No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Could Key Engine, as a new open-source for RES technology development, start the third industrial revolution?
Abstract
Given that the first industrial revolution was based on Steam Engine (coal as energy source), and the second on oil and electricity, where both these revolutions are actually "high carbon" revolutions, it is logical to expect that the third industrial revolution should be based on systems of renewable energy sources (RES), in order to minimize the problems arising from climate changes and to achieve sustainable development.
However, the usage of the RES technologies and daily/weekly storage of energy and their connection to smart grids is not enough for the expected third industrial revolution. The start of this revolution would require technologies that have a great potential for further development and ability to supply, at any time, the necessary energy and power to a settlement/city, as well as drinking water, meeting the peak load requirements, continuously throughout the year, and independently of external sources of energy and drinking water. This would be provided from intermittent RES energy (solar, wind, etc.) and sea or other unclean source of water as natural resources.
In that context, this paper presents a radically new technological solution: Key Engine which uses only natural resources: the sun, sea and gravity, in order to continuously and simultaneously supply a consumer with energy, power and drinking water. This solution has all the essential features required to start a third industrial revolution.
The basic unit of Key Engine consists of the solar thermal (ST) generator with parabolic trough collectors through which sea water flows directly, absorbing thermal energy of solar radiation. After the separation of steam from seawater, the steam drives turbines and generators and produces electricity that is delivered to Pump Storage Hydroelectric (PSH) facility with seawater, which balances the daily and seasonal surpluses and shortages of energy, thus ensuring a continuous supply of electric power and energy to a consumer. At the same time, the water that comes out of the turbine, passes through the water treatment unit and is stored in drinking water reservoir, enabling continuous supply of the same consumer with drinking water.
The paper presents theoretical aspects of Key Engine, model for optimal sizing and practical formulas for the calculation of characteristic values of the system, which could be the basis for further scientific research, development and innovative solutions that would help engineers in practice for numerous and diverse applications of Key Engine.
In order to verify the derived mathematical relationships and models for optimizing the Key Engine in real conditions, the case study of the island of Vis in the Adriatic Sea, Croatia, has been considered, along with total annual irradiance of 1575 kW h/m² a, total annual electric energy consumption of 20 GW h and drinking water consumption of 453,382 m³. The obtained results: power of ST generator of 52 MW, working volume of the upper reservoir of 7 hm³, total annual electric energy production of 62 GW h/a, and drinking water production of 480,754 m³/a, clearly show that the new technology can fully meet the needs of the considered consumer for energy and drinking water.
As the basic idea of Key Engine relies on the use of natural resources, i.e. RES energy and sea, the paper presents only the starting solution, whereby, apart from the sun, RES can be wind, or other renewable sources, that can perform separation of vapor from seawater and thus produce drinking water, as well as energy simultanously. Also, energy storage may not be performed solely by the PSH technology, but also by any other technology that can provide seasonal balancing of energy. All this suggests that the Key Engine can be understood as an open-source for RES technology development and thus bring changes in all three aspects of sustainable development: economy, society and environment.
... As stated in [6,[20][21][22], Seawater Steam Engine (SSE) technology uses three natural sources-RES energy, seawater or water from other unclean water sources (rivers, lakes, etc.) and gravity (thus, three natural resources)-in order to produce electricity and heat (for heating and cooling) and drinking water (which could also be referred to as "quadrigeneration"), which would be provided continuously throughout the year. Seasonally stored thermal energy would also be supplied by geothermal heat pumps, which means that the fourth natural resource, i.e., Earth, would be used. ...
... Considering that these are stochastic quantities (possibilities for energy production from solar radiation and energy consumption of the city, which need to be harmonized) and the energy is stored seasonally using PSH technology, the power (size) of the SSE system must match the energy consumption throughout the year from the available solar energy. This can be realized by optimizing the system, which was carried out in [20]. For this purpose, a simulation-optimization model based on dynamic programming was developed, because it is a multistage decision-making process in terms of time (discretization to "i" time steps), where the selected objective function is to determine the optimal power of the SSE generator P el(NOM). ...
... Formulas for the calculation of key parameters of the SSE system-nominal power of the SSE generator, produced heat and electricity and drinking water [20,23,24]-are as follows: ...
Considering that more than half of the world’s population today lives in cities and consumes about 80% of the world’s energy and that there is a problem with drinking water supply, this paper presents a way to solve the problem of the sustainability of cities by enabling their complete independence from external sources of energy and drinking water. The proposed solution entails the use of Seawater Steam Engine (SSE) technology to supply cities with electricity, thermal energy and drinking water. The system would involve the seasonal storage of electricity and thermal energy, supported by geothermal heat pumps. The strategy of the distribution network would be based on the original concept of the “loop”. In cities that do not have enough space, SSE collectors would be placed above the lower parts of the city like “canopies”. The city of Zagreb (Croatia) was selected as a case study due to its size, climate and vulnerability to natural disasters. The results show that Zagreb could become sustainable in 30 years with the allocation of less than 2% of GDP and could become a paradigm of sustainability for cities worldwide. This paper encourages the development of the “Philosophy of Sustainability” because the stated goals cannot be achieved without a change in consciousness.
... SSE technology is patented [38]; the present authors have published several scientific papers [39,40] on it, as well as a book in which they present its potential to launch the third industrial revolution [41]. ...
... Table 2 presents the values of individual parameters (1-10) using Equations (1)- (6), which prove the potential of SSE technology to simultaneously produce thermal and electric energy and drinking water. These calculations apply to the entire integrated system of SSE technology (including PSH for energy storage), as presented in previous papers by the authors [39][40][41]. Legend: (SSE-Seawater Steam Engine; PSH-Pump storage hydroelectric; 1-Total energy (TWh) and drinking water (km 3 ) consumption; 2-CF (%); 3-RES Total Power (TW); 4-RES Unit land use (km 2 /TWh); 5-RES Total land use (km 2 ); 6-PSH Volume (km 3 ); 7-PSH Energy (TWh); 8-Total energy (TWh) and drinking water (km 3 ) production; 9-Power and Heat CO 2 savings (Gt); 10-Total CO 2 savings (Gt)). ...
... In this case study, 2015 was taken as the reference year, while unit values of production of electric energy and drinking water data, as well as data for thermal energy, were taken from previous papers by the present authors [39,46]. ...
There is a broad consensus worldwide that anthropogenic climate change is a scientific
fact. Likewise, the fact is that the UN’s efforts to address climate change over the last 28 years have not been successful enough. It is evident that the global average temperature is on the rise (1.1 °C above pre-industrial levels in 2019). A particular concern comes from the fact that the Paris Agreement on keeping increases in the global average temperature to below +2 °C is an unenforceable ambition since the focus is more on consequences than causes. In addition, economic policies regarding global taxes, as well as adaptation and mitigation measures, are questionable, as there is no evidence that changes in the climate system will proceed at the same rate in the coming years. This paper proposes an engineering approach that considers all relevant aspects of the climate change problem and proposes a new policy, named the “Climate New Deal”. It deals with: (i)Reorientation from a high-carbon economy to a green economy; (ii) The intensive use of radically
new technology, e.g., “Seawater Steam Engine” technology for the simultaneous production of thermal and electric energy and drinking water; and (iii) The intensive use of energy efficient technologies and RES technologies, especially in transport.
... In the midst of these environmental, social, and economic challenges, the world will face another fundamental shift in the upcoming years, namely the technological developments coined as the Fourth Industrial Revolution (4IR). While earlier industrial revolutions relied mainly on fossil resources as a primary energy resource, the upcoming one will likely be based on renewable energy sources (RES) [6][7][8][9][10]. Associated trends of the 4IR, such as decarbonization, digitalization and decentralization, will profoundly change the underlying power and data infrastructures and substantially influence business models and industries within and beyond the energy market [11]. ...
Background
In this article, the concept of the Fourth Industrial Revolution and related implications for the measurement of sustainable development are analyzed. Technological innovations can play an important role in countering errant developments of the past and can support the transformation process towards a green economy in pursuit of the Sustainable Development Goals. On the other hand, they pose challenges to the social control of technology and represent a methodical quandary known as the Collingridge dilemma. The core statement of the dilemma is that the implications of new technologies will only be fully visible once they are embedded in socio-economic-ecological systems when the possibilities to control diminish. The main objective of this study is thus to develop a monitoring framework enabling the ex ante assessment of related technological shifts and their implications for sustainable development.
