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China has set a goal of carbon neutrality by 2060 and is determined to increase wind and solar power to 1200 GW by 2030, even though it already has the world's largest installed capacity of renewables. However, the lack of flexibility in the power system will limit the development of a higher proportion of renewable energy. This paper evaluates the applicability of different types of flexible power sources in China for the first time. Above all, it describes the current situation of China's power industry and the necessity of increasing flexible power sources, establishes an evaluation system from the perspectives of benefit, opportunity, cost & risk, then determines 19 evaluation criteria. The BOCR-ANP-TOPSIS method was used to evaluate the system, where the ANP method determines the weights and the TOPSIS method ranks the alternatives. The result shows that pumped storage hydropower has the highest overall ranking, followed by the flexibility transformation of coal-fired power. Coupled with sensitivity and comparative analysis, valuable findings that will help future energy policymakers are reported. • Evaluating the applicability of different flexible power sources in China for the first time. • The identification of criteria for the selection of flexible power sources was given. • Making recommendations for China's flexible power source development policy. • The BOCR-ANP-TOPSIS method adopted can be extended to select flexible power sources in different regions meticulously. [ABSTRACT FROM AUTHOR]

This paper compares different strategies to transform the heating sector into a future 100% renewable energy solution. It focuses on the consequences for infrastructures in terms of grids and storage across the electricity, gas and heating sectors. The hypothesis is that these consequences are rarely taken into proper consideration, even though the costs are significant and differ substantially between the alternative pathways. While the smart grid scenarios are based on electricity as an energy carrier, the “smart energy systems” approach is based on a cross-sectoral use of all grids. Using Denmark as a case, this paper shows how the current gas and district heating grids each have twice the capacity of the electricity distribution grid. Moreover, the existing gas and thermal storage capacities are substantially higher and the additional future capacities are more affordable than within the electricity sector. The conclusion is that the “smart grid” pathway requires a 2–4 times expansion of the electricity grid and significant investments in electricity storage capacities, while the “smart energy systems” pathway can be implemented with relatively few investments in affordable minor expansions of existing grids and storage capacities. [ABSTRACT FROM AUTHOR]

Lack of reliable data often prevents new private investments in renewable energy and government programs in this sphere. The paper offers a novel renewable energy resources system of potentials: energy, resource saving and environmental; better designed and more accurate methods for calculating the future exploitable technical potentials of wind and solar PV energy for a wide range of generating equipment in centralized and distributed power systems, taking into account existing social and environmental limitations. The paper also presents the latest assessments of these potentials for Russia and its 85 regions (in terms of fossil fuel saving and substitution, power and heat production and environmental effects), offering solutions to overcome methodological limitations of previous country-level assessments, such as incomplete or unreliable sources, absence of hourly, daily and monthly assessments, etc. Given the limitations of existing network of national meteorological stations and satellite monitoring systems it was decided to use NASA SSE database as a source of meteorological information. The methodology was validated through a comparative analysis of the data obtained in the course of this study and the data of wind monitoring campaign carried out by a German engineering company in one Russia's region for 18 months using 70 m masts. [ABSTRACT FROM AUTHOR]

While Asia as a continent has enjoyed nearly 40% of the total installed wind energy capacity, the contribution of some countries in the region is less significant. Turkmenistan as an important oil and gas producing country is a major exporter of electricity in the Central Asia region. The country has an enormous potential for wind and solar energy development overshadowed by its wealth of oil and gas. This paper aims to assess the wind energy potential of Turkmenistan by taking into account the hourly wind speed data of eighteen different locations in a typical meteorological year. The widely utilized and validated two-parameter Weibull distribution function is utilized for calculating the power and energy density of the locations in the country. Fifteen commercially available wind turbines are also employed and compared against each other in terms of annual power output, energy output, and capacity factor for the considered locations. Finally, the economic metric indicator of the levelized cost of energy (LCOE) is employed to assess the feasibility of the system. The obtained results are expected to be a guideline for investors and policymakers regarding the wind energy development in the country while showing a major opportunity for Central Asia's energy market in the future. • Assessing the wind energy potential of 18 locations in Turkmenistan. • Kazandzhi, Turkmenbashi, Dashhowuz, and Gyzylarbat are the best sites for harvesting wind energy. • Providing insight into the best wind turbine option for implementation. • The results show a major opportunity for Central Asia's energy market in the future. • The cheap electricity generated from wind energy can be exported to other countries facing energy crises in the near future. [ABSTRACT FROM AUTHOR]

