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An overview of renewable electric power capacity and progress in new technologies in the world

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Abstract

In recent years, the atmosphere has been exposed to a substantial increase in concentration of the trace gases. In 2012, energy-related CO2 emissions reached a record of 31.6 gigatonnes which corresponds to 1.4% comparing to 2011. According to the International Energy Agency (IEA), an energy revolution is needed to achieve a 50% reduction of global CO2 emissions relative to current levels by 2050. In this revolution, energy efficiency, energy storage, new transport technologies, nuclear energy and CO2 capture and storage should play a crucial role. Furthermore, renewable energy technologies comprise a large potential for emission reductions which takes second place after energy efficiency improvements. Until 2035, renewable energy will also have greater impact than other potential alternatives including both CO2 capture and storage or nuclear energy. For this reason, renewable energy industries, markets, and policy frameworks are developed rapidly in recent years, and they will play a substantial role in the world׳s future. This paper presents an overview of renewable electric power capacity worldwide and discusses the current status, technologies, industry and recent developments of renewable energy sources (RESs) in detail. In addition, the top countries in terms of total installed renewable electric power capacity are also identified.

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... As a result, there has been an increase in the search for the development of technologies to use these resources [5]. Renewable energies are exploited in different ways in different parts of the world [6]. The ranges of renewable resources used include biomass, geothermal energy, wind power, hydroelectricity, and solar energy. ...
... Solving optimization problems has become a central topic in operational research, as the number of decision support 6 Khare et al. [30] 2016 Concentrated on PV/wind based hybrid systems Discussed feasibility analysis, modeling, reliability issues, and control aspects of PV/wind based hybrid systems Optimization techniques reviewed are: ...
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The hybrid renewable energy system (HRES) has been presented as the most studied solution for improving the sustainability of energy production infrastructures in isolated areas. With the rapid growth of HRES markets, various issues and aspects must be taken into consideration when the major working about the hybridization of renewable energy sources, consequently optimization problem solving for this system is a requirement. Therefore, this paper presents a state-of-the-art review of hybrid meta-heuristic algorithms applied for the optimal size of HRES. The relevant literature source and their distribution are presented firstly. We then review the literature from two viewpoints, including existing applied hybrid meta-heuristic algorithms for single-objective and for multi-objective design. Finally, some promising paths ranging from improving algorithms to technical applications are outlined to encourage researchers to conduct research in related fields. Graphical abstract: Supplementary information: The online version contains supplementary material available at 10.1007/s11831-022-09730-x.
... Recently, renewable and clean energy sources have attracted increasing attention. With the continuous reduction in the price of photovoltaic (PV) power generation equipment, solar energy is being widely used in buildings globally (Bilgili et al., 2015). ...
... Therefore, the initial maximum size of the PV system was determined as the total area of the south roof of the house. Generally, the traditional method for determining the size of the storage battery is multiplying by 3 and dividing the depth of charge by the average daily load of the house as Equation (Bilgili et al., 2015), because of the fluctuating cooling electricity demand of the house in summer. ...
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Solar energy is used in buildings worldwide. However, because the efficiency of photovoltaic power generation varies with environmental fluctuations, it is difficult to control. Therefore, electricity generation from photovoltaics is often poorly matched to the electricity load of the house. The use of storage batteries and photovoltaic panels can effectively improve the stability of the energy supply; however, it also introduces the problem of higher initial costs. Generally, a larger photovoltaic area and battery capacity can lead to higher costs and more renewable energy; therefore, to determine a suitable size of photovoltaic and storage battery for a house, the energy demand of the house must also be considered. The traditional method for sizing photovoltaics and storage batteries mainly considers the daily average electricity demand and the useful area for installing photovoltaics. To size the photovoltaic in a more precise manner, we propose a mathematical model (nonlinear programming) for selecting a relatively optimal solution for the photovoltaic area, battery capacity, and photovoltaic installation angle by considering the hourly and annual demands for electricity from the grid. To validate this mathematical method, a detached house in Zhouzhi county, Shaanxi province, China, was selected to size the devices by the proposed method. Results show that the device sizes determined using the proposed mathematical model are significantly smaller than those determined using the traditional method, without suffering a significant increase in the demand for electricity from the grid. According to our economic analysis, although the proposed method for sizing devices reduces the device cost payback period by half compared to that of the traditional method, the payback period for the devices sized using the proposed method is still 10.6 years. The extremely low electricity price in China may contribute to the extended payback period and thus discourage residents from installing renewable energy devices.
... Tariff mechanisms, based on compensation for each unit of electricity produced, and the electricity sector liberalization in many countries in the last decade, have contributed to encourage distributed generation [12,13]. In this aspect, PV microgeneration systems have become popular as distributed generation due to their practicality (as they do not require a large footprint) and due to PV cells efficiency improvements over the last few years, which is proven by the continuous reduction of the Levelized Cost of Electricity (LCOE) for PV source worldwide [2,14]. ...
... Thus, it is noticed that the level of local solar radiation is the determining variable for electricity production performance [55]. In Eq. (2) the estimate of PV electricity generation is described: (2) where: h ¼ PV cells efficiency (dimensionless); r ¼ local irradiation (kWh/m 2 ); A ¼ occupation area by the system (m 2 ); g ¼ system losses (z19% [33]). ...
Article
This present study proposes to investigate whether the classification based on deterministic LCOE (Levelized Cost of Electricity) for PV microgeneration in twenty cities in Minas Gerais (Brazil) presents differences in relation to risk classification, based on a stochastic approach, namely CVaR-LCOE (Condi-tional Value at Risk e LCOE). In this stochastic approach, the Conditional Value at Risk (CVaR) is calculated with 99.9% confidence level for 5000 LCOE values for each city, generated by Monte Carlo Simulation. CVaR-LCOE results show a significant difference in ranking in relation to the deterministic approach. Diamantina city presented the best expected LCOE and the best CVaR-LCOE results. However, the cities located in Zona da Mata (Muria e, Juiz de Fora and Manhuaçu) are the worst in the deterministic ranking, but in CVaR-LCOE approach, Juiz de Fora and Manhuaçu results are better than Ipatinga, Gov-ernador Valadares, and Poços de Caldas, this last one which presents the worst CVaR-LCOE. It is also clear that in the CVaR-LCOE ranking, the cities in different regions appear in more shuffle positions in the ranking, the opposite was observed in the deterministic ranking. Cities with the lowest LCOE standard deviation had the best classification changes among the two rankings.
... The following are the most prominent of these types: 7.6.1. Ocean (or Marine) energy "Ocean energy systems" are defined as "all sorts of possible technologies which could lead to energy formation out of many related renewable resources such as tides, waves, currents, temperature gradients and concentration gradients" [71]. Of these mentioned resources, wave energy has attracted attention Wave energy is an effective form of energy. ...
... In 2011, South Korea developed the world's biggest ocean project. The ocean-based (i.e., tidal) energy projects were also developed by other countries like USA, Canada, France and the UK [71]. The Oman Sea near Iraq possesses sufficient wave energy levels of 2.6 kW/m. ...