Results
To approach the resulting difficulties for sustainability monitoring, digitization indicators should be accounted for in the German Sustainable Development Strategy. An enhanced strategy complemented by related Global Competitiveness Index 4.0 indicators, for which the Word Economic Forum assumes a modest link between competitiveness and inequality, illustrates the feasibility of linking research regarding the Fourth Industrial Revolution and sustainable development to measure its social and environmental consequences. The newly developed Sustainable Digital Socio-Economic-Ecological Indicator System categorizes the sustainability indicators into one index covering all Sustainable Development Goals along with four sub-indices emphasizing crucial aspects relevant to navigating a successful transformation. This novel and innovative approach is illustrated using the examples of Germany.
Conclusions
The Fourth Industrial Revolution is fundamentally driven by introducing renewable energy resources as a new energy regime. However, the effects extend beyond energy and necessitate comprehensive measurement frameworks for assessing sustainable development implications. This work contributes by analyzing the related impact on sustainable development and providing decision-makers with new insights for early recognition. Preliminary results for Germany expose a discrepancy between the status quo and the desired pathway, indicating emerging effects of the Fourth Industrial Revolution on inequality, employment, and education. While none of the sectors are sustainable, the sub-index analysis highlights distinct disparities among economic, social, and ecological sectors.
... The beginning of the onset of the industrial revolution 1 in the 19th century led to the global change of energy production by higher utilization of primary sources of energy like coal, wood, fuel, etc. This brought about the search for improvements in the utilization of these sources by newer technologies 2 being integrated to get maximum energy output using existing resources. ...
Enhancing the balance between demand and generation with smooth perfor-mance, the integration of renewable energy sources (RESs) plays a vital role inthe smart distribution system. However, due to the inherent uncertainty andintermittent nature of RESs, many issues and challenges such as power quality,efficiency, stability, and reliability need to be taken care of for achieving anoptimal operation. To resolve these associated problems, the virtual powerplant (VPP) has been introduced and integrated with present smart distribu-tion systems without sacrificing the grid stability and reliability along withoffering many techno-economic benefits. This article is a precise presentationof issues, modeling, effective management mechanism solutions, and prospects
... • The Third Industrial Revolution began with the first computer era [26][27][28][29][30]. These early computers were often very simple, unwieldy, and incredibly large relative to the computing power they were able to provide, but they laid the groundwork for the world today, which one is hard-pressed to imagine without computer technology. ...
The development of human civilization over the last decade has reached a landmark as
Industry 4.0 has been widely introduced. Several aspects of industry and manufacturing activities are changing due to the Internet of Things (IoT), location detection technologies, and advanced human–machine interfaces. To enact industrial affairs under those specifications, a sensor is required to transform physical events into numerical information. The use of sensors in marine applications also appears in research and studies, in which the sensor is used for both monitoring the phenomena
of a designated subject and data acquisition. Achievements in quantifying complex phenomena in critical maritime designs are fascinating subjects to discuss regarding their development and current states, which may be reliable references for further research on developing sensors and related measurement analysis tools in marine, shipbuilding, and shipping fields. This comprehensive review covers several discussion topics, including the origins and development of sensor technology, applied sensor engineering in logistic and shipping activities, the hydrodynamic characterization of
designed hulls, the monitoring of advanced machinery performance, Arctic-based field observations, the detection of vibration-based damage to offshore structures, corrosion control and monitoring, and the measurement of explosions on critical maritime infrastructures.
... International researchers of the energy policy [25][26][27][28] identify the modern development stage of the industry as the "third technology revolution", which envisages decarbonization of the energy system, i.e., transition from high-carbon raw materials as an energy source [29][30][31][32][33][34][35] to renewable sources of energy (RSE). This will help to address the problems both immanent to the energy sector (ageing infrastructure, emissions, etc.), and of external etymology (climate change, etc.) to achieve the goals of sustainable development of the UN established in the world consensus. ...
Today the world economy is handling an economic crisis caused by the pandemic of a new coronavirus infection (COVID-19), announced by the WHO, as well as by fluctuations in the international energy market and by the development of “green energy”. The crisis, named the “2020 crisis”, is notable for the divergence of the sectoral dynamics of development, with a declining development trend in some industries and the rapid growth of others. The crisis is etymologically relevant to the energy sector, a sector which is important for the survival and specialization of the Russian Federation. This research is aimed at describing the status and highlighting the socioeconomic effects, constraints (economic and social risks), and “growth points” of the energy sector in the modern realities of the 2020 crisis. Methods. The method of in-depth interview was used. The need for studying expert opinion is based on the fundamental principles of implementation research, according to which the success of state sectoral policy depends on its perception and support by stakeholders. Top managers of energy enterprises acted as the experts (N = 10). The interviews were conducted in April 2020. The method of incremental approximation and coding (open and axial) were used for a high-quality discourse analysis. Results. The conducted study revealed divergence of sectoral dynamics of energy consumption, which is a translation of the immanent features of the 2020 crisis into the energy sector. The detected constraints are reserved development prerequisites of “green energy” and reduced investments in development programs. The potential “growth points” include intensified digitalization of the energy sector and the need for institutional changes in taxation in the energy sector, recognized by experts.
... Since the first industrial revolution in 19th century, the world stepped into the era of steam engines leading to the increasing consumption of primary energy resources like coal, wood etc. [1]. Along with the tremendous improvements in social productivity, environmental pollution and energy depletion highlight the importance of sustainable development. ...
Constrained by low capacity and volatility, the rapid growth of distributed energy resources are obviously slowdown resulting in consumption difficulty and investment obstacle. As an effective integration and management technology, virtual power plant (VPP) becomes a suitable cornerstone of renewable energy future development. Based on current scientific research, this study intends to provide a detailed review of VPP from an internal perspective (e.g. energy resources' integration and operation) to the external aspect including participation in electricity market. In accordance with market diversity, different bidding strategy optimisation problems of VPP are formulated and their corresponding mathematical solution methods are literately reviewed. To extract characteristics of VPP, a comparison between energy management techniques (e.g. VPP, microgrid, active distribution network, and load aggregator) is conducted, where advantages and defects of VPP are also concluded. Meanwhile, realistic deployments of VPP in European electricity markets are elaborated to verify its feasibility and applicability. To better accommodate future development of renewable energy, a flexible structure and effective management mechanism of VPP should be built leading to its technical innovation and management reform. Possessed with the threefold development orientation, VPP will undoubtedly improve the utilisation and management of renewable energy sources as a coordinated and operational entity.
... Energy governance is at a crossroads, facing inevitable change, perhaps even a 'third industrial revolution' (Bradshaw 2014, Stirling 2014, Shum 2015, Glasnovic et al. 2016. Several coinciding elements constrain energy choices. ...
‘Energy democracy’ epitomizes hopes in energy transformation, but remains under-defined, a political buzzword rather than a real concept. After presenting its activist roots and mapping its usage, ‘energy democracy’ is positioned in relation to similar normatively derived concepts: environmental, climate, and energy justice, and environmental democracy. Drawing on insights from political theory and political sociology, it is shown what is democratic in energy democracy. Referencing the question of experts and democratic publics in complex technological areas, the paper explains why it is desirable for energy governance to be more democratic. To show what is unique in ‘energy democracy’ beyond increased participation in energy policy, the prosumer is introduced as the ideal-typical citizen, highlighting the importance of the energy transition, the agency of material structures and a new emergent governmentality. ‘Energy democracy’ is conceptualized as an analytical and decision-making tool, defined along three dimensions: popular sovereignty, participatory governance and civic ownership, and operationalized with relevant indicators.
... In recent years, many studies have modelled and optimized the coordinated operation of hydro-wind ( Papaefthymiou et al 2014, Pereira et al 2015, hydro-photovoltaic ( Tao et al 2015) or hydro-wind-photovoltaic ( Schmidt et al 2016) systems. The model objectives usually include the power generation ( Wang et al, 2013), economic benefits ( Kern et al 2014a), emissions reductions ( Azizipanah-Abarghooee et al 2012), water supply ( Glasnovic et al 2016), generation costs ( Pé rezDí az et al 2016), power curtailment ( Segurado et al 2016), output fluctuations ( Destro et al 2016), and flow regime of hydropower discharge ( Kern et al 2014b). The first 4 items, middle 2 items and last 2 items reflect the effects of coordinated operation in terms of its benefits, costs and influence, respectively. ...
