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Energy performance enhancement of a research centre based on solar potential analysis and energy management
Abstract
Energy management is very important for the effective operation of a hybrid system composed of various energy sources. The present work aims to develop an effective control strategy in order to reduce the grid-maximal contracted power of a hybrid building containing PV systems, combined heat and power (CHP) unit and battery energy storage system (BESS). The proposed solutions (new control strategy and increased PV system size) were carried out based on the analysis of monitored data collected from May 2016 to April 2017 representing the real behaviour of the hybrid system.
The obtained results demonstrated the effectiveness of the developed control strategy in decreasing the grid-maximal contracted power from 140 kW to 120kW and increasing the self-sufficiency of the building. Furthermore, by combining the proposed control strategy and the proposed PV system, the self-sufficiency can be even more increased and the grid-maximal power can be reduced by 30% leading to an annual savings of almost 4000 €/year.
Finally, the financial assessment revealed that the payback period of the proposed solution is less than 10 years confirming the profitability of the investment.
... The calibration of the PV model as well as the estimation of its unknown parameters was carried out by following the same procedure already published in [38]. The validation of the model was done based on real measured data from our PV plants consisting of polycrystalline PV panels [39]. The characteristics of the panel are listed in Table 2. ...
... The battery energy storage system (BESS) can mitigate the intermittency of the power generated from the PV system, store the surplus energy, and provide other ancillary services to the electricity grid. In this work, a lithium-ion (Li-Ion NMC) battery technology was considered in the simulations, as this type of batteries has been already modeled and validated in previous works [39,41]. The main parameters of a single battery module are listed in Table 2. ...
... The variable τ represents the internal timestep used by the software in the simulation. This battery model was already validated in previous works published in [39,41], and it presented a good accuracy in the estimation of the SOC of the battery. Root mean square error (RMSE) values less than 5% were obtained when comparing simulations and real measured data [39,41]. ...
This paper reports on the electrical performance of two bloc-of-flats buildings located in Prague, Czech Republic. Measured data of electrical consumption were used to investigate the effect of photovoltaic (PV) and battery energy storage system (BESS) systems on the overlap between generation and demand. Different PV array configurations and battery storage capacities were considered. Detailed solar analysis was carried out to analyze the solar potential of the building and to assess the PV electricity production. The evaluation of the building performance was done through MATLAB simulations based on one-year monitored data. The simulation results were used for the calculation of the load matching indices: namely, the self-consumption and self-sufficiency. It was found that optimized array tilt and orientation angles can effectively contribute to a better adjustment between electricity demand and solar PV generation. The addition of a façade PV system increases significantly the PV generation and thus the load matching during winter months. Mismatch is further reduced by using the energy flexibility provided by the BESS. Depending on the PV size and BESS capacity, the self-consumption and the self-sufficiency of the building could increase from 55% to 100% and from 24% up to 68%, respectively.
... In the Czech Republic context where there is small Feed-in-Tariff (FIT), Kichou et al. [14] propose two simulation models (one for summer and one for winter) to find the optimal solution between performance and financial cost for systems composed by PVs, CHPs and batteries for a research building. Performance is directly proportional to a ratio of energy bought from the grid over selfconsumption. ...
... By the end of line 6, the variable "memorySet" is empty and the root node is solved. In Figure 4, (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) solves the node with id=1, creates children of that node and adds two sets in the memory-Set. In Figure 5, the second and the third iteration of the loop (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) are shown. ...
... In Figure 4, (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) solves the node with id=1, creates children of that node and adds two sets in the memory-Set. In Figure 5, the second and the third iteration of the loop (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) are shown. In the second iteration, the node with id=2 does not generate the child c/c [1] = {W H} because that set is already in the variable "memorySet". ...
Smart homes allow optimized energy usage, allowing households to reduce electricity bills or even make profits. By 2020, 20% of all households in Europe and 35% in North America will be expected to become smart homes. Although smart homes seem to be the future for homes, many customers have the perception that a transition from current homes to smart ones is unprofitable. Adopting a smart home concept requires investments for which the households desire a positive return. A question in this context is the following: for a given household, when and/or what set of home appliances/technologies should be acquired so that the investment made by householder has a positive financial return? The available tool to answer that question can be time-consuming from a practical perspective. Based on our previous work, this paper proposes a framework to help the transition from current houses to smart homes considering customized electricity usage and economic measures. A tree algorithm is developed to decrease the time needed by an economic analysis of each possible acquisition combination of smart appliances or equipment for a given user. The proposed framework is tested on 40 cases covering all Brazilian capital cities, whose results are available online and may be used directly as an approximation for economic analyses. An example of one case is described in detail. Results show that the proposed tree algorithm is able to reduce days of CPU time to solve the problem and Net Present Value should be used as an economic measure to answer the aforementioned question.
... where Iph is the photogenerated current, Io is the reverse saturation current, n is the diode ideality factor, and Rs and Rsh are the series and shunt resistances, respectively, representing power losses. In previous studies, the model has been validated using real data from PV installations that utilize mono and poly-crystalline PV panels for roof ) and façade (Kichou et al. 2019) PV systems. The module temperature Tm for PV systems was determined using the nominal operating cell temperature (NOCT) formula, expressed in Eq. 2, considering ambient conditions for temperature (T α ) and POA irradiance (G). ...
... Finally, the net energy balance (1) and flexibility (2) of the neighborhood were assessed considering the energy consumption data, the PV generation potential, and the operation of a central battery storage system (BESS). A mathematical model for the BESS captures its dynamic behavior (Kichou et al. 2019), estimating the instantaneous value of the state of charge (SOC). Conceptually, we extend the building flexibility definition of BIPV by Skandalos and Karamanis to a net-zero energy community with the net energy balance of the community given as: ...
Integrating renewable energy systems into urban neighborhoods is essential for achieving sustainable development and decarbonization. This study investigates the integration of building-integrated photovoltaics and energy-sharing mechanisms to achieve net-zero energy communities in low-income urban neighborhoods. Using a social housing neighborhood in Ioannina, Greece, within Local Climate Zone 6, as a case study, we evaluated energy performance through hourly simulations. Annual PV generation (1096.2 MWh) exceeded the total load (931.5 MWh), achieving net-positive energy status. Incorporating a 1000 kWh battery energy storage system improved the hourly load match from 39.1 to 81% and reduced grid imports and exports by 52% and 37%, respectively. The findings underscore the potential of energy-sharing systems to enhance urban energy resilience and self-sufficiency. In addition, the study emphasizes the importance of leveraging Local Climate Zone characteristics to design energy systems tailored to urban contexts. Policy incentives and further research are recommended to promote cost-effective energy-sharing models in similar contexts.
... Where Tc is the cell temperature, Tα is the ambient temperature, and G is the solar irradiance on the PV module. The dynamic behavior of the Battery Energy Storage System (BESS) was modeled using a mathematical approach from previous studies [65]. The model estimates the state of charge (SOC) over time, represented as a normalized value (SOCn in [%]), using the following equation: ...
... Previous studies [65,66] have validated this model, achieving root mean square error (RMSE) values below 5 % when comparing simulations to real-world measurements. The energy management strategy and PV system are critical in the BESS operation. ...
Since the time to achieve the sustainable urban transformation to carbon neutrality and mitigate climate change is limited, rapid and deep actions are needed in a feasible pathway based on existing, scalable, and adaptable technological and natural solutions to be deployed within this decade. In this work, we explore, for the first time to the best of our knowledge, the feasibility of achieving carbon neutrality at representative building blocks of two neighborhoods at different climatic conditions and local climate zones in Europe by combining the already available cost-effective resources of greenery as trees, on-site clean electricity generation with well-developed photovoltaics and grid decarbonization with the current transition rate.
Using a robust methodological framework, the analysis integrates 3D urban modeling, radiance-based solar analysis, building energy simulations, and PV/Battery Energy Storage Systems design. Metrics such as self-sufficiency (Ss), self-consumption (Sc), and net energy and carbon balances were evaluated under current and future (SSP1-2.6) climate scenarios.
