Showing papers on "Solar power published in 2015"
TL;DR: In this paper, the current status of heat transfer fluid, which is one of the critical components for storing and transferring thermal energy in concentrating solar power systems, is reviewed in detail, particularly regarding the melting temperature, thermal stability limit and corrosion issues.
626 citations
TL;DR: In this article, an extensive literature survey on Hybrid Renewable Energy Systems (HRES) and state-of-the-art application of optimization tools and techniques to microgrids, integrating renewable energies is presented.
Abstract: Fast depleting fossil fuels and the growing awareness for environmental protection have led us to the energy crisis. Hence, efforts are being made by researchers to investigate new ways to extract energy from renewable sources. ‘Microgrids’ with Distributed Generators (DG) are being implemented with renewable energy systems. Optimization methods justify the cost of investment of a microgrid by enabling economic and reliable utilization of the resources. This paper strives to bring to light the concept of Hybrid Renewable Energy Systems (HRES) and state of art application of optimization tools and techniques to microgrids, integrating renewable energies. With an extensive literature survey on HRES, a framework of diverse objectives has been outlined for which optimization approaches were applied to empower the microgrid. A review of modelling and applications of renewable energy generation and storage sources is also presented.
538 citations
TL;DR: In this paper, the Advanced Research Projects Agency-Energy (ARPA-Energy) gave DE-AR0000471 and DE-ARM0000181 for the first time, respectively.
Abstract: United States. Advanced Research Projects Agency-Energy (Awards DE-AR0000471 and DE-AR0000181)
483 citations
TL;DR: In this paper, the influence of disaggregated renewable electricity production by source on CO2 emission in 23 selected European countries for the period of 1990-2013 was investigated, and the Pedroni cointegration results indicated that CO2 emissions, GDP growth, urbanization, financial development, and renewable electricity consumption by source were cointegrated.
Abstract: This study investigates the influence of disaggregated renewable electricity production by source on CO2 emission in 23 selected European countries for the period of 1990–2013. Panel data techniques were used in examining the relationships. The Pedroni cointegration results indicated that CO2 emission, GDP growth, urbanization, financial development, and renewable electricity production by source were cointegrated. Moreover, the fully modified ordinary least-square results revealed that GDP growth, urbanization, and financial development increase CO2 emission in the long run, while trade openness reduces it. Furthermore, renewable electricity generated from combustible renewables and waste, hydroelectricity, and nuclear power have a negative long-run effect on CO2 emission, while renewable electricity generated from solar power and wind power is insignificant. The VECM Granger causality also revealed that GDP growth is the only variable that has causal effects on CO2 emission in all the investigated models, while the rest of the variables have causal effects on CO2 emission in only a few models. A number of policy recommendations were provided for the European countries.
459 citations
TL;DR: In this article, the solar PV plant design aspects along with its annual performance is elaborated and various types of power losses (temperature, internal network, power electronics, grid connected etc.) and performance ratio are also calculated.
396 citations
TL;DR: In this article, the authors examine potential limits to PV deployment at the terawatt scale, emphasizing constraints on the use of commodity and PV-critical materials, and propose material complexity as a guiding framework for classifying PV technologies.
Abstract: Solar energy is one of the few renewable, low-carbon resources with both the scalability and the technological maturity to meet ever-growing global demand for electricity. Among solar power technologies, solar photovoltaics (PV) are the most widely deployed, providing 0.87% of the world's electricity in 2013 and sustaining a compound annual growth rate in cumulative installed capacity of 43% since 2000. Given the massive scale of deployment needed, this article examines potential limits to PV deployment at the terawatt scale, emphasizing constraints on the use of commodity and PV-critical materials. We propose material complexity as a guiding framework for classifying PV technologies, and we analyze three core themes that focus future research and development: efficiency, materials use, and manufacturing complexity and cost.
389 citations
TL;DR: In this article, the authors propose a framework to analyze and quantify the integration costs of wind and solar generators in power systems, based on the marginal economic value of electricity, or market value.
383 citations
TL;DR: In this paper, the authors presented the global solar PV developments, per capita values, government supportive invectives and policies of the top ten solar power producing countries and also presented the investments of global solar energy among the countries, and found that these top ten leading countries are following fulfilment of their projections, supportive tariff rates, net metering, green certificates and government incentive policies as their instruments.