The coordinated operation of a hydro-wind-photovoltaic system can mitigate the conflict between power generation and output fluctuations and overcome the bottleneck of new energy development. Because of the lack of available research on the coordination mechanism for analysing the relationship between power generation and output fluctuations, depicting the grid architecture and allocating power curtailment, this study establishes a multi-objective model for the coordinated operation of a hydro-wind-photovoltaic power system. The model seeks to maximize power generation and minimize output fluctuations under the constraints of multilayer architecture of the power network and balanced allocation of power curtailment. In a case study of a prefectural-level power grid in southwest China, three schemes are compared: independent operation with a single objective, coordinated operation with a single objective, and coordinated operation with multiple objectives. The complementary role of hydropower for increasing power generation and mitigating output fluctuations is explored; the effects of coordinated operation on transmission utilization and the hydrological regime are analysed; and the Pareto frontier of power generation and output fluctuations is obtained and the interaction of these factors is discussed. This study refines the model of a hydro-wind-photovoltaic system and investigates the complementary mechanism underlying multi-energy systems.
Analysis of pastoralism in the classified forest of Faya in Mali: issues, challenges and constraints
Due to complicated nature of asphalt pavements under various loading situations and environmental conditions, its behaviour is quit hard to comprehend. It is necessary to develop a mathematical relationship between outputs and various inputs in precise and simple manner for prediction of Marhsall Stability (MS) of flexible asphalt pavements. For this purpose, linear regression was applied to a comprehensive dataset of 157 samples for Asphalt Wearing Course (AWC), and 163 samples of Asphalt Base Course (ABC) of asphalt concrete to compute the MS. Linear regression model was developed using seven input parameters namely Voids Filled by Bitumen (VFA), Voids in Mineral Aggregate (VMA), Air Voids (Va), Maximum Specific Gravity of Paving Mix (Gmm), Bulk Specific Gravity of Aggregates (Gsb), Bulk Specific Gravity of Compacted Aggregates (Gmb), and Asphalt Content (Pb). MS was the output parameter of the developed models. The precision, and prediction capability of the proposed model were checked using various statistical checks such as Mean Absolute Error (MAE), Root Mean Square Error (RMSE), Relative Square Error (RSE), Correlation Coefficient (R), and Relative Root Mean Square Error (RRMSE). The results of R obtained for AWC showed strong correlation between predicted and experimental values, with an R of 0.93 while in case of ABC the results were considerably low having R of 0.09. The values of RRMSE for ABC and AWC were less than 0.1 i.e. 0.026 and 0.050, respectively, showing excellent results. The magnitude of errors can be calculated with the help of RMSE and MAE with results showing values of MAE less than RMSE are termed as good. The results of MAE were 28.21 and 98.96 for AWC and ABC, respectively. The results obtained for RMSE were 36.24 and 124.88, for AWC and ABC, respectively. The values of RSE are 0.13 and 0.01 for AWC and ABC, respectively. The
results are almost near to zero showing model’s predictability as good. From the results of statistical checks it is stated that both models developed for AWC and ABC could be acceptable based on the values of RRMSE, and RSE but through looking at the results of R, MAE, and RMSE, the model developed for AWC can be termed as a strong developed model while in
case of ABC’s model it can be termed as a weak model. In case of ABC model the value of R was very low with MAE, and RMSE had larger error values which contributed to weakness of the model, overall. Although in case of AWC model, all the results were in favour, labelling it as a strong model. Hence, to obtain consistency in the developed models, it is thus recommended that advanced machine learning and artificial intelligence techniques such as Multi Expression Programming (MEP), Adaptive Neuro Fuzzy Inference System (ANFIS), and Artificial Neural Networks (ANN) be used to develop models. With the help of these techniques we will have the consistency in results of the developed models with strong predication and generalisation capability.
This research is depend on the study of the Physio-chemical properties of the oils of one of the supposed oil compositions, such as the Specific gravity, the content of Asphalt, Wax, Ash and Sulphur for the Tertiary and Cretaceous oils in a hypothetical dome representing one of three domes forming a composition for one of the oil fields in Northern Iraq. Ten wells were selected, five (5) belong to the Tertiary reservoir and (5) belong to the Cretaceous reservoir from different locations along the dome, the data for the analyzes of the crude oil samples carried out in the laboratories section of the North Oil Company for these Ten wells, related to the Specific gravity of oil and the content of Asphalt, Wax, Ash and Sulfur, were taken and archived in Petroleum Engineering and Geology Departments, data on the physicochemical characteristics of oil were collected and placed in separate tables for each reservoir.
Mathematical and statistical methods that were used, such as Time Series Analysis, Star Diagrams, and Correlation Coefficients, all indicated that there is a correlation and common characteristics between the reservoir oils and that it can be concluded from this on the horizontal and vertical migration of oil from the Cretaceous reservoir to the Tertiary reservoir, and this supports the theory of the common origin of Tertiary reservoir.
This study is focused on the investigation of the antioxidant effect of tetraethylenepentamine (TEPA) on biodiesel oxidation resistance and metal ion content. The induction period of rapeseed oil biodiesel with different content of TEPA was determined by Rancimat assay. The content of metal elements in the extracted aqueous solution, before and after the addition of TEPA was analyzed by inductively coupled plasma mass spectrometry. The results show that the addition of TEPA chelates the free copper and iron ions in biodiesel and improves the oxidation stability of biodiesel. TEPA is a good antioxidant and chelating agent; however, its Fe ³⁺ chelating ability is weak.
This paper analyses the theoretical aspects of the use of solar energy and water storage for sustainable electric energy supply. Proposed hybrid concept observed as an open energy system that behaves according to the local conditions and renewable energy source technology used. Sustainability of hybrid system is based on stabile water and energy budget of power plant in the planning period. The key relationship for system design and interdependence between electric power of solar generator and working volume of water (energy) storage is set. Water storage is a main functional element of the proposed concept that allows efficient harvesting of sun energy as well as water resources and thus significantly affects on the features of hybrid solutions. The developed theoretical relationships and proposed hybrid system indicators have been tested on two different climate areas, as paradigms of Continental and Mediterranean climate. Based on obtained results it has been concluded that presented hybrid concept of solar-hydro systems provides a promising basis for the development of sustainable energy systems. The current technological development and use of renewable energy sources (RES) are not yet a complete and productive alternative to conventional energy sources. The problem is that the most important RES sources, such as solar and wind energy, cannot be directly directed toward energy consumption, and the remain ing stable and controllable sources, such as hydro, geothermal, bio and others do not have sufficient capacity and are not available everywhere. Solar and wind energy cannot produce energy continuously and supply a consumer, so it is necessary to hybridize them with conventional sources through the electric power system (EPS) or use energy storages. The problem of using these sources is somewhat resolved for s mall sources and energy users, but is far fro m an acceptable solution for reg ional or larger EPS [1-3] . Significant research is performed in solving this problem, but still without a satisfactory solution [4] . This means that the present planning methodology of intermittent RES (wind, photovoltaic (PV), solar thermal (ST)) share in energy supply in EPS has serious problems, if they are to have significant share in energy balance. Therefore, the solution of global energy sustainability is still a long-term goal without coverage in the currently applicable technical solutions. However, using intermittent RES in EPS instead conventional plants lead to reduction of CO 2 emission and conservation of non-renewable resources.
Analytical models for the physical processes governing direct steam generation line-focus solar thermal power plants are derived. Predictions compare favorably with the limited database available from published studies against which the accuracy of detailed model computations can meaningfully be assessed. That limited database should not be confused with extensive citations of system power delivery in the absence of comprehensive information. A physically transparent understanding is provided for heat transfer within the collectors, heat loss to ambient, fluid flow and steam cycle efficiency. With existing evacuated-tube parabolic-trough concentrators and steam turbines, net system conversion efficiencies can exceed 20% even for today's small-scale (<= 100 MW) power plants. A key limiting factor is that relatively low-power turbines inherently have poorer isentropic efficiencies than their high-power counterparts. Although a few strategies for improving system efficiency have previously been proposed, the analytical models presented here provide the ability to rapidly (a) quantify the performance advantages of these strategies and (b) project how assorted modifications should affect system behavior, in both cases, without the need for expansive simulations. Examples of these design options include (1) multiple fluid extractions in a regenerative turbine cycle, (2) higher isentropic efficiencies for larger turbines, and (3) raising cycle temperature.
Recent efforts to promote a transition to a low carbon economy have been influenced by suggestions that a low carbon transition offers challenges and might yield economic benefits comparable to those of the previous industrial revolutions. This paper examines these arguments and the challenges facing a low carbon transition, by drawing on recent thinking on the technological, economic and institutional factors that enabled and sustained the first (British) industrial revolution, and the role of ‘general purpose technologies’ in stimulating and sustaining this and subsequent industrial transformation processes that have contributed to significant macroeconomic gains. These revolutions involved profound, long drawn-out changes in economy, technology and society; and although their energy transitions led to long-run economic benefits, they took many decades to develop. To reap significant long-run economic benefits from a low carbon transition sooner rather than later would require systemic efforts and incentives for low carbon innovation and substitution of high-carbon technologies. We conclude that while achieving a low carbon transition may require societal changes on a scale comparable with those of previous industrial revolutions, this transition does not yet resemble previous industrial revolutions. A successful low carbon transition would, however, amount to a different kind of industrial revolution.