Results indicate that rooftop PV systems coupled with BESS improve Ss to 55.1% in the Ioannina neighborhood and 16.2% in the corresponding Prague, requiring expanded PV facade systems. Integrating nature-based solutions (NBS) contributes to carbon sequestration (21.6 tons/year in Ioannina; 43.2 tons/year in Prague) and enhances urban cooling while mitigating rising energy demands driven by climate change. Carbon neutrality is projected by 2030 in Ioannina and by 2038 in Prague, highlighting the potential of PV and NBS integration as scalable strategies for decarbonizing urban neighborhoods and providing actionable insights for stakeholders in city planning and energy sustainability. Therefore, the clear unlocking of combined effects of contextual relevance can rapidly scale up the reduction of carbon emissions and mitigate climate change.
... MWh of electrical energy was sufficient [23]. Kichou et al. (2019) aimed to save energy for a combined system together with solar energy and heat power batteries. between May April 2016 and April 2017, energy design was achieved by reducing the energy from 140 kw to 120 kw for energy management. ...
... between May April 2016 and April 2017, energy design was achieved by reducing the energy from 140 kw to 120 kw for energy management. Self-generating buildings have been designed and have achieved an energy saving of 30% and a saving of 4000 euros each year [24]. SW TECH Energy has completed the installation and preacceptance of Solar Power Plant with a power of 2,530 kWp in Selim District of Kars province [25]. ...
In this study, the total installation cost was calculated with the selection of solar panels (PV) to be used, Control Monitoring System, number of inverters when applying solar energy from renewable energy sources to Kars Airport in order to obtain a clean environment and clean energy. According to the latest two-year data obtained with the permission of the institution from Kars Harakani Airport Electricity Distribution, the total electricity consumption was calculated by the amount of electricity produced by the SPP project. In the continuation, the cost analysis tables are given when there is an overdraft and non-credit installation with the amortization time required for installation. For installation, statistical data on annual hours of sunshine and rainy days were taken from the General Directorate of Meteorology of Kars province. As a result of calculations; since the service life of a SPP project is 25 years; when the entire project is made without credit,the installation cost of TL 19,917,859.75 (74,391,336. 52 ) . It was found that when the entire loan was established, it paid off in 8 years. From these calculations, if the airport uses an overdraft system, it will pay off in about 8 years and the system will generate and sell its own electricity for 17 years . It was calculated that it would have a profit of 495.177.856,89 TL (74,391,336. 52 ) to the institution, where it can pay off in 4.5 years and produce and sell its own electricity for 20.5 years.
... A mathematical model of the battery is used for the validation of the proposed EES sizing methodology. The chosen model has been already described in our previous publication [28,30] and validated with the same type of battery technology considered in this work. The model is used for the simulation of the real behavior of the battery energy storage system (BESS), and provides long-term validations based on the available measured data described in Section 2. One of the most important parameters of the BESS is the normalized instantaneous state-of-charge value SOC n (given in [%]) at time (t), which can be estimated using Eq. ...
... SOC m is the maximum battery capacity in [Wh]. Battery voltage represented by V bat varies with the battery resistance according to the charging and discharging modes, more details can be found in [30][31][32]. I bat is the battery current, it can be negative (charge mode) or positive (discharge mode). ...
The use of the electrical energy storage (EES) plays an important role in the transition of energy generation towards renewable energy sources (RESs). An effective sizing of EES systems is very important in order to cope with the volatility of RESs and to ensure a reliable energy supply. The present paper provides a methodology which helps to determine the minimum required EES size for conceiving a fully standalone system. Its approach is based on the evaluation of the energy balance for a given design period, and it can also be applied for sizing the EES system in grid-connected applications. The methodology was validated using measurement data obtained from two different systems corresponding to: a) a near-zero energy building with local generation sources, and b) a large-scale battery energy storage system (BESS) installed in a factory and used for peak-shaving. The obtained results confrmed the effectiveness of the proposed methodology by estimating the required size of the EES system. A good correlation was found between the estimated and the installed BESS size in the considered
systems. The deviation between real and estimated BESS capacities was found to be less than 5%.
... Finally, a shunt resistance Rsh and a series resistance Rs represent the power losses. The model was validated by experimental measurements performed for both technologies and the different climatic zones [16][17]. ...
The current work reports on the effect of local climatic conditions on electricity generation of typical building integrated photovoltaic systems (BIPVs). Three different climates of a) semi-continental with increased heating needs, b) Mediterranean with moderate heating and cooling needs and c) hot desert with high cooling needs are considered for BIPV systems. The evaluation of the BIPV electricity generation was done through validated TRNSYS simulations. The findings show that local climatic conditions influence the BIPV electricity generation due mainly to the temperature effect and the different interaction of the solar radiation components with the PV building integration.
... The initial and annual operating costs of the newly designed floating PV system was estimated in accordance with the initial investment cost standards of a PV system in the Czech Republic. Considering the actual size and tilt angle of the systems, typical values were used for supplying modules (c-Si technology) and electrical components [48], floats and anchoring [22], as well supporting structure (polygon configuration) and tracking mechanism. Total investment costs presented in Table 10 fit within the price range of real FPV systems of similar size around the globe [4], indicating reasonable assumptions. ...
Floating photovoltaics (FPVs) provide various benefits especially where land is scarce (e.g., reducing land occupancy, water evaporation and environment control…), or when they are combined with hydropower plants (enhanced capacity factor and green energy generation). Software such as PV*SOL, SAM and PVSyst® are commonly used for the design and simulation of land-based photovoltaic (PV) systems. However, when it comes to the simulation of photovoltaics installed on water surface, such software does not offer the option to directly simulate FPV systems.
In this work, a new approach combining MATLAB and Rhino/Grasshopper environments is proposed for the assessment of FPV systems performance. The approach is divided into various steps considering major influencing parameters such as temperature, irradiance, albedo, PV modelling, panel rows spacing, tilt angle, as well as the benefits of including a tracking mechanism. The proposed approach was validated against PV*SOL simulations for land-based PV systems with a small deviation of less than 2.4%. FPVs simulations considering climatic conditions of Štěchovice, Czechia, showed an increase of the performance in the range of 3% compared to terrestrial PVs. This result is in accordance with some published studies based on real FPVs installations. Finally, the developed approach was applied in the simulations of two large-scale FPV systems with different designs (fixed and with a tracking mechanism) including economical aspects.
... Alternatively, some authors reported on the combination of PV with Battery Energy Storage Systems for increasing the PV self-consumption [115] or grid-peak shaving [117]. The optimum design and control of such PV-BESS systems is under active current research as an intensively investigated topic among researchers [118,119]. Besides, significant research has been done to analyze the effect on the built environment. BIPV systems are investigated through validated models for their effect on both a) building energy demand and b) indoor comfort (thermal, visual). ...
Despite the technical maturity and substantial potential cost reduction of BIPV technologies, there are still challenges to overcome for the expansion of BIPV applications and their wider adaptation at global level. Among these, the alignment of PV integration with particular climate and environmental conditions of the local solar architecture is crucial. This will facilitate the transition to sustainable buildings and the mitigation of climate change. In this context, this study proposes for the first time, a novel BIPV climatic design framework for PV buildings positioning and adaptation to local climate towards the minimization of energy expenditure and use of resources. With the review and analysis of a large numbers of BIPV studies globally for seventy parameters grouped in eight main categories of an open-access database, the global horizontal irradiation (GHI) value is selected as an additional index to the Köppen-Geiger classification scheme. The extension accounts for the urban suitability and vulnerability and prioritize the building integration of photovoltaics. Four zones of cold (low GHI), moderate (medium GHI), warm (high GHI) and hot (very high GHI) climatic regions are considered and applied for 127 cities globally. In this framework, the sequence of PV building component integration is proposed according to local climate of each zone and the energy performance of buildings is maximized towards their positive energy contributions and sharing in local, district and city grids. Barriers and limitations of the BIPV implementation at a larger scale are discussed and the emerging research needs are revealed.
... However, the refrigerants used in the system are not eco-friendly and may lead to environmental damage, thus potentially reducing the ecological benefits of a solar energy system. The inclusion of a battery or a heat pump increases the cost of the solar energy system [89], and sometimes using excess battery energy can impact [90] the sizing of the actual PVT system. Thus, Behzadi et al. [91] proposed a novel PVT system (excluding battery and pump) with a thermal storage unit with the potential to zero energy bills for buildings via two-way trade of low-temperature heat and electricity by the local grids. ...
