GHGs), in particular CO2 emissions. When compared to the mean 2019 levels, daily worldwide CO2 emissions had fallen by-17 % (-11 to-25 % for 1) by early April 2020, with changes in surface transportation accounting for little under half of the decline. The total global CO2 reduction from January to April 2020 was predicted to be more than 1749 Mt CO2 (a 14.3 % decline), with the transportation sector contributing the most (58%) followed by coal power generation (29%), and industry (10%). As a result, transportation was identified as the primary source of more than half of the emissions reduction during the epidemic. As of August 23, 2021, 193 countries produced 8.4 million tons of pandemic-related plastic waste, with 25.9 thousand tons dumped into the ocean, accounting for 1.5 percent of total riverine plastic discharge globally. As a result of China and India's record-breaking confirmed cases, MMPW generation and discharge are projected to be more skewed toward Asia. The study found that hospital trash accounts for 73% of global discharge and that Asia accounts for 72% of global discharge, indicating the need for better medical waste management in emerging countries. This review highlights the brief lessening in GHG outflows and expanded request for single-use plastics, including the weight of an as of now out-of-control worldwide plastic squander emergency caused by the COVID-19 widespread. This review also will be helpful for people to understand the COVID-19 impact on climate change point of view. There is advantage and disadvantage brought by this pandemic and it's the best time to change the new normal of globalization. Global policies makers should consider the acute need to change the policies for a circular economy with the best environment sustainable, both during the pandemic and, more significantly, thereafter. The authors of the reference articles on the COVID-19 pandemic hope their findings will aid attempts to better understand the disease's relationship to climate change. If lessons from both global crises are learned, the world may be better prepared to deal with global climate change, which has local consequences.
... In general, a lack of high temporal resolutions can lead to difficulties when estimating the optimal level of variable renewable generation, often either over-or underestimating the market value of solar or wind generation, the challenges of variable renewable integration, the peak hourly residual demand, and the need for energy storage and baseload Haydt et al., 2011;Ludig et al., 2011;Kannan and Turton, 2013;Welsch et al., 2014;Pietzcker et al., 2017;Bistline, 2021). While approximate methods such as parameterization via residual load duration curves (RLDCs) are able to capture the supply-side dynamics of VREs, they remain methodologically limited for representing the flexible demand-side dynamics (Ueckerdt et al., 2015;Creutzig et al., 2017). Besides limited temporal resolutions, IAMs also usually have coarse spatial resolutions, which can lead to an under-or overestimation of transmission grid bottlenecks, geographical variability of wind and solar resources, and of the flexibility requirements to balance supply and demand (Aryanpur et al., 2021;Frysztacki et al., 2021;Martínez-Gordón et al., 2021). ...
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Integrated assessment models (IAMs) are a central tool for the quantitative analysis of climate change mitigation strategies. However, due to their global, cross-sectoral and centennial scope, IAMs cannot explicitly represent the spatio-temporal detail required to properly analyze the key role of variable renewable electricity (VRE) for decarbonizing the power sector and end-use electrification. In contrast, power sector models (PSMs) incorporate high spatio-temporal resolutions, but tend to have narrower scopes and shorter time horizons. To overcome these limitations, we present a novel methodology: an iterative and fully automated soft-coupling framework that combines the strengths of a IAM and a PSM. This framework uses the market values of power generation as well as the capture prices of demand in the PSM as price signals that change the capacity and power mix of the IAM. Hence, both models make endogenous investment decisions, leading to a joint solution. We apply the method to Germany in a proof-of-concept study using the IAM REMIND and the PSM DIETER, and confirm the theoretically prediction of almost-full convergence both in terms of decision variables and (shadow) prices. At the end of the iterative process, the absolute model difference between the generation shares of any generator type for any year is <5% for a simple configuration (no storage, no flexible demand), and 6-7% for a more realistic and detailed configuration (with storage and flexible demand). For the simple configuration, we mathematically show that this coupling scheme corresponds uniquely to an iterative mapping of the Lagrangians of two power sector optimization problems of different time resolutions, which can lead to a comprehensive model convergence of both decision variables and (shadow) prices. Since our approach is based on fundamental economic principles, it is applicable also to other IAM-PSM pairs.
... Two more recent datasets from NGFS and ENGAGE based on IAMs that include recent trends and understanding (Creutzig et al. 2017;Riahi et al. 2021) yield comparably higher estimates of the additional total energy investments for 2020-2024 (335 and 227 billion US$/year; green and black horizontal bars in Fig. 2b, respectively). On the other hand, our argument that very high near-term carbon prices suppress final energy demand and further reduce additional total energy investments does not explain some of the model results. ... Article Full-text available It has been claimed that COVID-19 public stimulus packages could be sufficient to meet the short-term energy investment needs to leverage a shift toward a pathway consistent with the 1.5 °C target of the Paris Agreement. Here, we provide complementary perspectives to reiterate that substantial, broad, and sustained policy efforts beyond stimulus packages will be needed for achieving the Paris Agreement long-term targets. Low-carbon investments will need to scale up and persist over the next several decades following short-term stimulus packages. The required total energy investments in the real world can be larger than the currently available estimates from integrated assessment models (IAMs). Existing databases from IAMs are not sufficient for analyzing the effect of public spending on emission reduction. To inform what role COVID-19 stimulus packages and public investments may play for reaching the Paris Agreement targets, explicit modelling of such policies is required. ... However, downstream of the city, it deteriorates strongly, impacting people's health and livelihoods (W6-access to water, F5-pressure on rural livelihoods). Despite ambitious decarbonization plans by national and state government and the high potential of competitive renewable energy generation [86,87], coal power plants still account for 59% of Maharashtra's installed capacity, compared to 30% of renewables [88]. The latter includes large-scale hydropower with its own environmental impacts (E1-energy-intensive lifestyles, W3-water scarcity, cf. ... Article Full-text available Systems models of the Food–Water–Energy (FWE) nexus face a conceptual difficulty: the systematic integration of local stakeholder perspectives into a coherent framework for analysis. We