Search

Contagion tests through mean and volatility channels are developed based on an exponential generalized autoregressive conditional heteroskedastic model to investigate the effects of China's 2009–2020 solar power policies on the economic performance of different sectors. By examining the fluctuations in the daily stock prices of nine major economic sectors in China, we show the transmission mechanisms of policy shocks and find evidence that China's major solar energy policies, including feed-in tariffs, solar subsidies, and market-based instruments, have significant effects on most of the studied sectors in China through both mean and volatility contagion channels. Among the three types of policies, feed-in tariffs and solar subsidies are found to be the most effective instruments in improving sector performance, while market-based instruments have the least effect. The risk premium effect is weak, but the asymmetric effect is strong, suggesting that market volatility responds considerably less to positive news than to negative news for the majority of sectors investigated. • The highlights of this paper include. • The impacts of China's 2009–2020 solar industry policies on its sector performance. • Policy contagion is developed to identify how policy shocks affect economic sectors. • Feed-in tariffs and solar subsidies are found to be effective instrument. • Significant asymmetric effect is observed in major economic sectors. [ABSTRACT FROM AUTHOR]

• Comprehensive review on individual and hybrid wind-solar energy policy. • Evolution and current status of Indian wind and solar energy policy framework. • Techno-economic parameters for the hybridization of wind and solar power projects. • Barriers and recommendation regarding renewable energy policies. Wind and solar energy are currently the most prominent and reliable sources of renewable energy. Wind and solar power deployment largely depend on government policies and have a specific policy and regulatory provisions. The declaration of hybrid wind–solar policy has changed the dynamics of individual wind and solar power projects by introducing the scope for developing hybrid power projects to harness wind and solar energy simultaneously. The techno-economic structure and the existing scenarios of the fractional contribution of wind and solar sectors are going to play an important role in the development of hybrid power projects. This paper aims to present a comprehensive review of the impact of the existing individual wind and solar energy policies along with the recently declared hybrid policy in India and how this hybrid policy will affect the techno-economic structure of the existing and new power projects. Further, various kind of barriers faced by project developers while establishing renewable energy-based power projects and recommendations which can be practically implemented have been elaborated to facilitate and achieve the faster deployment of wind and solar power generation. [ABSTRACT FROM AUTHOR]

With the rapidly growing interest in bifacial photovoltaics (PV), a worldwide map of their potential performance can help assess and accelerate the global deployment of this emerging technology. However, the existing literature only highlights optimized bifacial PV for a few geographic locations or develops worldwide performance maps for very specific configurations, such as the vertical installation. It is still difficult to translate these location- and configuration-specific conclusions to a general optimized performance of this technology. In this paper, we present a global study and optimization of bifacial solar modules using a rigorous and comprehensive modeling framework. Our results demonstrate that with a low albedo of 0.25, the bifacial gain of ground-mounted bifacial modules is less than 10% worldwide. However, increasing the albedo to 0.5 and elevating modules 1 m above the ground can boost the bifacial gain to 30%. Moreover, we derive a set of empirical design rules, which optimize bifacial solar modules across the world and provide the groundwork for rapid assessment of the location-specific performance. We find that ground-mounted, vertical, east-west-facing bifacial modules will outperform their south-north-facing, optimally tilted counterparts by up to 15% below the latitude of 30°, for an albedo of 0.5. The relative energy output is reversed in latitudes above 30°. A detailed and systematic comparison with data from Asia, Africa, Europe, and North America validates the model presented in this paper. [ABSTRACT FROM AUTHOR]

Today the global energy industry is undergoing major changes shifting towards the green growth and circular economy solutions. The paper offers the outcomes of the foresight study of the Russian renewable energy sector and focuses on three areas: converting solar energy into electricity; converting wind energy into electricity; and converting biomass into thermal energy and electricity. The goal of the study was to foresee and agree on the visionary future for the nascent renewable energy sector in the country, as well as to provide the scientifically justified grounds for government and corporate decision-makers. The research is based on a mixture of methods: bibliometric analysis and text mining, literature review, expert surveys and interviews, workshops, STEEPV analysis of trends, scenario analysis, and applied policy analysis. As a result of the study, major trends and uncertainties that may affect the Russian and global renewable energy sector in the next 15–20 years were identified. Other results include the scenarios for Russia's renewable energy sector that are proposed together with recommendations for the Russian companies and public authorities. The study's policy and market implications go beyond Russia: the outcomes may be useful for similar studies, early stage renewable energy policy planning and investment decision. • The foresight study of the Russian renewable energy sector is presented. • The focus is on solar, wind and biomass energy production until 2035. • Four scenarios of the Russian renewable energy sector are discussed. • Recommendations may be used in research, policy planning and investment decisions. [ABSTRACT FROM AUTHOR]

Highlights • Capacity expansion planning model for the integration of CSP-TES. • Evaluation of the systemic economic and operational benefits provided by CSP-TES. • Analysis of multiple technology and policy scenarios for the Chilean power system. • Study of complementarities between CSP-TES and other technologies. • Investigation on the role of CSP-TES as a flexibility provider to the system. Abstract This paper presents a study about the impacts of the integration of concentrated solar power (CSP) with thermal energy storage (TES) in electric power systems. The main tool for this study is a comprehensive long-term power system capacity expansion planning model that integrates a specific module to represent the operation of CSP-TES power plants. The model determines the optimal investments on generation and transmission assets over a twenty-year planning horizon, ranging from 2018 until 2037, and employs projections for the various parameters involved (e.g. load growth, capital costs for the different generation technologies, fuels costs). One of the main features of the model is its ability to capture the hourly operational dynamics of the system through the consideration of multiple representative days for each of its investment periods. This feature allows a better understanding of the role of CSP-TES as a significant provider of flexibility to support a high penetration of variable renewable energy sources, as compared with traditional planning models based on load blocks. The model is applied to a case study for the Chilean electricity system. In order to study the impacts of CSP-TES, various scenarios of future capital costs and carbon tax levels are defined and analyzed for two market dominant CSP-TES technologies. The results show that for low CSP-TES capital costs, or high carbon taxes, the integration of CSP-TES in the system is significant towards year 2037, potentially reaching about one third of the total dispatched energy in the Chilean electric power system, yielding important operational, economic, and environmental benefits. [ABSTRACT FROM AUTHOR]