Solar energy has been one of the accessible and affordable renewable energy technologies for the last few decades. Photovoltaics and solar thermal collectors are mature technologies to harness solar energy. However, the efficiency of photovoltaics decays at increased operating temperatures, and solar thermal collectors suffer from low exergy. Furthermore, along with several financial, structural, technical and socio-cultural barriers, the limited shadow-free space on building rooftops has significantly affected the adoption of solar energy. Thus, Photovoltaic Thermal (PVT) collectors that combine the advantages of photovoltaic cells and solar thermal collector into a single system have been developed. This study gives an extensive review of different PVT systems for residential applications, their performance indicators, progress, limitations and research opportunities. The literature review indicated that PVT systems used air, water, bi-fluids, nanofluids, refrigerants and phase-change material as the cooling medium and are sometimes integrated with heat pumps and seasonal energy storage. The overall efficiency of a PVT system reached up to 81% depending upon the system design and environmental conditions, and there is generally a trade-off between thermal and electrical efficiency. The review also highlights future research prospects in areas such as materials for PVT collector design, long-term reliability experiments, multi-objective design optimisation, techno-exergo-economics and photovoltaic recycling.
... No contexto da República Tcheca, onde há um programa feed-in-tariff (FIT), Kichou et al. (2019) propõem dois modelos de simulação (um para o verão e outro para o inverno) para encontrar a solução ideal entre desempenho e retorno financeiro, considerando sistemas compostos por painéis fotovoltaicos, CHPs e baterias para um edifício de pesquisa. O desempenho é diretamente proporcional a uma proporção de energia comprada da rede em relação ao autoconsumo. ...
Casas inteligentes são uma tendência mundial. Elas permitem o uso otimizado de energia, permitindo que as famílias reduzam as contas de eletricidade ou até lucrem. O número de residências inteligentes nos EUA e no Reino Unido atingiu 40,3 milhões e 5,3 milhões, respectivamente, em 2018. Até 2024, 53,1% de todos os lares nos EUA e 39% no Reino Unido são esperados a se tornarem residências inteligentes. No entanto, no Brasil, existem apenas 1,2 milhão de residências inteligentes registradas em 2018. Embora as residências inteligentes pareçam ser o futuro das residências, muitos clientes têm a percepção de que a transição das residências atuais para as residenciais inteligentes não é lucrativa devido ao investimento inicial necessário e o risco de não haver retorno para cobrir esse investimento. Este artigo propõe um estudo de caso com o objetivo de avaliar a rentabilidade de muitos projetos de implementação de casas inteligentes para uma determinada casa no Ceará. Com foco na maximização do valor presente líquido, os resultados indicam o conjunto de eletrodomésticos / tecnologias que devem ser adquiridos para que o investimento feito pelo agregado familiar tenha um retorno financeiro positivo.
... Many efforts have been made in the field of the cooling effect of photovoltaic cells [23], increasing efficiency by reducing the cell temperature [24] or expanding thermal regulation time during the charging and discharging process in sensible, latent, or thermochemical storage mechanisms [12,[25][26][27][28][29][30][31][32]. A review on PV cooling technologies regarding the three-heat transfer mechanism (convection, conduction, and radiation) can be found in literature [33]. ...
Efficient photon to charge (PTC) transfer is considered to be the cornerstone of technological improvements in the photovoltaic (PV) industry, while it constitutes the most common process in nature. This study aims to investigate the parameters that impact efficient PV-cell photon to charge conversion in two ways: (a) providing a brief research analysis to extract the key features which affect the electrical and optical performance of PV cells’ operation, and (b) investigating the dependance of these characteristics on the photon to charge mechanisms. The former direction focuses on the latest advances regarding the impacts of the microenvironment climate conditions on the PV module and its operational performance, while the latter examines the fundamental determinants of the cell’s efficient operation. The electrical and optical parameters of the bulk PV cells are influenced by both the external microenvironment and the intrinsic photon to charge conversion principles. Light and energy harvesting issues need to be overcome, while nature-inspired interpretation and mimicking of photon to charge and excitation energy transfer are in an infant stage, furthering a better understanding of artificial photosynthesis. A future research orientation is proposed which focuses on scaling up development and making use of the before mentioned challenges.
... The shunt resistance R sh and a series resistance R s represent the power losses [67]. The validation of the model was done based on real measured data considering crystalline and amorphous silicon PV modules published in [68] and [28] respectively. A good agreement between simulated and measured power was achieved with a corresponding index of coefficient of variation with root-mean-square deviation as the standard deviation (Cv (RMSE)) of less than 5%. ...
Building integrated photovoltaic systems (BIPVs) focusing on windows, such as semi-transparent photovoltaic (STPV) or PV shading devices (PVSD), are proposed as efficient approaches to the production of electricity and the improvement of building energy performance. However, glass replacement with advanced PV concepts needs thorough energy and environmental assessment, since it took more than a millennium to produce transparent window glass of high visibility. Despite the many published studies in relation to the performance of each technology, there are limited comparative investigations of the proposed PV integration options and the most appropriate integration solutions for different climatic regions. Here, we report, for the first time, on the energy performance of four BIPVs that control solar radiation through windows and their effect on the built environment for three different climatic zones. The evaluation was done through TRNSYS simulations and calculation of representative indexes associated with thermal and visual comfort. A BIPV-flexibility index, given as a ratio of self-sufficiency to self-consumption, is proposed as a figure of merit for the assessment of each BIPV technology’s electricity production and its effect on building energy performance. The findings clearly show that BIPVs could substantially contribute to the transition to zero energy buildings due to their passive energy benefits (up to 43% savings) in addition to their electricity production. Opaque module, PV shadings and PV windows optimize the BIPV-flexibility index (up to 0.57) for cold, moderate and hot climates, with acceptable indoor thermal (up to 54% of time) and visual (up to 83% of time) comfort.
... On the contrary, the system incorporating micro-CHP engines, PV modules, and solar-thermal units provided the lowest fuel consumption, CO 2 emissions, and the highest LCC amongst all other scenarios. A practical implementation of such model could be observed in Ref. [63]. Authors developed an operative control scheme for UCEEB university in Czech Republic with the intention to reduce grid-maximal contracted power. ...
Renewable energy sources have gained prominence due to sustainability and less environmental impacts. With increasing energy consumption and depleting fossil fuel sources, emphases have been given to develop environmental-friendly energy systems and expand renewable energy penetration. In this regard, energy integration systems, that can satisfy energy demands in various forms, are considered as a viable approach for increasing the utilization of renewable resources and improving the efficiency of generation. Over the past decades , combined heat and power systems have been associated with energy savings and less environmental consequences. To this end, these systems attracted research community for further investigations and developments of renewable-based combined heat and power configurations in residential as well as industrial sector. In this study, energy generation by means of renewable resources including: solar, wind, and geothermal when operated as a cogeneration system, or integrated with a combined heat and power system is reviewed. The primary objectives of this study are to analyze the performance of most recent state-of-the-art designs, and present a comprehensive review that underlines the current research trends in the field of solar, wind, and geothermal energies. This review attempts to elaborate on integration of single or multiple renewable energies in combined heat and power systems. In this regard, preliminary research works are classified based on utilization of renewable resources in single and multiple integration. Further classifications are carried out based on the most cited research trends in that particular renewable energy field, in order to realize the current research objectives and the challenges every renewable field is facing today. Every presented system is evaluated in terms of implemented components, employed methods, and the objectives as well as key findings. This method of classification results in three primary research focuses including: model development and application in solar-integrated systems, thermo-economic optimization in geothermal-integrated systems, and scheduling and minimizing curtailment in wind-integrated systems. Finally, the future perspective of this field is proposed based on the current status of renewable integration to facilitate more effective and feasible operation in the future.
... They showed that the heat pump has a significant portion of the overall system costs. In a recent study, a dynamic simulation of a solar-based system consisting of a PV panel, combined heat, and power unit, and battery storage system was investigated by Kichou et al. [24]. ...