present a novel procedure to co-produce and systematize the real-life complexity of stakeholder knowledge and forge it into a clear-cut set of challenges. These are clustered into the Pressure–State–Response (PSIR) framework, which ultimately guides the development of a conceptual systems model closely attuned to the needs of local stakeholders. We apply this approach to the case of the emerging megacity Pune and the Bhima basin in India. Through stakeholder workshops, involving 75 resource users and experts, we identified 22 individual challenges. They include exogenous pressures, such as climate change and urbanization, and endogenous pressures, such as agricultural groundwater over-abstraction and land use change. These pressures alter the Bhima basin’s system state, characterized by inefficient water and energy supply systems and regional scarcity. The consequent impacts on society encompass the inadequate provision with food, water, and energy and livelihood challenges for farmers in the basin. An evaluation of policy responses within the conceptual systems model shows the complex cause–effect interactions between nexus subsystems. One single response action, such as the promotion of solar farming, can affect multiple challenges. The resulting concise picture of the regional FWE system serves resource users, policymakers, and researchers to evaluate long-term policies within the context of the urban FWE system. While the presented results are specific to the case study, the approach can be transferred to any other FWE nexus system. ... Solar power is the most available renewable energy source, with great potential to replace fossil fuels to reduce greenhouse gas (GHG) emissions and mitigate climate change (Nemet, 2009;Creutzig et al., 2017). Photovoltaic (PV) technology can convert solar energy directly into electricity with large PV arrays. ... Article Full-text available Photovoltaic (PV) technology, an efficient solution for mitigating the impacts of climate change, has been increasingly used across the world to replace fossil fuel power to minimize greenhouse gas emissions. With the world's highest cumulative and fastest built PV capacity, China needs to assess the environmental and social impacts of these established PV power plants. However, a comprehensive map regarding the PV power plants' locations and extent remains scarce on the country scale. This study developed a workflow, combining machine learning and visual interpretation methods with big satellite data, to map PV power plants across China. We applied a pixel-based random forest (RF) model to classify the PV power plants from composite images in 2020 with a 30 m spatial resolution on the Google Earth Engine (GEE). The resulting classification map was further improved by a visual interpretation approach. Eventually, we established a map of PV power plants in China by 2020, covering a total area of 2917 km 2. We found that most PV power plants were situated on cropland, followed by barren land and grassland, based on the derived national PV map. In addition, the installation of PV power plants has generally decreased the vegetation cover. This new dataset is expected to be conducive to policy management , environmental assessment, and further classification of PV power plants. The dataset of photovoltaic power plant distribution in China by 2020 is available to the public at https://doi.org/10.5281/zenodo.6849477 (Zhang et al., 2022). Article Full-text available The costs of wind and solar technologies have dropped rapidly, but unknowns about technological change and emissions policies create uncertainty about future deployment. We compare projections of U.S. wind and solar costs across published studies and use an energy systems model to evaluate how these reductions could alter electric sector planning decisions and costs under deep decarbonization. Model results indicate that wind and solar are the largest generation resources for many scenarios and regions, but shares depend on assumptions about costs, policy targets, and policy timeframes (spanning 14% to 67% of national generation by 2035). Renewables cost reductions lower decarbonization costs and reduce projections for nuclear and carbon-captured-equipped generation, but policy decisions have a larger influence on future trajectories. Lower wind and solar costs have more limited impacts on deployment of carbon removal technologies and the capacity of clean firm technologies in reaching net-zero emissions in the electric sector. Article Efficient capture, conversion and storage of solar energy has been a long-term pursuit facing the green and low-carbon strategic goal. Nevertheless, fast-charging solar-thermal conversion and sustainable stable energy output are the key challenges in current solar-thermal energy storage systems. Herein, we rationally designed a sustainable stable and fast-charging solar-driven energy storage system that can simultaneously supply electricity and heat by integrating phase change materials (PCMs) and metal-organic framework (MOF) derived magnetic Co-decorated hybrid graphitic carbon and N-doped carbon ([email protected]) nanocage. Benefiting from the synergistic effect between magnetic Co nanoparticles and [email protected] carbon hybrid, the resultant magnetic carbon nanocage demonstrates superior full-spectrum absorption and [email protected] composite PCMs exhibit a high solar-thermal conversion efficiency of 90.7%. More attractively, the solar-thermal energy conversion and storage efficiency of [email protected] composite PCMs is significantly enhanced by 115.8% due to the excellent magnetic manipulation ability of nanocage when a magnetic field was applied. Meanwhile, the designed solar-thermal energy conversion and storage system achieves a maximum output voltage of 290 mV and current of 92.6 mA. This magnetic nanocage-accelerated strategy provides constructive insights into the targeted construction of sustainable and stable fast-charging solar-driven energy storage systems. Article Full-text available Learning curves play a central role in power sector planning. We improve upon past learning curves for utility-scale wind and solar through a combination of approaches. First, we generate plant-level estimates of the levelized cost of energy (LCOE) in the United States, and then use LCOE, rather than capital costs, as the dependent variable. Second, we normalize LCOE to control for exogenous influences unrelated to learning. Third, we use segmented regression to identify change points in LCOE learning. We find full-period LCOE-based learning rates of 15% for wind and 24% for solar, and conclude that (normalized) LCOE-based learning provides a more complete view of technology advancement than afforded by much of the existing literature—particularly that which focuses solely on capital cost learning. Models that do not account for endogenous LCOE-based learning, or that focus narrowly on capital cost learning, may underestimate future LCOE reductions. Article Photovoltaic poverty alleviation project (PPAP) is one of China's essential targeted poverty alleviation projects. This study proposes a machine learning model and uses satellite images to evaluate the performance of PPAP in China. The trained deep convolutional neural network (DCNN) with transfer learning was first used to identify the scale of photovoltaic (PV) power stations. Then the PV power capacity for poverty alleviation and carbon emission mitigation were estimated. The results identified 38 large-scale centralized and approximately 