Highlights • An accurate and efficient radiative transfer model is developed. • This model combined multiple steps in the current transposition and spectral models. • The POA irradiances are computed by integrating radiances in space. Abstract The solar energy industry often uses individual steps to empirically compute plane-of-array (POA) irradiance from horizontal irradiance and decompose it to narrow-wavelength bands. Conventional radiative transfer models designed for meteorological applications requires significant computing efforts in practice; however, they provide a physics-based solution of radiance and therefore are capable of computing spectral POA irradiances in a single step. In this study, we integrate the advantages of the current models and develop an innovative radiative transfer model, the Fast All-sky Radiation Model for Solar applications with Narrowband Irradiances on Tilted surfaces (FARMS-NIT), to efficiently compute irradiances on inclined photovoltaics (PV) panels for 2002 narrow-wavelength bands from 0.28 to 4.0 µm. This study is reported in two parts. Part I presents the methodology and performance evaluation of the new model under clear-sky conditions. The Simple Model of the Atmospheric Radiative Transfer of Sunshine (SMARTS), which was designed to compute clear-sky irradiances, is employed to rapidly provide the optical properties of a given clear-sky atmosphere. The clear-sky radiances in the narrow-wavelength bands are computed by considering three paths of photon transmission and solving the radiative transfer equation with the single-scattering approximation. The Bi-directional Transmittance Distribution Function (BTDF) of aerosols is given by their single-scattering phase function with a correction using a two-stream approximation. The validation analysis confirms that FARMS-NIT has improved accuracy compared to TMYSPEC as evaluated by both surface observations and a state-of-the-art radiative transfer model. This model substantially improves computational efficiency compared to other radiative transfer models though it uses slightly more computing time than TMYSPEC. Part II of this study addresses the model in cloud-sky conditions and will be published as a companion paper. [ABSTRACT FROM AUTHOR]

Highlights • Development of a spatio-temporal framework for residential PV power integration. • Assessment of the impact of battery storage and electric vehicles on PV integration. • Variations identified in self-consumption and avoided emissions among neighbourhoods. • PV integration policies should focus on areas with high PV potential and low demand. Abstract Cities have a significant potential to host residential photovoltaic systems (PV). The direct consumption of PV generated electricity reduces the need for electricity import, while excess PV electricity production can be stored for later usage or can be used directly to charge electric vehicles (EVs). In this way, more energy is locally consumed, greenhouse gas emissions are reduced, and self-sufficiency of cities can be increased. In this paper, we present a spatio-temporal framework to evaluate the electricity demand that can be fulfilled by PV energy. We assess the impact of penetration of EVs and the influence of battery energy storage. We demonstrate the usefulness of this framework for 88 neighbourhoods in the city of Utrecht, the Netherlands. Spatial mapping was used to identify areas with high potential for EVs and storage. Results shows that direct PV self-consumption ratios vary between 34% and 100%. When EVs charging is included in the neighbourhoods, then self-consumption is increased on average by 12%. Battery energy storage increases the self-consumption with an average of 25%. The self-sufficiencies due to direct PV energy consumption are between 6% and 40% in the neighbourhoods. These are decreased by EVs with an average of −0.6%, and increased by battery energy storage with an average of 14%. Avoided life cycle greenhouse gas emissions over a 30-year period are on average 12 tCO 2 -eq per address. The large variation in results between neighbourhoods indicates that area dependent investments and supporting policies could improve the PV power integration in cities. Our developed framework can be easily adapted and used for other cities. Moreover, our results are useful for local governments to guide and design effective policies to accelerate the transition to more sustainable cities. [ABSTRACT FROM AUTHOR]

Our study investigates solar energy justice in the province of Saskatchewan, Canada. In 2017, we were engaged by the Saskatchewan Power Corporation (SaskPower), a government owned electric utility, to conduct stakeholder engagement workshops for the development of new solar energy programs in Saskatchewan. In coordination with SaskPower we developed a deliberative dialogue approach to the consultation process. Select stakeholders were invited to participate in a half-day workshop. In this workshop participants were asked for input on the principles that would guide SaskPower’s solar energy strategy, the barriers that prevent solar energy from being installed in the province, and their ideas for effective solar energy programs. Participants worked in small groups to design solar energy programs, creating opportunities for mutual learning and deliberation. This research is the first application of deliberative dialogue to the design of solar energy programs of which we are aware and offers an example of due process in the program design stage of energy planning. We use an energy justice decision-making (Sovacool et al., 2014) tool to evaluate the process of designing SaskPower’s solar energy strategy and the content of recommendations made by participants to answer the question, can due process help to achieve energy justice? Participants in our deliberative dialogue suggested guiding principles that were similar to the dimensions of the energy justice decision-making tool. The deliberative process also highlighted tensions between dimensions of the energy justice decision-making tool. In this paper, we suggest avenues to improve the deliberative dialogue process and conclude that centering due process as a core element of the energy justice decision-making tool can help to achieve energy justice. Our results contribute to the growing field of study on how deliberative dialogue can allow for better decisions in complex fields such as energy policy. [ABSTRACT FROM AUTHOR]

The prospective cost-benefit of CSP (concentrated solar power) is the attention focus for policy-making and investment decisions. In order to analyze cost-benefit evolution of CSP, the paper adopted the net present value and discounted cash flows techniques to develop a mathematical model, and calculated LCOE (levelized cost of energy) of CSP between 2018 and 2050 by taking the CSP industry of China as an example. The results show that: Firstly, CSP has a large potential in the LCOE reduction, and the values of parabolic trough and solar tower CSP systems reduce by 46%–57% and 47%–56% from 2018 to 2050, respectively. Secondly, predicted evolution for the LCOE of CSP strongly depends, not only on the cumulative installed capacity determined by the specific growth paths of Blue Map and Roadmap Scenarios, but also on the learning curves impacted by technical progress and experience accumulation. Thirdly, to select the sites with higher direct normal irradiation and land cost exemption is crucial to improve cost-benefit evolution of CSP. Lastly, the expected returns (i.e. discount rate) have important effect on the LCOE evolution of CSP, high expected returns lead to high the LCOE, and vice versa. [ABSTRACT FROM AUTHOR]

Off-grid solar electric power is a promising technology for remote regions in rural Africa where expansion of the electricity grids is prohibitively expensive. Using household data from a target region of an off-grid solar promotion program in the Kénédougou province in Burkina Faso, this paper explores the role of quality-verified branded solar home systems (SHS) versus non-branded ones. We find that the adoption rate of non-branded SHS is considerably higher at 36% compared to 8% for branded SHS. We compare potential quality differences as well as the cost-effectiveness of branded and non-branded solar products. We show that non-branded SHSs offer a similar service level as branded solar, that they do not fall behind in terms of consumer satisfaction and durability, and that non-branded products are more cost-effective. These findings suggest that promotion programs and branded solar products do not seem to be necessary in Burkina Faso and might also not be needed to establish sustainable off-grid solar markets elsewhere provided that non-branded products are available. The challenge however is to reach the very poor who are unable to bring up investment costs for any electricity. [ABSTRACT FROM AUTHOR]