In this study, a novel design of ‘smart building energy systems’ is proposed. In the proposed system, solar photovoltaic-thermal (PVT) panels are integrated with a heat storage tank to supply a significant portion of the building’s heat and electricity demands. The system does not have any battery making it considerably cheaper and may have a two-way interaction with both of the local heat and electricity grids. In this way, the proposed system is strongly compatible with countries with both electricity and heat grids, e.g., Denmark. By such a system, not only the share of renewable energy in the national energy matrix may securely increase, but also the building will benefit the cheap, environmentally-friendly energy flows produced by its own. Considering the local weather data of a real smart building located in Western Denmark, the proposed building energy system is investigated. The results reveal that the system not only provides the entire annual domestic hot water building but also it generates 402.8 m³ hot water of 40 °C to be sold to the local ultralow-temperature district heating grid. With 2083 kWh electricity bought from the grid vs. 1938 kWh sold to that, the building’s yearly electricity cost is almost compensated.
... 90 the integration of PV resources and lead to a sustainable power grid. 92 Nevertheless, energy storage technology is relatively expensive and a massive amount of energy storage capacity is required to achieve the aforementioned purposes. 93 • Potential attack risks: A solar farm is usually connected near to the power distribution loads to reduce system losses. ...
Solar photovoltaic technology is intermittent in nature and employs power converters for grid‐interconnection, which can bring stability and power quality (PQ) issues to the power grid. Therefore, a set of testing guidelines is required to assure that solar plants comply with the grid and inverter requirements. As such, this article presents comprehensive testing guidelines for the interconnection of solar systems into Malaysian power grid, including inverter and PQ tests. The test points, conditions, parameters and acceptable limits for both tests are discussed in detail. This article also presents the results of a case study in which the testing guidelines were applied to examine the PQ of an actual grid‐connected solar photovoltaic plant in Malaysia and to assess the performance of the smart inverter used in the tested solar system. The testing outcomes, which were recorded by a PQ analyser, showed that the tested solar system was in compliance with all the requirements stipulated in the testing guidelines. The findings presented in this article will help relevant parties to understand these solar testing guidelines and serve to promote the wide deployment of solar technology towards a clean and sustainable future.
Rapid growth in industrialization and increased consumerism is continuously exploiting conventional energy sources and their nonsustainability would soon be disastrous for mankind. The ever-increasing energy demand around the globe is reinforcing the bulk and
sustainable utilization of renewable energy sources for day- today energy needs. Continuous research for the development of advanced
technologies that can sufficiently utilize renewable energy sources are progressing. Two of the most abundantly present renewable
sources, like solar radiation and biomass, have considerable potential to fulfill the energy demand up to a significant extent. Therefore,
this chapter briefly explores solar and biomass-based technologies, their efficiencies at individual and combined states. The combined
heat and power (CHP) phenomenon, its classification and the role of solar and biomass renewable sources in the CHP system have
been discussed in detail. Moreover, individual discussions of solar, biomass and hybrid solar-biomass-based cogeneration systems and
their chronological progress have been included in this chapter. The broad inference of research work in solar and biomass-based
cogeneration suggests that the development of the high hybrid solar-biomass system is well-proven for augmented solar-to-fuel
conversion, minimization of direct biomass burning and finally significant reduction in greenhouse gas emission.
Building integrated photovoltaic (BIPV) system attracts increasing attention of researchers due to environmentally friendly and saving land resource. Combining storage battery with BIPV can improve the flexibility of the entire system, which is promising for distributed renewable energy application. However, how to optimally dispatch the hourly energy flow of PV panel, storage battery and power grid based on a building load is crucial and less investigated. In the paper, a multi-restricted condition nonlinear optimization model is established for a BIPV-battery storage hybrid system under different building loads at a clear day. The optimization model was solved by fmincon function through MATLAB code. In the optimization, overall minimum daily cost including facility cost of the hybrid system, electric price and carbon price were considered as objective function to obtain optimal operation strategy of hourly power distributions of PV, battery and grid for daily building consumption. The key finding indicates that the system has high dependence on power gird when the office building load is heavy, while reduces the depending of power grid as the electrical demand is decreased. Under full-load resident building scenario, when the system with battery cost of 800 Yuan/kW·h or higher, the redundant green power generated by photovoltaic (PV) is sold to power grid in real time to earn extra profit, while the green power is accumulated in the storage batteries as storage battery cost is declined. Moreover, the resident building with BIPV-battery storage hybrid system has less dependence on power gird during day time, realizing self-sufficiency. Under all the scenarios, high storage battery cost limits the capacity of storage battery. And the CO2 emission is reduced as the BIPV-battery storage hybrid system is adopted.
This project considers a solar power and battery system to provide the electricity and cooling of food and fast-food restaurants which is off-grid. This off-grid restaurant is designed to be considered for the world cup 2022 which will be held in Qatar, and it has been modeled in Open Studio software with renewable energy. The system uses solar energy as renewable energy and to store the surplus electricity; battery banks are considered for nights. TRNSYS software with the ability of transient simulation of renewable energy systems is used. This research has been simulated using weather data from Doha in Qatar with its high solar radiation transiently at all hours of the year. The results showed that photovoltaic panels in Doha, Qatar, with their high solar radiation can provide 56% of the annual energy for the off-grid restaurant without batteries. Using batteries alongside these panels could reduce the grid dependency down to 9% per year, which could be provided using diesel-based generators due to being low. Furthermore, batteries could create complete grid independence for the off-grid in some months. The usage of batteries in solar panel systems considerably reduces the Conex box grid dependency. They provide 35% of the annual Conex box power consumption rate based on results from this modeling. This research provides significant results and impacts for the upcoming world cup where a lot of people from various countries will go to Qatar and off-grid restaurants in addition to reducing the emission can also highlight the importance of using renewable energy for future sustainability.
The hybrid renewable system's potential to create standard type E capsules for Covid-19 patients was explored in this study. In addition to delivering the requisite energy to the building, standard oxygen capsules were produced using the electrolysis of water using nanomaterial-supported electrolysis in the hydrogen storage system. In addition to the simulation, multi-objective optimization was done using a deep learning neural network and a genetic algorithm to maximize the number of oxygen capsules generated in a year and the system price, and the system's front beam was acquired. The system can produce 19530 units of type E oxygen capsules in a year, and the price of the electrolyzer and fuel cell is 120296 Euros at the best point of the front beam, considering both the objective variable of price and the number of produced oxygen capsules. In this scenario, the electrolyzer and fuel cell have rated powers of 61.9 kW and 15.3 kW, respectively. After determining the optimal point, researchers investigated the connection between meteorological data and other system characteristics including the amount of hydrogen in the tank, the number of oxygen capsules generated each hour, fuel cell power, and the electrolyzer. Lastly, the system's capacity to lower the amount of power required for the office building from the municipal network was investigated, indicating the system's excellent capability in this respect.
Unequal solar irradiance of the Photovoltaic (PV) modules diminishes the PV array's maximum power output; this effect is due to Partial Shading Conditions (PSCs). There are a few technical options to fix this issue. One of these is the dynamic reconfiguration technique, which means that the electrical connections between the PV modules in the array are dynamically modified to spread shading effects and increase the power output. This paper proposed a novel adaptive reconfiguration method for 3×3 Total-Cross-Tied (TCT) PV array to enhance the maximum power under partial shading conditions. In this work, the PV module's electrical connections are altered dynamically with the proposed logic algorithm's help to maintain the identical row currents in the array. This technique is implemented on 3×3 size of an array using MATLAB and validated experimentally using OPAL-RT software. Further, the proposed technique performance is compared with the existing PV array connections such as Series-Parallel (SP), Total-Cross-Tied (TCT), Bridge-Link (BL), Honey-Comb (HC), and Shade Dispersion Positioning (SDP). Additionally, for different reconfiguration methods, revenue generation from energy savings is estimated. Based on the observations from the results, it is understood that the proposed technique enhanced the maximum power of the TCT array at a higher level as compared to the other PV array connections under PSCs.