5,063,293 m2PV power stations built in Jinzhai County, Anhui province, China, by November 2020. The main findings are as follows. (1) The power generation and carbon mitigation of PPAP in Jinzhai County is about 1.8×103 MWh and 1.389 Mt per year. (2) The PPAP in Jinzhai County can recover the total costs and get benefits within three years, at least after completion. (3) Dynamic subsidy policy is needed to prevent over-scale or excessive government investment in PPAP. (4) The utilization of PPAP needs to be strengthened to transform the current “blood transfusion type” of poverty alleviation that relies more on government subsidies into more sustainable “hematopoietic style” poverty alleviation. This study is of significance to more accurately and comprehensively evaluate the performance of PPAP and give better utilize the role of renewable energy in promoting energy conservation, carbon emission reduction, and economic development. Article Full-text available The rapid anthropomorphic emission of greenhouse gases is contributing to global climate change, resulting in the increased frequency of extreme weather events, including unexpected snow, frost, and ice accretion in warmer regions that typically do not encounter these conditions. Adverse weather events create challenges for energy systems such as wind turbines and photovoltaics. To maintain energy efficiently and operational fidelity, snow, frost, and ice need to be removed efficiently and rapidly. State‐of‐the‐art removal methods are energy‐intensive (energy density > 30 J cm⁻²) and slow (>1 min). Here, pulsed Joule heating is developed on transparent self‐cleaning interfaces, demonstrating interfacial desnowing, defrosting, and deicing with energy efficiency (energy density < 10 J cm⁻²) and rapidity (≈1 s) beyond what is currently available. The transparency and self‐cleaning are tailored to remove both snow and dust while ensuring minimal interference with optical light absorption. It is experimentally demonstrated a multi‐functional coating material on a commercial photovoltaic cell, demonstrating efficient energy generation recovery and rapid ice/snow removal with minimal energy consumption. Through the elimination of accretion, this technology can potentially widen the applicability of photovoltaics and wind technologies to globally promising locations, potentially further reducing greenhouse gas emissions and global climate change. Article Non-hardware costs are majority of the cost of producing solar photovoltaic (PV) electricity. We use matched data on patents and over 125,000 residential PV installations to estimate the effects of three learning mechanisms in reducing PV costs: learning by doing, searching, and interacting. While previous work in this area has focused predominantly on learning by doing, we find that learning by searching and interacting are also significant mechanisms to facilitate non-hardware cost reductions. Including these two mechanisms reduces the effect of learning by doing in explaining non-hardware cost reductions by 43%. Our results suggest that prior work may overemphasize the role of learning by doing and the policies that help generate learning by doing. Analysis of the supplier-network between installers and their suppliers shows that concentrated supplier networks are associated with lower non-hardware costs, although there are key differences between installer-panel and installer-inverter manufacturer networks. An important implication is that policies for reducing non-hardware costs need to take a more complete view of how different learning mechanisms engender cost reductions. They should particularly consider the important role of learning in supplier networks in cost reductions—an effect that until now has largely been missing in analyses of solar non-hardware costs. Article Many economic and environmental studies on novel perovskite solar cells (PSCs), published ex post the development stage to investigate the market competitiveness, have focused on laboratory‐scale PSC architectures that are not amenable for upscaling. In this paper, we evaluate the market potential and environmental sustainability of a scalable carbon‐electrode‐based PSC by benchmarking it to the market dominating c‐Si photovoltaics and CIGS thin film photovoltaics. The analysis covers the PSCs full lifecycle, at the module and system levels (residential and utility scale), and is based on realistic annual energy output data derived from energy yield calculations. We find that this PSC can produce electricity at low cost (3–6 €cents/kWh), with lowest energy payback (0.6–0.8 years) and greenhouse gas emissions (15–25g CO2 eq./kWh) compared with grid‐connected PV market alternatives, assuming 25years of lifetime, expected PV system cost reductions, and PSC module recycling and refurbishment. Market potential and environmental sustainability evaluation of a scalable carbon‐based perovskite solar cell (PSC) benchmarked to c‐Si and CIGS PVs. The analysis covers the PSCs full lifecycle and is based on energy yield data. This PSC can produce electricity at low cost (3–6 €cents/kWh), with lowest energy payback (0.6–0.8 years) and greenhouse gas emissions (15–25 g CO2 eq./kWh) compared with grid‐connected PV market alternatives, assuming 25 years of lifetime, expected PV system cost reductions, and module recycling and refurbishment. Article Carbon‐based materials have been successfully applied in the zinc ion batteries to improve the energy storage capability and durability of zinc anodes. In this review, four types of carbon materials (conventional carbons, fiber‐like carbons, carbon nanotubes, graphene and other 2D carbon materials) are introduced based on the electrode preparation, physicochemical property and battery performance. Several modification strategies are also illustrated, such as heteroatom doping, hierarchical design and metal/carbon composites. Besides the discussion of existing issues of zinc anodes, the structure‐performance relationships are analyzed in depth. Finally, conclusive remarks of this review are summarized and prospects of the future improvement are proposed. This review summarizes carbon‐based materials in Zn anodes for zinc ion batteries including the energy storage mechanisms, challenges of Zn anodes and the promotional impacts of carbon materials applied in the Zn anodes. Article Full-text available Particulate matter (PM) in the atmosphere and deposited on solar photovoltaic (PV) panels reduce PV energy generation. Reducing anthropogenic PM sources will therefore increase carbon-free energy generation and as a cobenefit will improve surface air quality. However, we lack a global understanding of the sectors that would be the most effective at achieving the necessary reductions in PM sources. Here we combine well-evaluated models of solar PV performance and atmospheric composition to show that deep cuts in air pollutant emissions from the residential, on-road, and energy sectors are the most effective approaches to mitigate PM-induced PV energy losses over East and South Asia, and the Tibetan Plateau, Central Asia, and the Arabian Peninsula, and Western Siberia, respectively. Using 2019 PV capacities as a baseline, we find that a 50% reduction in residential emissions would lead to an additional 10.3 TWh yr-1 (US$878 million yr-1) and 2.5 TWh yr-1 (US$196 million yr-1) produced in China and India, respectively. Article Full-text available Sb‐substituted Cs2AgBiBr6 single crystals and powders were synthesized by various wet‐chemical routes as well as