Electricity supply in remote areas of the Russian territory is heavily dependent on diesel sources. Diesel generation imposes an important economic and social burden on the local population, besides the environmental impact of greenhouse gas emissions, black carbon and oil spills. Switching to renewable energy could reduce the current economic, social and environmental cost of electricity supply in Russia׳s remote areas. The objective of this paper is to review Russia׳s off-grid renewable energy policy by focusing on the promotion of wind- and solar-diesel hybrid energy in the Russian Arctic. Taking a mainly regulatory perspective, this paper identifies existing barriers to the development of hybrid renewable-diesel investments. Building further on the international experience with the promotion of renewable energy in Arctic climates ( e.g., in Alaska and Canada), this paper tests the feasibility of alternative ‘best practice’ mechanisms to support off-grid renewable energy in Russia. [ABSTRACT FROM AUTHOR]

According to UNDP Policy Note 2014, only 23% of Yemen rural community have access to electricity – having connected to national grid or use small isolated generating units – while the country is one of the richest in solar energy with over 3000 h per year clean blue sky. The objectives of this paper is to concentrate on the utilization and the cost effectiveness of photovoltaic solar energy for electrification of Yemeni rural and desert communities, which will result in enhancing education, culture, science, medical services, and improve the living conditions in rural areas. Otherwise, energy poverty that is a facet of a multidimensional poverty in Yemen will persists because the possibility of connecting rural communities to the national grid, even in the next ten years, is invisible due to major political and financial problems that the country is facing. Moreover, PV energy is environmentally clean and has proved to be one of the best solutions for rural electrification in many countries worldwide due to noticeable drop of PV systems prices with the advance in PV technology. Accordingly, it should be the best solution for rural electrification in Yemeni as well. The paper demonstrates the cost effectiveness and the design procedure of utilization of solar energy for rural and desert communities in Yemen using a number of subsequent cases typical to Yemeni communities and provides also a practical study to support Bedouin backpackers. [ABSTRACT FROM AUTHOR]

Solar PV has been a cornerstone for the energy policy makers around the globe. It is because the environmental effects of solar energy are low as compared to the conventional energy sources. It is free and virtually inexhaustible. Developed countries have long been in the business of using solar energy for energy generation. However, for the third world countries like Pakistan, the use of solar energy for power generation is a relatively new experience. In recent months, Pakistan has shown a paradigm shift in its renewable energy policy and invested on mega power plants based on solar PV system. This paper reviews the recent exponential rise of using solar energy for power generation in Pakistan. The results of this paper will not only help in understanding and hence, curbing the power crisis in Pakistan, but will also be relevant to the other countries of the third world. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the positions of some European Union (EU) countries on the development of PV systems. After a review of the main support policies for PV systems in Europe, the specific situations of five representative countries (France, Germany, Greece, Italy and the U.K.) are examined, with the purpose of describing the main differences in their implementation of support policies adopted for PV systems. In particular, comparisons based on economic indexes such as the net present value (NPV) and the internal rate of return (IRR) are carried out for different sized PV systems, showing that in some situations support policies can be inconvenient for the PV system owner. The paper also shows that the best profitability for a PV system owner is obtained in those countries in which there is an active electricity compensation scheme. The comparative analysis carried out in this work could help: – to assess the impact of PV energy policies in European member states; – to predict how the PV market could evolve in the selected EU member states; – to gain an insight into the future of possible energy policies. [ABSTRACT FROM AUTHOR]

Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because they can, in principle, exponentially exceed the world׳s energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy resources. [ABSTRACT FROM AUTHOR]

Abstract: Japan started implementing a national Feed-In Tariff (FiT) mechanism on the 1st July 2012, which included specific payment tariffs for solar photovoltaic (PV) installations. This marks a new era in the renewable energy landscape in Japan. This paper aims at analysing the solar PV prospect in Japan, particularly in both residential and non-residential sectors. The paper presents, first, an overview of energy trends in Japan prior to the Fukushima event. This is followed by a short review of solar PV progress in the country, highlighting the major policies and programmes that have been implemented as well as the installations that have been carried out over the past two decades. Next, the financial impact of the new FiT scheme on consumers is evaluated. The financial analysis investigates the total profit, the average annual return on investment and the payback period. For a comparison purposes, a similar financial analysis is also conducted with selected countries around the world – namely Germany, Italy and the United Kingdom. The results from this analysis indicate that the new Japanese FiT rate generates a good profit, a moderate annual return on investment and an acceptable payback period, suggesting an increasing trend of solar PV uptake over the next years. [Copyright &y& Elsevier]

Abstract: Situated at equator level, Central Africa is a wetted area, sunny and not that windy. The region owns important renewable energy potential, namely solar, hydro and biomass. For a number of reasons, this important potential is still suffering from poor development. The main cause of the poor use of renewable energy is the poor commitment and dedication of governments who have not taken the necessary measures to boost enough decentralized and renewable energy. Thermal plants are hence unfortunately heavily used where other alternatives are possible. The purpose of this paper is among other things aiming at showing how solar and hydro energy sources of Central Africa are currently developed and addressing the problems faced. The work also addresses the issue of filling the gap between the abundant solar and hydro resources and its poor development compare to the rest of the world. Based on some case studies in Cameroon, actions to sustain ongoing initiatives and promote their development are suggested. This paper also addresses the problems actually faced and recommends actions for mitigation for a significant improvement of energy infrastructure in remote areas. In such areas, the promotion of renewable energy and energy efficiency are very important for poverty alleviation. From lessons learned, suggestions will be made to help the countries of the region develop a vision aiming at developing adequate clean energy policy to increase the status of solar and microhydro energy sources and, thus, better contribute to fight against climate change. [Copyright &y& Elsevier]

Renewable energy is a focal point of discussion in the European Union, as clean production technologies contribute to all three aims of energy policy (security, competitiveness, and sustainability). This paper focuses on an empirical assessment of feed-in tariff and quota obligation policies, as well as their policy design elements, applied to solar photovoltaic energy in the European Union over the period 2000–2014. The results indicate that only feed-in tariff policy has significant impacts in terms of installed photovoltaic capacity. However, its main policy design elements (tariff size and contract duration) have a positive but not significant influence on the development of this clean production technology. Policy-makers should consider the importance of reducing regulatory uncertainty about these parameters. [ABSTRACT FROM AUTHOR]

India receives sun's energy over 300 days a year most of the time. About 5000 trillion kWh per year sun's energy is incident over India's land area. Theoretically, a small fraction of total incident solar energy can meet the entire country's power requirements. There are many government schemes to promote solar power generation. The government of India initiated solar PV/BIPV policies to encourage industries and individuals to use solar energy powered systems for electricity generations. This article provides an overview of the solar energy status and application of BIPV system in India. It includes an assessment of the region's solar energy potential and solar PV/BIPV installed capacity. This paper gives a brief description barriers and challenges facing solar BIPV development in India. This study also provides the solar PV/BIPV policies and recommendations with reference to the Indian context. [ABSTRACT FROM AUTHOR]