Energy transformation losses occurred during the conversion process from solar panel to end use are serious concern for the reduction of solar energy. To eliminate the intermediate conversion losses, a novel embedded controller based R‐2R scheme is proposed, which conducts the solar powered supply side management (SSM), wherein the R‐2R network is utilized to manage and control the solar and mains supplies by using a current control methodology. The IEEE 1149.1 specification compliant mixed signal embedded platform of C8051F226DK is incorporated to control the entire system. Also, the SAR‐based 8‐bit ADC was utilized for the A/D data conversion and Darlington drivers were used for the inductive loads of switching network. The experimental work on the hardware prototype of the system is capable to achieve the average energy of 42.22% and 39.31% as well as average efficiency of 43.05% and 41.8% for the summer and winter seasons, respectively. In addition to this, comparatively higher values of 60.24% and 58.29% for the daily electricity cost saving were resulted in these summer and winter seasons, respectively. As compared to the traditional methods, a novel R‐2R technique extracts the solar power instantly with zero response time and also utilizes the problem of nonlinear behavior and random connectivity of solar supply in the supply side energy management. These characteristics together with plug‐n‐play installation strategy based user‐friendly operation make this indigenously developed device competitive among other energy management solutions.
This work highlights the Building-Integrated Photovoltaics (BIPV) potential in two urban areas with different characteristics in the city of Prague. The representative building blocks were selected and the CitySim software tool was used for the assessment of the hourly irradiation profiles on each surface over a one-year period. Considering appropriate irradiation thresholds, suitable surfaces were then quantified. Integration criteria are discussed and suitable BIPV applications are proposed considering, not only energy performance, but also their impact on the quality of the built environment. The Photovoltaic (PV) potential is compared with the estimated local electricity demand derived from the population distribution within the building block. Analysis indicated that only 5.5% of the total area can be used in Vinohrady and 13.7% in Jizni Mesto contributing by 32% and 31% on average on the hourly electricity demand, respectively. The PV generation exceeds the local non-baseload demand during the summer period, but is less significant during winter. A preliminary financial analysis reveals a payback time of 17.5 and 20 years for Vinohrady and Jizni Mesto areas, respectively. It is evident that, even in the areas with a sensitive built environment, adoption of solar energy is still possible for balancing local electricity needs.
A two-stage hierarchical Microgrid energy management method in an office building is proposed, which considers uncertainties from renewable generation, electric load demand, outdoor temperature and solar radiation. In stage 1, a day-ahead optimal economic dispatch method is proposed to minimize the daily Microgrid operating cost, with the virtual energy storage system being dispatched as a flexible resource. In stage 2, a two-layer intra-hour adjustment methodology is proposed to smooth the power exchanges at the point of common coupling by coordinating the virtual energy storage system and the electric vehicles at two different time scales. A Vehicle-to-Building control strategy was developed to dispatch the electric vehicles as a flexible resource. Numerical studies demonstrated that the proposed method is able to reduce the daily operating cost at the day-ahead dispatch stage and smooth the fluctuations of the electric power exchanges at the intra-hour adjustment stage.
The aim of this work is to discuss the potential of facades and other vertical features for the photovoltaic potential of the cityscape. The photovoltaic potential in two representative case studies in the city of Lisbon, Portugal, is computed using a digital surface model determined from LiDAR (Light Detection And Ranging) measurements and local typical meteorological year time series. Results are compared with estimated local electricity demand derived from the population distribution. The annual analysis shows that roof and facade PV potential exceeds the local non-baseload demand and can contribute to 50–75% of the total electricity demand. Hourly breakdown shows peak PV power can only achieve winter mid-day electricity demand if the solar potential of facades is also taken into account. Its added value for off-peak PV supply is less significant in winter since non-south facades are not particularly exposed. In summer, however, facades can satisfy non-baseload morning and afternoon demand. A conservative economic analysis shows payback times below 10 years can only be achieved with PV on roofs while a 50/50 mix would lead to payback times of 15 years.
BIPV technologies applied to façades are strongly affected by complex and dynamic shadings especially when located in dense urban environments. In this case, the shading effects need to be evaluated in detail in order to properly estimate the energy yield and optimise the energy harvest of such PV systems.
This paper investigates solar potential in urban residential buildings at low, medium and high levels of site densities. The effects of three major design parameters (i.e. building aspect ratio, azimuth and site coverage) on solar potential are evaluated, respectively. Solar potential is measured, respectively, by photovoltaic (PV) and solar thermal (ST) yields per building floor space, taking into account the effect of irradiation threshold and incidence angle of the Sun’s rays. The results show that increasing building aspect ratio tends raise solar potential, and so does increasing site coverage. Additionally, there is a preferred range of building azimuth, under which PV yield remains at a higher level and out of which PV yield plummets. However, ST yield is affected modestly by building azimuth. This study also reveals that while mutual shadings may decrease PV yield by up to 50% and ST yield by up to 26% in the high-density scenario, it is still possible for PV and ST yields to meet annual electrical and thermal demands of residential buildings, respectively, by selecting appropriate design parameters. Most importantly, a promising result is observed that 6-story buildings in the low-density scenario can achieve net zero energy status when considering combined use of PV and ST.
Energy management in microgrid has been become an important issue in recent studies. Nowadays, energy management strategies are grown rapidly. In this paper, a new energy management strategy has been proposed for a hybrid microgrid including demand response and internal power market. In this regard, multiple markets configuration is considered in the proposed method and interaction between the consumers, microgrid and incentive strategies are included in the presented planning. Due to presence of various types of consumers, such as critical and normal loads, different power tariffs and contracts are utilized in energy management. Moreover, the effects of shiftable loads behavior have been investigated on the planning. Shiftable loads that cause problems such as sudden demand and frequency drop are considered in the presented strategy. In order to overcome this problem, electrical energy storage systems have been used as the transient power supplier. The proposed method is a stochastic linear programming that loads, wind speed, solar radiation and price of energy are considered as uncertain parameters and the microgrid cost, emission and demand cost are utilized as objective functions. Simulation results show a great reduction in microgrid cost, pollution and demand payments as well validate the effectiveness the proposed strategy.
The design of building integrated photovoltaics (BIPV) often involves complex geometries, non-uniform irradiance conditions and partial shading. This can lead to high energy losses if not considered adequately. This paper presents a BIPV modeling and optimization method which uses a parametric 3D modeling tool, coupled to a high-resolution ray-tracing irradiance simulation and an electrical model based on the single diode model on a subcell level. With the use of a genetic algorithm, electrical interconnections of the modules are optimized for maximum yield. The presented approach allows the simulation and optimization of BIPV in urban environments where complex shading occurs and high electrical mismatch of photovoltaic cells and modules is to be expected. It allows specific geometric design and optimization of photovoltaic installations and their electrical layout. The electrical simulation is validated for both flat and curved thin-film CIGS modules, as well as for two connected thin-film CIGS modules under deferring irradiance and partial shading conditions. The presented method is further applied in a case study on a double-curved roof shell. The results show that by using genetic algorithms the layout can be optimized to minimize the string mismatch losses for BIPV networks with a variety of modules. The detailed electrical simulation allows to quantify effects of module designs and inverter concepts on the system performance. This is demonstrated for the case study, indicating that thin-film modules with longitudinal cell direction outperform modules with orthogonal cell direction by up to 8%. Furthermore, module-integrated bypass diodes show little benefits for the best performing module technologies. Post-processing the results allows the evaluation of annual, seasonal, daily and hourly losses on a highly disaggregated level.
Oman is a country characterised by high solar availability, yet very little electricity is produced using solar energy. As the residential sector is the largest consumer of electricity in Oman, we develop a novel approach, using houses in Muscat as a case study, to assess the potential of implementing roof-top solar PV/battery technologies, that operate without recourse to the electricity grid. Such systems target the complete decarbonisation of electricity demand per household and are defined in this study as grid-independent systems. The approach adopted starts with a technical assessment of grid-independent systems that evaluates the characteristics of the solar panel and the battery facility required to provide grid-independence. This is then compared to a similar grid-connected system and any techno-economic targets necessary to enhance the feasibility of residential roof-top PV systems in Muscat are identified. Such an analysis was achieved through developing a detailed techno-economic mathematical model describing four sub-systems; the solar panel DC source, the grid-independent sub-system, the grid-connected sub-system and the economic sub-system. The model was implemented in gPROMS and uses real hourly weather and climate conditions matched with real demand data, over a simulated period of 20 years. The results indicate that, in the context of the system studied, grid-independent PV systems are not feasible. However, combined with a sufficiently high electricity price, grid-independent systems can become economically feasible only with significant reductions in battery costs (>90% reductions).
