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Solar home systems (SHSs) are the real hope for electrification of the off-grid areas in Bangladesh by utilizing the solar energy in renewable and sustainable basis. This paper demonstrates the solar energy prospect, the present status and dissemination schemes of SHSs in off-grid and coastal areas of Bangladesh by several government and Non-government organizations (NGOs). The country has an average daily solar radiation ranges between 4–6.5 kWh/m 2 . Currently, more than 3.8 million SHSs of capacity range 10–135 Wp (watt peak) with a total capacity of 150 MW have been disseminated in rural and isolated areas in Bangladesh. In this paper, ten case studies of capacity 20 Wp, 30 Wp and 42 Wp were investigated to evaluate economic viability at two randomly selected villages in Sirajgonj district and Jessore district, Bangladesh. The analysis showed that the SHSs for small business enterprise and household with small income generation are economically viable rather than only household lighting. [ABSTRACT FROM AUTHOR]

Given that the first industrial revolution was based on Steam Engine (coal as energy source), and the second on oil and electricity, where both these revolutions are actually "high carbon" revolutions, it is logical to expect that the third industrial revolution should be based on systems of renewable energy sources (RES), in order to minimize the problems arising from climate changes and to achieve sustainable development. However, the usage of the RES technologies and daily/weekly storage of energy and their connection to smart grids is not enough for the expected third industrial revolution. The start of this revolution would require technologies that have a great potential for further development and ability to supply, at any time, the necessary energy and power to a settlement/city, as well as drinking water, meeting the peak load requirements, continuously throughout the year, and independently of external sources of energy and drinking water. This would be provided from intermittent RES energy (solar, wind, etc.) and sea or other unclean source of water as natural resources. In that context, this paper presents a radically new technological solution: Key Engine which uses only natural resources: the sun, sea and gravity, in order to continuously and simultaneously supply a consumer with energy, power and drinking water. This solution has all the essential features required to start a third industrial revolution. The basic unit of Key Engine consists of the solar thermal (ST) generator with parabolic trough collectors through which sea water flows directly, absorbing thermal energy of solar radiation. After the separation of steam from seawater, the steam drives turbines and generators and produces electricity that is delivered to Pump Storage Hydroelectric (PSH) facility with seawater, which balances the daily and seasonal surpluses and shortages of energy, thus ensuring a continuous supply of electric power and energy to a consumer. At the same time, the water that comes out of the turbine, passes through the water treatment unit and is stored in drinking water reservoir, enabling continuous supply of the same consumer with drinking water. The paper presents theoretical aspects of Key Engine, model for optimal sizing and practical formulas for the calculation of characteristic values of the system, which could be the basis for further scientific research, development and innovative solutions that would help engineers in practice for numerous and diverse applications of Key Engine. In order to verify the derived mathematical relationships and models for optimizing the Key Engine in real conditions, the case study of the island of Vis in the Adriatic Sea, Croatia, has been considered, along with total annual irradiance of 1575 kW h/m 2 a, total annual electric energy consumption of 20 GW h and drinking water consumption of 453,382 m 3 . The obtained results: power of ST generator of 52 MW, working volume of the upper reservoir of 7 hm 3 , total annual electric energy production of 62 GW h/a, and drinking water production of 480,754 m 3 /a, clearly show that the new technology can fully meet the needs of the considered consumer for energy and drinking water. As the basic idea of Key Engine relies on the use of natural resources, i.e. RES energy and sea, the paper presents only the starting solution, whereby, apart from the sun, RES can be wind, or other renewable sources, that can perform separation of vapor from seawater and thus produce drinking water, as well as energy simultanously. Also, energy storage may not be performed solely by the PSH technology, but also by any other technology that can provide seasonal balancing of energy. All this suggests that the Key Engine can be understood as an open-source for RES technology development and thus bring changes in all three aspects of sustainable development: economy, society and environment. [ABSTRACT FROM AUTHOR]

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%. [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]