Abstract: The mitigations of global energy demands, climate change and energy related greenhouse gas effects are the most important factors in the modern days. However, renewable energy is one of the alternative sources which has the capacity to mitigate all the above. Among all the renewable energy sources, solar energy is one of the most abundant and the cleanest energy source. Different laboratories of the world have achieved different solar cell efficiencies, which are also discussed in the present paper. This paper presents the global solar PV developments, per capita values, government supportive invectives and policies of the top ten solar power producing countries. This paper also presents the investments of the global solar energy among the countries. Finally, through the study, it is found that these top ten leading countries are following fulfilment of their projections, supportive tariff rates, net metering, green certificates and government incentive policies as their instruments.
285 citations
TL;DR: In this article, an analog ensemble (AnEn) method was proposed to generate probabilistic solar power forecasts (SPF) based on an historical set of deterministic numerical weather prediction (NWP) model forecasts and observations of the solar power.
284 citations
TL;DR: In this paper, the impact of VRE forecast errors on balancing reserve requirements, the supply of balancing services by VRE generators, and the incentives to improve forecasting provided by imbalance charges are reviewed.
Abstract: Balancing power is used to quickly restore the supply-demand balance in power systems. The need for this tends to be increased by the use of variable renewable energy sources (VRE) such as wind and solar power. This paper reviews three channels through which VRE and balancing systems interact: the impact of VRE forecast errors on balancing reserve requirements; the supply of balancing services by VRE generators; and the incentives to improve forecasting provided by imbalance charges. The paper reviews the literature, provides stylized facts from German market data, and suggests policy options. Surprisingly, while German wind and solar capacity has tripled since 2008, balancing reserves have been reduced by 15%, and costs by 50%.
271 citations
TL;DR: The use of PTC technology in the operational CSP projects is 95.7% and has decreased to 73.4% for the under-construction projects as mentioned in this paper, while the use of TSP technology has reached to 71.43%, compared to 28.57% for PTC.
Abstract: The conventional ways for generating electricity around the world face two main problems, which are gradual increase in the earth׳s average surface temperature (global warming) and depleting fossil fuel reserves. So switching to renewable energy technologies is an urgent need. Concentrating solar power (CSP) technologies are one of renewable technologies that are able to solve the present and future electricity problems. In this paper the historical evolution for the cornerstone plants of CSP technologies to generate clean electricity was reviewed and the current projects worldwide of CSP technologies were presented to show that the CSP technologies are technically and commercially proven and have the possibility for hybridization with fossil fuel or integration with storage systems to sustain continuous operation similar to conventional plants. Among all solar thermal technologies parabolic trough is the most technically and commercially proven. It also has the possibility for hybridization since it is proven by operating in several commercial projects for more than 28 years. It has a high maturity level and able to provide the required operating heat energy either as a stand-alone or in hybrid systems at the lowest cost and lower economic risks. For this reason, this technology is dominant in the operational and under-construction projects. However, currently there is a trend toward employing the other CSP technologies in the future projects as a result of the improvement in their performance. The use of PTC technology in the operational CSP projects is 95.7% and has decreased to 73.4% for the under-construction projects. Meanwhile, the uses of Fresnel collector (LFC), Tower power (TSP) and Stirling dish (SDC) technologies in the operational projects are 2.07%, 2.24%, and 0% respectively and have increased to 5.74%, 20.82% and 0.052% respectively for the under-construction projects. For the development projects, the use of TSP technology has reached to 71.43%, compared to 28.57% for PTC.
TL;DR: In this article, the authors analyzed the Italian day-ahead wholesale electricity market, finding empirical evidence of the merit-order effect and showed that, over the period 2009-2013, solar production has generated higher monetary savings than wind production, mainly because the former is more prominent than the latter.
TL;DR: In this paper, the authors review the current trends in the pumped hydroelectric energy storage operation, discuss why current practices should be reexamined, and present the main challenges faced by PHES operators who will need to adapt their scheduling and bidding models to optimize jointly the operation in the energy and in the ancillary services markets.