This paper presents an exploratory analysis of microgeneration installer businesses in the UK during a period of intense change in policies supporting microgeneration from 2010 to 2012. The research examines the influence of installer businesses on rates of uptake and standards of installation, and the interplay between business practices and the policy environment. The research developed new detailed datasets through a nationwide survey, to which 388 installers responded, and follow-up interviews with 22 installers. Focusing on solar photovoltaics and air source heat pumps installed in households, the results show the fundamental dependence of installer businesses on government financial incentives and on the quality assurance scheme in operation. Market confidence was compromised by the sharp reduction in the Feed-In Tariff (FIT) for residential solar PV in 2012 and long delays to the equivalent Renewable Heat Incentive for residential installations. Nevertheless, more modest FIT levels have reduced the risk of sub-optimal installations and inappropriate specification of microgeneration systems. The findings underline the need for consistent policy to allow installer businesses and their supply chains to develop and mature, and thus facilitate commercial deployment of microgeneration of high quality, raise its competiveness with incumbent forms of energy supply and contribute to decarbonisation goals. [ABSTRACT FROM AUTHOR]

A significant increase in the use of solar energy can be observed. Solar energy is not, however, widely used in Latvia. The aim of this paper is to devise an algorithm to evaluate the possibility of integrating solar energy into the district heating system (DHS) of Latvia for both space heating and the supply of domestic hot water. The methodology was tested on a district heating system in a municipality in Latvia with 20 000 inhabitants. The existing DHS operation data were processed for the analysis and optimization of the system. Optimization of the system includes energy efficiency measures (EEM). Results show the possible energy production from solar energy depends on the area of different solar collector fields and thermal water storage tank volumes, as well as the probable costs of the system. It would be necessary to install solar collection fields of 9000 m 2 to 72 900 m 2 with a properly sized TES in order to produce from 6000 MWh/year up to 23 700 MWh/year. With this system it would be possible to supply 10% to 78% of the total heat demand with solar energy in any given DHS. If EEM have also been implemented, solar energy share can be increased. [ABSTRACT FROM AUTHOR]

According to energy policies, it is necessary to replace electrical energy or fossil fuels by renewable energy sources. Solar energy systems are recognized as one of these sources. In such systems, high-performance is one of the essential needs. Porous materials have been introduced as one of the most efficient and affordable techniques to improve the heat transfer and energy efficiency in solar energy systems. In this review, the applications of porous materials and their advantages and limitations on different types of solar energy systems are summarized. Moreover, the structures of each system with their applications are briefly introduced. Solar energy systems covered in this paper contains both energy conversion and energy storage systems. [ABSTRACT FROM AUTHOR]

This paper debates the main reasons why Chinese and Brazilian energy policies have not focused on Concentrating Solar Power (CSP) deployment until now. Like most emerging economies, China and Brazil have registered large increases in energy demand, as well as considerable growth of energy-related greenhouse gas (GHG) emissions. On the other hand, both countries have played an important role on the expansion of renewable energy infrastructure and - considering that large portions of their territories present high levels of "Direct Normal Irradiation" (DNI) - CSP technologies might have figured as an important strategy for the mitigation of atmosphere pollution and global warming. Since large scale deployment of CSP technologies still implies high "Levelized Costs Of Electricity" (LCOE) that could affect the competitiveness of national industry in global markets, we argue that a comprehensive answer for this question must place national energy policies in the context of a "world-system" analysis. CSP has not benefited from the international demand that has boosted wind turbines and photovoltaic cells with their subsequent price reductions. Furthermore, we will discuss the "elective affinities" between thermal solar investments and the development of those regions that present the lowest performances in the Chinese and Brazilian socioeconomic realities. [ABSTRACT FROM AUTHOR]

Abstract: China''s PV industry has developed rapidly in recent years due to the dramatic demand from the world market. In contrast, until 2010 China''s domestic PV market has been very small due to lack of sufficient incentives in the country to promote domestic PV deployment. However, since early 2009 many incentives have been implemented in China. The paper makes an analysis on China''s solar PV incentive policies, particularly the national FIT scheme. Policy recommendations are made with regard to the promotion of the domestic solar PV market, including the construction of an effective national FIT scheme, the imposition of renewable portfolio system as well as the establishment of sound technical and administration standards for the grid-connection of PV systems. The paper contributes to the academic literature over China''s solar PV power policy. [Copyright &y& Elsevier]

Abstract: Solar water heating (SWH) systems have a widespread usage and applications in both domestic and industrial sectors. According to Renewable Energy Policy Network data (2010), 70 million houses worldwide were reported to be using SWH systems. Solar water heating is not only environmentally friendly but requires minimal maintenance and operation cost compared to other solar energy applications. SWH systems are cost effective with an attractive payback period of 2–4 years depending on the type and size of the system. Extensive research has been performed to further improve the thermal efficiency of solar water heating. This paper presents a detailed review exclusively on the design aspects of SWH systems. The first part of the paper provides a consolidated summary on the development of various system components that includes the collector, storage tank and heat exchanger. The later part of this paper covers the alternative refrigerant technology and technological advancements in improving the performance as well as the cost effectiveness of the SWH system. [Copyright &y& Elsevier]

Abstract: The paper focuses on the possibilities of generating electrical energy by means of on-grid PV solar systems of 1kW in the Republic of Srpska (Bosnia and Herzegovina). The paper proceeds to tackle with the legislative concerning renewable sources of energy and current state of the use of PV systems in the Republic of Srpska and Bosnia and Herzegovina, climate conditions and energy potential of the renewable sources in the Republic of Srpska. Based on PVGIS program, the results of calculation of the yearly average values of the optimal panel inclination, solar irradiation on the horizontal, vertical and optimally inclined plane, ratio of diffuse to global solar irradiation, linke turbidity, average daytime temperature and 24h average of temperature for 13 cities in the Republic of Srpska are given. Total for year sum of global irradiation per square meter received by the modules of the optimally inclined fixed PV solar plants of 1kW, optimally inclined one-axis and dual-axis tracking PV solar plants of 1kW, and total for year electricity production of different types of PV solar plant of 1kW for 13 cities in the Republic of Srpska, obtained by PVGIS are given. Comparison of the total for year electricity production of different types of PV solar plant of 1kW with monocrystaline silicon, CdTe and CIS solar modules, respective, to 13 cities in the Republic of Srpska are given. Calculations performed by PVGIS program have shown that irrespectable of the type of PV solar plants, most electrical energy in the Republic of Srpska can be generated by means of PV solar plants with CdTe solar cells. Some practical data and considerations given in this paper can be used by a customer or company keen to invest in the PV sector in the Republic of Srpska. [Copyright &y& Elsevier]