Increased levels of renewable energy penetration have created new congestion patterns in recent years. Since the grid is not designed for the new patterns, the operators may need to curtail renewable energy to maintain transmission flows within acceptable limits. Transmission line impedance control, using flexible ac transmission system (FACTS) devices, has been proposed as an approach to relieve congestion in transmission systems and enhance renewable energy utilization. In this paper, we conduct a comprehensive study to provide insights on FACTS implementation's impact on renewable energy integration and carbon emission reduction. The study considers variations in renewable energy penetration level, system loading patterns, location of renewable generation, and location of FACTS devices. Furthermore, generation mix data from prominent regional transmission organizations (RTO) are used to achieve more realistic results. Simulations studies are carried out on a modified RTS-96 system with a two-stage stochastic unit commitment model. The results show that, even though impedance control is effective in cost reduction, it has limitations in facilitating renewable energy integration in systems with prominent cheap fossil fuel power plants. • Impedance control reduces cost but may not always enhance renewable integration. • Generation mix highly influences the effectiveness of FACTS in emission reduction. • For high levels of renewable penetration, transmission expansion is necessary. [ABSTRACT FROM AUTHOR]

In the present context, energy access to remote rural households through local energy generating systems has been recognized as a cost effective and extent efficient option. With increased emphasis on eco-friendly technologies and high fuel cost associated with conventional energy generation, the use of renewable energy resources (small hydro, biomass, solar, wind energy etc.) are being explored. The present paper is focused on the optimal sizing of a stand-alone Integrated Renewable Energy System (IRES) which comprises the resources of micro hydro power (MHP), biogas, biomass, solar and wind energy. Initially, a demand response (DR) strategy based on energy consumption scheduling of appliances has been suggested and modelled in the paper. This strategy aims to minimize the peak hourly energy consumption of the study area. Further, different combinations of system components without and with DR strategy were considered and optimized for power reliability criteria of 0% and 5% unmet load. It has been found that significant amount of savings in system sizes and costs are obtained with DR strategy compared to system without DR. [ABSTRACT FROM AUTHOR]

This paper quantifies that current net-zero building definitions will remain as necessary but not sufficient conditions in sustainable decarbonization efforts until they recognize exergy destructions as one of the root causes of emission responsibilities. A direct relationship between exergy destructions and nearly-avoidable carbon dioxide emissions has been set as a sufficient condition to upgrade the decarbonization mindset. This relationship is demonstrated in a case study where a solar prosumer building with photovoltaic panels and a ground-source heat pump, known as a net-zero energy building, is responsible for emissions. Based on the second law, emission responsibilities, primarily at the PV panels and the heat pump, were identified. By replacing them with advanced photo-voltaic-heat panels with temperature peaking and heat pump with adsorption cooling machines, carbon dioxide emission responsibility due to avoidable exergy destructions was reduced by 96%. The main attribute is using solar power only for electric power instead of downgrading it downstream to heat or cold by the heat pump, minimizing exergy mismatches between electrical and thermal power. The paper also shows that a net-zero energy building may neither be a net-zero exergy building nor a zero-carbon building due to these exergy destructions. • Second Law redefines Net-zero buildings, showing unrecognized root emissions causes. • Exergy destructions are responsible for these root causes. • Unrecognized root emission causes are at least 60% of known sources. • A case study shows that solar prosumers may be upgraded for nearly nearly-zero carbon building. • Net-zero carbon building is not possible for inevitable and irreversible exergy destructions. [ABSTRACT FROM AUTHOR]