... Prior empirical evidence suggests that there may be a strong basis for expecting the relationship of interest to behave differently based on the crisis. First, renewable energy industry capacity growth rates and technology efficiencies were less developed during the 1997 crisis than during the 2008 crisis (Bilgili et al., 2015;Gielen et al., 2019). These growth rates were relatively lower post-1997 crisis, and higher post-2008 crisis, especially for those using solar thermal and geothermal power (Bilgili et al., 2015). ...
... First, renewable energy industry capacity growth rates and technology efficiencies were less developed during the 1997 crisis than during the 2008 crisis (Bilgili et al., 2015;Gielen et al., 2019). These growth rates were relatively lower post-1997 crisis, and higher post-2008 crisis, especially for those using solar thermal and geothermal power (Bilgili et al., 2015). In addition, post-2008 crisis, many commercialized renewable energy costs were comparable to fossil fuel costs (Gielen et al., 2019). ...
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This paper examines whether the 1997 Asian financial crisis affected the renewable energy/carbon dioxide (CO2) emissions relationship differently when compared to the 2008 global financial crises. Using the Dynamic Panel Data methodology, we examine separately the impact of the 1997 crisis and the 2008 crises on the stated relationship for annual data between the 1987 – 2018 period for a group of high, upper-middle, and lower middle-income countries. Our findings suggest that the results were crisis and country specific. For the overall sample, the relationship between the two variables was positive (and significant post-1997 and pre-2008 crises) but negative post-2008 crisis. In contrast, the positive relationship remained unchanged for the lower middle-income subsample through the two crises. We also find evidence that the 1997 Asian crisis altered the relationship differently than the 2008 financial crisis especially for the upper and middle-income groups. Clearly, reduction of CO2 emissions may not be guaranteed even if host countries adopt renewable energy sources since country income levels and the nature of the crisis may matter. Future research may consider how the degree of pollution controls and differential costs of renewable energy adoption in countries may alter this relationship.
... Recently, global energy demand has increased remarkably due to emerging technologies, population growth, and declining resources of fossil fuels. In this respect, global warming, efficient use of energy sources and greenhouse gas (GHG) emissions resulting from fossil energy consumption have become the most attractive issues in the present decade [4][5][6][7]. ...
... Global installed wind generation capacity has enhanced nearly 70 times in the last two decades, from 7.5 GW in 1997 to more than 540 GW in 2018 [18]. Nowadays, for electricity generation wind power is the fastest growing sector and, it has also been seen that the wind power is the fastest growth among RESs in recent years [4]. Figure 4 indicates the total wind power installed capacity in Europe and the world between 2010 and 2018. ...
... As a renewable energy, electricity can be generated by solar or wind. However, these technologies cannot directly provide either continuous base-load power or peak-load power due to their low power density and discontinuous nature (Bilgili et al. 2015). Compressed air energy storage (CAES), which compresses air into a suitable storage medium and reconverts it to electricity by a turbine generator (Budt et al. 2016), is characterized by large capacity and continuity in providing electrical power. ...
Article
During the operation of a compressed air energy storage (CAES) salt cavern, the surrounding rock experiences creep damage during the stages of constant internal pressure and undergoes fatigue damage due to the periodical injection-production. To describe the damage evolution of salt rock under creep-fatigue loading, a novel damage accumulation model based on the ductility exhaustion concept is proposed by applying a nonlinear summation method to represent the synergistic effect of creep and fatigue damage. Low-cycle fatigue (LCF) and creep-fatigue tests of rock salt were conducted under stress-control mode for various cycle stress amplitudes and hold times. Results show that the deformation of rock salt under creep-fatigue loading consists of initial, steady and accelerated phases. The proposed model matches well with the test data and can accurately describe the damage evolution as the applied stress amplitudes and dwell times change. The introduction of the hold times at the upper limit stress causes a strain increment and life reduction, which become more evident as the duration periods prolong and can be understood by the dislocation theory of crystals.
... It is important to identify the worldwide electric power capacity and the technologies, developments of renewable energy sources. Also, it is necessary to address the climatic change issues related to electricity generation and the improvements in energy efficiency are analyzed with respect to the global reduction of CO 2 emissions [37]. Table 2 presents the existing literature studies, methodologies, and forecasting models for energy forecasting. ...
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In order to formulate the long-term and short-term development plans to meet the energy needs, there is a great demand for accurate energy forecasting. Energy autonomy helps to decompose a large-scale grid control into a small sized decisions to attain robustness and scalability through energy independence level of a country. Most of the existing energy demand forecasting models predict the amount of energy at a regional or national scale and failed to forecast the demand for power generation for small-scale decentralized energy systems, like micro grids, buildings, and energy communities. A novel model called Sailfish Whale Optimization-based Deep Long Short- Term memory (SWO-based Deep LSTM) to forecast electricity demand in the distribution systems is proposed. The proposed SWO is designed by integrating the Sailfish Optimizer (SO) with the Whale Optimization Algorithm (WOA). The Hilbert-Schmidt Independence Criterion (HSIC) is applied on the dataset, which is collected from the Central electricity authority, Government of India, for selecting the optimal features using the technical indicators. The proposed algorithm is implemented in MATLAB software package and the study was done using real-time data. The optimal features are trained using Deep LSTM model. The results of the proposed model in terms of install capacity prediction, village electrified prediction, length of R & D lines prediction, hydro, coal, diesel, nuclear prediction, etc. are compared with the existing models. The proposed model achieves percentage improvements of 10%, 9.5%,6%, 4% and 3% in terms of Mean Squared Error (MSE) and 26%, 21%, 16%, 12% and 6% in terms of Root Mean Square Error (RMSE) for Bootstrap-based Extreme Learning Machine approach (BELM), Direct Quantile Regression (DQR), Temporally Local Gaussian Process (TLGP), Deep Echo State Network (Deep ESN) and Deep LSTM respectively. The hybrid approach using the optimization algorithm with the deep learning model leads to faster convergence rate during the training process and enables the small-scale decentralized systems to address the challenges of distributed energy resources. The time series datasets of different utilities are trained using the hybrid model and the temporal dependencies in the sequence of data are predicted with point of interval as 5 years-head. Energy autonomy of the country till the year 2048 is assessed and compared.
... However, these new types of energy generation are greatly affected by the weather, and so cannot provide energy consistently. Energy storage technology is one solution to the instability of these new energy sources (Bilgili et al., 2015). At present, energy storage technologies are mainly divided into chemical battery storage, compressed air energy storage (CAES), and underground pumped storage hydropower stations (UPSHs) (Rahman et al., 2020;Fan et al., 2020a). ...