by solvent‐free mechanochemical synthesis. Phase purity and resulting optical properties of differently synthesized Sb‐substituted Cs2AgBiBr6 absorbers were investigated and compared. X‐ray diffraction confirmed that Sb‐substitution results in an apparent single‐phase formation with a unit cell shrinkage up to a certain substitution limit, which varies depending on the synthesis routes. Questions about the phase identification determined by X‐ray diffraction were raised and thoroughly investigated by Raman spectroscopy. UV‐Vis spectroscopy revealed that Sb3+ substitution induced a reduction in the optical bandgap of Cs2AgBiBr6, whereas octahedral factor calculations provided that SbBr6 octahedra can be hardly stable in a Cs2AgBiBr6 double perovskite. Our experimental results of the occurrence and evolution of Raman bands and theoretical calculations of structural stability of SbBr6 octahedra in Cs2AgBiBr6 unambiguously raised doubts about the Sb‐substitution feasibility in Cs2AgBiBr6, and a general substitution strategy in Cs2AgBiBr6 is discussed. This article is protected by copyright. All rights reserved. Article Full-text available Sustainable energy transition, air pollution reduction and climate change mitigation are the most challenging themes in nowadays energy sector. Microgrids (MGs) are one of the most effective ways to integrate Renewable Energy Sources (RES), and among them PhotoVoltaic (PV)-Storage (ST) configuration is relevantly promising. Focusing the attention on the PV and ST converters primary control, the main needs are to properly regulate voltage and frequency and optimally exploit the energy coming from the sun and manage the ST operation without any communication among the converter controllers. The conventional converter control approach presents several drawbacks and thus a strategy based on Higher Order Sliding Mode (HOSM) is presented in this work. The HOSM converter control strategy is fully analysed defining its control laws and the control schemes. A comparison between the HOSM and conventional control is performed with dedicated simulations on a common benchmark MG in order to highlight the advantages of the proposed strategy. Article Solar vapor generation has become a promising technology for water harvesting owing to the abundant and costless solar energy. However, there still remains great challenges to improve the usability of solar absorbers and realize high-efficient vapor generation. Herein, novel solar absorber is constructed using electrospun hydrophilic cellulose acetate/hydrophobic polyvinyl butyral amphipathic Janus nanofibers as substrate. Owing to the unique composition and structure, the electrospun Janus nanofibers film realizes the integration of water-pumping, thermal-resisting, self-floating, and salt-resisting functions in a monolayered film, which is desirable for designing solar absorbers. Highly efficient photothermal conversion material composed of carbon nanotubes, SiO2 nanoparticles and polydopamine is modified onto the surface of the Janus nanofibers film to obtain the solar absorber. With the solar absorber, a state-of-the-art water evaporation rate (2.398 kg m⁻²h⁻¹) can be reached under 1 sun irradiation, and satisfactory reusability is guaranteed as well. Moreover, the solar absorber based on the Janus nanofibers film also shows promising desalination performance. The constructed solar absorber with excellent comprehensive performance provides potential strategy and new design philosophy for clean water generation. Article A prominent feature of photovoltaic devices is their ability to drive photo-generated charges to pathways of asymmetrical conductivity, guiding them to the corresponding electrodes. Under this guideline, the crystalline silicon (c-Si) solar cells dominate the photovoltaic (PV) market for decades and several optoelectronic losses and technological limitations are gradually emerging by now. To circumvent these issues, here, we replaced the doped-silicon emitter layer with a gradient copper-doped nickel oxide (Gd-NiOx), and incorporated a silicon oxide passivation (SOP) layer at the Gd-NiOx/c-Si interface, to construct the novel c-Si PV devices. Interestingly, it was observed that the Gd-NiOx hole selective layer can strengthen the built-in field by minimizing the front electrode/hole-selective layer barrier width and the SOP can reduce interface recombination simultaneously, thereby yielding a remarkable 20.3% efficiency for the proof-of-concept device. We believe the design proposed in this may be of interest for applications in PVs and other optoelectronic devices. Article Full-text available Understanding carrier loss mechanisms at microscopic regions is imperative for the development of high-performance polycrystalline inorganic thin-film solar cells. Despite the progress achieved for kesterite, a promising environmentally benign and earth-abundant thin-film photovoltaic material, the microscopic carrier loss mechanisms and their impact on device performance remain largely unknown. Herein, we unveil these mechanisms in state-of-the-art Cu2ZnSnSe4 (CZTSe) solar cells using a framework that integrates multiple microscopic and macroscopic characterizations with three-dimensional device simulations. The results indicate the CZTSe films have a relatively long intragrain electron lifetime of 10–30 ns and small recombination losses through bandgap and/or electrostatic potential fluctuations. We identify that the effective minority carrier lifetime of CZTSe is dominated by a large grain boundary recombination velocity (~10⁴ cm s⁻¹), which is the major limiting factor of present device performance. These findings and the framework can greatly advance the research of kesterite and other emerging photovoltaic materials. Article Various methods for solar energy utilisation are being developed for reducing the emission of CO2 from fossil fuels, and perfect solar absorbers are attracting increasing attention. In the present study, a metamaterial solar absorber is proposed. The absorber consists of an array of Ni notched nanorings that are periodically arranged on a gold substrate with a layer of SiO2 dielectric between the rings. The proposed absorber achieves nearly perfect harvesting of incident solar energy, which is attributed to the integration of multiple modes of resonances from the notched nanorings on the top, including electric and magnetic polaritons. However, the composition, geometries, and arrangement of the notched nanorings significantly affect the absorption properties of our absorbers with a small tolerance. Additionally, the incident angle of light significantly affects the absorptance of our absorber because of the non-rotationally symmetric notched nanorings. When submerged in water, the absorbers that totally harvest solar energy can act as solar evaporators, which in turn promise potential applications involving solar vapour generation, sterilisation, and seawater treatment that can be enabled by solar energy for producing freshwater. Article This study exhibits potential prospects in thermal management fields and promising alternatives for the thermal harvesting of renewable energy. Article In recent years, solar energy has been increasing in usage throughout the world, especially in the United States. Market transformation (a concept based on collaborative efforts between industry advocates and policy-makers to increase adoption through economies of scale) plays a fundamental role in expanding the adoption of solar energy. However, there are currently limited