Due to emission regulations, the ship is sometimes restricted or even prohibited to use diesel when berthing in port, and the shore power (called the “cold-ironing”) takes part as power supplier. For a green ship with onboard photovoltaic (PV) systems, energy management for maritime PV/battery/diesel/cold-ironing hybrid energy system (HES) can significantly reduce the electricity cost of a ship. In this paper, the optimal operation of HES on a ship is modelled as an optimization problem subject to a number of constraints, including emission regulations of ports. Optimal control and model predictive control (MPC) methods are developed to dispatch the power flow when the ship is in port. Finally, the proposed approaches are tested by simulation experiments for different cases of cold-ironing service prices and emission regulations. Experimental results show that the optimal operation of maritime HES can bring promising electricity cost savings and robustness.
Photovoltaic (PV) modules are the main element responsible for the harvesting of solar radiation in PV systems. Thus, their reliability and durability are two crucial factors to take in consideration for conceiving performant PV systems and improve the energy generation. The outdoor comportment analysis of different PV module technologies has gained an increased interest in last years in order to gain insight on the degradation of their performance.
The present work studies the behaviour of three different PV modules based on cadmium telluride (CdTe), monocrystalline (c-Si) and multicrystalline silicon (mc-Si) technologies deployed outdoor in a humid continental climate. The period under scrutiny ranges from August 2015 to September 2017. Moreover, a new approach based on artificial neural network (ANN) was developed for the prediction of missing weather data.
The obtained results showed that c-Si and mc-Si PV modules presented a slight performance degradation following the seasonal changes. The worst degradation rate of −5.55%/year was obtained for CdTe PV modules. Finally, the effects of the degradation on the I-V curve were proven by an indoor characterization of CdTe PV modules.
Abstract— this article describes a method to optimize the utilization of a BIPV system with battery energy storage at an administrative office building in Jeseník, Czech Republic. Solar analysis is taking into account constraints from the architecture and surrounding of the building in order to identify suitable surfaces and propose BIPV solutions. A validated PV model is used for the estimation of the annual energy output depending on the PV configuration (technology, capacity etc.). Based on real data from one year of operation, an emphasis is also be given on the optimal control strategy for the operation of the system with the aim to increase the self-sufficiency of the building. To this end, optimal solution is proposed indicating the optimal strategy in terms of increasing the sustainability of the building with the minimum required cost.
In order to reduce the building's energy demand, different glass innovative technologies are currently under intensive research and development. However, applicability of a particular technology requires its extensive environmental and energy characterization in building integration. In this work, overall performance (thermal, optical, and electrical) of semitransparent PV windows from different technologies has been assessed and compared with conventional windows. Characterization studies include both field measurements and numerical simulations and reveal the energy saving potential of PV windows on the overall energy demand of an office room and Mediterranean climate conditions. Finally, building integration is optimized by maximizing energy efficiency while keeping acceptable indoor visual comfort for different PV technology, ratio of the glazing surface replaced by PV windows (cover ratio), and orientation.
The successful deployment of distributed photovoltaic (PV) systems requires assessment of the potential of possible installations. This depends mainly on their exposure to solar radiation, which can vary substantially with location, especially in the urban landscape. This paper seeks to estimate the potential for electricity generation by building-integrated PV in typical residential building types in dense urban locations, accounting for shading by adjacent structures. 3D modeling of the shadows cast by buildings is carried out with a new R package, developed as part of the study. The algorithm can assess the shadows cast on vertical surfaces (typically walls) or horizontal ones (typically roofs), given a database of obstacles representing buildings in the form of extruded polygons, and the sun's position at any desired time interval. The methodology is demonstrated for a case-study neighborhood in Rishon LeZion, Israel, with diverse building typologies. The simulation shows which building typologies offer the greatest solar potential, calculated per dwelling, building plot area or for the entire neighborhood. The results show that although roofs are less affected by mutual shading than vertical facades, some facades (mainly south and east oriented) can still make a substantial contribution to the overall solar potential of urban buildings.
Energy storage plays a crucial role in ensuring reliable power supply in a renewable microgrid. The supply and demand variability is found in different time scales (i.e., instantaneous, diurnal, and seasonal). The nominal discharge duration of multiple storage options can be matched effectively for variability in all relevant time scales. An optimum mix of storage options is important to design a cost-effective system.
This paper proposes a generic sizing methodology using pinch analysis and design space for hybrid energy storage in a PV-based isolated power system. Pinch analysis utilises a time series simulation of the system where generation should always exceed the load. The methodology defines the design space as feasible combinations of short, medium, and long-term storage size and PV array rating for the given loads. These design space curves are approximated by quadratic equations and the correlations are used as constraints to determine the optimal mix of supply and storage that minimise the life cycle cost.
Four different practical cases in Indian context —a remote village, telecom tower, welding shop, and a standby system for a lift load - are analysed to illustrate the sizing method. As an example, the optimal size for a PV based microgrid supplying a remote telecom tower with an average load of 72 kWh/day is 40 kWp of PV, 5 m3 of hydrogen storage and 58 kWh of battery. The proposed methodology extends the design space approach to obtain an optimal minimum cost solution.
Analysis of solar radiation on buildings at the urban or individual scale has an important share in the formation of a sustainable environment. The accuracy of solar radiation analysis in buildings depends on the holistic analysis of the buildings and the efficiency of the model. Traditional solar radiation analysis approaches use some technologies such as LIDAR, ALS, aerial photographs, satellite images, and MLS. These technologies are expensive and not suitable for non-existing structures. In this paper, a novel approach is presented to evaluate the potential direct and diffuse solar radiation aggregated on 3D structures which can be either in planning stage or completed at the urban or individual scale. During the study, Angstrom–Prescot model is validated for the target region, and it is used for estimating the global solar radiation potential at specific points. Dynamical changes of shadow areas on building surfaces affect solar energy estimations, different algorithms are required for precise radiation analyzes on 3D buildings. In the proposed approach, finite element method, back-face detection and ray-tracing algorithms are utilized to obtain more precise results. Thus, real-time shadow analysis and analysis of the desired sensitivity and time scale can be obtained using the proposed approach. In the last phase of the study, a nearby site with various building layout scenarios is designated as test bed. Each scenario is analyzed separately using the proposed approach and the results are presented in the paper. The proposed work-model creates an ideal tool for urban planners, architects, civil engineers and energy investors.
Hybrid energy system based on solar and wind power coupled with energy storage unit provides a reliable and cost effective energy alternative above the commonly used diesel based standalone power system. Various methodologies are adopted for modeling hybrid energy system component. They are modeled either by deterministic or probabilistic methods. The current study considers the hardware failure of photovoltaic panels while modeling. A probability distribution (PD) represents the various capacity states due to hardware failure of photovoltaic panels and corresponding probabilities. A concept based on random number generation is adopted to calculate the actual hourly available photovoltaic power. Wind turbine power output modeling incorporate force outage rate of the turbine. A new meta-heuristic algorithm called Cuckoo Search is applied for solving the hybrid energy system optimization problem. Photovoltaic-Battery, Wind-Battery and Photovoltaic-Wind-Battery system applicable to a remote area located in Almora district of Uttarakhand, India are considered. The effectiveness of Cuckoo Search in solving hybrid system design problem is investigated and its performance is compared with other well known optimization algorithms like Genetic Algorithm and Particle Swarm Optimization algorithm. Furthermore, this paper investigates the sensitivity of various input parameters like solar, wind resources and capital cost on the cost of energy.
Electricity demand in remote and island areas are generally supplied by diesel or other fossil fuel based generation systems. Nevertheless, due to the increasing cost and harmful emissions of fossil fuels there is a growing trend to use standalone hybrid renewable energy systems (HRESs). Due to the complementary characteristics, matured technologies and availability in most areas, hybrid systems with solar and wind energy have become the popular choice in such applications. However, the intermittency and high net present cost are the challenges associated with solar and wind energy systems. In this context, optimal sizing is a key factor to attain a reliable supply at a low cost through these standalone systems. Therefore, there has been a growing interest to develop algorithms for size optimization in standalone HRESs. The optimal sizing methodologies reported so far can be broadly categorized as classical algorithms, modern techniques and software tools. Modern techniques, based on single artificial intelligence (AI) algorithms, are becoming more popular than classical algorithms owing to their capabilities in solving complex optimization problems. Moreover, in recent years, there has been a clear trend to use hybrid algorithms over single algorithms mainly due to their ability to provide more promising optimization results. This paper aims to present a comprehensive review on recent developments in size optimization methodologies, as well as a critical comparison of single algorithms, hybrid algorithms, and software tools used for sizing standalone solar and wind HRES. In addition, an evaluation of all the possible combinations of standalone solar and wind energy systems, including their assessment parameters of economical, reliability, environmental, and social aspects, are also presented.