Abstract Providing electricity generation is a crucial indicator for development of a country's progress index. Renewable energy resources are rapidly being recognized as important alternatives for clean production of electricity. The present paper aimed to assess the wind and solar data from selected metrological stations in the province of Sistan and Baluchistan in Iran in order to produce hydrogen as a clean fuel. For using wind and solar energies, a detailed techno-economical analysis was presented. At first, the solar energy potential was assessed; indicating that the most part within the province possesses a high radiation intensity of more than 500 W/m2. Secondly, wind resources were examined, revealing the high power density of about 500 W/m2 in Lutak station. According to evaluation of hydrogen production from several small wind turbines, it was shown that the maximum amount of 39.7 ton-H 2 can be produced every year. It was observed that in the best conditions, the cost of 1 kWh electrical energy generated by wind turbine was 2 cents cheaper than the market energy unit price while this value is 8 cents cheaper by employing both wind and solar energies. GIS maps of hydrogen production, wind speed, wind power and global horizontal radiation were produced. Highlights • Wind/solar potentials in the province of Sistan & Baluchistan in Iran are assessed. • A detailed techno-economical analysis is presented using wind/solar energies. • Economical solar energy above 500 W/m2 is observed in several stations. • High hydrogen production of 39.7 ton-H 2 is observed in Lutak station. • The GIS maps of solar/wind/hydrogen are reported. [ABSTRACT FROM AUTHOR]

Abstract Solar aided coal-fired power system has been proven to be a promising way to utilise solar energy in large scale. In this paper, the performances of the solar tower aided coal-fired power (STACP) system at 100% load, 75% load, and 50% load for different days are investigated and the maximum solar power that the boiler can absorb under different plant loads are explored. Then, the effects of solar multiple (SM) and the thermal energy storage (TES) hour on the daily performance of STACP system are investigated. Results show that the maximum solar power that a 600 MW e boiler can absorb at 100% load, 75% load and 50% load are 76.4 MW th , 54.2 MW th and 23.0 MW th , respectively. Due to the augmented energy from the solar field, the maximum standard coal consumption rate is reduced by 13.53 g/kWh, 12.81 g/kWh and 8.22 g/kWh at 100% load, 75% load and 50% load, respectively. With an increase of solar power input, the boiler efficiency, overall system efficiency and solar thermal-to-electricity efficiency show a downward trend. In addition, the daily coal consumption of summer solstice is the lowest while the winter solstice is the highest for a particular SM and TES hour. Highlights • Performances of STACP system are investigated at different loads with different solar shares. • The maximum solar energy that the boiler can absorb is determined. • Performances of STACP system are investigated at different weather conditions. • Daily performance of STACP system are explored with different SM and TES hours. [ABSTRACT FROM AUTHOR]

In this paper, a review on solar drying is presented. The review comprises the main components, classifications and affecting parameters. Advantages, disadvantages and limitations of such technology are also investigated. That said, solar dryers are assessed according to three key-elements: way of air movement (passive and active), mode of transferring heat (direct and indirect, hybrid and mixed) and type of drying chamber (cabinet, greenhouse and tent). Moreover, economic and environmental studies are performed for the Lebanese case in order to assess the Payback Period (PP) and the amount of CO 2 reduction. The examined parameters are the percentage of time where solar dryer is utilized (Pr), the mass of dried food and food type. Results show that for Pr equals to 0.6, when drying 120 kg of carrots using solar dryer the amount of Saved Money (SM) is 780 $/month, PP is 10 months and the amount of CO2 emissions decreases by 6400 kg/month. [ABSTRACT FROM AUTHOR]

Floating photovoltaic systems (FPV) can be a more sustainable alternative for the energy transition than ground-mounted photovoltaic systems, as they avoid occupying useable land and the power generation is more distributed. This paper presents the first study that calculates the FPV technical potential at the province/municipality level, focusing on water irrigation ponds, which it is a novelty in the literature that usually focuses on large water infrastructures in a national approach. In the province of Jaén (Spain), more than 3000 ponds dedicated to agricultural irrigation have been identified and their surface area and location was obtained. The results, calculated for each pond, reveal that, in a conservative scenario, in which only 25% of their surface area is covered, a minimum of 490 MWp can be installed, which can provide 251% of the province agricultural electricity consumption and 27% of the total electricity needs. This analysis has also been performed at the municipal level, where all possible FPV plants have been aggregated and compared with consumption that would be covered at this scale. Furthermore, this technology brings additional benefits, as it avoids the occupation of 12 km2 of useable land, 8.8·106 m3/year of water evaporated, while creating more than 7000 jobs. • A Technical floating PV potential assessment on water irrigation ponds is done • A Technical floating PV potential assessment at a municipal level is done • A calculation of Multi-benefits of floating PV installation is done • An energy consumption coverage assessment at municipal level with floating PV is done [ABSTRACT FROM AUTHOR]