To assess water savings in households using efficient devices and to understand how savings vary between different socio-demographic groups in the community, high resolution end use water consumption data is required (i.e. disaggregating water use for showers, toilets, clothes washers and garden irrigation etc.). This paper reports selected findings from the Gold Coast Residential End Use Study (Australia), which focussed on the relationship between a range of socio-demographic and household stock efficiency variables and water end use consumption levels. A mixed methods approach was executed using qualitative and quantitative data. The study provided evidence as to the potential savings derived from efficient appliances as well as socio-demographic clusters having higher water consumption across end uses. The payback period for some water efficient devices was also explored. The study has implications for urban water demand management planning and forecasting.
Direct steam generation collectors are considered with the aim to improve the performance of a parabolic trough collector leading to a reduction of operating costs of solar electric generation systems. In this study a hydrodynamic steady state model is developed and linked with a thermal model to optimize the performance of once-through direct steam generation solar collectors. The hydrodynamic model includes flow pattern classification and a pressure drop model. Flow pattern maps for typical DSG collectors with horizontal and inclined absorber tubes are generated to investigate the variation of flow conditions with radiation level, tube diameter, tube length and flow rate. Two-phase flow frictional pressure drop correlations for the range of operating conditions in a DSG collector are selected from the wide range of published correlations by comparison with experimental data for typical steam-water flow conditions in a DSG collector. Pressure drop is calculated for different operating conditions for both horizontal and inclined solar absorber tubes. Alternative operational strategies are evaluated to achieve optimum performance of a direct steam generation collector at different radiation levels.
This paper presents arguments for the use of direct steam generation (DSG) in preference
to other forms of generation in particular locations according to the prevailing environmental
and economic conditions. In addition, the paper describes the development of a
software tool based on Microsoft Excel and Visual Basic for Applications (VBA), which
draws upon established physical relationships in the heat transfer literature to perform
plant capacity calculations in a fast and convenient manner. The results of the VBA program
determine the solar fraction of the plant, assuming that the plant is in operation for
10 h per day (07:30–17:30 hours), the solar fraction is shown to be 76% and the DSG
plant achieves a 76% reduction in emissions. Construction costs are also estimated based
on formulae from previous work.
The DISS (DIrect Solar Steam) project is a complete R+TD program aimed at developing a new generation of solar thermal power plants with direct steam generation (DSG) in the absorber tubes of parabolic trough collectors. During the first phase of the project (19961998), a life-size test facility was implemented at the Plataforma Solar de Almeria (PSA) to investigate the basic DSG processes tender real solar conditions and evaluate the unanswered technical questions concerning this new technology. This paper updates DISS project status and explains O&M-related experience (e.g., main problems faced and solutions applied) with the PSA DISS test facility since January 1999.
This article presents the latest experimental results of the European DISS (DIrect Solar Steam) project. The experiments are subdivided into steady state and transient tests. The goal of the steady state tests is the investigation of the thermohydraulic phenomena of the occurring two phase flow, whereas the transient tests are needed for the controller design. The experimental results are compared to simulation studies. Implications for the plant operation will be discussed.
Solar electric generation systems (SEGS) currently in operation are based on parabolic trough solar collectors using synthetic oil heat transfer fluid in the collector loop to transfer thermal energy to a Rankine cycle turbine via a heat exchanger. To improve performance and reduce costs direct steam generation in the collector has been proposed. In this paper the efficiency of parabolic trough collectors is determined for operation with synthetic oil (current SEGS plants) and water (future proposal) as the working fluids. The thermal performance of a trough collector using Syltherm 800 oil as the working fluid has been measured at Sandia National Laboratory and is used in this study to develop a model of the thermal losses from the collector. The model is based on absorber wall temperature rather than fluid bulk temperature so it can be used to predict the performance of the collector with any working fluid. The effects of absorber emissivity and internal working fluid convection effects are evaluated. An efficiency equation for trough collectors is developed and used in a simulation model to evaluate the performance of direct steam generation collectors for different radiation conditions and different absorber tube sizes. Phase change in the direct steam generation collector is accounted for by separate analysis of the liquid, boiling and dry steam zones.
The use of water in Croatia and in Europe is analyzed. Factors influencing water resources and various adverse actions originating from urban areas, industry, agriculture, etc., are described. An interdisciplinary procedure for identifying, analyzing and estimating processes that define current and future condition of water resources, is applied in the paper. The author cautions that water must be used prudently and efficiently and that the correct water management will result in notable positive environmental effects.
This chapter analyses the possibility of implementation of Sustainable Electric Power System (SEPS) as a totally green strategy of electric energy production for the world by the year 2040. The analysis presented in the paper is based on the EREC strategy which foresees the share of 82% of Renewable Energy Sources (RES). The problem of implementation of this strategy is that the more significant RES (Sun and wind) are characterized by intermittence of input energy, for which reason they cannot provide continuous and reliable supply of energy to consumers without electric storage. The solution to this problem and to creating conditions for achieving SEPS is an innovative concept of Solar Hydro Electric (SHE) power plant which is a basically combined photovoltaic power plant and pump storage which can produce and store relatively large quantities of energy and provide continuous supply of electric power and energy to consumers. In this way SHE is put into equal position with power plants using conventional power fuels, and because of that, SHE is presented in this paper as the main building element of the future SEPS. The conducted analysis and results clearly point not only to the reality, but the necessity for SEPS and to the exceptionally big achievements which the PV generator use will reach in the future. The proposed strategy of SEPS development could significantly contribute to realization of sustainability objectives, particularly to reduction of the problem of global warming.
Various ecological footprint calculators, carbon footprint calculators and water footprint calculators have been developed in recent years. The basic concepts of ecological behaviour record notebooks and of carbon dioxide emission calculators have been developed since the late 20th century. The first carbon dioxide emission calculator was developed in 1991. Likewise, water pollutant discharge calculators have been developed to estimate the effects of soft measures introduced into households to reduce pollutant discharge since 2004. The soft measures which have been developed in Japan may consist of a wider framework, household sustainable consumption, which has been developed in Europe, and can be referred to cleaner consumption. In this research, summarisation of the short history of ecological behaviour record notebooks and ecological footprint calculators in Japan since the 1980s was conducted, and the soft measures in households to reduce pollutant discharge were evaluated for their effects on ambient water quality improvement as well as household and industry economies. Effects of the soft measures on related industry economies were investigated using an Input Output Table analysis and the effects of the imported goods were evaluated with an import effect matrix, which was developed in this research. The effects of the soft measures on household expenditures were estimated to be a decrease by 2.5% or USD 285 person(-1) year(-1) in 2003-2006. The results show that the soft measures positively affect the chemical fibre industry and significantly affect the detergent industry. Analysis of the import effect matrix proved that the six industries were tightly related through extensive amounts of imported goods. The soft measures in households may lead to household sustainable consumption and thus reduce disadvantageous human impacts on water environments. The effects of the measures introduced to improve the environment should be qualitatively and quantitatively evaluated to avoid redundant concerns and discord between the environment and the economy, which may be worried when the relationship is not well understood.
This paper presents the characteristics of a power plant that combines renewable energy sources (RES), that is, a photovoltaic (PV) power plant and pump storage hydroelectric (PSH), to achieve sustainable production of green electric energy equal to that of conventional energy sources. The proposed solution does not produce CO 2 and does not significantly use freshwater or other resources. The PSH storage is the main element of the proposed power plant system, which provides a continuous and reliable supply of green energy. Its size significantly affects the size of the PV generator and operation characteristics of the hybrid plant. The paper elaborates in detail the functional relationship between the choice of the PV generator power and the PSH upper storage volume and presents the basic mathematical relations. The algorithm of the system development is presented, along with the procedure choice solutions. The results from the case study show that the concept is flexible in design, construction, and operation.