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The acoustic emission, energy, and damage evolution of coal samples for three kinds of uniaxial cyclic loading and unloading are deeply analyzed in this study. The evolution of total absorption energy, elastic strain energy, and dissipated energy of coal samples is related to the stress path, and the increasing amplitudes cycle loading has an obvious damage effect on coal samples. During the loading stage, the acoustic emission phenomenon is most active when loading is increasing and the Felicity and post-Kaiser phenomena appear. The acoustic emission phenomenon during constant loading does not obviously change, but rather becomes active with the increase of the equivalent load. The damage to the coal sample shows nonlinear change increasing loading and unloading and shows linear change for other stress paths. Compared to waveforms with stepwise increasing amplitudes cyclic loading, the failure process of the coal sample is more closely related to the size of the external load, which indicates that reasonable hydraulic design is beneficial to the stability of the confining pressure in the chamber of an underground pumped storage hydropower station.
... Recently, global electricity energy consumption (EEC) has been increasing due to the growth in population, emerging technologies, the progress of living standards and industrialization of the developing countries [6]. In this respect, the increase in electricity demand also requires a cheaper and safer electricity supply. ...
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Electricity is the most substantial energy form that significantly affects the development of modern life, work efficiency, quality of life, production, and competitiveness of the society in the ever-growing global world. In this respect, forecasting accurate electricity energy consumption (EEC) is fairly essential for any country's energy consumption planning and management regarding its growth. In this study, four time-series methods; long short-term memory (LSTM) neural network, adaptive neuro-fuzzy inference system (ANFIS) with subtractive clustering (SC), ANFIS with fuzzy c-means (FCM), and ANFIS with grid partition (GP) were implemented for the short-term one-day ahead EEC prediction. Root mean square error (RMSE), correlation coefficient (R), mean absolute error (MAE) and mean absolute percentage error (MAPE) were considered as statistical accuracy criteria. Those forecasted results by the LSTM, ANFIS-FCM, ANFIS-SC and ANFIS-GP models were evaluated by comparing with the actual data using statistical accuracy metrics. According to the testing process, the best MAPE values were obtained to be 4.47%, 3.21%, 2.34%, and 1.91% for the ANFIS-GP, ANFIS-SC, ANFIS-FCM, and LSTM, respectively. Furthermore, the best RMSE values were found as 25.94 GWh, 41.17 GWh, 29.50 GWh, and 80.14 GWh for the LSTM, ANFIS-SC, ANFIS-FCM, and ANFIS-GP models, respectively. As a consequence, the LSTM model generally outperformed all ANFIS models. The results revealed that forecasting of short-term daily EEC time series using the LSTM approach can provide high accuracy results.
... Kebijakan mitigasi diperlukan untuk mengendalikan pertumbuhan produksi emisi CO2 dari sektor tersebut, risiko pertumbuhan emisi dapat meningkat. Secara revosioner Gaya hidup dan kemewahan yang diperoleh dengan mengkonsumsi Energy terlalu tinggi, perlu dikurangi (Bilgili et al., 2015). Di sektor industri, penggunaan energi, khususnya energi BBF (Bahan Bakar Fosil), proses produksi, dan limbah adalah sumber emisi gas rumah kaca. ...
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Environmental issues have now become a critical topic for the attention of countries around the world, especially efforts to prevent climate change by mitigating greenhouse impacts. There are six types of greenhouse gases, namely Carbon dioxide (CO2), Methane ( CH4 ), Nitrous oxide ( N2O ), Hydro perfluorocarbons ( HFC ), Perfluorocarbons ( CFCs ), Sulfur Hexafluoride ( SF6) this which naturally exists in the air (atmosphere). The gas layer causes infrared heat rays A to reflect sunlight, causing geothermal heat that reaches 13°C. The earth's temperature will increase when the greenhouse gas layer gets bigger. Increased greenhouse gas (GHG) concentrations contribute to climate change by destroying stratospheric ozone and trapping excessive heat in the atmosphere. CO2 contributes 76.7% of total GHG emissions. Industrial activities are suspected to be one of the sources of co2 emission production. Research using the Analytic Hierarchy Process (AHP) method aims to analyze impact mitigation policies and GHG reduction strategies carried out by PT XYZ as one of the manufacturing industries committed to contributing to mitigating the impact of greenhouse gases. The research results obtained the Priority Policy on the operation of production machines at the Factory 1 location. The strategies carried out include replacing old machines that are no longer efficient with new machines that are more productive, and efficient in their electricity use, the use of high technology, and changing the layout or layout of machines that are more compact and grouped based on the type of product. From the analysis using the Analytical Hierarchy Process (AHP) method, it was concluded that the most priority greenhouse gas (GHG) impact mitigation policy was to reduce CO2 emissions based on the use of electrical energy by Reducing the use of electrical energy.
... Renewable Energy Sources (RES), and especially solar energy, have been growing rapidly over the last few years. Additionally, the depletion of fossil fuels, rising oil prices and increased electricity demand are important factors in the growing interest in RES [1]. Furthermore, buildings in Europe are responsible for 40% of total energy consumption in the European Union (EU), thus contributing to greenhouse gas emissions and, possibly, climate change. ...
Article
The increasing penetration of renewable energy technologies causes major problems in the power network, as their generation cannot be totally predicted. Along with fluctuations in the generation of renewables due to weather uncertainties, storage is very important for mitigating several problems that may arise, affecting the stability and reliability of the grid. In particular, in recent years there has been an emphasis on residential storage applications (behind-the-meter storage), with the aim of increasing the energy self-consumption and therefore reducing electricity bills. The proposed model consists of a 3 kWp rooftop solar photovoltaic (PV) system connected to the grid through converters and a battery-supercapacitor hybrid energy storage system. The model is developed and simulated in the MATLAB/Simulink software environment, based on mathematical analysis and average modeling. The supercapacitor handles rapid changes that occur within 0.2 s, and this can relieve the battery stress and extend the battery lifetime. The building’s electricity demand is satisfied through the PV, hybrid energy storage and/or grid. A new filtration-based power management algorithm (PMA) is proposed here, prioritizing the utilization of the PV and battery-supercapacitor instead of the grid, thus achieving a reduced power exchange between the building and the grid and increasing the PV self-consumption and self-sufficiency of the building. The dynamic performance of the proposed model is verified through several simulations over short time periods (10–30 s) for different scenarios that could occur. The obtained results show that the model works properly and responds extremely fast during the different mode transitions, exhibiting a very fast DC-bus voltage regulation with a very small ripple voltage of up to 5 V (a maximum of ± 0.625%). Additionally, both battery and supercapacitor remain between their minimum and maximum limits. Finally, an effective power sharing is achieved between the PV, the battery-supercapacitor storage, the building load and the grid.
... Renewable energy is defined as energy obtained from inexhaustible sources that generate low levels of greenhouse gas emissions [10]. The policy of increasing the share of renewable energy in countries around the world is high on the agenda. ...