resources to identify the optimal locations for increasing the likelihood of industry advocates interested in exploiting opportunities related to solar energy technologies. This study aims to showcase a visual mapping tool to assist with solar energy market transformation. By combining data from different sources, a unique process and output were created. The factors considered in this study include cost of electricity, net metering policies study, cost of solar energy systems, solar irradiance, annual sunshine rates, annual snowfall rates, and annual precipitation rates. All the factors were considered on both a residential and commercial level. The findings rank states from most viable to least viable with respect to the combined input factors. The results show that states with a high likelihood of market transformation at the residential level also have a high likelihood of market transformation at the commercial level. Article Full-text available Faced with interrelated challenges of climate change and energy crises, Africa’s future energy system orientation could be steered toward sustainable development. In this study, we contextualized diverging fossil fuels-dominated and renewable energy-based pathways toward sustainable development in Africa. A novel and sophisticated techno-economic energy modeling tool is used to describe the scope of the pathways in high geo-spatial and full hourly resolution for Africa covering the entire energy system. This study demonstrates that a renewable energy pathway is not only climate-compatible, but also delivers a lower cost system structure than alternative pathways. Our results show that Africa can leapfrog carbonization by using its low-cost renewable electricity and green hydrogen. Furthermore, Africa can become a self-sufficient green economy and an exporter of green fuels. Notably, solar photovoltaic-battery hybrid systems and electrolyzers are instrumental in achieving carbon-neutrality in Africa. This research presents a “true-zero emission” pathway for Africa. Article Eric O’Shaughnessy is a renewable energy research consultant. Kristen Ardani, Paul Denholm, Trieu Mai, Timothy Silverman, and Jarett Zuboy are analysts in the Strategic Energy Analysis Center at the US National Renewable Energy Laboratory. Robert Margolis is the group manager in the Washington, DC office of the Strategic Energy Analysis Center of the US National Renewable Energy Laboratory. Article Retrospective evaluation of energy system models and scenarios is essential for ensuring their robustness for prospective policy support. However, quantitative evaluations currently lack systematic methods to be more holistic and informative. This paper reviews existing accuracy indicators used for retrospective evaluations of energy models and scenarios with the aim to find a small suite of complementary indicators. We quantify and compare 24 indicators to assess the retrospective performance of D-EXPANSE electricity sector modeling framework, used to model 31 European countries in parallel from 1990–2019. We find that symmetric mean percentage error, symmetric mean absolute percentage error, symmetric median absolute percentage error, root-mean-squared logarithmic error, and growth error together form the most informative suite of indicators. This study is the first step towards developing a model accuracy testbench to assess energy models and scenarios in multiple dimensions retrospectively. Article Microbial photoelectrochemical systems (MPECs) is promising for sustainable energy and resources recovery from wastewater, however, the synergistic effects between the photoelectrode and bioelectrode remain unclear. In this study, a hybrid MPEC configurated with a Fe2O3 photo-bioanode and a black-silicon (b-Si) photocathode was proposed for sustainable electricity and H2 production from wastewater. The dual photoelectrodes utilized solar light to generate photoelectrons and holes with enhanced light absorption. Mixed-culture biofilm formed on the photo-bioanode generated electrons and protons from wastewater.. Photoelectrons were transferred from the photoanode to the bioanode, and later arrived at the photocathode for electricity and H2 production. The electrons transfer mechanisms were studied under different irradiation conditions. The system achieved a maximum current density of 0.8 mA/cm² and a H2 production rate of 5.1 µmol/h/cm² (113 µL/h/cm²) under 1 sun irradiation. The syngenetic effects between the photoelectrodes and the bioanode are significant for sustainable electricity and H2 production. Article Full-text available This study addresses the greatest concern facing the large-scale integration of wind, water, and solar (WWS) into a power grid: the high cost of avoiding load loss caused by WWS variability and uncertainty. It uses a new grid integration model and finds low-cost, no-load-loss, nonunique solutions to this problem on electrification of all US energy sectors (electricity, transportation, heating/cooling, and industry) while accounting for wind and solar time series data from a 3D global weather model that simulates extreme events and competition among wind turbines for available kinetic energy. Solutions are obtained by prioritizing storage for heat (in soil and water); cold (in ice and water); and electricity (in phase-change materials, pumped hydro, hydropower, and hydrogen), and using demand response. No natural gas, biofuels, nuclear power, or stationary batteries are needed. The resulting 2050-2055 US electricity social cost for a full system is much less than for fossil fuels. These results hold for many conditions, suggesting that low-cost, reliable 100% WWS systems should work many places worldwide. Conference Paper Full-text available Global energy demand has grown steadily since the industrial revolution. During the two decades from 1991 to 2012, total primary energy demand (TPED) grew from 91,200 to 155,400 TWhth, or by 70%, and projections expect this number to increase by a further 40% by 2040. Although greenhouse gas emissions in the energy sector have to be reduced to zero by mid-century or earlier to avoid an ecologic disaster, less than 15% of this energy demand is supplied by renewable resources nowadays. The International Energy Agency (IEA) has a significant impact on both political and economic decisions of governments and stakeholders regarding energy. The World Energy Outlook (WEO) report published annually by the IEA projects for the decades to come how TPED and electricity generation, amongst others, will evolve for all major technologies. Since the WEO is often used as a basis for policy making on renewable and conventional energy, a comprehensive analysis of past WEO projections is crucial. Such analysis will ensure well-grounded and realistic energy policy making and can contribute to efforts to fight climate change and to achieve energy security. In this article, the deviation between the real figures documented in the latest WEO reports and the projections of earlier ones is analysed, as well as the different projections of all reports from 1994 to 2014. The results obtained so far show that projections for solar technologies and wind energy have been strongly underestimated, whereas projections for nuclear energy are contradictory from one year to the next. A key reason for the high deviations of solar PV and wind capacities in the projections and the historic data is an incorrectly applied growth pattern. The WEO reports assume linear growth, whereas history shows an exponential growth for