The Liquid Solar Fuel (LSF) concept aims to provide renewable-energy-based fuels like synthetic Diesel and Kerosene for long-distance transport via trucks, ships and airplanes and for remote machinery. The purpose of this paper is to present a preliminary design and performance model of a small scale plant with a rated production capacity of 100 barrels per day. First technical and economic performance estimates suggest that an achievable process efficiency around 50% and a product cost of ca. 1 US$/liter for large scale units in the medium term future can be attractive when compared to similar processes like power-to-liquid or biomass-to-liquid. A key attribute of the LSF concept is to maximize efficiency of all physical and chemical processes involved by continuous full-load operation of the synthesis process avoiding any transients, and by integrating and recycling all involved energy and material flows. How to achieve this in an effective way in spite of mainly using variable renewable energy from sunshine and wind for power supply is a key finding of the analysis, significantly reducing the need for major storage facilities for hydrogen and other involved substances. A major implication of the study is that carbon-free production of synthetic liquid hydrocarbon fuels is possible with present state-of-the-art technologies and can be efficient and affordable under appropriate frame conditions that exist in many parts of the world. The analysis has been made in the frame of internal activities of the Department of Systems Analysis and Technology Assessment at the German Aerospace Center (DLR) in Stuttgart, Germany, since 2008, and had the goal to identify sustainable solutions for future long-distance transport fuels. The model analysis provides technical and economic performance estimates of a first prototype. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) cell plays crucial role to utilize the solar energy. The regional differences in the PV industry have created unbalanced flows of PV cells. This paper examined patterns of the PV cells international trade from spatial and temporal perspectives. Data sources are regional monetary import-export tables and the world renewable energy statistics in 1996–2015. Based on the Haggett's cognitive model of spatial structure, the patterns and evolution characteristics are identified with an aid of ArcGIS. This study revealed most PV cells exporters are distributed in East Asia and Southeast Asia intensively whereas relatively balanced exports are presented in Europe and North American in recent years. Most PV cells are flowing from east to west while the pattern of PV cells international trade has transformed from single-pole to multi-pole. Meanwhile, the international trade intensity of PV cells grew steadily at the global scale, and evolution features of PV cells trades varied from region to region. Economics conditions, incentive policy and producers' demand are three critical factors. These findings provide a useful reference for identifying the intensity, orientation, main connections and development trend of traders. Moreover, the PV industrial practitioners can benefit from this research to develop corresponding international business strategies. [ABSTRACT FROM AUTHOR]

A microgrid optimal scheduling model is developed in this paper to demonstrate microgrid's capability in offering ancillary services to the utility grid. The application of localized ancillary services is of significant importance to grid operators as the growing proliferation of distributed renewable energy resources, mainly solar generation, is causing major technical challenges in supply-load balance. The proposed microgrid optimal scheduling model coordinates the microgrid net load with the aggregated consumers/prosumers net load in its connected distribution feeder to capture both inter-hour and intra-hour net load variations. In particular, net load variations for three various time resolutions are considered, including hourly ramping, 10-min based load following, and 1-min based frequency regulation. Numerical simulations on a test distribution feeder with one microgrid and several consumers/prosumers indicate the effectiveness of the proposed model and the viability of the microgrid application in supporting grid operation. [ABSTRACT FROM AUTHOR]