Concentrated solar power plants (CSPs) are gaining increasing interest, mostly as parabolic trough collectors (PTC) or solar tower collectors (STC). Notwithstanding CSP benefits, the daily and monthly variation of the solar irradiation flux is a main drawback. Despite the approximate match between hours of the day where solar radiation and energy demand peak, CSPs experience short term variations on cloudy days and cannot provide energy during night hours unless incorporating thermal energy storage (TES) and/or backup systems (BS) to operate continuously. To determine the optimum design and operation of the CSP throughout the year, whilst defining the required TES and/or BS, an accurate estimation of the daily solar irradiation is needed. Local solar irradiation data are mostly only available as monthly averages, and a predictive conversion into hourly data and direct irradiation is needed to provide a more accurate input into the CSP design. The paper (i) briefly reviews CSP technologies and STC advantages; (ii) presents a methodology to predict hourly beam (direct) irradiation from available monthly averages, based upon combined previous literature findings and available meteorological data; (iii) illustrates predictions for different selected STC locations; and finally (iv) describes the use of the predictions in simulating the required plant configuration of an optimum STC. The methodology and results demonstrate the potential of CSPs in general, whilst also defining the design background of STC plants.
The environmental performance of a 50 MW parabolic trough Concentrated Solar Power (CSP) plant hybridised with different fuels was determined using a Life Cycle Assessment methodology. Six different scenarios were investigated, half of which involved hybridisation with fossil fuels (natural gas, coal and fuel oil), and the other three involved hybridisation with renewable fuels (wheat straw, wood pellets and biogas). Each scenario was compared to a solar-only operation. Nine different environmental categories as well as the Cumulative Energy Demand and the Energy Payback Time (EPT) were evaluated using Simapro software for 1 MW h of electricity produced. The results indicate a worse environmental performance for a CSP plant producing 12% of the electricity from fuel than in a solar-only operation for every indicator, except for the eutrophication and toxicity categories, whose results for the natural gas scenario are slightly better. In the climate change category, the results ranged between 26.9 and 187 kg CO2 eq/MW h, where a solar-only operation had the best results and coal hybridisation had the worst. Considering a weighted single score indicator, the environmental impact of the renewable fuels scenarios is approximately half of those considered in fossil fuels, with the straw scenario showing the best results, and the coal scenario the worstones. EPT for solar-only mode is 1.44 years, while hybridisation scenarios EPT vary in a range of 1.72–1.83 years for straw and pellets respectively. The fuels with more embodied energy are biomethane and wood pellets.
This assessment aims to identify the most suitable concentrated solar power (CSP) technologies to hybridize with Rankine cycle power plants using conventional fuels, such as gas and coal, as well as non-conventional fuels, namely biomass and waste materials. The results derive from quantitative data, such as literature, industry information and own calculations, as well as qualitative data from an expert workshop. To incorporate the variety of technology criteria, quantitative and qualitative data the Analytical Hierarchy Process (AHP) is used as the multi-criteria decision making (MCDM) tool. Only CSP technologies able to directly or indirectly generate steam are compared in regards to feasibility, risk, environmental impact and Levelised Cost of Electricity (LCOE). Different sub-criteria are chosen to consider the most relevant aspects. The study focuses on the suitability of CSP technologies for hybridisation and results obtained are reality checked by comparison with plants already being built/under construction. The results of this assessment are time dependant and may change with new CSP technologies maturing and prices decreasing in the future.
George Petrie of the Seastanding Institute, a nonprofit that wants to build floating communities out at sea, explains why the idea holds so much promise
Solar thermal plants are among the most promising technologies to replace fossil fuel stationary applications, and within solar thermal technologies, parabolic troughs are considered the most mature application in the market. This paper compares different solar field technologies, in terms of both performance at design conditions and annual energy production; an in-house code, PATTO, was used to perform energy balances. We considered a reference case reflecting state-of-the-art Nevada Solar One, which showed a design efficiency and annual average efficiency of 22.4% and 15.3%, respectively, in agreement with actual performance. If solar salts are used as heat-transfer fluid instead of synthetic oil (e.g. ARCHIMEDE plant), the efficiency improved within the range of 6% due to the higher maximum temperature. Further thermodynamic advantages can be achieved with a direct steam generation plant; the main drawback is the more complex transient control and no commercially available storage systems. We propose the innovative Milan configuration, which combines advantages of direct steam evaporation and the use of a heat-transfer fluid, to investigate both synthetic oil and solar salts for steam superheating and reheating. Results for this configuration are very promising, with a sun-to-electric annual average efficiency of 17.8%, which is 16% higher than the reference case. Detailed daily simulations showed that advantages are more significant at low radiation. However, the plant should be optimized on an economic basis and we will discuss this in a future paper.
Since the main problem of continuous energy supply from photovoltaic (PV) power plant is intermittence and inability to provide continuous energy supply, this paper proposes its hybridization with hydro energy, or with pump storage hydroelectric (PSH) as a possible solution. This creates a new type of sustainable hybrid power plant which can work continuously, using solar energy as primary energy source and water for energy storage. The characteristics of the solution as an open thermodynamic system are presented, as well as the basic theoretical settings for its application, i.e. key relationships between power and collector field area of PV power plant and working volume of upper storage. The paper introduces hydrological and hydro-energetic indicators for the hybrid plant description, “artificial rainfall”, as the relationship between the water pumped into the upper water storage of the PSH (artificial water inflow) and collector field area of the PV power plant, as well as hydroenergy potential. The proposed hybrid electric power plant does not emit greenhouse gases, produce waste or significantly exploit water resources while the risks to humans and the environment are far smaller than when using conventional technology. This solution is flexible for implementation and can be applied in various climates, hydrological and physical conditions. It is especially productive in cases of joint use of solar and hydro energy where they naturally complement each other as natural energy sources in the annual working cycle.
This paper describes the influence of the solar multiple on the annual performance of parabolic trough solar thermal power plants with direct steam generation (DSG). The reference system selected is a 50 MWe DSG power plant, with thermal storage and auxiliary natural gas-fired boiler. It is considered that both systems are necessary for an optimum coupling to the electricity grid. Although thermal storage is an opening issue for DSG technology, it gives an additional degree of freedom for plant performance optimization. Fossil hybridization is also a key element if a reliable electricity production must be guaranteed for a defined time span. Once the yearly parameters of the solar power plant are calculated, the economic analysis is performed, assessing the effect of the solar multiple in the levelized cost of electricity, as well as in the annual natural gas consumption.
This paper presents the artificial water inflow created by the photovoltaic (PV) or solar thermal (ST) generator which pumps it into the upper water/energy storage of pump storage hydroelectric (PSH) for continuous green energy production. Formulas have been derived for the calculation of artificial water inflow created by the PV and ST generator, as well as the general formula for calculating the artificial water inflow created by solar energy and formulas for calculating the corresponding energy, all in order to assess the site location suitability for solar hydro system applications. In order to verify the obtained formulas, two sites were observed at typical climate areas, i.e. Mediterranean (Vis, 1575 kWh/m2y) and Continental (Osijek, 1262 kWh/m2y) climate of Croatia, and as expected, the PV generator provides more stable time series in both climates than the ST generator that creates high energy dissipation and therefore less reliable energy production, particularly in the areas with Continental climate. Compatibility analysis of natural and artificial water inflows, with the use of a small water reservoir, showed that the PV-PSH system can ensure a continuous supply of energy throughout the whole year, while winter energy shortages in the ST-PSH system can be solved by using a larger reservoir. The obtained results show that the integrated solar-hydro system is efficient and desirable in terms of achieving goals related to the increase of green energy production.
This paper presents the development and testing of an innovative code for the prediction of thermodynamic performances at nominal conditions, as well as a preliminary plant sizing and investment costs estimation for different parabolic trough solar fields. Part A of the paper presented in detail the model and validated it toward existing plants. This part discusses potentialities of the PATTO code (Parabolic Trough Thermodynamic Optimization) in terms of the capability (i) to compare the HCEs performances of various manufacturers, (ii) to accomplish an economic analysis and evaluate the specific investment costs of different technologies, (iii) to carry out a sensitivity analysis on the HCE performances and (iv) to implement innovative plant configurations. The potentiality of the economic analysis has been tested toward the recently built Nevada Solar One plant, while the sensitivity analysis of collector performances has been validated with a parametric study found in literature. PATTO allowed to propose and test an original hybrid solution with potential thermodynamic and economic advantages: results obtained by the code at nominal conditions show an efficiency gain of 1.2% points and potential investment costs saving of 6.5% with respect to a state-of-the-art reference plant.