This paper proposes a simplified method to determine an index to quantify the influence of partial shadings on the performance of BIPV systems based on the relation between the shading percentages and the reduction of the incident irradiation on a given surface. The research is divided in two papers: Part 1: Theoretical study and Part 2: Application in case studies. Part 1 consists in identifying and quantifying the shading on a surface, and relates the fraction of shaded area with the percentage of incident irradiation reduction during the same period, in order to propose a shading index (SI) that represents the energy losses due to shadings on PV systems. The method was developed for a theoretical shaded case study simulated in two cities located at low latitude, tropical regions: Singapore (1.35°N) and Florianópolis-Brazil (27.48°S). Results showed that the shading percentage on the analysed surface on an annual basis is closer to the percentage of incident irradiation reduction at same period than when these values are compared on other time bases, as hourly, daily or monthly. Therefore, in this case, the annual percentage of shading can be adopted as the SI. SI was validated using different computer software packages and it was proved to be a convenient way of estimation the PV generation of similar cases of partially shaded PV systems, that could be used even before the PV electrical desing has been done.
This paper investigates the energy and economic profitability of renovating residential
buildings in temperate climate through the integration of PV panels on façades. The investigation regards a real multi-storey apartment block, representative of a significant
amount of edifices built in Italy in 1950-1990, which often need refurbishment because of
obsolescence. This building type is generally well suited to receive a new double-skin façade,
supporting both PV and other common cladding materials, while also representing a good
compromise in terms of aesthetic quality, cost, weight, durability and ease of maintenance.
In order to make general conclusions, a parametric analysis is performed, by virtually
changing the orientation, the number of floors and the climatic conditions, and by considering
different PV technologies. The results show that for an 8-storey building with the main axis
along E-W, the initial investment can be repaid within around nine years, if considering the
current fiscal incentives and a 50% self-consumption rate for the electricity produced by the
PV modules. The presence of fiscal incentives is essential to make the investment attractive.
Better PV efficiencies, lower prices and higher self-consumption rates can enhance the
economic profitability, which may generate a significant impact on the retrofit of European
multi-storey residential stock. These results can be effectively extended to the PV integration
on the façades of new apartment blocks too.
Simulation is of primal importance in the prediction of the produced power and automatic fault detection in PV grid-connected systems (PVGCS). The accuracy of simulation results depends on the models used for main components of the PV system, especially for the PV module. The present paper compares two PV array models, the five-parameter model (5PM) and the Sandia Array Performance Model (SAPM). Five different algorithms are used for estimating the unknown parameters of both PV models in order to see how they affect the accuracy of simulations in reproducing the outdoor behavior of three PVGCS. The arrays of the PVGCS are of three different PV module technologies: Crystalline silicon (c-Si), amorphous silicon (a-Si:H) and micromorph silicon (a-Si:H/μc-Si:H).
The accuracy of PV module models based on the five algorithms is evaluated by means of the Route Mean Square Error (RMSE) and the Normalized Mean Absolute Error (NMAE), calculated for different weather conditions (clear sky, semi-cloudy and cloudy days). For both models considered in this study, the best accuracy is obtained from simulations using the estimated values of unknown parameters delivered by the ABC algorithm. Where, the maximum error values of RMSE and NMAE stay below 6.61% and 2.66% respectively.
Curtain walls are believed to be “energy sinks” because of their relatively low thermal performance; however, the integration of energy generating technologies such as photovoltaic (PV) panels may enable converting these systems to “energy positive” curtain walls. A methodology using the Analysis of Variance (ANOVA) approach is developed and implemented to identify configurations of energy positive curtain walls by accounting for the complex interacting effect of facade design parameters. The “energy positive” curtain wall in this paper is defined as the energy generated by the curtain wall facade on an annual basis exceeds the energy consumption of a perimeter zone office enclosed by this curtain wall facade. Ten design parameters are studied, including glazing U-value, solar heat gain coefficient (SHGC), and visible transmittance (T
v
); U-value of the spandrel panel; U-value of the mullion; window wall ratio (WWR); infiltration rate; depth and inclination of overhang; and efficiency of PV modules. The significance of individual design parameters on the energy performance is ranked for four cardinal orientations based on the total sensitivity index. The WWR, U-glazing, and infiltration rate are the three most significant parameters influencing the total annual energy consumption of the office unit simulated, while the WWR, PV efficiency, and U-glazing are the most significant design parameters for achieving energy positive curtain walls. The methodology presented in this paper helps facilitate the design process to resolve the issues with conflicting effects of design parameters.
The first BIPV system of Turkey was installed on the façade and two towers of the Staff's Block of Education Faculty building of Mugla Sitki Koçman University in February 2008. The PV systems cover 405m2 (60 tilted surface and two vertical towers on east and west sides of the building) with single and triple junction amorphous (3j-aSi) photovoltaic modules. The total installed power of the BIPV system is 40.3kWp. Total cumulative produced electricity of the BIPV system at the end of 2014 from the start up is exceeding 200,000kWh. In this work, the shading effect on the performance of two PV systems based on 3j-aSi photovoltaic modules on the façade is analysed. There are 5 rows on the façade of the building and two identical strings' energy rating values are compared. One string has only row shading but the second string has smaller shading. In this comparison it is found that energetic performances so called energy rating (kWh/kWp) values of the arrays differ 16% for an annual average between 10% and 24% monthly intervals. In winter months the shading effect is caused by the tree is less than 1% in the electricity yield where there is no row shading in winter months. But in summer months (because of the height of the sun) the calculated energy yield difference is about 15%. In 21st of June between 9.00 and 13.00 it is calculated that the output between the inverters is 15% where there is no shading because of the tree all shading is from the upper rows. PV data is collected with a Sunlog data logger. Daily power and electricity production values and the shading effect on different seasons are also analysed.
This study presents a 2-years performance assessment of a 2.18 kWp grid-connected PV (photovoltaic) system, installed in the premises of the Technical University of Crete, Chania; important normalized parameters such as yields, losses and efficiencies are calculated and related to the local climatic characteristics. The scopes of this paper are: (i) the quantification of the effect of high temperature conditions on the electrical performance of a thin film PV system; (ii) the verification and comparison amongst the existing empirical models used to estimate PV frames operating temperature emphasizing on the accuracy of their predictions; (iii) the development of a new customized empirical model in order to determine the PV frames operating temperature, under real field conditions. The output provides safe estimates and information about the potential improvements in order to create small and large scale thin film PV installations in areas with similar climatic characteristics such as the Mediterranean coastal areas.
Since fossil fuels will be depleted and their environmental effects are becoming a major
concern, renewable energy sources (RES) are taking the lead in providing humans' energy
needs. Among them, solar energy is much more convenient since it is more available. In
order to provide energy needs for a stand-alone electrical user, a hybrid system consisting
of photovoltaic panels (PV), battery storage and fuel cells (FC) has been used in this paper.
There are many ways to design a power management strategy for dispatching energy
between the energy source, the energy storage and the electrical load. Three different
power management strategies (PMS) have been proposed in this paper and three different
sizing methods have been used as well. Performance analysis has been undertaken using
TRNSYS software, and battery state of charge and hydrogen tank pressure is monitored.
Finally the best combination of a power management strategy and sizing method has been
outlined.
Estimates of solar radiation distribution in urban areas are often limited by the complexity of urban environments. These limitations arise from spatial structures such as buildings and trees that affect spatial and temporal distributions of solar fluxes over urban surfaces. The traditional solar radiation models implemented in GIS can address this problem only partially. They can be adequately used only for 2-D surfaces such as terrain and rooftops. However, vertical surfaces, such as facades, require a 3-D approach. This study presents a new 3-D solar radiation model for urban areas represented by 3-D city models. The v.sun module implemented in GRASS GIS is based on the existing solar radiation methodology used in the topographic r.sun model with a new capability to process 3-D vector data representing complex urban environments. The calculation procedure is based on the combined vector-voxel approach segmenting the 3-D vector objects to smaller polygon elements according to a voxel data structure of the volume region. The shadowing effects of surrounding objects are considered using a unique shadowing algorithm. The proposed model has been applied to the sample urban area with results showing strong spatial and temporal variations of solar radiation flows over complex urban surfaces.