Renewable energy plays significant role in achieving energy savings and emissions reduction. As a sustainable and environmental friendly renewable energy source, concentrated solar power (CSP) is of interest for research and development. This is because CSP plants can be equipped with thermal storage systems, thereby producing electricity when sunlight is not available. The installation of CSP plants also leads to substantial ‘peak shaving effects’. However, the cost of CSP generation is an obstacle hampering the commercialization of this emerging industry. This paper constructs a mathematical model of the levelized cost of energy (LCOE) to calculate the power generation cost of CSP projects on the basis of lifetime cost structure analysis. A sensitivity analysis is conducted to examine the impact of different variables on the LCOE of CSP projects. The variables considered in this study are investment cost over the construction period, annual operation and maintenance cost, annual electricity production and the discount rate. Finally, the influence of incentive policies such as preferential loans, tax support and zero land cost for power stations is analyzed. This research offers a new method for power generation cost calculation of CSP projects and provides support for governments to formulate incentive policies for the industry. [ABSTRACT FROM AUTHOR]

The paper investigates the application of solar energy in public lighting for realizing a street lighting sub-grid with positive yearly energy balance. The focus is given to the central controller, which ensures the adaptive behavior of the overall system and provides smart city services to the end users via its web-based user interface. A functionality of the controller of special interest is the optimization of the energy management of the system, i.e., determining when to sell and buy electricity to/from the grid, in order to minimize the cost of electricity (or to maximize the profit) subject to a given, time-of-use variable energy tariff. This requires precise forecasts of the energy produced and consumed, as well as appropriate robust optimization techniques that guarantee that the system bridges potential power outages of moderate duration in island mode. The algorithms implemented in the controller are presented in detail, together with the evaluation of the operation of a deployed physical prototype with 191 luminaries over a horizon of six months, based on the monitoring data collected by the proposed controller. [ABSTRACT FROM AUTHOR]

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 energy requirements of the planetary exploration spacecrafts constrain the lifetime of the missions, their mobility and capabilities, and the number of instruments onboard. They are limiting factors in planetary exploration. Several missions to the surface of Mars have proven the feasibility and success of solar panels as energy source. The analysis of the exergy efficiency of the solar radiation has been carried out successfully on Earth, however, to date, there is not an extensive research regarding the thermodynamic exergy efficiency of in-situ renewable energy sources on Mars. In this paper, we analyse the obtainable energy (exergy) from solar radiation under Martian conditions. For this analysis we have used the surface environmental variables on Mars measured in-situ by the Rover Environmental Monitoring Station onboard the Curiosity rover and from satellite by the Thermal Emission Spectrometer instrument onboard the Mars Global Surveyor satellite mission. We evaluate the exergy efficiency from solar radiation on a global spatial scale using orbital data for a Martian year; and in a one single location in Mars (the Gale crater) but with an appreciable temporal resolution (1 h). Also, we analyse the wind energy as an alternative source of energy for Mars exploration and compare the results with those obtained on Earth. We study the viability of solar and wind energy station for the future exploration of Mars, showing that a small square solar cell of 0.30 m length could maintain a meteorological station on Mars. We conclude that the low density of the atmosphere of Mars is responsible of the low thermal exergy efficiency of solar panels. It also makes the use of wind energy uneffective. Finally, we provide insights for the development of new solar cells on Mars. [ABSTRACT FROM AUTHOR]

Ever-increasing price of conventional energy resources and related environmental concern enforced to explore alternative energy sources. Inherent uncertainty of power generation and demand being strongly influenced by the electricity market has posed severe challenges for DRPs (Demand Response Programs). Definitely, the success of such uncertain energy systems under new market structures is critically decided by the advancement of innovative technical and financial tools. Recent exponential growth of DG (distributed generations) demanded both the grid reliability and financial cost–benefits analysis for deregulated electricity market stakeholders. Based on the SGT (signaling game theory), the paper presents a novel user-aware demand-management approach where the price are colligated with grid condition uncertainties to manage the peak residential loads. The degree of information disturbances are considered as a key factor for evaluating electricity bidding mechanisms in the presence of independent multi-generation resources and price-elastic demand. A correlation between the cost–benefit price and variable reliability of grid is established under uncertain generation and demand conditions. Impacts of the strategies on load shape, benefit of customers and the reduction of energy consumption are inspected and compared with Time-of-Used based DRPs. Simulation results show that the proposed DRP can significantly reduce or even eliminate peak-hour energy consumption, leading to a substantial raise of revenues with 18% increase in the load reduction and a considerable improvement in system reliability is evidenced. [ABSTRACT FROM AUTHOR]