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This research investigates the impact of oil price, income and carbon dioxide emissions on renewable energy consumption in Russia for the data period from 1990 to 2015, using the Vector Error Correction Models and the Canonical Cointegrating Regression method. This article is the only study conducting individual time-series analysis that emphasizes the effect of oil price on renewable energy consumption in the case of Russia. The results of empirical analysis conclude that oil price affects renewable energy consumption negatively. The negative oil price effects on renewable energy use can be interpreted as a sign of issue that stems from higher oil prices and slows the transition from conventional to renewable energy sources. Additionally, we found that there is a positive and statistically significant influence of real GDP per capita as a proxy of income on renewable energy consumption, whereas the carbon dioxide emissions have a negative and statistically insignificant influence on renewable energy consumption. Considering these empirical results, Russia, which has a significant share in energy production in the world, should focus on the use of renewable energy in order to maintain this superiority and its sustainability. The findings of this paper may be useful to policymakers and may help to contribute to existing literature for future research in the case of oil-exporting countries.
... Solar cells work through the photovoltaic process by utilizing photons in sunlight to flow electrons in semiconductor materials. The flow of electrons will be converted into electric current [3]. The amount of solar irradiation that can be converted into electrical energy by solar cells ranges from 15% to 20%, the rest will turn into heat. ...
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Fossil-based energy is diminishing due to the increasing global energy demand. The sun as a renewable energy source can be converted into electrical energy using solar cells. The performance of solar cells is influenced by the operational temperature produced. This article discusses the use of copper heat sink with aluminum fins as passive cooling to reduce operating temperatures to improve the performance of solar cells. The performance of solar cells using a heat sink with a copper base variation of 5 and 10 aluminium fins compared to solar cells without cooling. The results show that at the same intensity of 1100 W / m ² , the solar cell without cooling gets an operating temperature of 64.6 °C, an efficiency of 9.50% and an output power of 36.63 W. Solar cells with a 5-fin heat sink, can reduce the operating temperature is 57.7 °C, an efficiency of 11.42% and an output power of 44.02 W. Whereas the cooling panel with 10 fins obtains a temperature of 55.6 °C, maximum efficiency and power are 12.03% and 46.37 W respectively. The addition of 10-fin heat sinks to solar cells produces the best performance which can reduce operating temperatures by 9 °C, increasing efficiency and output power are 2.53% and 9.74 W respectively compared to solar cells without cooling.
... As a renewable energy, electricity can be generated by solar or wind. However, these technologies cannot directly provide either continuous base-load power or peak-load power due to their low power density and discontinuous nature (Bilgili et al. 2015). Compressed air energy storage (CAES), which compresses air into a suitable storage medium and reconverts it to electricity by a turbine generator (Budt et al. 2016), is characterized by large capacity and continuity in providing electrical power. ...
Article
Full-text available
During the operation of a compressed air energy storage (CAES) salt cavern, the surrounding rock experiences creep damage during the stages of constant internal pressure and undergoes fatigue damage due to the periodical injection-production. To describe the damage evolution of salt rock under creep-fatigue loading, a novel damage accumulation model based on the ductility exhaustion concept is proposed by applying a nonlinear summation method to represent the synergistic effect of creep and fatigue damage. Low-cycle fatigue (LCF) and creep-fatigue tests of rock salt were conducted under stress-control mode for various cycle stress amplitudes and hold times. Results show that the deformation of rock salt under creep-fatigue loading consists of initial, steady and accelerated phases. The proposed model matches well with the test data and can accurately describe the damage evolution as the applied stress amplitudes and dwell times change. The introduction of the hold times at the upper limit stress causes a strain increment and life reduction, which become more evident as the duration periods prolong and can be understood by the dislocation theory of crystals.
... Fossil energy resources have declined rapidly over the past decade; on the other hand, the frequent increasing population and technological developments in parallel have substantially increased the demand for energy [1]. Thus, the use of fossil energy sources and the ever-increasing global warming associated with the greenhouse gas emissions are unfortunately the most critical and urgent global problems at the present time [2][3][4]. ...
... Thanks to growing sensitivity on these topics, the development of efficient and clean power generation systems has become the focus of both industries and researchers working in the energy systems field. For this reason, in recent decades the installed capacity of renewable energy systems has shown a strong growth trend [2] and, in order to improve the flexibility of such systems, there has been increasing interest in batteries, hydrogen storage and hydrogen-based power plants [3]. Among the latter, fuel cells are one of the most promising technologies, thanks to their high energy conversion efficiencies, which can theoretically reach values > 75% [4]. ...
Article
The purpose of this paper regards the design and testing of control systems for a 30-kW turbocharged solid oxide fuel cell system fuelled with biogas. The adoption of a turbocharger, instead of a micro gas turbine, for the fuel cell stack pressurisation, is an innovative solution that is expected to decrease the capital cost of such systems and to facilitate their penetration into the energy market. However, not being connected to an electric generator, the turbocharger rotational speed, and thus the air mass flow, cannot be directly controlled as in microturbines. The control of turbocharged solid oxide fuel cell systems is a novel topic, characterised by many technical challenges that have not been addressed before. To regulate the stack temperature, a cold bypass valve is included, connecting the compressor outlet to the turbine inlet. A dynamic model of this system was developed in Matlab-Simulink® to analyse the response of the turbocharged solid oxide fuel cell system to a cold bypass valve opening step change. System information obtained from this analysis was used to design and tune four controllers: a conventional proportional integral controller and three different cascade controllers. The controller performance was evaluated under two different scenarios, considering quite aggressive power ramps. The best results were obtained with a cascade controller, where the feedback loop was complemented by a feed-forward contribution based on power demand. This analysis demonstrated that such a control system effectively tracks the fuel cell maximum temperature target, complying with all the system operative constraints.
... These products, in turn, are used for the production of numerous consumer goods, such as cars, household goods, packaging, etc. The constantly growing demand for flat-rolled products of increasingly higher quality, while striving to reduce the costs of their production [33], forces enterprises to look for new technological and structural solutions and is one with challenges for modern science [34,35]. For example, a modern rolling mill that produces steel strips must meet the following requirements: use the most economical COS feedstock, ensure high the reproducible quality of finished steel strips, provide high yield and efficiency, and consume limited energy and tools [36,37]. ...
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This paper presents an algorithm for modeling electricity and natural gas consumption in a walking furnace with the use of artificial intelligence and simulation methods, depending on the length of the rolling campaign and the established rolling program. This algorithm is the basis for the development of a proposal for a set of minimum requirements characterizing the Best Available Techniques (BAT) for beam furnaces intended for hot rolling, taking into account the requirements set out in national regulations and the recommendations described in the BREF reference documents. This information should be taken into account when drawing up an application for an integrated permit, as well as when setting emission limit values. Based on the constructed algorithm, it was shown that depending on their type and technical specification, the analyzed projects will offer measurable economic benefits in the form of reducing the amount of energy consumed by 1,076,400 kWh during the implementation of 50 rolling campaigns to reduce gas by 14,625 GJ and environmental benefits in the form of reduction of pollutant emissions into the atmosphere 80–360 g/Mg. The constructed algorithm was validated in the Dosimis-3 program, based on a discrete event-driven simulation. Thanks to this representation of the model, its user can interactively participate in changes that take place in the model and thus evaluate its behavior. The model, verified in real conditions, can be the basic source of information for making effective operational technological decisions related to the preparation of production at the rolling mill as part of planning and long-term activities.