Due to the increasing awareness of environmental and social issues, many practitioners and researchers have paid much attention to the sustainable supply chain management (SSCM) in recent years. Sustainable supplier selection is one of the most critical activities in the SSCM which can affect supply chain performance. However, the previous literature rarely considers the interrelationships between economic, environmental, and social evaluation criteria in the supplier selection. Moreover, the effect of the criteria importance on the criteria interrelationships is scarcely discussed in previous researches. To deal with these problems, a novel integrated methodology is developed in this paper. The proposed method integrates the merit of pairwise comparison method in determining relative importance, the strength of decision making trial and evaluation laboratory (DEMATEL) in manipulating the complex and intertwined problems with fewer data, and the rough number's advantage in flexibly dealing with vague information. A case study in a solar air-conditioner manufacturer is provided to show the feasibility and effectiveness of the proposed methodology. [ABSTRACT FROM AUTHOR]

Greater penetrations of variable renewable generation on some electric grids have resulted in increased levels of curtailment in recent years. Studies of renewable energy grid integration have found that curtailment levels may grow as the penetration of wind and solar energy generation increases. This paper reviews international experience with curtailment of wind and solar energy on bulk power systems in recent years, with a focus on eleven countries in Europe, North America, and Asia. It examines levels of curtailment, the causes of curtailment, curtailment methods and use of market-based dispatch, as well as operational, institutional, and other changes that are being made to reduce renewable energy curtailment. [ABSTRACT FROM AUTHOR]

The electrical power distribution network in Pakistan is a complex system with many geographical regions suffering from frequent blackouts, limited and intermittent supply. Investment in mega-scale solar energy generation projects could help mitigate these supply related problems and counterbalance the country׳s growing dependence on imported oil. The purpose of this paper is to explore the economic and technical impact of connecting a mega-scale PV plant to the national grid. The area of Kharan in Balochistan province was chosen due to desired solar irradiation (7–7.5 kW h/m 2 /day). The simulations were carried out with existing and planned interconnected transmission system of Pakistan that has not been pre-designed to incorporate such intermittent generation. Load flow studies and short circuit analysis were carried out and it was established that power from this solar power project can be evacuated to the 220 KV system of National Transmission & Despatch Company (NTDC), Pakistan without any transmission constraints. The three phase and single phase short circuit current studies further confirmed reliable grid interconnection in terms of power quality indices. Furthermore recommendations encompassing the economics and technical sides are presented for the successful commissioning of this installation. [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]

In this paper we present an up-to-date literature review on employment opportunities associated with the deployment of renewable energy technology. We identified approximately 70 studies and data sources published over the past decade that report analysed or observed employment impacts of renewable energy growth. These publications cover many different countries and several technology options, and present widely varying results derived from distinct methodological approaches. Our first overall conclusion is that there is clear lack of authenticity of findings in this literature, since recursive referencing abounds and relatively few studies yield truly original research. When we omit non-authentic analyses, as well as those that aggregate results in a way that does not allow us to calculate ‘employment factors’ (defined as the number of jobs or amount of work generated per unit of electricity production capacity), the total list of references is brought to 31 independent items. Of these, only 14 references provide separate estimates of the employment factors for the stages of manufacturing and installation, respectively, as opposed to employment factors for these two activities combined. A total of 23 items provide values for operation and maintenance (O&M) employment factors. We observe significant uncertainties in quoted figures for job creation, both across and within publications. [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]

Solar energy is considered to be the most reliable source in the future, and applying solar energy for flight is one of the most promising utilizations of renewables. Since the invention of solar-powered aircraft in 1974, the methods to extract and store energy for it have become the important research points all around the world. Currently, the main methods to do so are photovoltaic cell, rechargeable battery, and component of maximum power point tracking (MPPT). These years, many institutions and scholars have dedicated great efforts to the relative research. Besides, there are also several other methods in consideration, such as to extract energy from wind shear and store energy by gravitational potential. However, it is still not a simple task for the designers of solar-powered aircraft to select a particular technique from a number of existing techniques, since each technique has certain advantages and disadvantages with respect to different performance indices to fulfill the special requirements. Thus, the aim of this paper is to review in detail the working principle of different methods to extract and store energy, and to compare their performances on the basis of desirable features applied on solar-powered aircraft, and to provide some guidance principles for designers to select proper methods. [ABSTRACT FROM AUTHOR]