Abstract: NZEB (Net zero energy building) is regarded as an integrated solution to address problems of energy-saving, environmental protection, and CO2 emission reduction in the building section. NZEB could be even possible with electricity production if enough renewable energy could be used. Moreover, various building-service systems with renewable energy sources have been widely considered for potential applications in NZEB. All of these new features extend the technical boundary of the conventional energy-efficient buildings, attach a more profound implication to the sustainable development of building technology, and therefore pose a challenge to evaluation works on NZEB performance. This paper presents a guided tour on NZEB evaluation through literature-research. An overview about definitions and energy-efficient measures of NZEB is presented so that the research object and technology boundary can be clarified for NZEB evaluation. Then, a summary of widely-used research method, tool and performance indicator in evaluation is provided for the methodology part. This part also includes a discussion on the application of LCA (life cycle assessment) in NZEB evaluation and LCA's role in promoting a well-defined NZEB. Finally, potential progress in NZEB evaluation with possible development trends is highlighted in terms of energy storage, load match and smart grid. [Copyright &y& Elsevier]

Abstract: Energy security is sometimes used to advocate renewable energy systems. Renewable energy systems can improve some aspects of security, but they will not automatically lead to the removal of all types of security problems and new problems will most certainly arise. This paper analyses energy security aspects of renewable energy systems on the basis of a broad typology on energy and security. Renewable energy sources do not suffer from the same long-term resource availability problems as finite fossil resources and their geographical location is less concentrated, but other issues such as dependence on variable flowing resources and competition for scarce land resources will grow in importance. Many security issues related to energy are also dependent on the energy carrier rather than the energy resource and on the existence of effectively functioning institutions and regulations. New interdependencies will appear and will have to be handled within future international and bilateral institutional frameworks. [Copyright &y& Elsevier]

Abstract: The various forms of solar energy – solar heat, solar photovoltaic, solar thermal electricity, and solar fuels offer a clean, climate-friendly, very abundant and in-exhaustive energy resource to mankind. Solar power is the conversion of sunlight into electricity, either directly using photovoltaic (PV), or indirectly using concentrated solar power (CSP). The research has been underway since very beginning for the development of an affordable, in-exhaustive and clean solar energy technology for longer term benefits. This paper, therefore, reviews the progress made in solar power generation research and development since its inception. Attempts are also made to highlight the current and future issues involved in the generation of quality and reliable solar power technology for future applications. A list of 121 research publications on the subject is also appended for a quick reference. [Copyright &y& Elsevier]

Abstract: There is a potential to utilize a significant amount of renewable energy in Sweden and European union (EU). Biomass can fulfil some 8500–12,500 TW h/y in EU, while the total utilization was 16,084 TW h/y 2009. Even though there is a significant amount of wind power, hydro power and potentially also solar power, it still is most economical to reduce the consumption of heat, electricity and fuels for vehicles. A saved kWh is normally cheaper than to produce one extra. In this paper different opportunities for saving energy will be discussed. This includes manufacturing industries, process industries, power plants and energy systems including distribution of power and smart grids, food production and transportation. There is also a major potential to save energy in buildings, both in the north where it is cold, and in the south where it can be very hot summer time. Here the potential is to avoid cooling instead. Technical solutions as well as economic incentives are covered. Environmental aspects are addressed, so that the solutions will be long term sustainable. [Copyright &y& Elsevier]

Abstract: Renewable sources of energy are anticipated to play a major role in electricity generation in Ireland in the future. Currently, electricity is mainly generated from imported gas and coal due to a lack of indigenous fossil fuel resources in Ireland. Solar energy is omnipresent, freely available and environmental friendly. The utilisation of solar energy to produce electricity has become increasingly attractive worldwide. However, solar electricity generation has not been very popular in Ireland to-date either on a large scale or on a domestic scale. The unclear economics of domestic solar PV systems, under Irish conditions, is considered the biggest obstacle for expanding domestic solar PV system installation in Ireland. This paper presents a methodology to accurately evaluate the economic viability of a domestic solar PV system on a case-by-case basis. The methodology utilises the software programmes HOMER and Microsoft Excel 2007 for the energy and economic analyses. Utilising this methodology, a realistic economic analysis of eight sample domestic solar PV systems available in Ireland is presented. Based on the predictions, the domestic solar PV system is not economically viable under current conditions in Ireland. Domestic solar PV systems still do not look promising even if better financial support is given. [Copyright &y& Elsevier]