... Increased energy demand, along with the depletion of fossil fuels, has heightened the need for rapid development of renewable energy (RE) sources to meet demand. However, the use of renewable energy as a percentage of total energy consumption in many nations is still at a low level [2]. RE is needed for a variety of activities, including lighting, heating, and cooking, and it may originate from a variety of sources, including biomass, solar, wind, and hydropower. ...
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Smart technology has potential in tracking the key challenges based on population based on the sustainable future. In today’s cultures, a smart approach enables for the integration of information needed to address crucial concerns. The critical challenge is to limit the effects of global warming while maintaining a balanced economic growth. The impact of global warming mitigates the fundamental problem while ensuring the balance economic development. Intense research efforts should be directed toward balanced resource utilization, renewable energy system integration, efficient energy conversion technologies, effective process integration, effective techniques to enable a circular economy framework, and other issues that are important to the population. This paper finds the latest technology in the field of smart grid technologies which focused on the effective enhancement and efficient utilization of resource. The issues and challenges in using sustainable future are discussed and bring new ideas towards the sustainable future base on the application of smart technologies.
... However, in this world of technical advancement and development only conventional energy resources are not sufficient. Therefore, renewable resources have also been explored and research on these fields is also getting maturity [1][2]. The local demand of energy is fulfilled with distributed energy generation, and micro grid is one of such ways that consists of resources like wind, solar, hydro, and biogas etc. [3][4][5]. ...
... All countries have at least one large number of RES power plants, and many countries have a resource portfolio in this sector. Among whole RESs, wind energy has become widely used in the World and makes an essential contribution to renewable energy generation (Bilgili et al. 2015;Bulut and Muratoglu 2018;Wang and Wang 2015;Jones and Eiser 2010;Zheng et al. 2016). Besides, wind power has become a reliable and competitive electric-producing technology. ...
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Accurate forecasting of wind speed (WS) data plays a crucial role in planning and operating wind power generation. Nowadays, the importance of WS predictions overgrows with the increased integration of wind energy into the electricity market. This work proposes machine learning algorithms to forecast a one-hour ahead short-term WS. Forecasting models were developed based on past time-series wind speeds to estimate the future values. Adaptive Neuro-Fuzzy Inference System (ANFIS) with Fuzzy c-means, ANFIS with Grid Partition, ANFIS with Subtractive Clustering and Long Short-Term Memory (LSTM) neural network were developed for this purpose. Three measurement stations in the Marmara and Mediterranean Regions of Turkey were selected as the study locations. According to the hourly WS prediction, the LSTM neural network based on the deep learning approach gave the best result in all stations and among all models applied. Mean Absolute Error values in the testing process were obtained to be 0.8638, 0.9603 and 0.5977 m/s, and Root Mean Square Error values were found to be 1.2193, 1.2573 and 0.7531 m/s from the LSTM neural network model for measuring stations MS1, MS2, and MS3, respectively. In addition, the analyzes revealed that the best correlation coefficient (R) results among the algorithms in the test processes were obtained to be 0.9498, 0.9147, and 0.8897 for the MS1, MS2, and MS3 measurement stations, respectively. In this regard, it is shown that the LSTM method gave high sensitive results and mainly provided greater performance than the ANFIS models for one hour-ahead WS estimations.
... Interestingly, the existing literature so far fails to explain this puzzling variance. Even so, it identifies essential structural factors for renewable energy expansion like economic development levels (Lund, 2009;Bilgili et al., 2015), (alternative) energy resources, and the available space for expansion (MacKay, 2013;Wurster and Hagemann, 2020), which help to explain different results between developed and less developed countries. However, the variance beyond this is still to a large extent unexplained and remains to be investigated at a global level. ...
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... The rapid growth of the population and economy has long been a global issue that intensifies the demand and consumption of the world's energy resources [1]. This looming challenge has stimulated the spotlight research of unlimited and environmentally friendly solar energy, which is deemed a latent remedy to alleviate global climate change and the energy crisis for the sustainable development of human civilization [2,3]. ...
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... It is considered a more stable RES compared to wind and solar energy because of its higher energy density and lower intermittency [123]. The commonly used ocean energy is the mechanical energy of waves, tides and currents, mainly converted to electrical energy through the use of energy converters [124]. ...
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... It has been suggested that renewable energy can be seen as a viable option for Australia to solve these concerns; thus, renewable-energy potential, renewable-energy output, and laws and incentives must all be extensively researched and planned as a top priority [13]. Renewable energy is defined as energy derived from non-depletable sources that emit minimal greenhouse gases [14][15][16]. Given that an average of 1.6 MWh/m 2 of solar energy is yearly cast onto the Earth's surface, solar energy has the potential to meet the complete yearly global energy needs [13]. ...
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... Issues of non-renewable resources are getting less encouraging researchers to develop renewable energy sources. Various experts have conducted renewable energy research, such as solar energy [2,3]. Solar energy is a renewable energy source with an unlimited supply and produces few emissions. ...
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Meeting greenhouse gas (GHG) reduction targets will require a significant increase in electricity production from sustainable and renewable sources such as solar energy. Farmers have recognized this need as a chance to increase the profitability of their farms by allocating farmland to solar power production. However, the shift from agriculture to power production has many tradeoffs, arising primarily from alternative land uses and other means of production. This paper models the farmers’ decision as a constrained profit maximization problem, subject to the amount of land owned by the farmers, who have to allocate it between agriculture and solar power fields, while considering factors affecting production costs. The farmers’ problem is nested in the social welfare maximization problem, which includes additional factors such as ecological and aesthetical values of the competing land uses. Empirical analysis using data from a solar field operating in Israel shows that landowners will choose to have solar power production on their land unless agricultural production generates an unusually high net income. Adding the values of non-market services provided by agricultural land does not change this result. The consideration of the reduction in GHG emissions further increases the social welfare from solar fields.
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Triboelectric nanogenerators (TENGs) are one of the most promising energy sources for self-powered electronic devices in the near future. Improving the dielectrics with high tribo-potential is a primary requirement to increase the output performance of TENGs. In this study, spring supported TENGs consisting of polyvinylpyrrolidone/ethyl-cellulose (PVP/EC) nanofibers and various carbon-doped polyacrylonitrile (PAN) nanofibers as positive and negative dielectric layers, respectively, were fabricated. According to the experimental results, reduced graphene oxide (rGO) and carbon nanotube (CNT) which were grafted to PAN matrix, both increased surface charge density and enhanced the output voltage of the TENGs. On the other hand, carbon black (CB) reduced the tribo-potential of PAN as a negative dielectric layer. As the best result, a 40 × 40 mm2 TENG constructed of PVP/EC and 3 wt% CNT doped PAN nanofibers demonstrates high triboelectric characteristics with a charge capacity of 259.82 nC (under 0.022 μF capacitive load), a maximum peak output voltage of 960 V (under a 70 MΩ load resistance), and a maximum peak power density of 14.53 W/m2 (under a 14.6 MΩ load resistance). In other words, the addition of 3 wt% CNT to PAN increased the charge amount by 136%, and the maximum peak power density by 125%. This work presents an effective way to take advantage of the coupling effect of carbon additive and nanofiber structure to significantly enhance the output performance of TENGs.