Increasing the use of variable renewable electricity (VRE) such as solar and wind power will impose major challenges to existing energy systems. The increased variability needs to be considered, but also how to optimally operate the remaining power system. In this paper, we present a fast and easy-to-use optimization model to find cost-optimal ways to manage the energy system with large-scale VRE. This is done by minimizing the running costs and maximizing revenues of the energy production. The model accounts for the energy system dynamics. It can handle both electric and thermal loads at different scales (building, city) and allows incorporating different flexibility strategies. The model is applied to analyzing a very large wind power scheme for Helsinki city (Finland), coupled to the existing CHP-dominated district heating schemes through power-to-heat conversion for more optimal system integration leading to major CO 2 emission reductions. The model is well suited to studying integration of renewable energy, to design better policies for introducing VRE and to find solutions to increase energy system flexibility, among others. [ABSTRACT FROM AUTHOR]

The Indian power sector is a key factor in the development of economic growth rates in the country. Most of the power generating stations in India are based on fossil fuels. Furthermore, there are various issues in the climate changes and global warming. The state of Odisha is located in the eastern part of the India at 17° 49׳ North −22°0 34׳ North Latitude and 81° 29׳ East –87° 29׳ East Longitude with an area of 155,707 sq. km. In this state, people depend on hydroenergy and thermal energy to meet their energy demands. However, currently, not many water reservoirs are available for generating the required power. On the other hand, the thermal power plants are unable to meet their power generation potentials due to shortage of coals. So, an alternative source is required that can fulfill the energy demands. Among all renewable sources, solar energy is abundant and offers a solution to fulfill the demand for energy, reduce fossil fuel emissions and global climate change. This state receives a huge amount of solar energy insolation. This paper highlights the solar energy development in the state of Odisha, the state government supportive policies, the central government supportive policies and the future plans for the implementation of solar energy. [ABSTRACT FROM AUTHOR]

Abstract: The limited availability of fossil energy carriers and environmental impact of energy consumption demand mid- and long-term strategies both for the rational use of energy and for increased renewable energy utilization. Despite the establishment of the National Energy Policy, there is still an obstacle in reaching those objectives and targets. In the 7th Malaysia Plan for instance, the government has highlighted that a third of the Government''s total allocation of RM469 million for rural electrification programmes under the has been allocated for the provision of solar powered installations for rural and remote communities. This paper outlines a detailed description of various existing solar technologies, the understanding of each technology and its associated challenges, which will provide a suitable basis to recognize advantages and drawbacks in its implementation in Malaysia. The paper finally justifies some of the barriers in promoting the full scale utilization for the solar energy in Malaysia. [Copyright &y& Elsevier]

Abstract: Pakistan energy situation is seriously troubling today due to lack of careful planning and implementation of its energy policies. To avoid the worse situation in the years ahead, the country will have to exploit its huge natural renewable resource. In this paper a review is being presented about renewable energy resource potential available in the country to be exploited for useful and consistent energy supplies. On average solar global insolation 5–7kWh/m2/day, wind speed 5–7.5m/s, Biogas 14 millionm3/day, microhydel more than 600MW (for small units) with persistency factor of more than 80% over a year exist in the country. Solar and wind maps are presented along with identification of hot spring sites as resource of geothermal energy. The research results presented in this paper are not only useful for government policy makers, executing agencies but also for private sector national and international agencies and stake holders who want to invest in Pakistan for renewable energy projects or business. [Copyright &y& Elsevier]

This paper presents an agent-based model of the technological adoption of solar panels, including potential adopters' characteristics and their interactions. This study analyzes the theoretical impact of seven social influence strategies on the adoption of solar panels by householders within a solar neighborhood in the Providencia district, Chile. In this case study, established adopters account for 0.9% of the population, opinion leaders for 1.3%, and individuals in the network for 97.8%. Considering the population's high-level ambition and tolerance of uncertainty, we found that householders are mainly characterized as optimizers (89.7%), followed by inquirers (7.6%), repeaters (2.3%), and imitators (0.3%) agents. Our agent-based simulation model evaluated the social influence strategies based on economic, environmental, and social benefits. The results show that social influence strategies lead to a 19.27% increase, on average, in the total number of adopters concerning the base case. Then, we performed a multi-objective analysis to select the best adoption strategy. These results show that selecting the most connected agents in the network is a robust strategy the decision-makers have environmental or financial concerns. However, if the decision-makers' primary interest is maximizing the diffusion scope of solar panel neighborhoods, random agent selection is the most advisable strategy, given its ease of implementation. [Display omitted] • Consumat approach and Campbell's paradigm were integrated into a simulation model. • The results from seven social influence strategies are compared. • Selective seeding and random seeding are found to be the most effective strategies. [ABSTRACT FROM AUTHOR]

The mitigation of global energy demands and climate change are the most important factors in the modern days. Development and application of solar energy have been regarded by the government of India and common people, and they thought that solar photo voltaic energy can provide more energy in future compare to other renewable energies. In the last decade, solar photovoltaic energy research and development has supported by the central government and state governments. This paper discusses the progress of current solar photovoltaic energy in India. It highlights the renewable energy trend in India with major achievements, state wise analysis of solar parks and industrial applications. Finally, it discusses the Indian government policies and initiatives to promote solar energy in India. This review on solar photovoltaic energy will help decision makers and various stakeholders to understand the current status, barriers and challenges for better planning and management in this field. [ABSTRACT FROM AUTHOR]

Governments and network utilities are grappling with how to manage increasing costs of electricity supply, the prospect of distributed generation while still meeting social objectives of access and affordability in remote areas. Due to geographical isolation and dispersed populations, remote Australian communities are generally electrified by distributed networks using diesel generation. This is expensive, environmentally damaging and fails to exploit vast renewable resources available. These communities are often regarded as “low hanging fruit” from a renewable energy deployment perspective. This paper examines why that fruit has not been readily picked in Australia in the context of a case study of three remote West Australian communities. In Western Australia, the local electricity distribution network service provider (DNSP) responsible for regional networks, developed a scheme (the Scheme) to incentivise renewable energy deployment in remote communities. This scheme aims to encourage communities to install renewable energy from the “bottom up” by providing a feed-in tariff capped at $0.50/kW h, to reduce the supply cost and environmental damage from diesel generation. However, to date there has been limited deployment of renewable energy in remote communities. The scheme and viability of renewable energy is assessed for three indigenous communities located in the Kimberley region of Western Australia. These communities are connected to isolated, diesel powered networks. Viability is assessed from the DNSP and community perspectives and incorporates quantitative and qualitative financial, social / human and institutional factors. Renewable energy deployment is found to benefit the DNSP and can also benefit communities subject to their cost of capital and to the imposition of connection charges. However a range of barriers are currently frustrating deployment and a dynamic and adaptive approach that recognises local challenges and provides the communities with a pathway to installation is needed. [ABSTRACT FROM AUTHOR]