Abstract: This paper describes the theoretical rationale for a new low temperature phase-change desalination process, and six examples of applications to illustrate how this process can be engineered for sustainable desalination. In this process, brackish water is evaporated at near-ambient temperatures under near-vacuum pressures created by the barometric head without any mechanical energy input. Thermodynamic advantages and benefits of low temperature phase-change desalination are discussed and results from simulation studies and a prototype test system are presented. Three of the examples illustrate how the proposed process can be driven by solar energy: a) utilizing direct solar energy; b) inclusion of an external reflector; c) utilizing photovoltaic energy during non-sunlight hours. The other examples illustrate how the proposed process can be driven by waste heat: i) waste heat rejected by an absorption refrigeration unit driven by grid power; ii) waste heat rejected by an absorption refrigeration unit driven by solar collectors; and iii) waste heat rejected by an absorption refrigeration unit supported by a photovoltaic array. Merits of utilizing solar energy and process waste heat in reducing energy consumption and greenhouse gas emissions are discussed in detail. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical model for the collection and efficient use of solar energy in hot water systems at permafrost regions. A case study was presented for northern territories of the Russian Federation in the Republic of Sakha (Yakutia). Daily maximum diffuse solar radiation on a horizontal and inclined surface was predicted during the year taking into account cloud coverage. The cloud coverage data was taken from the results of five-year monitoring on the heliometric station of the Yakutsk city. The modelling of the hourly, daily, monthly, and annual amount of solar radiation was performed. The mathematical model was turned and finally proved by experimental data obtained from the testing rig. The modelling of the domestic hot water supply system of particular northern territories was performed using solar energy and energy storage. Both models were integrated and verified by experimental data accounting a seasonal fluctuation. The estimation of the solar energy potential for practical application in Yakutia was executed. The operating features of permafrost regions were analysed by the developed experimental unit. The application of solenoid valve reduces the heat losses during the night by 57% in June and by 69% in November. The case study provides the results of modelling and efficient use of solar energy for different daily water flow rates during January and June. The results of the case study show the possibility to use of solar energy in a hybrid energy system at permafrost regions, decarbonize the energy input and contribute regional sustainability of northern territories. • A modelling of solar energy for DHW in permafrost regions was performed. • Experimental unit for solar energy harvesting in northern territories was developed. • The mathematical model was proved by experimental data. • A case study presents the solar energy use in permafrost region. • The operating features of solar energy at permafrost regions were analysed. [ABSTRACT FROM AUTHOR]

The concentrating solar power (CSP) plant with the thermal energy storage (TES) is one of the most effective methods to solve the intermittent characteristics of solar energy. CSP plants combined with wind farms could provide continuous, stable power generation and reduce the uncertainty of the wind power. In this paper, a look-ahead technique is proposed to optimize the bidding strategy for a joint system of CSP plants with wind farms considering both the day-ahead and the following day. It is assumed that the CSP plant participates in the ancillary service (AS) market bidding while providing the reserve capacity for the wind farm to counteract the output fluctuations. As the price-taker, the joint system has different levels of attention to the market price and renewable energy output. Therefore, the scenario set and the chance-constrained programming (CCP) is used to describe its uncertainty, respectively. Besides, in order to further enhance the flexibility and maximize the economic revenues of the system, an electric heater (EH) is added to the model. The joint operator can adjust the final heat storage level to balance profit opportunities during the current market window against potential opportunities in the subsequent market window. Finally, we compare the results of different bidding models to demonstrate the effectiveness of the proposed model and the advantages of the joint system. • We propose a look-ahead bidding strategy for CSP plants with wind farms. • The CSP plant is assumed to provide reserve capacity to counteract fluctuations. • An EH is added to enhance flexibility and maximize revenues. • We balance current profit opportunities against subsequent potential opportunities. [ABSTRACT FROM AUTHOR]