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The depletion of fossil fuel, the instability of oil price and the effect it has on the environment has made it made not just unreliable but also a hazard to humans. Renewable energy is the way out of these problems, the use of tidal energy will reduce the greenhouse gas effect. Tides are natural phenomenon caused by the sun and the moon, because it is regular and very predictable it has given tidal energy edge over other renewable energy forms. This study present details of tidal energy harnessing process and also theoretical modelling and simulation of tidal turbine that generates electrical power, the simulation is done on MATHLAB/Simulink using a mathematical model that considered all the parameter like power coefficient, tidal current speed profile etc. Tidal energy harnessing growth within the next five years will be rapid. The increase in energy consumption drives the need for a sustainable and clean energy like tidal energy which is very attractive, nevertheless, sustaining tidal energy will encompass solving all environmental issues that conflict with tourism, aquatic life or traffic. 1.0 Introduction Water spreads over 71% of the earth's surface and 96.5% of that water is the ocean body. The ocean possesses many forms of energy, which include chemical, biological product, thermal and kinetic energy used for wave and Tidal. Considering the economic aspect of the energy sources highlighted above coupled with limitation in technology makes tidal energy the most suitable for commercial purposes as well as its ability of seamless integration into the grid system. Tidal energy is the most suitable for commercial purposes and tidal energy can be integrated into the grid system (Villate et al. 2011). Tidal energy possesses the principal characteristics of predictability and sustainability which is suitable for electricity generation. This was discovered by exploration of sites within Europe using tidal currents (Hammons 1993). The total of 105TWh/year energy potential is to be realised, 50TWh/year should be from the United Kingdom and 44TWh/year should be from France. The world energy that can be generated from tide is five to ten times the amount of energy that can be generated from Europe. The motion of the water is brought mainly by way of the gravitational interaction of the sun, moon and earth. As the season changes so also the velocity of the tide changes in two weeks, one month, one year and even longer. (Hammons 1993, WATCHORN and TRAPP 2000). Tidal energy resources are advantageous over other renewable energy sources because of the fact of long time of prediction, in addition to the fact that tidal turbine can't be seen since they are submerge in water and they are not considered as threat to the aquatic life due to the slow rotational speed (O'Rourke, Boyle and Reynolds 2010).The global energy demand is on a steady increase and this demands are met mainly by the combustion of fossil fuel. The fossil fuels that are being burnt to produce energy are depleting, the fossil fuels being burnt to produce energy are depleting which is the major cause of global warming that has attracted global interest. Kyoto protocol is a treaty signed by many countries to commit to the reduction of greenhouse gas emissions. The reduction of CO2 emission will also lead to the reduction of burning fossil fuel, this has led to other ways of energy production known as the alternative energy schemes or renewable energy sources with zero or minimal environmental hazard. In this line of reasoning, policy makers are now recognising the importance of sustainable and renewable energy development so that the future generation will not suffer from the effect caused presently. So, having sustainable development strategies that will provide energy for the present without a negative effect on the future in terms of raw material
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Modern electronic devices are usually subjected to thermo-mechanical loads and prone to buckle during their operation. Thermo-mechanical stability is a crucial standard for their reliable applications. This paper explores the size effect on the thermo-mechanical behavior of the organic solar cells. An effective isogeometric analysis method combined with modified couple stress theory is presented. The thermo-mechanical buckling load-bearing capacities of the organic solar cells subjected to various in-plane loadings, temperatures, and geometrical parameters are discussed. Numerical results show that the size effect has significant effect on the thermo-mechanical load-bearing capacity. The stability region changes minimally when the material length scale parameter \(l\) to cell thickness \(h\) ratio is less than 0.2, while the stability region increases remarkably when it is larger than 0.2. Notably, if the material length scale parameter increases to its thickness, the stability region increased almost 25 times than that without size effect. Furthermore, the stability region is narrowest if the temperature is uniform across the thickness direction of the cell.
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Electrical power generation is changing dramatically across the world because of the need to reduce greenhouse gas emissions and to introduce mixed energy sources. The power network faces great challenges in transmission and distribution to meet demand with unpredictable daily and seasonal variations. Electrical Energy Storage (EES) is recognized as underpinning technologies to have great potential in meeting these challenges, whereby energy is stored in a certain state, according to the technology used, and is converted to electrical energy when needed. However, the wide variety of options and complex characteristic matrices make it difficult to appraise a specific EES technology for a particular application. This paper intends to mitigate this problem by providing a comprehensive and clear picture of the state-of-the-art technologies available, and where they would be suited for integration into a power generation and distribution system. The paper starts with an overview of the operation principles, technical and economic performance features and the current research and development of important EES technologies, sorted into six main categories based on the types of energy stored. Following this, a comprehensive comparison and an application potential analysis of the reviewed technologies are presented.
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Feed-in-Tariff (FiT) mechanisms have been important in boosting renewable energy, by providing a long-term guaranteed subsidy of the kWh-price, thus mitigating investment risks and enhancing the contribution of sustainable electricity. By ongoing PV development, the contribution of solar power increases exponentially. Within this significant potential, it is important for investors, operators, and scientists alike to provide answers to different questions related to subsidies, PV efficiencies and costs. The present paper therefore (i) briefly reviews the mechanisms, advantages, and evolution of FiT; (ii) describes the developments of PV, (iii) applies a comprehensive literature-based model for the solar irradiation to predict the PV solar energy potential in some target European countries, whilst comparing output predictions with the monthly measured electricity generation of a 57 m² photovoltaic system (Belgium); and finally (iv) predicts the levelized cost of energy (LCOE) in terms of investment and efficiency, providing LCOE values between 0.149 and 0.313 €/kWh, as function of the overall process efficiency and cost. The findings clearly demonstrate the potential of PV energy in Europe, where FiT can be considerably reduced or even be eliminated in the near future.