Abstract: The increasing penetration of renewable energy sources (RESs) in the power system has highlighted the benefits of being able to store energy in a more efficient manner, and the need of holding additional operating reserves to manage the system under more demanding conditions due to the inherent uncertainty and variability of wind and solar power. Pumped hydroelectric energy storage (PHES) is by far the most established technology for energy storage at a large-scale. PHES units have also participated in the active power-frequency control for years, and last technical developments in PHES have been oriented to improve their capability of providing regulation reserves by means of variable speed design or by hydraulic short-circuit configurations. This fact, together with the impact of RES on spot-market energy and ancillary services prices, is changing the operation and market conditions faced by PHES plants. The aim of this paper is to review the current trends in the PHES operation, to discuss why current practices should be re-examined, and to present the main challenges faced by PHES operators who will need to adapt their scheduling and bidding models to optimize jointly the operation in the energy and in the ancillary services markets.
TL;DR: In this article, the authors proposed a multi-scale cooling and electricity coordinated schedule for optimal microgrid operation, which achieves an integrated optimization for multi-energy type supply, and makes the MG be controllable as seen from the main grid.
Abstract: For optimal microgrid (MG) operation, one challenge is the supply of cooling and electricity energy is a coupled co-optimization issue when considering the combined cooling, heating and power (CCHP) units and ice-storage air-conditioners. Another challenge is the inherent randomness of renewable energy within the MG should be accommodated by MG itself. In Part I of this two-part paper, the partial load performance of CCHPs and the performance of ice-storage air-conditioners are modeled, and the cooling and electricity coordinated MG day-ahead scheduling and real-time dispatching models are established. In day-ahead scheduling model, the uncertainty of wind and solar power is represented by multi-scenarios and the objective is to achieve the minimal expected MG operation cost. In real-time dispatching model, the different time-scale dispatch schemes are respectively applied for cooling and electricity to smooth out the fluctuations of renewable energy supply and to follow the variations of cooling and electricity demands by the fine dispatching of the components within MG such that the impact of MG to the connected main grid is minimal. The proposed MG multi time-scale cooling and electricity coordinated schedule achieves an integrated optimization for multi energy-type supply, and makes the MG be controllable as seen from the main grid.
TL;DR: In this article, the authors analyze three major integration challenges related to the structural matching of demand with the supply of wind and solar power: low capacity credit, reduced utilization of dispatchable plants, and over-produced generation.
TL;DR: In this paper, a hybridized power panel that can simultaneously generate power from sunlight, raindrop, and wind is proposed and demonstrated, when any or all of them are available in ambient environment.
Abstract: With the solar panels quickly spreading across the rooftops worldwide, solar power is now very popular. However, the output of the solar cell panels is highly dependent on weather conditions, making it rather unstable. Here, a hybridized power panel that can simultaneously generate power from sunlight, raindrop, and wind is proposed and demonstrated, when any or all of them are available in ambient environment. Without compromising the output performance and conversion efficiency of the solar cell itself, the presented hybrid cell can deliver an average output of 86 mW m−2 from the water drops at a dripping rate of 13.6 mL s−1, and an average output of 8 mW m−2 from wind at a speed of 2.7 m s−1, which is an innovative energy compensation to the common solar cells, especially in rainy seasons or at night. Given the compelling features, such as cost-effectiveness and a greatly expanded working time, the reported hybrid cell renders an innovative way to realize multiple kinds of energy harvesting and as an useful compensation to the currently widely used solar cells. The demonstrated concept here will possibly be adopted in a variety of circumstances and change the traditional way of solar energy harvesting.
TL;DR: In this paper, a case study of the City of Seoul, South Korea using the solar city concept and assessment methods for estimating the solar electric potential of an often neglected but vital city resource in energy matters is presented.