the new renewable energy (RE) technologies. The current exponential growth is part of long-term logistic growth of new RE technologies. Furthermore, a model proposed regarding RE technologies shows that to satisfy the world's needs with sustainable technologies in the decades to come, the approach of the WEO reports needs to be substantially reworked. Due to continuously falling prices of renewable energy technology, one can expect a fast deployment of renewables and a replacement of conventional energy. In its latest projections the WEOs did not take into account recent developments, including measures on climate protection and divestment of finance from the conventional energy sector. Therefore, policy-makers are advised to consider the expansion of renewables well beyond the WEO projections in their energy policies in order to avoid stranded investments in future. Article Full-text available Balancing power is used to quickly restore the supply-demand balance in power systems. The need for this tends to be increased by the use of variable renewable energy sources (VRE) such as wind and solar power. This paper reviews three channels through which VRE and balancing systems interact: the impact of VRE forecast errors on balancing reserve requirements; the supply of balancing services by VRE generators; and the incentives to improve forecasting provided by imbalance charges. The paper reviews the literature, provides stylized facts from German market data, and suggests policy options. Surprisingly, while German wind and solar capacity has tripled since 2008, balancing reserves have been reduced by 15%, and costs by 50%. Article Full-text available To properly evaluate the prospects for commercially competitive battery electric vehicles (BEV) one must have accurate information on current and predicted cost of battery packs. The literature reveals that costs are coming down, but with large uncertainties on past, current and future costs of the dominating Li-ion technology. This paper presents an original systematic review, analysing over 80 different estimates reported 2007-2014 to systematically trace the costs of Li-ion battery packs for BEV manufacturers. We show that industry-wide cost estimates declined by approximately 14% annually between 2007 and 2014, from above US$1,000 per kWh to around US$410 per kWh, and that the cost of battery packs used by market-leading BEV manufacturers are even lower, at US$300 per kWh, and has declined by 8% annually. Learning rate, the cost reduction following a cumulative doubling of production, is found to be between 6 and 9%, in line with earlier studies on vehicle battery technology. We reveal that the costs of Li-ion battery packs continue to decline and that the costs among market leaders are much lower than previously reported. This has significant implications for the assumptions used when modelling future energy and transport systems and permits an optimistic outlook for BEVs contributing to low-carbon transport.
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This article presents the synthesis of results from the Stanford Energy Modeling Forum Study 27, an inter-comparison of 18 energy-economy and integrated assessment models. The study investigated the importance of individual mitigation options such as energy intensity improvements, carbon capture and storage (CCS), nuclear power, solar and wind power and bioenergy for climate mitigation. Limiting the atmospheric greenhouse gas concentration to 450 or 550 ppm CO2 equivalent by 2100 would require a decarbonization of the global energy system in the 21st century. Robust characteristics of the energy transformation are increased energy intensity improvements and the electrification of energy end use coupled with a fast decarbonization of the electricity sector. Non-electric energy end use is hardest to decarbonize, particularly in the transport sector. Technology is a key element of climate mitigation. Versatile technologies such as CCS and bioenergy are found to be most important, due in part to their combined ability to produce negative emissions. The importance of individual low-carbon electricity technologies is more limited due to the many alternatives in the sector. The scale of the energy transformation is larger for the 450 ppm than for the 550 ppm CO2e target. As a result, the achievability and the costs of the 450 ppm target are more sensitive to variations in technology availability.
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Photovoltaics (PV) has recently undergone impressive growth and substantial cost decreases, while deployment for concentrating solar power (CSP) has been much slower. As the share of PV rises, the challenge of system integration will increase. This favors CSP, which can be combined with thermal storage and co-firing to reduce variability. It is thus an open question how important solar power will be for achieving climate mitigation targets, and which solar technology will be dominant in the long-term.
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The feasibility of achieving climate stabilization consistent with the objective of 2°C is heavily influenced by how the effort in terms of mitigation and economic resources will be distributed among the major economies. This paper provides a multi-model quantification of the mitigation commitment in 10 major regions of the world for a diversity of allocation schemes. Our results indicate that a policy with uniform carbon pricing and no transfer payments would yield an uneven distribution of policy costs, which would be lower than the global average for OECD countries, higher for developing economies and the highest, for energy exporters. We show that a resource sharing scheme based on long-term convergence of per capita emissions would not resolve the issue of cost distribution. An effort sharing scheme which equalizes regional policy costs would yield an allocation of allowances comparable with the ones proposed by the Major Economies. Under such a scheme, emissions would peak between 2030 and 2045 for China and remain rather flat for India. In all cases, a very large international carbon market would be required.
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This study explores a situation of staged accession to a global climate policy regime from the current situation of regionally fragmented and moderate climate action. The analysis is based on scenarios in which a front runner coalition – the EU or the EU and China – embarks on immediate ambitious climate action while the rest of the world makes a transition to a global climate regime between 2030 and 2050. We assume that the ensuing regime involves strong mitigation efforts but does not require late joiners to compensate for their initially higher emissions. Thus, climate targets are relaxed, and although staged accession can achieve significant reductions of global warming, the resulting climate outcome is unlikely to be consistent with the goal of limiting global warming to 2 degrees. The addition of China to the front runner coalition can reduce pre-2050 excess emissions by 20–30%, increasing the likelihood of staying below 2 degrees. Not accounting for potential co-benefits, the cost of front runner action is found to be lower for the EU than for China. Regions that delay their accession to the climate regime face a trade-off between reduced short term costs and higher transitional requirements due to larger carbon lock-ins and more rapidly increasing carbon prices during the accession period.