This paper presents an innovative code for predicting performances, as well as preliminary plant sizing and investment costs estimation, for different parabolic trough solar fields operating at nominal conditions. The code allows a preliminary design of the solar field lay-out, the sizing of the main components of the plant and the optimization of the steam cycle. The code, named PATTO (PArabolic Trough Thermodynamic Optimization), allows to separately calculate the thermal efficiency of parabolic trough systems in commerce as well as combination of components of various commercial systems, in order to exploit different technology solutions: combination of mirrors, receivers and supports. The code is flexible in terms of heat transfer fluid, temperature and pressure range. Regarding the power block, a conventional steam cycle with super-heater and re-heater sections and up to seven regenerative bleedings is adopted. In part A of the paper a detailed description of the code is presented, with calibration toward real applications and reference values found in literature. Part B reveals capability of the code in predicting performances of different solar technologies and their costs. Finally an innovative solar plant configuration is proposed.
This paper presents the model for optimal sizing of a Solar Thermal (ST) power plant with parabolic collectors, which operates with Pump Storage Hydroelectric (PSH), all for the purpose of providing full energy independence of an isolated consumer. The sustainability of such system is based exclusively on solar energy input (without hybridization with any fossil fuel), as a renewable and pure energy resource, and the use of hydro energy, due to the possibility of its continuous production of energy. The feasibility and characteristics of the ST-PSH power plant were tested on power supply of the Island of Vis in Croatia, and the results show that the proposed model describes the operation of the power plant very well. For average solar irradiation of about 1500kWh/m2/a, precipitation 644mm/a, evaporation 1444mm/a, volume of PSH upper reservoir of 20hm3, electric energy consumption of 18GVAh/a and reserve in the system for 3–4 months, the obtained power of the ST power plant is 22MW, which can produce unit value of the annual thermal energy of 459kWh/m2/a and electric energy of 160kWh/m2/a, while the total collector aperture in the observed case is about 16ha. These results show that ST-PSH plants can be successfully applied on locations with relatively low irradiation, wherein the key element that ensures continuous production of energy is precisely the PSH technology that can in the best way, in economic-technical, and especially in ecological sense, balance the relatively large summer surpluses and winter energy shortages.
This paper analyzes the reality of sustainable energy supply (SEPS) from renewable energy sources (RES) as a totally green strategy of electric energy production. The paper is based on the Advanced International Policies (AIP) scenario of the European Renewable Energy Council agency forecast by the year 2040, which foresees the share of 82% of RES, extended to 100% of RES. The key element that creates conditions for achieving this ambitious scenario is an innovative solution of the so-called solar hydroelectric power plant (SHE) which is basically combined photovoltaic (PV) power plant and pump storage hydro (PSH) which can provide continuous supply of electric power and energy to consumers. Therefore, SHE is presented in this paper as the main building element of the future SEPS. For covering unit consumption of electric energy of 1 GWh in a power system, the paper calculates unit values of the SHE system: 0.73 MW of PV generator; 4,545 m(2) of PV generator; 0.36 hm(3) of reservoir volume, 0.21 GWh of PSH energy and 0.24 MW of PSH. In the case of the power system in Croatia, which is rich in solar and hydroenergy and whose climate conditions are very similar to those in the European countries, it has been shown that implementation of the green strategy of energy balance fulfilling can be realized with present day technology. Precisely, this fact shows that further increase of efficiency of SHE and other RES and their combining into RES+PHS power plants, along with increase in the cost of classic power fuels and the growing needs for environment protection, the proposed solution of SEPS realization could be widely important and thus become a serious alternative to the existing energy strategies and a guideline to decision makers in many countries.
The long-term annual thermal energy delivery per unit of collector area of commonly used collector types and configurations, for a range of operating temperatures, are calculated for representative locations in Zimbabwe. A well-known model found in the literature is the basic tool of analysis, the only modifications being, the use of a locally-derived correlation of the monthly average diffuse fraction of hemispherical radiation to the monthly average clearness index, and the use of temperature-dependent collector heat loss coefficients. The results are presented as plots of annual specific thermal energy output against collector receiver temperature gain (Tr−Ta).The results, though founded on a number of simplifying assumptions on some collector parameters, provide a sound basis for the economic evaluation of solar thermal applications in Zimbabwe.
This paper describes the development and use of a thermofluidynamic model for parabolic trough collectors, specifically suited for carrying out systematic calculations on different design options. The model is based on detailed energy balances, and it has been applied to evaluate collector thermal performances with different working fluids: oil, molten salt, or water/steam. For each heat transfer fluid technology, four parameters have been analyzed: collector length, absorber tube diameter, working temperature, and pressure. The influence of these factors has been studied from the point of view of heat loss, pressure drop, energy, and exergy efficiencies. Exergy is considered the suitable magnitude to guide any optimization process in this field, because it accounts for all relevant energy gains and losses, characterized by their corresponding temperature and pressure. Preliminary conclusions point out that direct steam generation is more efficient than oil and molten salt systems. [DOI: 10.1115/1.4001399]
Acquiring a pumped-storage power generation site utilizing river water recently faces several restrictions due to environmental assessment. On the other hand, there are many sites favorable for constructing a pumped-storage power plant utilizing seawater in Japan, which is surrounded by the sea. Seawater pumped-storage power plants have several advantages such as lower civil construction cost and lower power distribution cost due to their proximity to nuclear or steam turbine power plants. Seawater pump turbines are used under the condition where the corrosion environment is noticeably severe, rather than conventional river water pump turbines. In addition, pump turbines have many narrow spaces between parts and their major parts are embedded, so that it would be very difficult to apply proper corrosion prevention measures. This problem cannot be solved only by conventional corrosion-preventive engineering. The Agency of Natural Resources and Energy of the Ministry of International Trade and Industry entrusted Electric Power Development Co., Ltd. with the construction of the world's first seawater pumped-storage pilot plant in Kunigami Village in Okinawa Prefecture, Japan, to execute verification tests for five years after the completion of construction in March, 1999. This paper will deal with materials, structure, and corrosion-preventive engineering of the pump turbine for the seawater pumped-storage power plant.
The paper deals with the preliminary design and optimization of cogenerative solar thermodynamic plants for industrial users. The considered plants are all based on proven parabolic trough technology, but different schemes have been analyzed: from a conventional configuration with indirect steam cycle and a heat transfer fluid such as synthetic oil or molten salts, to a more innovative arrangement with direct steam generation in the solar field. Thermodynamic parameters of the steam cycle have been optimized considering some constraints due to the heat requirements of the user, leading to a preliminary design of the main components of the system and an estimation of costs. Resulting net electric efficiency is about 10% for conventional synthetic oil plant, while 13% for innovative molten salts and DSG.A comparison with conventional solar thermodynamic systems for electricity production and photovoltaic power plants shows the economic and energetic benefits of the cogenerative solution. Cost of electricity for solar plant is cheaper of about 20 €/MWh than conventional solar power application. Moreover, heat recovery allows to achieve a further 50% of CO2 emission savings compared to reference solar plants for only electricity production.
This work presents the main features of the new power plant that comprises the modified reversible hydroelectric (HE) power plant operating together with the photovoltaic (PV) power plant. Such Solar Hydroelectric Power Plant (SHE) uses solar energy as the only input for production of solar and hydro energy. Thereat, water reservoir serves for daily and seasonal energy storage, thus basically solving the problem of energy storage, which is the biggest problem of wider use of solar energy. The most expensive part of SHE is the PV generator, whose optimal sizing is essential for providing energetic independence of a settlement or isolated consumer. A systematic approach that includes all relevant elements of this system has been implemented for optimal sizing of the PV power plant. The developed model was used in analysis of certain parameters of the SHE system. The results of the analysis show the system characteristics and that the proposed model describes the operation of the power plant very well. The feasibility and characteristics of the power plant were tested on electric energy supply of the island of Vis in Croatia. It has been established that the system is real, feasible and can be very successfully applied on different locations, for different consumers and can vary in size. The prerequisite for realization of such system is the construction of a modified reversible HE power plant. The presented SHE represents a permanently sustainable energy source that can continuously provide power supply to a consumer, using exclusively natural and renewable energy sources, without causing harmful effects on the environment.
Literature values of osmotic coefficients of NaCl solutions from 1 to 4m and 25° to 100°C. and from 1 to 3m and 125° to 270°C. were fitted to an extended Debye-Hückel equation. By the use of the parameters of fit and the required theoretical change in the limiting slope, vapor pressures of sea salt solutions from 25° to 175°C. and 1 to 28 wt. % solids were calculated and compared with experimental values. In addition, boiling point elevations were calculated for the ranges 2 to 28 wt. % salts and 25° to 260°C., theoretical minimum energies of recovery of water from sea water were calculated for the ranges 0 to 100% recovery and 25° to 200°C., and osmotic pressures were calculated for sea salt solutions of 1 to 25 wt. % solids and for 0.01 to 5m NaCl solutions over the temperature range 25° to 100°C. Where NaCl solutions were desirable as a stand-in for sea salt solutions, the thermodynamic properties appear to be much more alike for solutions of the same total concentration of ions than for those of the same ionic strength ( at least at the lower temperatures).