Abstract: Energy economy restructuring at the city level is an essential prong in any strategy that aims to address the dual energy and climate change challenges. Cities form hubs of human activity that are accompanied by high levels of energy consumption and emissions but also contain existing resources and infrastructure to transition to a greener energy economy. This paper reviews efforts to date to define the ‘solar city’ concept and assessment methods for estimating the solar electric potential of an often neglected but vital city resource in energy matters – its rooftop real estate. From this review, an application of the solar city concept is formulated and an assessment method is offered for its investigation. An illustrative case study is provided, using the City of Seoul, South Korea. Representing nearly one-quarter of South Korea’s population and a one-third of its economic activity, the application of the solar city concept to the city can have significant consequences for the future energy development pathway of the municipality and the country (the metropolitan area of Seoul encompasses nearly one-half of the national population). The research demonstrates that a technical potential equivalent to almost 30% of the city’s annual electricity consumption can be supplied by widespread deployment of rooftop-based distributed photovoltaic systems. Using the methodology developed in the paper, we estimate that sixty-six percent of the annual daylight-hours electricity needs of the City of Seoul can be served by distributed solar power systems on a typical day. It is additionally found that considerable peak shaving is possible, lessening the pressure on the city’s electricity grid. These findings can be expected to extend to other large cities when the solar city concept is thoughtfully applied.
TL;DR: In this paper, the Carnegie Energy and Environmental Compatibility model was used to quantify each installation according to environmental and technical compatibility and evaluated installations according to their proximity to protected areas, including inventoried roadless areas, endangered and threatened species habitat, and federally protected areas.
Abstract: Decisions determining the use of land for energy are of exigent concern as land scarcity, the need for ecosystem services, and demands for energy generation have concomitantly increased globally. Utility-scale solar energy (USSE) [i.e., ≥1 megawatt (MW)] development requires large quantities of space and land; however, studies quantifying the effect of USSE on land cover change and protected areas are limited. We assessed siting impacts of >160 USSE installations by technology type [photovoltaic (PV) vs. concentrating solar power (CSP)], area (in square kilometers), and capacity (in MW) within the global solar hot spot of the state of California (United States). Additionally, we used the Carnegie Energy and Environmental Compatibility model, a multiple criteria model, to quantify each installation according to environmental and technical compatibility. Last, we evaluated installations according to their proximity to protected areas, including inventoried roadless areas, endangered and threatened species habitat, and federally protected areas. We found the plurality of USSE (6,995 MW) in California is sited in shrublands and scrublands, comprising 375 km2 of land cover change. Twenty-eight percent of USSE installations are located in croplands and pastures, comprising 155 km2 of change. Less than 15% of USSE installations are sited in “Compatible” areas. The majority of “Incompatible” USSE power plants are sited far from existing transmission infrastructure, and all USSE installations average at most 7 and 5 km from protected areas, for PV and CSP, respectively. Where energy, food, and conservation goals intersect, environmental compatibility can be achieved when resource opportunities, constraints, and trade-offs are integrated into siting decisions.
TL;DR: A suite of generally applicable and value-based metrics for solar forecasting for a comprehensive set of scenarios that were developed as part of the U.S. Department of Energy SunShot Initiative's efforts to improve the accuracy of solar forecasting show that the proposed metrics can efficiently evaluate the quality of solar forecasts and assess the economic and reliability impacts of improved solar forecasting.
TL;DR: In this paper, the point estimate method is applied for modeling the wind power and solar power uncertainties, and robust optimization technique is utilized to model load demand uncertainty, and a comparison is done between deterministic and probabilistic management in different scenarios.
TL;DR: In this paper, the authors proposed a comprehensive computational framework for quantification and integration of uncertainties in distributed power systems (DPSs) with IRESs, such as electrical load, wind and solar power forecasts and generator outages.
TL;DR: The deployment of solar-based electricity generation, especially in the form of photovoltaics (PVs), has increased markedly in recent years due to a wide range of factors including concerns over greenhouse gas emissions, supportive government policies, and lower equipment costs.
Abstract: The deployment of solar-based electricity generation, especially in the form of photovoltaics (PVs), has increased markedly in recent years due to a wide range of factors including concerns over greenhouse gas emissions, supportive government policies, and lower equipment costs. Still, a number of challenges remain for reliable, efficient integration of solar energy. Chief among them will be developing new tools and practices that manage the variability and uncertainty of solar power.
TL;DR: In this article, the authors developed a set of protective overlayers for stabilizing photoabsorber materials for photoelectrochemical (PEC) water splitting, which greatly extend the durability of hydrogen-evolving Cu2O-based materials.