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This paper provides an overview of the AMPERE modeling comparison project with focus on the implications of near-term policies for the costs and attainability of long-term climate objectives. Nine modeling teams participated in the project to explore the consequences of global emissions following the proposed policy stringency of the national pledges from the Copenhagen Accord and Cancún Agreements to 2030. Specific features compared to earlier assessments are the explicit consideration of near-term 2030 emission targets as well as the systematic sensitivity analysis for the availability and potential of mitigation technologies. Our estimates show that a 2030 mitigation effort comparable to the pledges would result in a further “lock-in” of the energy system into fossil fuels and thus impede the required energy transformation to reach low greenhouse-gas stabilization levels (450 ppm CO2e). Major implications include significant increases in mitigation costs, increased risk that low stabilization targets become unattainable, and reduced chances of staying below the proposed temperature change target of 2 °C in case of overshoot. With respect to technologies, we find that following the pledge pathways to 2030 would narrow policy choices, and increases the risks that some currently optional technologies, such as carbon capture and storage (CCS) or the large-scale deployment of bioenergy, will become “a must” by 2030.
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While the international community aims to limit global warming to below 2 ° C to prevent dangerous climate change, little progress has been made towards a global climate agreement to implement the emissions reductions required to reach this target. We use an integrated energy–economy–climate modeling system to examine how a further delay of cooperative action and technology availability affect climate mitigation challenges. With comprehensive emissions reductions starting after 2015 and full technology availability we estimate that maximum 21st century warming may still be limited below 2 ° C with a likely probability and at moderate economic impacts. Achievable temperature targets rise by up to ~0.4 ° C if the implementation of comprehensive climate policies is delayed by another 15 years, chiefly because of transitional economic impacts. If carbon capture and storage (CCS) is unavailable, the lower limit of achievable targets rises by up to ~0.3 ° C. Our results show that progress in international climate negotiations within this decade is imperative to keep the 2 ° C target within reach.
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Realizing the environmental benefits of solar photovoltaics (PV) will require reducing costs associated with perception, informational gaps and technological uncertainties. To identify opportunities to decrease costs associated with residential PV adoption, in this letter we use multivariate regression models to analyze a unique, household-level dataset of PV adopters in Texas (USA) to systematically quantify the effect of different information channels on aspiring PV adopters' decision-making. We find that the length of the decision period depends on the business model, such as whether the system was bought or leased, and on special opportunities to learn, such as the influence of other PV owners in the neighborhood. This influence accrues passively through merely witnessing PV systems in the neighborhood, increasing confidence and motivation, as well as actively through peer-to-peer communications. Using these insights we propose a new framework to provide public information on PV that could drastically reduce barriers to PV adoption, thereby accelerating its market penetration and environmental benefits. This framework could also serve as a model for other distributed generation technologies.
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This paper uses the EMF27 scenarios to explore the role of renewable energy (RE) in climate change mitigation. Currently RE supplies almost 20 % of global electricity demand. Almost all EMF27 mitigation scenarios show a strong increase in renewable power production, with a substantial ramp-up of wind and solar power deployment. In many scenarios, renewables are the most important long-term mitigation option for power supply. Wind energy is competitive even without climate policy, whereas the prospects of solar photovoltaics (PV) are highly contingent on the ambitiousness of climate policy. Bioenergy is an important and versatile energy carrier; however—with the exception of low temperature heat—there is less scope for renewables other than biomass for non-electric energy supply. Despite the important role of wind and solar power in climate change mitigation scenarios with full technology availability, limiting their deployment has a relatively small effect on mitigation costs, if nuclear and carbon capture and storage (CCS)—which can serve as substitutes in low-carbon power supply—are available. Limited bioenergy availability in combination with limited wind and solar power by contrast, results in a more substantial increase in mitigation costs. While a number of robust insights emerge, the results on renewable energy deployment levels vary considerably across the models. An in-depth analysis of a subset of EMF27 reveals substantial differences in modeling approaches and parameter assumptions. To a certain degree, differences in model results can be attributed to different assumptions about technology costs, resource potentials and systems integration.
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The global energy system has to be transformed towards high levels of sustainability in order to comply with the COP21 agreement. Solar photovoltaic (PV) offers excellent characteristics to play a major role in this energy transition. The key objective of this work is to investigate the role of PV in the global energy transition based on respective scenarios and a newly introduced energy transition model developed by the authors. A progressive group of energy transition scenarios present results of a fast growth of installed PV capacities and a high energy supply share of solar energy to the total primary energy demand in the world in the decades to come. These progressive energy transition scenarios can be confirmed. For the very first time, a full hourly modelling for an entire year is performed for the world, subdivided in 145 sub-regions, which is required to reflect the intermittent character of the future energy system. The model derives total installed solar PV capacity requirements of 7.1–9.1 TWp for the electricity sector (as of the year 2015) and 27.4 TWp for the entire energy system in the mid-term. The long-term capacity is expected to be 42 TWp and, because of the ongoing cost reduction of PV and battery technologies, this value is found to be the lower limit for the installed capacities. Solar PV electricity is expected to be the largest, least cost and most relevant source of energy in the mid-term to long-term for the global energy supply.
Article
The need for deep decarbonisation in the energy intensive basic materials industry is increasingly recognised. In light of the vast future potential for renewable electricity the implications of electrifying the production of basic materials in the European Union is explored in a what-if thought-experiment. Production of steel, cement, glass, lime, petrochemicals, chlorine and ammonia required 125 TW-hours of electricity and 851 TW-hours of fossil fuels for energetic purposes and 671 TW-hours of fossil fuels as feedstock in 2010. The resulting carbon dioxide emissions were equivalent to 9% of total greenhouse gas emissions in EU28. A complete shift of the energy demand as well as the resource base of feedstocks to electricity would result in an electricity demand of 1713 TW-hours about 1200 TW-hours of which would be for producing hydrogen and hydrocarbons for feedstock and energy purposes. With increased material efficiency and some share of bio-based materials and biofuels the electricity demand can be much lower. Our analysis suggest that electrification of basic materials production is technically possible but could have major implications on how the industry and the electric systems interact. It also entails substantial changes in relative prices for electricity and hydrocarbon fuels.