Grid connected solar photovoltaic (GCPV) systems are fast becoming a regular feature of electricity power networks in urban and peri-urban areas within most Pacific Island Countries. A number of systems have been installed with many in the pipeline. This relatively new technology, utilizing the intermittent solar energy resource has presented new challenges to small island utilities that were hitherto almost completely dependent on diesel generators and hydropower. The present paper describes the current status of GCPV systems in the Pacific region and reviews some of the issues that arise in the deployment of this technology. It also reports a case study involving a 45 kW p GCPV system located at the University of the South Pacific (USP) marine campus in Fiji. One of the first two GCPV systems established in Fiji, this system has an annual production of ~54,000 kW h and supplies about 10% of the electricity requirements of the campus. The actual system performance agreed well with the simulated results. This system also reduces USP׳s annual carbon footprint by more than 27,000 kg CO 2e . [ABSTRACT FROM AUTHOR]

The introduction of renewable energy technologies (RET), like solar and wind power plants, into a power system introduces both expansion and operational challenges. Earlier studies have indicated the requirements for additional backup power facilities requirements for every addition of RET plants, due to the unique generation characteristics of these RET plants. Of late, alternative strategies of creating power storage facilities using power from RETs and drawing constant supply from such storage facilities are drawing the attention of power system planners. In this paper, generation expansion planning (GEP) mathematical modeling studies are carried for a candidate power system, to study the impact of introduction of solar power plant with storage facility. The study is planned in a four-level hierarchy, based on (a) investment strategies of introducing solar plants as an alternative candidate plant or as a replacement of existing high emission plants (HEP) (b) whether the solar plant with storage (SPWS) or with no storage (SPWNS) capacity and (c) inclusion of treatment/penalty costs on emissions from high emission plants. The sensitivity of the system performance factors, like, the capacity added, overall costs and EENS for variations in assumed Forced outage rate (FOR%) for SPWNS and SPWS is also carried for assumed solar penetration levels of 5–10% and 10–20% for 6-year and 14-year planning horizons. The system performance was highly sensitive to the assumed FOR%. The model investigations offer an encouraging scenario in power system planning when SPWS is introduced as an alternative investment candidate plants into the system. This study, while attempting to illustrate the complexity of decision making process in introducing solar plants into an existing system provides a four-level hierarchy in understanding comprehensive set of policy issues that might arise in GEP and enables planners to adopt situation-specific solutions. [ABSTRACT FROM AUTHOR]

Sichuan Province is one of the most important economic inland areas and is characterized by an abundance of renewable energy resources in the form of solar, wind, biomass, and, in particular, hydropower. After the rapid growth of installed hydropower capacity during the past decade, the non-hydro renewable energy resource development is booming in Sichuan Province. This development is bringing about a series of problems as well. In this paper, we give an overview of Sichuan׳s renewable energy development in the past five years, analyze the existing problems, and examine the underlying causes in terms of environment, market, technology, and policy. On that basis, we propose a method for future renewable energy development in Sichuan and suggest that Sichuan׳s government should improve the pricing mechanism and the mandatory share policy for non-hydro renewable energy. Additionally, R&D on the plateau type of wind turbines and the smart micro-grid should be strengthened. Finally, given the mature hydropower industry in Sichuan, the combined operation of wind–hydro and solar–hydro plants is recommended to improve the stability of renewable electricity generation output. [ABSTRACT FROM AUTHOR]

This paper deals with the simultaneous scheduling of electrical vehicles and responsive loads to reduce operation cost and emission in presence of wind and PV powers in microgrid. In the proposed method, the electrical vehicles are used for peak shaving and load curve modification while the responsive loads are employed to supply the reserves needed to compensate the intrinsic uncertainties of wind and PV powers. Furthermore, a developed two-stage model is proposed to determine the expected operation cost of microgrid (energy and reserve). In the first stage, the generation and reserve power costs are minimized while in the second stage, the costs associated with unit scheduling changes resulting from wind and PV power variations are minimized. The proposed model is implemented in a microgrid with various distributed generations. The simulation results have shown that the incorporation of electrical vehicles and responsive loads leads to decrease the system operation costs and emissions while the uncertainties related to wind and PV are compensated. [ABSTRACT FROM AUTHOR]

The protection of micro-grid should be in such a way that a safe and secure protection is provided in both grid-connected and stand-alone operation modes. Nevertheless, the function of micro-grid in these two modes creates some new protection problems. During grid-connected operation mode, since micro-grid provides a large short-circuit current to the fault point, the protection can be performed by existing protective devices within the distribution networks, but in islanded mode, fault currents are drastically lower than those of grid-connected mode; hence, the employment of traditional overcurrent-based protective devices in micro-grids is no longer valid. In order to overcome this challenge, different approaches have recently appeared in the literatures. This paper presents a micro-grid protection scheme based on positive-sequence impedance using Phasor Measurement Units (PMUs) and designed Microprocessor- Based Relays (MBRs) along with a digital communication system. The proposed scheme has the ability to protect radial and looped micro-grids against different types of faults with the capability of single-phase tripping. Furthermore, since the MBRs are capable of updating their pickup values (upstream and downstream equivalent positive-sequence impedances of each line) after the first change in the micro-grid configuration (such as transferring from grid-connected to islanded mode and or disconnection of a line, bus, or DG either in grid-connected mode or in islanded mode), they can protect micro-grid lines and buses against subsequent faults. Finally, in order to verify the effectiveness of the suggested scheme and the designed MBR, several simulations have been undertaken by using DIgSILENT PowerFactory and MATLAB software packages. [ABSTRACT FROM AUTHOR]

India has an active participation in global solar energy contribution through the Jawaharlal Nehru National Solar Mission (JNNSM) and its many states are also walking hand in hand with the national government through individual state solar policies. The state of Gujarat, through the ‘Gujarat Solar Power Policy 2009 (GSPP 2009)’, has been leading the country in solar power generation. The feed-in-tariff based GSPP 2009 is a unique experiment of the state to develop individual solar projects as well as public-private partnership based large-scale ‘solar parks’. Of the about 2700 MW (in September 2014) installed solar energy capacity in India, Gujarat occupies a share of more than 900 MW. This paper, through semi-structured in-depth interviews conducted with project developers involved in implementation of the Charanka solar park, Gujarat, investigates the industry perspectives on the GSPP 2009. With an installed capacity of 216 MW (in April 2012), the Charanka Solar Park is the Asia׳s largest solar park. Findings from this study indicate that the attractive fixed feed-in-tariff and strong implementation mechanisms are the key strengths of the policy. On the other hand, the key challenges are lack of trust of financial institutions on solar energy projects, and tradability and bankability of the solar power purchase agreements. [ABSTRACT FROM AUTHOR]