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Current efforts to improve electricity services in Uganda evolve around satisfying growing urban demand as well as stabilizing and boosting a low electricity supply. Although virtually non-existent, rural electrification is receiving very little attention. This paper investigates the potential of wood-based biopower fueled from coppicing shrubs on its feasibility to provide affordable basic electricity services to rural Ugandan households. Gasification was the specific technology we assessed. In the calculations, a worst case scenario was chosen for wood-based biopower to compete with alternative sources of electricity: Cost and land use estimates assumed a rather high household consumption (30 kWh/month), a low household size (8 persons), a low area productivity (3 oven-dried tons per ha per year), a low electrical conversion efficiency (15%) and a high demand competing for fertile land with the biopower system. Cost estimates considered a high biomass price (18.5 US$/odt), a low capacity factor for the biopower system of 0.5 (therefore requiring installation of a larger unit) and high capital costs of 2300 US$ per kW installed. Additional pressure on fertile land would be negligible. Such biopower systems can outcompete other sources of electricity from a micro and macro-economic standpoint when looking at the local scale. Results indicate that biopower can deliver better and more energy services at 47 US$/yr and household or 0.11 US$/kWh which is below current average costs for e.g. off-grid lighting in rural Ugandan households. Additionally, only this biopower option offers the ability to households, sell wood to the biopower system and contribute at least four times as much to the local economy than the other electricity options used as terms of comparison. Further research has to focus on developing business plans and loan schemes for such biopower options including sustainable fuelwood supply chains based on coppicing shrubs which have the ability to contribute to agricultural site improvements. The approach outlined in this paper can further serve as a general framework to compare different options of electricity production across technologies and fuel sources especially for rural development purposes incorporating a multitude of aspects. [ Full text available at: http://bit.ly/ZXtFug ]
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It is usually mentioned that renewable energy sources (RES) have a large potential to contribute to the sustainable development of specific territories by providing them with a wide variety of socioeconomic benefits, including diversification of energy supply, enhanced regional and rural development opportunities, creation of a domestic industry and employment opportunities. The analysis of these benefits has usually been too general (i.e., mostly at the national level) and a focus on the regional and especially the local level has been lacking. This paper empirically analyses those benefits, by applying a conceptual and methodological framework previously developed by the authors to three renewable energy technologies in three different places in Spain. With the help of case studies, the paper shows that the contribution of RES to the economic and social dimensions of sustainable development might be significant. Particularly important is employment creation in these areas. Although, in absolute terms, the number of jobs created may not be high, it may be so with respect to the existing jobs in the areas considered. Socioeconomic benefits depend on several factors, and not only on the type of renewable energy, as has usually been mentioned. The specific socioeconomic features of the territories, including the productive structure of the area, the relationships between the stakeholders and the involvement of the local actors in the renewable energy project may play a relevant role in this regard. Furthermore, other local (socioeconomic) sustainability aspects beyond employment creation should be considered.
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Renewable energy sources and technologies have potential to provide solutions to the long-standing energy problems being faced by the developing countries. The renewable energy sources like wind energy, solar energy, geothermal energy, ocean energy, biomass energy and fuel cell technology can be used to overcome energy shortage in India. To meet the energy requirement for such a fast growing economy, India will require an assured supply of 3–4 times more energy than the total energy consumed today. The renewable energy is one of the options to meet this requirement. Today, renewable account for about 33% of India's primary energy consumptions. India is increasingly adopting responsible renewable energy techniques and taking positive steps towards carbon emissions, cleaning the air and ensuring a more sustainable future. In India, from the last two and half decades there has been a vigorous pursuit of activities relating to research, development, demonstration, production and application of a variety of renewable energy technologies for use in different sectors. In this paper, efforts have been made to summarize the availability, current status, major achievements and future potentials of renewable energy options in India. This paper also assesses specific policy interventions for overcoming the barriers and enhancing deployment of renewables for the future.
Chapter
Every cell in the body contains ion channels. These ion channels are proteins embedded in the cell membrane and regulate the electrical signaling of each cell via egress and ingress of various intracellular and extracellular ions (predominantly Na+, K+, Ca2+ and Cl−). Defects to the genes encoding ion channel proteins result in the impairment of the functional properties of the ion channels.
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In this paper, the feasibility of generating electricity from EGS (enhanced geothermal systems) by oilfield produced water circulating through reservoir stimulated by staged fracturing technology for horizontal wells is investigated based on the geological data of Xujiaweizi area, located in the Daqing Oilfield, northeast China. HDR (hot dry rock) resource potential assessment is carried out by using volumetric method. Reservoir stimulation is numerically simulated based on the geological data of well YS-1 and field fracturing experience in this region. Geometric dimensions and flow conductivity of the resulting fracture are imported into the hydro-thermal model to calculate the electricity generation potential of the proposed EGS power plant. An EGS design scheme is proposed based on the simulation results. The system is also evaluated from the economic and environmental aspects. The results indicate that HDR resource in Xujiaweizi area is of great potential for development. Through the staged fracturing technology for horizontal wells, electricity generation power of the proposed EGS project can roughly meet the commercial standard. For 20 years of continuous production, power generation from the proposed EGS power plant is economic feasible. Meanwhile, significant reductions in greenhouse gas emissions can be achieved.
Article
With the rapid growth of wind energy development and increasing wind power penetration level, it will be a big challenge to operate the power system with high wind power penetration securely and reliably due to the inherent variability and uncertainty of wind power. With the flexible charging-discharging characteristics, Energy Storage System (ESS) is considered as an effective tool to enhance the flexibility and controllability not only of a specific wind farm, but also of the entire grid. This paper reviews the state of the art of the ESS technologies for wind power integration support from different aspects. Firstly, the modern ESS technologies and their potential applications for wind power integration support are introduced. Secondly, the planning problem in relation to the ESS application for wind power integration is reviewed, including the selection of the ESS type, and the optimal sizing and siting of the ESS. Finally, the proposed operation and control strategies of the ESS for different application purposes in relation to the wind power integration support are summarized. The conclusion is drawn in the end.
Article
Concentrated solar power plants (CSPs) are gaining increasing interest, mostly as parabolic trough collectors (PTC) or solar tower collectors (STC). Notwithstanding CSP benefits, the daily and monthly variation of the solar irradiation flux is a main drawback. Despite the approximate match between hours of the day where solar radiation and energy demand peak, CSPs experience short term variations on cloudy days and cannot provide energy during night hours unless incorporating thermal energy storage (TES) and/or backup systems (BS) to operate continuously. To determine the optimum design and operation of the CSP throughout the year, whilst defining the required TES and/or BS, an accurate estimation of the daily solar irradiation is needed. Local solar irradiation data are mostly only available as monthly averages, and a predictive conversion into hourly data and direct irradiation is needed to provide a more accurate input into the CSP design. The paper (i) briefly reviews CSP technologies and STC advantages; (ii) presents a methodology to predict hourly beam (direct) irradiation from available monthly averages, based upon combined previous literature findings and available meteorological data; (iii) illustrates predictions for different selected STC locations; and finally (iv) describes the use of the predictions in simulating the required plant configuration of an optimum STC. The methodology and results demonstrate the potential of CSPs in general, whilst also defining the design background of STC plants.
Article
This paper reviews the scientific production of renewable energies, namely, solar, wind, biomass, hydropower and geothermal, from 1979 to 2009. The production of all the countries in the world is analysed, paying particular attention to renewable energies and research institutions. The production of scientific research for each type of energy is represented on world maps to show the degree of relationship between this research and the resources of these energies. It is observed that biomass is the most studied, both by number of publications, with 56% of the publications on renewable energy, and by geographical distribution. The next in importance by number of publications is solar energy (26%). The countries investigating solar energy, however, are not necessarily those with the greatest availability of this resource. Wind is the third positioned in publication (11%). Wind is being investigated by countries that most have implemented this type of energy production. Hydro and geothermal energies are also investigated by countries with great abundance of this resource. It is observed that research on renewable energy is highly concentrated in a few countries (12 or 14, depending on the energy type), accounting for between 70 and 80% of scientific production. The role of the USA as a leader in research in all renewable energies studies is emphasised. NASA is the leading institution for solar and wind energy, the Chinese Academy of Sciences leads in hydropower and biomass, and the U.S. Geological Survey leads in geothermal energy.