Uneconomical extension of the grid has led to generation of electric power at the end user facility and has been proved to be cost effective and to an extent efficient. With augmented significance on eco-friendly technologies the use of renewable energy sources such as micro-hydro, wind, solar, biomass and biogas is being explored. This paper presents an extensive review on various issues related to Integrated Renewable Energy System (IRES) based power generation. Issues related to integration configurations, storage options, sizing methodologies and system control for energy flow management are discussed in detail. For stand-alone applications integration of renewable energy sources, performed through DC coupled, AC coupled or hybrid DC–AC coupled configurations, are studied in detail. Based on the requirement of storage duration in isolated areas, storage technology options can be selected for integrated systems. Uncertainties involved in designing an effective IRES based power generation system for isolated areas is accounted due to highly dynamic nature of availability of sources and the demand at site. Different methodologies adopted and reported in literature for sizing of the system components are presented. Distributed control, centralized and hybrid control schemes for energy flow management in IRES have also been discussed.
Air pollution and climate change increased the importance of renewable energy resources like solar energy in the last decades. Rack-mounted PhotoVoltaics (PV) and Building Integrated PhotoVoltaics (BIPV) are the most common photovoltaic systems which convert incident solar radiation on façade or surrounding area to electricity. In this paper the performance of different solar cell types is evaluated for the tropical weather of Singapore. As a case study, on-site measured data of PV systems implemented in a zero energy building in Singapore, is analyzed. Different types of PV systems (silicon wafer and thin film) have been installed on rooftop, façade, car park shelter, railing and etc. The impact of different solar cell generations, arrays environmental conditions (no shading, dappled shading, full shading), orientation (South, North, East or West facing) and inclination (between PV module and horizontal direction) is investigated on performance of modules. In the second stage of research, the whole PV systems in the case study are simulated in EnergyPlus energy simulation software with several PV performance models including Simple, Equivalent one-diode and Sandia. The predicted results by different models are compared with measured data and the validated model is used to provide simulation-based energy yield predictions for wide ranges of scenarios. It has been concluded that orientation of low-slope rooftop PV has negligible impact on annual energy yield but in case of PV external sunshade, east façade and panel slope of 30–40° are the most suitable location and inclination.
GANIL operation has been orientated towards an increase of intensities
these last years, for production of both radioactive beams by
fragmentation through SISSI device and exotic nuclei in the experimental
caves, and in view of Spiral start up. Usual running statistics are
presented, as well as the operation conditions and results in terms of
beam intensities. Different improvements and equipment renovations have
been realized consequently: beam production method developments on the
ECR sources, hard-ware renovations, tuning and control programs,
development of high intensity beam diagnostics. A review of these works
is reported. .
Over the next few decades, severe cuts in emissions from energy will be required to meet global climate change mitigation goals. These emissions reductions imply a major shift toward low-carbon energy technologies, and the economic cost and technical feasibility of mitigation is therefore highly dependent on the future performance of energy technologies. Yet existing models do not readily translate into quantitative targets against which we can judge the dynamic performance of technologies. Here we present a new, simple model for evaluating energy-supply technologies and their improvement trajectories against climate-change mitigation goals. We define a target for technology performance in terms of the carbon intensity of energy consistent with emissions reduction goals, and show how the target depends on energy demand levels. Because the cost of energy determines the level of adoption, we then compare supply technologies to one another and to this target based on their position on a cost and carbon trade-off curve---and how the position changes over time. Applying the model to US electricity we show that the target for carbon intensity will approach zero by midcentury for commonly cited emissions reduction goals, even under a high demand-side efficiency scenario. For Chinese electricity, the carbon intensity target is relaxed and less certain due to lesser emissions reductions and greater variability in energy demand projections. Examining a century-long database on changes in the cost-carbon space, we find that the magnitude of past changes in cost and carbon intensity that are required to meet future performance targets is not unprecedented, providing some evidence that these targets are within engineering reach. The cost and carbon trade-off curve can be used to evaluate the dynamic performance of existing and new technologies against climate change mitigation goals.
This paper presents a method to quantify the potential of facades and roofs located in urban areas for active and passive solar heating, photovoltaic electricity production and daylighting. Solar irradiation and illuminance values obtained through numerical simulations form the core part of the method. Results obtained from a case study comparing different building layouts at constant density in Fribourg (Switzerland) reveal large variations of the potential for solar energy collection on buildings facades. Thus, the proposed method could greatly help to optimise solar collection still at the early urban planning phase.
The simulation of module temperature from Nominal Operation Cell Temperature (NOCT) is widely used to easily estimate module performance along the year. In this context, it is important to determine this parameter in a reliable way, as it is used to compare the performance of different module designs and can influence system predictions. At present there are several international standards that indicate the method to calculate NOCT in crystalline and thin-film terrestrial photovoltaic modules. This work presents the results obtained when applying these standards to different types of PV modules, including glass–glass and glass–tedlar structures, crystalline and thin-film technologies, and some special module designs for building integration applications. NOCT values so calculated have been used to estimate the yearly module temperature and performance for different orientations and tilted angles, analysing temperature influence in these estimations. Possible error sources that could bring about erroneous values of NOCT are also analysed.
Recent facts about photovoltaics in Germany. Fraunhofer ISE
- H Wirth
Wirth H. Recent facts about photovoltaics in Germany. Fraunhofer ISE. 2018.
Available
at:
www.ise.fraunhofer.de/content/dam/ise/en/documents/
publications/studies/recent-facts-about-photovoltaics-in-germany.pdf.
Sensitivity analysis of four variables to the Net Present Value and Payback period of the investment
- Fig
Fig. 19. Sensitivity analysis of four variables to the Net Present Value and Payback period of the investment.
Geraç~ ao Solar Fotovoltaica: estimativa do fator de sombreamento e irradiaç~ ao em modelos tridimensionais de edificaç~ oes. Escola Polit ecnica. Universidade de S~ ao Paulo
- Melo Egd
Melo EGd. Geraç~ ao Solar Fotovoltaica: estimativa do fator de sombreamento e
irradiaç~ ao em modelos tridimensionais de edificaç~ oes. Escola Polit ecnica.
Universidade de S~ ao Paulo; 2012.
In: 50th international universities power engineering conference. UPEC)
- M Abunku
- Wjc Melis
Abunku M, Melis WJC. Modelling of a CHP system with electrical and thermal
storage. In: 50th international universities power engineering conference.
UPEC); 2015. p. 1e5. 2015.
Developing a model for a CHP system with storage
- M Abunku
- T K Genger
- P I Udenze
Abunku M, Genger TK, Udenze PI. Developing a model for a CHP system with
storage. Am J Eng Res (AJER) 2016;5:15e27.
Podpora fotovoltaických projekt u pro podnikatele v roce 2018 (1. c ast)
- P Novotný
Novotný P. Podpora fotovoltaických projekt u pro podnikatele v roce 2018 (1.
c ast). 2019. https://oze.tzb-info.cz/fotovoltaika/.
Energy price statistics
- Eurostat
Eurostat. Energy price statistics. Tech. Rep.. 2017. http://ec.europa.eu/
eurostat.
Geração Solar Fotovoltaica: estimativa do fator de sombreamento e irradiação em modelos tridimensionais de edificações. Escola Polit ecnica
- Melo Egd
Melo EGd. Geração Solar Fotovoltaica: estimativa do fator de sombreamento e
irradiação em modelos tridimensionais de edificações. Escola Polit ecnica.
Universidade de São Paulo; 2012.
33rd european photovoltaic solar energy conference and exhibition
- L Maturi
- J Adami
- M Lovati
- F Tilli
- D Moser
- Bipv Affordability
Maturi L, Adami J, Lovati M, Tilli F, Moser D. BIPV affordability. 33rd european
photovoltaic solar energy conference and exhibition. 2017. p. 2621e5.
Amsterdam, the Netherlands.
Developing a model for a CHP system with storage
- Abunku