The Spanish power generation sector is facing dire problems: generation overcapacity, various tariff hikes over recent years, uncertainty over the financial viability of many power plants and a regulatory framework that lacks stability. This situation is the consequence of both poor energy policies and the economic crisis in the late 2000s and early 2010s. In this paper we analyze the following three points from an energy planning perspective: how the country has arrived at this situation; whether other alternatives would have been possible through adequate planning; and the quantitative benefits that would have been accrued from such planning. We do so by developing a LEAP model, and building three scenarios that allow to segregate the costs of the economic crisis from the costs of the lack of planning. We find that appropriate energy planning could have reduced investments in the Spanish power sector by 2010€28.6 billion without compromising on performance in terms of sustainability or energy security, while improving affordability. The main causes of these surplus investments were two supply bubbles: those of gas combined cycles and of solar technologies. The results of this work highlight the value of rigorous, quantitative energy planning, and the high costs of not doing it. [ABSTRACT FROM AUTHOR]

The substantial increase in deployment of customer-sited solar photovoltaics (PV) in the United States has been driven by a combination of steeply declining costs, financing innovations, and supportive policies. Among those supportive policies is net metering, which in most states effectively allows customers to receive compensation for distributed PV generation at the full retail electricity price. The current design of retail electricity rates and the presence of net metering have elicited concerns that the possible under-recovery of fixed utility costs from PV system owners may lead to a feedback loop of increasing retail prices that accelerate PV adoption and further rate increases. However, a separate and opposing feedback loop could offset this effect: increased PV deployment may lead to a shift in the timing of peak-period electricity prices that could reduce the bill savings received under net metering where time-varying retail electricity rates are used, thereby dampening further PV adoption. In this paper, we examine the impacts of these two competing feedback dynamics on U.S. distributed PV deployment through 2050 for both residential and commercial customers, across states. Our results indicate that, at the aggregate national level, the two feedback effects nearly offset one another and therefore produce a modest net effect, although their magnitude and direction vary by customer segment and by state. We also model aggregate PV deployment trends under various rate designs and net-metering rules, accounting for feedback dynamics. Our results demonstrate that future adoption of distributed PV is highly sensitive to retail rate structures. Whereas flat, time-invariant rates with net metering lead to higher aggregate national deployment levels than the current mix of rate structures (+5% in 2050), rate structures with higher monthly fixed customer charges or PV compensation at levels lower than the full retail rate can dramatically erode aggregate customer adoption of PV (from −14% to −61%, depending on the design). Moving towards time-varying rates, on the other hand, accelerates near- and medium-term deployment (through 2030) but slows adoption in the longer term (−22% in 2050). [ABSTRACT FROM AUTHOR]

Energy production in a safe and hazard free manner is one of the world׳s greatest concern. Since the inception of Kyoto Protocol, which was adopted in 1997 and entered into force in February 2005, countries have started to adopt different measures for emission reduction such as electricity generation from renewable energy sources; as the source is free from green house gas (GHG) or CO 2 emission. Legislations and financial incentives have been provided by some governments for encouragement and ensuring good returns to the investors in renewable energy sector. This paper analyzes how a 500 kWp solar photovoltaic (PV) system for electricity generation contributes significantly in the GHG emission reduction and also the potential impact of introducing CO 2 emission reduction cost in the solar PV electricity generation. The result shows that the emission reduction is of the order of hundreds of tons of CO 2 and CO 2 emission reduction cost has a positive impact on the cumulative cash flow of the system. [ABSTRACT FROM AUTHOR]

Limited fossil resources, the continuous increment in fuel prices and severe environmental problems require new sustainable electricity generation options, which utilize renewable energies. Solar photovoltaic generation is a proven renewable energy technology and has the potential to become cost-effective in the future, for it produces electricity from the solar radiation. In Ghana, the electricity demand is rapidly increasing at a rate of 10% annually. In the attempt to change the conventional energy intensive economical development and its negative impact on the environment, the government has begun to support the development of the solar photovoltaic technology strongly. In this paper, the state of solar photovoltaic, the challenges facing the industry, the potential of the technology, the policies and strategies to promote development of the technology have been presented. [ABSTRACT FROM AUTHOR]

A techno-economic analysis is undertaken to assess hybrid PV/solar-thermal (PVT) systems for distributed electricity and hot-water provision in a typical house in London, UK. In earlier work (Herrando et al., 2014), a system model based on a PVT collector with water as the cooling medium (PVT/w) was used to estimate average year-long system performance. The results showed that for low solar irradiance levels and low ambient temperatures, such as those associated with the UK climate, a higher coverage of total household energy demands and higher CO 2 emission savings can be achieved by the complete coverage of the solar collector with PV and a relatively low collector cooling flow-rate. Such a PVT/w system demonstrated an annual electricity generation of 2.3 MW h, or a 51% coverage of the household’s electrical demand (compared to an equivalent PV-only value of 49%), plus a significant annual water heating potential of to 1.0 MW h, or a 36% coverage of the hot-water demand. In addition, this system allowed for a reduction in CO 2 emissions amounting to 16.0 tonnes over a life-time of 20 years due to the reduction in electrical power drawn from the grid and gas taken from the mains for water heating, and a 14-tonne corresponding displacement of primary fossil-fuel consumption. Both the emissions and fossil-fuel consumption reductions are significantly larger (by 36% and 18%, respectively) than those achieved by an equivalent PV-only system with the same peak rating/installed capacity. The present paper proceeds further, by considering the economic aspects of PVT technology, based on which invaluable policy-related conclusions can be drawn concerning the incentives that would need to be in place to accelerate the widespread uptake of such systems. It is found that, with an electricity-only Feed-In Tariff (FIT) support rate at 43.3 p/kW h over 20 years, the system cost estimates of optimised PVT/w systems have an 11.2-year discounted payback period (PV-only: 6.8 years). The role and impact of heat-based incentives is also studied. The implementation of a domestic Renewable Heat Incentive (RHI) at a rate of 8.5 p/kW h in quarterly payments leads to a payback reduction of about 1 year. If this incentive is given as a one-off voucher at the beginning of the system’s lifetime, the payback is reduced by about 2 years. With a RHI rate of 20 p/kW h (about half of the FIT rate) PVT technology would have approximately the same payback as PV. It is concluded that, if primary energy (currently dominated by fossil fuels) and CO 2 emission minimisation are important goals of national energy policy, PVT systems offer a significantly improved proposition over equivalent PV-only systems, but at an elevated cost. This is in need of careful reflection when developing relevant policy and considering technology incentivation. Currently, although heat outweighs electricity consumption by a factor of about 4 (by energy unit) in the UK domestic sector, the support landscape has strongly favoured electrical microgeneration, being inclined in favour of PV technology, which has been experiencing a well-documented exponential growth over recent decades. [ABSTRACT FROM AUTHOR]