The work presents a technological concept of energetically independent and ecologically sustainable system of electric energy production by joint operation of photovoltaic (PV) and hydro electric (HE) power plant as a unique technological system of solar hydroelectric (SHE) power plant. The sustainability of such system is based exclusively on the solar energy input, as the renewable and pure energy resource, and the use of hydro energy, due to the possibility of its continuous production of energy and its well-known flexibility in covering the consumers' needs. For the purpose of connecting all relevant values into one integral SHE system, a mathematical model was developed for selecting the optimal size of the PV power plant as the key element for estimating the technological feasibility of the overall solution. The model was tested on electric energy supply from the island of Vis in Croatia. The obtained power of the PV power plant was 41 MWp which corresponds to collector field of approximately 25 ha, while the estimated related storage was 20 hm3. The results show that the subject model describes the SHE very well and that the proposed concept of joint operation of PV and HE power plants is real and possible. The application of such sustainable SHE systems could significantly increase PV industry worldwide, i.e. the share of solar energy in energy balances of numerous countries. Proposed hybrid simulation-dynamic programming model is suitable to optimize PV plant in accordance with system characteristics. Copyright © 2009 John Wiley & Sons, Ltd.
The paper presents a new type of Renewable Energy Sources (RES) suitable for exploitation watercourse with periodical-temporary water flow. This innovative solution consist of Hydroelectric Plant (HEP) and solar Photovoltaic (PV) generator working together as one hybrid power plant, producing green energy with the same characteristics as classical hydroelectric plants. The main objective of this hybrid solution is achievement of optimal renewable energy production in order to increase the share of RES in an Electricity Power System (EPS). As a paradigm of such exploitation of RES, the example of HEP Zavrelje/Dubrovnik in Croatia was used, where it was ascertained that the proposed solution of hybrid PV-HEP system is natural, realistic and very acceptable, which enhances the characteristics of both energy sources. The application of such hybrid systems would increase the share of high quality RES in energy systems.Research highlights► A hybrid power plant based on solar energy and temporary water flow is introduced. ► This is innovative system consists of HE power plant and PV generator. ► The achievement is reliable green energy production for certain consumer or EPS. ► As a case study, existing HE Zavrelje–Croatia was used. ► The application of such systems would increase the share of renewable energy.
This paper presents the conceptual design of the first solar power plant using Direct Steam Generation (DSG) in a parabolic-trough solar field. Experience and know-how in the DSG process acquired during the DISS project were applied in designing the solar field of this plant. The 5-MWe plant is composed of a DSG parabolic-trough solar field connected to a superheated steam Rankine power cycle. The solar field produces 410 °C/70-bar superheated steam. Detail engineering of this plant is currently underway within the framework of the INDITEP project, which is promoted by a German-Spanish consortium with the financial support of the European Commission (Contract No. ENK5-CT-2001-00540). The main design objective is to assure high operational flexibility and reliability. This is the reason why a robust superheated steam turbine has been selected, though the efficiency of its power block is modest.
This work focuses on innovation in CSP technologies over the last decade. A multitude of advancements has been developed during this period, as the topic of concentrated solar power is becoming more mainstream. Improvements have been made in reflector and collector design and materials, heat absorption and transport, power production and thermal storage. Many applications that can be integrated with CSP regimes to conserve (and sometimes produce) electricity have been suggested and implemented, keeping in mind the environmental benefits granted by limited fossil fuel usage.Graphical abstractHighlightsThis work focuses on the latest developments in concentrated solar power, such as ► Parabolic trough collectors. ► Heliostat field collectors. ► Linear Fresnel reflectors. ► Parabolic dish collectors.
This paper sets out a new approach to understanding the relationship between migration and climate change. Based on the understanding that migration is a significant, growing, but also complex phenomenon, this approach seeks to address the sensitivity of existing migration drivers in specific contexts to climate change. In contrast to existing approaches which have sought to generate global-level estimates of the numbers of ‘climate migrants’, this integrated assessment approach seeks instead to understand how and why existing flows from and to specific locations may change in the future, and provide a practical tool for climate adaptation planning. Examples of the application of this approach are provided for Ghana and Bangladesh.
This paper analyses the reality of total renewable electricity scenario (TRES) from renewable energy sources (RES) as a totally green strategy of electric energy production. The paper is based on the EREC's Agency forecast until the year 2040, which foresees the share of 82% of RES, extended to 100% of RES. The key element that creates conditions for achieving this ambitious scenario is an innovative combination of RES and pump storage hydroelectric (PSH) power plants, the so-called Concept-H, which can simultaneously use the energy of local RES (sun and wind) and local precipitation (natural waterflows) and in this way can provide continuous supply of electric power and energy to consumers. The methodology is based on the model of equivalent RES and equivalent reservoir that allows a comprehensive view of available RES and hydro system. The total required land use of RES system would be 29,517Â km2 of RES (which would amount to about 0.5% of the total technical potential of using RES), total reservoir volumes would be 880Â km3 (which is only 8% of all artificial reservoirs built in the world to the date) and the orientation estimate of investment in TRES would then be approximately 1% of world GDP in 2009, which clearly shows that the TRES is realistically feasible. It has been shown that implementation of the green strategy of energy balance fulfilling can be realized with present day technology. Precisely this fact shows that further increase of efficiency of RES and their combining into RES-PSH power plants, along with increase in the cost of classic power fuels and the growing needs for environment protection, the proposed solution of TRES realization could be widely important and thus become a serious alternative to the existing energy strategies and a guideline to decision makers throughout the world.
This paper analyses the hybrid solar and hydro (SHE) system as a unique technological concept of the sustainable energy system that can provide continuous electric power and energy supply to its consumers and the possibilities of its implementation in Europe and areas with similar climate. The sustainability of such system is based on solar photovoltaic (PV) and hydroelectric (HE) energy as renewable energy sources (RES). For the purpose of connecting all relevant values into one integral SHE system, a mathematical model was developed for selecting the optimal size of the PV power plant as the key element for estimating the technological feasibility of the overall solution. Sensitivity analysis (parameter analysis) was made for the model, where local climate parameters were varied: solar radiation, air temperature, reservoir volume, total head, precipitation, evaporation and natural water inflow. It has been established that, apart from total head (which is to be expected), solar radiation, hydro accumulation size and natural water inflow have the biggest effect on the calculated power of the PV power plant. The obtained results clearly show a wide range of implementation of the new energy source (SHE system), i.e. from relatively cold climates to those abundant in solar energy, but also with relatively small quantity of water, because it only recirculates within the system. All this points to the necessity for further development of hybrid systems (RESÂ +Â HE systems) and to the fact that they could play an important role in achieving climate objectives.
An inherent characteristic of renewable energy sources (RES)-based electricity generation systems is intermittency and non-controllability.
Therefore, the prerequisite for a more significant use of RES within the energy system is the corresponding capacity of Electric
Energy Storage (EES). The existing storage of Hydro Electric Power (HEP) is suggested as a possible solution to this issue.
The paper contains a detailed analysis of the possible joint operation of Photovoltaic (PV) generator and HEP. The key element
of this scenario is the HEP storage that would serve as EES. The analysis of the possible joint operation of the PV generator
and HEP shows it as a natural, feasible and very acceptable solution that would enhance the features of both energy sources.
Joint operation would increase the energy production sustainability, cut volatility and increase reliability, and therefore
the value of the RES energy, as well as the efficiency of the HEP. The application of the hybrid system will significantly
contribute to the share of RES in the energy system and thus to achieving the climate protection objectives.
KeywordsHydro energy–Hydro electric power–Renewable energy sources–Hybrid energy systems–Energy storage–Sustainable energy supply
Parabolic trough power plants are currently the most commercially applied systems for CSP power generation. To improve their costeffectiveness,
one focus of industry and research is the development of processes with other heat transfer fluids than the currently used
synthetic oil. One option is the utilization of water/steam in the solar field, the so-called direct steam generation (DSG).
Several previous studies promoted the economic potential of DSG technology (Eck et al., 2008b; Price et al., 2002; Zarza, 2002).
Analyses’ results showed that live steam parameters of up to 500 C and 120 bars are most promising and could lead to a reduction
of the levelized electricity cost (LEC) of about 11% (Feldhoff et al., 2010). However, all of these studies only considered plants without
thermal energy storage (TES).