Abstract: The amount of solar power striking the earth’s surface is vastly superior to humanity’s present day energy needs and can easily meet our increasing power demands as the world’s population grows. In order to make solar power cost competitive with fossil fuels, the conversion devices must be made as cheaply as possible, which necessitates the use of abundant raw materials and low energy intensity fabrication processes. Cuprous oxide (Cu2O) is a promising material with the capacity for low cost, large-scale solar energy conversion due to the abundant nature of copper and oxygen, suitable bandgap for absorption of visible light, as well as effective, low energy intensity fabrication processes such as electrodeposition. For photoelectrochemical (PEC) water splitting, protective overlayers have been developed that greatly extend the durability of hydrogen-evolving Cu2O-based materials. Recent developments in the advancement of protective overlayers for stabilizing photoabsorber materials for water splitting are...
TL;DR: In this paper, the authors examined how the latest generation of climate models used for the 5th IPCC report projected potential changes in surface solar radiation over the coming decades, and how this may affect, in combination with the expected greenhouse warming, solar power output from photovoltaic (PV) systems.
TL;DR: This paper presents a new spatial-temporal forecasting method based on the vector autoregression framework, which combines observations of solar generation collected by smart meters and distribution transformer controllers, leading to an improvement on average between 8% and 10%.
Abstract: The solar power penetration in distribution grids is growing fast during the last years, particularly at the low-voltage (LV) level, which introduces new challenges when operating distribution grids Across the world, distribution system operators (DSO) are developing the smart grid concept, and one key tool for this new paradigm is solar power forecasting This paper presents a new spatial-temporal forecasting method based on the vector autoregression framework, which combines observations of solar generation collected by smart meters and distribution transformer controllers The scope is 6-h-ahead forecasts at the residential solar photovoltaic and medium-voltage (MV)/LV substation levels This framework has been tested in the smart grid pilot of Evora, Portugal, and using data from 44 microgeneration units and 10 MV/LV substations A benchmark comparison was made with the autoregressive forecasting model (AR-univariate model) leading to an improvement on average between 8% and 10%
TL;DR: In this article, a detailed assessment of a large range of clear-sky solar radiation models under Algerian climate to select the more accurate one for estimating the performance of solar power projects where meteorological and radiometric measurement stations are not available.
TL;DR: This paper analyses the challenges of solar power forecasting and then presents a similar day-based forecasting tool to do 24-h-ahead forecasting for small-scale solar power output forecasting.
Abstract: Because of the rapid growth of small-scale solar electricity generation over the past few years, forecasting solar power output is becoming more important. However, changes in weather conditions cause solar power generation to be highly volatile. This paper analyses the challenges of solar power forecasting and then presents a similar day-based forecasting tool to do 24-h-ahead forecasting for small-scale solar power output forecasting.
TL;DR: In this article, the main barriers in the diffusion of wind and photovoltaic (PV) solar power in the Greek electricity sector were discussed by drawing on the literature of technological innovation systems and system functions.
TL;DR: In this paper, the authors presented a dynamic simulation model of a prototype of a 6kW e solar power plant, which is based on the coupling of innovative solar thermal collectors with a small organic Rankine Cycle (ORC), simultaneously producing electric energy and low temperature heat.
TL;DR: In this paper, the welfare-optimal market share of wind and solar power, explicitly taking into account their output variability, is estimated from a calibrated numerical model, and the optimal long-term wind share is found to be 20%, three times more than today.
Abstract: This paper estimates the welfare-optimal market share of wind and solar power, explicitly taking into account their output variability. We present a theoretical valuation framework that consistently accounts for the impact of fluctuations over time, forecast errors, and the location of generators in the power grid on the marginal value of electricity from renewables. Then the optimal share of wind and solar power in Northwestern Europe's generation mix is estimated from a calibrated numerical model. We find the optimal long-term wind share to be 20%, three times more than today; however, we also find significant parameter uncertainty. Variability significantly impacts results: if winds were constant, the optimal share would be 60%. In addition, the effect of technological change, price shocks, and policies on the optimal share is assessed. We present and explain several surprising findings, including a negative impact of CO2 prices on optimal wind deployment.