Croatia has enormous renewable energy potential, particularly solar, but it is underperforming with regard to its use both for electricity production and heating. Paper focuses on the reasons therefor by analyzing the policy with regard to environment, subsidies, the role of international financial institutions, monopoly dimension of power utility companies, as well as social dimension. The author presents proposals for changing the status quo in order for Croatia to catch up with regard to securing reasonable solar and other renewable energy share in its energy supply. Apart from the state as regulator which has various instruments at its disposal to implement thoroughly the renewable energy use, local authorities should assume central role and responsibility for solarizing their territories and generating the energy locally from other renewable energy sources available on their territory. Municipal utility companies would thus add electricity production to their regular activities and could provide installation and maintenance services for individual energy generating systems within the territory of their competence. [ABSTRACT FROM AUTHOR]

Ambitious policy targets together with current and projected high growth rates indicate that future power systems will likely show substantially increased generation from renewable energy sources. A large share will come from the variable renewable energy (VRE) sources wind and solar photovoltaics (PV); however, integrating wind and solar causes challenges for existing power systems. In this paper we 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. Based on residual load duration curves we define corresponding challenge variables and estimate their dependence on region (US Indiana and Germany), penetration and mix of wind and solar generation. Results show that the impacts of increasing wind and solar shares can become substantial, and increase with penetration, independently of mix and region. Solar PV at low penetrations is much easier to integrate in many areas of the US than in Germany; however, some impacts (e.g. over-production) increase significantly with higher shares. For wind power, the impacts increase rather moderately and are fairly similar in US Indiana and Germany. [ABSTRACT FROM AUTHOR]

Providing affordable and clean energy for all is a global priority, especially for off-grid and low-income regions. New business models, such as Pay-as-you-go (PAYG), has been a strategy for providing sustainable electricity in off-grid regions, especially in African countries. However, there is a need for analysis tools, such that we can test upfront the potential for this scheme varies according to local context. In this paper, we propose the use of system dynamics for energy policy assessment. We set-up the methodology considering the off-grid context, and then we developed a system dynamics model to assess the effect of the PAYG scheme in the diffusion of solar energy in off-grid and low-income regions. The method is tested using a case study, the Colombian case. The application of the methodology depicts simulations that indicate that effect of PAYG is limited under the current market conditions of Colombian off-grid regions, considering that solar companies obtain most of their income directly from Government's subsidy. Better results are obtained when implementing PAYG in a lower subsidy scenario, which indicates the potential to optimize the allocation of subsidies. We finally discuss the importance of the local conditions to use the proposed methodology. • Pay-as-you-go is analyzed to promote solar energy in Colombian off-grid areas. • A System Dynamics model is developed based on the Bass' diffusion theory. • The effect achieved is low under current market conditions. • Better results are obtained under a hypothetical scenario of subsidy redistribution. [ABSTRACT FROM AUTHOR]

Providing affordable and clean energy for all is a global priority, especially for off-grid and low-income regions. New business models, such as Pay-as-you-go (PAYG), has been a strategy for providing sustainable electricity in off-grid regions, especially in African countries. However, there is a need for analysis tools, such that we can test upfront the potential for this scheme varies according to local context. In this paper, we propose the use of system dynamics for energy policy assessment. We set-up the methodology considering the off-grid context, and then we developed a system dynamics model to assess the effect of the PAYG scheme in the diffusion of solar energy in off-grid and low-income regions. The method is tested using a case study, the Colombian case. The application of the methodology depicts simulations that indicate that effect of PAYG is limited under the current market conditions of Colombian off-grid regions, considering that solar companies obtain most of their income directly from Government's subsidy. Better results are obtained when implementing PAYG in a lower subsidy scenario, which indicates the potential to optimize the allocation of subsidies. We finally discuss the importance of the local conditions to use the proposed methodology. • Pay-as-you-go is analyzed to promote solar energy in Colombian off-grid areas. • A System Dynamics model is developed based on the Bass' diffusion theory. • The effect achieved is low under current market conditions. • Better results are obtained under a hypothetical scenario of subsidy redistribution. [ABSTRACT FROM AUTHOR]

Integrating variable and non-dispatchable renewable power generation into existing power systems will have consequences for their operation and future expansion. These impacts will depend on two factors: (1) the variability of the total renewable power generation on different time scales and (2) the possibilities of accurately forecasting these fluctuations. In this paper, previous research on variability assessment and forecasting of solar, wind, wave and tidal energy resources is reviewed. The aim is to summarize the state of knowledge in each area and to compare the approaches used for the respective resources. For temporal variability, methods and models used for assessing the variability are surveyed, as well as what is known about the variability at individual sites and for larger aggregates of sites. For forecasting, an overview of forecasting methods for the different resources is made, and selected forecasting methods are compared over different time horizons. An important finding is that it is hard to draw strong conclusions from the existing studies due to differences in approaches and presentation of results. There is a need for further, more coherent studies that analyze the variability for the different resources in comparable ways, using data with the same resolution, and for studies that evaluate the smoothing effect and complementarity of combinations of several renewable energy resources. For forecasting, future research should suggest ways to evaluate forecasts from different renewable energy sources in easily comparable ways, using data from the same locations or regions, with the same temporal and spatial resolution, and with comparable metrics for the forecasting errors. [ABSTRACT FROM AUTHOR]

A significant number of Life Cycle Assessment (LCA) analyses of renewable energy technologies is available in the literature, even though there is a lack of consistent conclusions about the life cycle impacts of the different technologies. The reported results vary consistently, according to the size and the technology of the considered plant, thus limiting the utility of LCA to inform policy makers and constituting a barrier to the deployment of a full awareness on sustainable energies. This variability in LCA results, in fact, can generate confusion regarding the actual environmental consequences of implementing renewable technologies. The article reviews approximately 50 papers, related to more than 100 different case studies regarding solar energy (Concentrated Solar Power, Photovoltaic), wind power, hydropower, and geothermal power. A methodology for the harmonization of the results is presented. The detailed data collection and the results normalization and harmonization allowed a more reliable comparison of the various renewable technologies. For most of the considered environmental indicators, wind power technologies turn out to be the low end while geothermal and PV technologies the high end of the impact range where all the other technologies are positioned. [ABSTRACT FROM AUTHOR]