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Solar irradiation and wind speed vary with climatic, as well as seasonal and daily weather conditions. In order to represent these variable renewable energy (VRE) resources in specialized energy system models, high temporal and spatial resolution information on their availability is used. In contrast, integrated assessment models (IAM), typically characterized by long-term time scales and low temporal and spatial resolution, require aggregated information on VRE availability and balancing requirements at various levels of VRE penetration and mix. Parametric studies that provide such information typically regard solar energy synonymously with photovoltaic power generation. However, solar energy can also be harvested with concentrating solar power (CSP) plants, which can be dispatchable if equipped with thermal storage. Accounting for this dispatchable use of the variable solar resource can change the balancing requirements at any solar energy penetration level. In this paper, we present an application of the high-resolution energy system model REMix to a set of European supply scenarios with theoretical VRE shares ranging from 0% to 140%, three solar-to-wind ratios, with CSP included in the solar share. We evaluate balancing measures, curtailments and costs and compare the findings to previous results in which CSP is regarded a backup option among other dispatchable power plants. The results show that CSP potentials in Europe are widely exploited in most scenarios. System costs are found to be lowest for wind-dominated systems or balanced mixes of wind and solar and for an overall VRE share between 40% for a low and 80% for a high scenario of the future CO2 emission certificate price. The comparison with previous results shows that storage capacity is the only system variable that is significantly affected by allocating CSP to the VRE resources category. It is reduced by 24% on average across all VRE shares and proportions and by around 80% at most.
Article
We present two advances in representing variable renewables (VRE) in global energy-economy-climate models: accounting for region-specific integration challenges for eight world regions and considering short-term storage. Both advances refine the approach of implementing residual load duration curves (RLDCs) to capture integration challenges. In this paper we derive RLDCs for eight world regions (based on region-specific time series for load, wind and solar) and implement them into the REMIND model. Therein we parameterize the impact of short-term storage using the highly-resolved model DIMES. All RLDCs and the underlying region-specific VRE time series are made available to the research community. We find that the more accurate accounting of integration challenges in REMIND does not reduce the prominent role of wind and solar in scenarios that cost-efficiently achieve the 2 °C target. Until 2030, VRE shares increase to about 15–40% in most regions with limited deployment of short-term storage capacities (below 2% of peak load). The REMIND model's default assumption of large-scale transmission grid expansion allows smoothening variability such that VRE capacity credits are moderate and curtailment is low. In the long run, VRE become the backbone of electricity supply and provide more than 70% of global electricity demand from 2070 on. Integration options ease this transformation: storage on diurnal and seasonal scales (via flow batteries and hydrogen electrolysis) and a shift in the non-VRE capacity mix from baseload towards more peaking power plants. The refined RLDC approach allows for a more accurate consideration of system-level impacts of VRE, and hence more robust insights on the nature of power sector decarbonization and related economic impacts.
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Solar power is increasingly economical, but its value to the grid decreases as its penetration grows, and existing technologies may not remain competitive. We propose a mid-century cost target of US\$0.25 per W and encourage the industry to invest in new technologies and deployment models to meet it.
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In order to define a cost optimal 100% renewable energy system, an hourly resolved model has been created based on linear optimization of energy system parameters under given constrains. The model is comprised of five scenarios for 100% renewable energy power systems in North-East Asia with different high voltage direct current transmission grid development levels, including industrial gas demand and additional energy security. Renewables can supply enough energy to cover the estimated electricity and gas demands of the area in the year 2030 and deliver more than 2000 TW hth of heat on a cost competitive level of 84 €/MW hel for electricity. Further, this can be accomplished for a synthetic natural gas price at the 2013 Japanese liquefied natural gas import price level and at no additional generation costs for the available heat. The total area system cost could reach 69.4 €/MW hel, if only the electricity sector is taken into account. In this system about 20% of the energy is exchanged between the 13 regions, reflecting a rather decentralized character which is supplied 27% by stored energy. The major storage technologies are batteries for daily storage and power-to-gas for seasonal storage. Prosumers are likely to play a significant role due to favourable economics. A highly resilient energy system with very high energy security standards would increase the electricity cost by 23% to 85.6 €/MW hel. The results clearly show that a 100% renewable energy based system is feasible and lower in cost than nuclear energy and fossil carbon capture and storage alternatives.
Article
This paper reviews the available literature dealing with the barriers to the dissemination of decentralized renewable energy systems. Decentralized renewable energy systems may face a range of technical, economic, institutional, socio-cultural and environmental barrier to their dissemination. In the paper, barriers impeding the dissemination of decentralized renewable energy systems have been identified and assessed. In addition, appropriate remedial measures and corresponding responsibility centers as reported in the literature have also been discussed. Inappropriateness of technology, unavailability of skilled manpower for maintenance, unavailability of spare parts, high cost, lack of access to credit, poor purchasing power and other spending priorities, unfair energy pricing, lack of information or awareness, and lack of adequate training on operation and maintenance of decentralized renewable energy systems are found to be the most critical barriers. Long-term conducive policies, appropriate regulatory framework, financial incentives (capital subsidies and soft loans) to users, technology and skill development, internalization of externalities in the cost of energy, withdrawal of subsidies presently being given to fossil fuels, development of specialized institutions, cooperation with international agencies, participation of local community and awareness generation have been recommended for increased dissemination of decentralized renewable energy systems.
Article
Scenarios of low-carbon transport demonstrate that a vast range of different outcomes is possible and contingent on policy, technology and cultural developments. But a closer look indicates that different schools of thought suggest possible pathways diverging in their fine structure. This perspective reveals how three different scientific communities — integrated assessment modelers, transport-sector modelers, and place-based modelers — emphasize distinct solution domains. While integrated assessment models focus on fuel composition, transport-sector models put slightly higher emphasis on efficiency measures; in turn place-based research specifies idiosyncratic behavioral and infrastructural mitigation options that are likely to be beneficial in realizing local co-benefits. These specific local approaches could mitigate urban transport emissions by 20–50%, higher than that revealed in aggregate global models. We discuss differences in approach, possibilities for reconciliation, and the implications of normative assumptions. Targeted three-directional interactions would foster comprehensive understanding of possible low-carbon transportation futures.
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