Therefore, a system analysis including integrated TES was performed by Flagsol GmbH and DLR together with Solar Millennium
AG, Schott CSP GmbH and Senior Bergho¨ fer GmbH, all Germany. Two types of plants are analyzed and compared in detail: a power
plant with synthetic oil and a DSG power plant. The design of the synthetic oil plant is very similar to the Spanish Andasol plants (Solar
Millennium, 2009) and includes a molten salt two-tank storage system. The DSG plant has main steam parameters of 500 C and
112 bars and uses phase change material (PCM) for the latent and molten salt for the sensible part of the TES system. To enable comparability,
both plants share the same gross electric turbine capacity of 100 MWel, the same TES capacity of 9 h of full load equivalent
and the same solar multiple of the collector field of about two.
This paper describes and compares both plants’ design, performance and investment. Based on these results, the LEC are calculated and
theDSGplant’s potential is evaluated. One key finding is that with currently proposedDSGstorage costs, the LEC of aDSGplant could be
higher than those of a synthetic oil plant. When considering a plant without TES on the other hand, the DSG system could reduce the LEC.
This underlines the large influence of TES and the still needed effort in the development of a commercial storage system for DSG.
The direct steam generation (DSG) in parabolic trough collectors is a promising option to improve the mature parabolic trough solar thermal power plant technology of the Solar Energy Generating Systems (SEGS) in California. According to previous studies, the cost reduction of the DSG process compared to the SEGS technology is expected to be 8 to 25%. All these studies were more or less preliminary since they lacked detailed information on the design of collector fields, absorber tubes required for steam temperatures higher than 400°C and power blocks adapted to the specific needs of the direct steam generation.
Power blocks and collector fields were designed for four different capacities (5, 10, 50 and 100 MWel) and different live steam parameters. The live steam temperature was varied between saturation temperature and 500°C, and live steam pressures of 40, 64 and 100 bar were investigated. To assess the different cases, detailed yield analyses of the overall system were performed using hourly data for the direct normal irradiation and the ambient temperature for typical years. Based on these results the levelized costs of electricity were determined for all cases and compared to a reference system using synthetic oil as heat transfer fluid (HTF).
This paper focuses on two main project findings. First, the 50 MWel DSG system parameter comparisons are presented. Second, the detailed comparison between a DSG and a SEGS-like 100 MWel system is given. The main result of the investigation is that the benefit of the DSG process depends on the project site and can reach an 11% reduction of the levelized electricity cost (LEC).
This paper presents a summary of the main results and conclusions achieved in the DISS (Direct Solar Steam) project. The test facility implemented at the Plataforma Solar de Almería (PSA) in 1997–8, the so-called PSA DISS test facility, was operated for more than 3000 h in 1999–2000 and 2001 to investigate the Direct Steam Generation (DSG) process under real solar conditions. The feasibility of the DSG process in horizontal parabolic trough collectors has been proven and an important know how has been acquired by the project partners regarding the thermo-hydraulic parameters of the water/steam flow in DSG solar fields.
The direct steam generation (DSG) in parabolic trough collectors is an attractive option regarding the economic improvement of parabolic trough technology for solar thermal electricity generation in the multi Megawatt range. The European DISS project has proven the feasibility of the direct steam generation under real solar conditions in more than 4000 operation hours. Within the European R&D project INDITEP the detailed engineering for a pre-commercial DSG solar thermal power plant with an electrical power of 5MW is being performed. This small capacity was chosen to minimise the risk for potential investors.In regards to DSG solar thermal power plants, only steam cycles using superheated steam have been investigated so far. The paper will investigate the advantages, disadvantages, and design considerations of a steam cycle operated with saturated steam for the first time. For near term applications, saturated steam operated DSG plants might be an interesting alternative for power generation in the small capacity range due to some specific advantages:•Simple set up of the collector field.•Proven safe collector field operation.•Higher thermal efficiency in the collector field.
With levelized electricity costs (LEC) of 10–12USCts/kWh the well-known SEGS (Solar Electric Generating Systems) plants in California are presently the most successful solar technology for electricity generation [Price and Cable (2001) Proc. ASME Int. Solar Energy Conf. Forum 2001]. The SEGS plants apply a two-circuit system, consisting of the collector circuit and the Rankine cycle of the power block. These two-circuits are connected via a heat exchanger. In the case of the Direct Steam Generation (DSG) in the collector field [Zarza et al. (2001) Proc. Solar Forum 2001, Washington], the two-circuit system turns into a single-circuit system, where the collector field is directly coupled to the power block. This renders a lower investment and higher process temperatures resulting in a higher system efficiency. Due to the lower investment and the higher efficiency a reduction of the LEC of 10% is expected when the DSG process is combined with improved components of the solar collectors [Zarza (2002) DISS Phase II Final Report, EU Contract No. JOR3-CT98-0277]. Within the European DISS (Direct Solar Steam) project the feasibility of the direct steam generation has been proven in more than 3700 operation hours. Steam conditions of 100bar and 400°C have been demonstrated. This paper presents the main scientific results of the DISS project that aims at the investigation and demonstration of the DSG process in parabolic troughs under real solar conditions.
The direct steam generation (DSG) is an attractive option regarding the economic improvement of parabolic trough technology for solar thermal electricity generation in the multi megawatt range. According to Price, H., Lupfert, E., Kearney, D., Zarza, E., Cohen, G., Gee, R. Mahoney, R., 2002, "Advances in Parabolic Trough Solar Power Technology," J. Sol. Energy Eng., 124 and Zarza, E., 2002, DISS Phase H-Final Project Report, EU Project No. JOR3-CT 980277 a 10% reduction of the LEC is expected compared to conventional SEGS like parabolic trough power plants. The European DISS project has proven the feasibility of the DSG process tinder real solar conditions at pressures up to 100 bar and temperatures up to 400 degrees C in more than 4000 operation hours (Eck, M., Zarza, E., Eickhoff, M., Rheinlander J., Valenzuela, L., 2003, "Applied Research Concerning the Direct Steam Generation in Parabolic Troughs," Solar Energy 74, pp. 341 351). In a next step the detailed engineering for a precommercial DSG solar thermal power plant will be performed. This detailed engineering of the collector field requires the consideration of the occurring thermohydraulic phenomena and their influence on the stability of the absorber tubes.
This paper analyzes a possibility of upgrading hydroelectric plant (HEP) with solar photovoltaic (PV) generator. The main objective of this solution is maximization of green energy production in accordance with local and existing HEP framework. The example of HEP Zavrelje/Dubrovnik in Croatia was used as a paradigm of such exploitation of RES. The results of the analysis confirm that the proposed solution of hybrid work PV-HEP system is natural, realistic, and very promising. By hybridization of these two main natural energy sources, the characteristics of both energy sources are enhanced. The application of such hybrid systems would increase the share of green energy in the electric power systems and thus reduce the CO<sub>2</sub> emission from energy sources.
Despite the abundance of renewable energy resources in the Arab region, the use of solar thermal, solar photovoltaics, and wind is still in its technological and economic infancy. Great potential exists, but economic constraints have impeded more rapid growth for many applications. These technologies have certainly advanced technically over the last quarter century to the point where they should now be considered clean-energy alternatives to fossil fuels. For the Arab countries and many other regions of the world, potable water is becoming as critical a commodity as electricity. As renewable energy technologies advance and environmental concerns rise, these technologies are becoming more interesting partners for powering water desalination projects. We evaluate the current potential and viability of solar and wind, emphasizing the strict mandate for accurate, reliable site-specific resource data. Water desalination can be achieved through either thermal energy (using phase-change processes) or electricity (driving membrane processes), and these sources are best matched to the particular desalination technology. Desalination using solar thermal can be accomplished by multistage flash distillation, multi-effect distillation, vapor compression, freeze separation, and solar still methods. Concentrating solar power offers the best match to large-scale plants that require both high-temperature fluids and electricity. Solar and wind electricity can be effective energy sources for reverse osmosis, electrodialysis, and ultra- and nano-filtration. All these water desalination processes have special operational and high energy requirements that put additional requisites on the use of solar and wind to power these applications. We summarize the characteristics of the various desalination technologies. The effective match of solar thermal, solar photovoltaics, and wind to each of these is discussed in detail. An economic analysis is provided that incorporates energy consumption, water production levels, and environmental benefits in its model. Finally, the expected evolution of the renewable technologies over the near- to mid-term is discussed with the implications for desalination applications over these timeframes.