Article
Recent success in the installation of renewable energy is largely due to public financial incentives. Data reported in this article show the incessant growth of renewable energy implementation and the key process for achieving the complete replacement of mixed electric generation in the European Union; specifically, this paper focuses on the case of Spain.These data also emphasize the creation of skilled jobs is taking place and the source of economic growth that renewable energy will promote.The potential for solar and wind energy in Spain, if exploited efficiently [1], will result in energy independence and protection against negative environmental effects.
Article
Considering that the major part of greenhouse gases is carbon dioxide, there is a global concern aimed at reducing carbon emissions. In addition, major consumer countries are looking for alternative sources of energy to avoid the impact of higher fossil fuel prices and political instability in the major energy supplying countries. In this regard, different policies could be applied to reduce carbon emissions, such as enhancing renewable energy deployment and encouraging technological innovation and the creation of green jobs. This study compares three main support mechanisms employed by governments to finance renewable energy development programs: feed-in-tariffs, tax incentives, and tradable green certificates. Considering that many of the promising technologies to deploy renewable energy require investment in small-scale energy production systems, these mechanisms could be used to enhance renewable energy development at the desired scale. Employing a carbon emission tax or emission trading mechanism could be considered ideal policies to mitigate emissions at the lowest cost. The comparison of feed-in-tariffs and renewable portfolio standard policies showed that the former is good when a policy to develop renewable energy sources with a low level of risk for investors is considered. However, the latter is an appropriate policy when a market view policy is applied by the government. Finally, considering technological progress and the cost reduction for power generation by renewable energy sources, we suggest that support mechanism policies should be reconsidered from the financial point of view.
Article
In this work, the feasibility of using enhanced geothermal system correlation techniques (hydraulic fracturing and heat extraction) to develop medium–low temperature geothermal resources for heating purposes in northeast China is investigated. A detailed experiment on field hydraulic fracturing stimulation is conducted. Combining with numerical simulation approaches, heat production potential of this system is forecasted. Field hydraulic stimulation results indicate that the matrix acidizing treatment significantly limits near wellbore friction loss. For network fracturing treatment, however, the formation of branching fractures and its enhancing effects on reservoir flow conductivity needs to be verified by production tests in the future. The geometric dimension and flow conductivity of the induced fracture are determined by numerical simulation of hydraulic fracturing process. The accuracy of the numerical model is verified through matching well head pressure curve. Parameters including production flow rate, flow impedance, production temperature, heat extraction rate and energy efficiency are determined through the simulation results of heat production forecast. The results indicate that thermal energy production from the stimulated reservoir is satisfactory for heating purpose. However, water flow impedance maintains at a relative high level during production period.
Article
In the Republic of Croatia there is some medium temperature geothermal fields (between 100 and 180 °C) by means of which it is possible to produce electricity. However, only recently concrete initiatives for the construction of geothermal power plants have been started. In previous papers, the possible cycles for geothermal fields in the Republic of Croatia are proposed: ORC (Organic Rankine Cycle) and Kalina cycle. Also for the most prospective geothermal fields, energy and exergy analysis for the proposed cycles are performed, on the basis of which the most suitable cycle is proposed. It is ORC which in all cases has better both the thermal efficiency (the First Law efficiency) and the exergy efficiency (the Second Law efficiency). With aim to further improving of geothermal energy utilization in this paper the replacement of a basic ORC with a dual-pressure ORC is analysed. A dual-pressure cycle reduces the thermodynamic losses incurred in the geothermal water-working fluid heat exchangers of the basic ORC, which arise through the heat transfer process across a large temperature difference. The dual-pressure cycle maintains a closer match between the geothermal water cooling curve and the working fluid heating/boiling curve and these losses can be reduced. Now, on the example of the most prospective geothermal field, Velika Ciglena (175 °C), energy and exergy analysis for the proposed the dual-pressure cycle are performed. As a conclusion, in case of Geothermal Power Plant Velika Ciglena, a dual-pressure ORC has slightly lower thermal efficiency (13.96% vs. 14.1%) but considerably higher both exergy efficiency (65% vs. 52%) and net power (6371 kW vs. 5270 kW).
Article
A significant percentage of the global energy demand is expected to be met through widespread supply of renewable electricity in the near future. However, renewable energy outputs are variable due to a stochastic characteristic of their sources. Electrical power system operators around the world are faced with difficulties of integrating these variable power sources into the existing power grids. Energy storage systems are one of the possible solutions for mitigating the effects of intermittent renewable resources on networks, allowing increased renewable energy utilization, and providing flexibility and ancillary services for managing future electricity supply/demand challenges. This paper presents a comprehensive review of energy storage technologies that are currently engaged for power applications, including pumped hydro, compressed-air, battery, flywheel, capacitor, supercapacitor, superconducting magnetic and thermal systems. The study compares the characteristics of these systems, and presents their technological development status and capital costs. Some directions for future work are also highlighted. Furthermore, particular attention is paid to some new storage technologies such as: adiabatic, underwater, isothermal and small-scale compressed-air; sub-surface, seawater and variable-speed pumped hydro, and pumped heat systems, which hold opportunity for future smart electrical grid applications, but there is need for more research to actualize their promising potentials.
Article
The first and a crucial step in development of tidal power, which is now attracting more and more attention worldwide, is a reliable survey of temporal and spatial distribution of tidal energy along coastlines. This paper first reviews the advance in assessment of tidal energy, in particular marine hydrokinetic (MHK) energy, and discusses involved challenges and necessary approaches, and then it makes a thorough survey as an illustrative case study on distributions and top sites of MHK energy within the Might-Atlantic-Bight (MAB) with emphasis on the New Jersey (NJ) coastlines. In view of the needs in actual development of tidal power generation and sensitivity of tidal power to flow speed, the former being proportional to the third power of the latter, a high-resolution and detailed modeling is desired. Data with best available accuracy for coastlines, bathymetry, tributaries, etc. are used, meshes as fine as 20 m and less for the whole NJ coast are generated, and the unstructured grid finite volume coastal ocean model (FVCOM) and high performance computing (HPC) facilities are employed. Besides comparison with observation data, a series of numerical tests have been made to ensure reliability of the modeling results. A detailed tidal energy distribution and a list of top sites for tidal power are presented. It is shown that indeed sea-level-rise (SLR) affects the tidal energy distribution significantly. With SLR of 0.5 m and 1 m, tidal energy in NJ coastal waters increases by 21% and 43%, respectively, and the number of the top sties tends to decrease along the barrier islands facing the Atlantic Ocean and increase in the Delaware Bay and the Delaware River. On the basis of these results, further discussions are made on future development for accurate assessment of tidal energy.
Article
The aim of the present study is to apply an artificial neural network method for daily, weekly, and monthly wind speed predictions in some parts of the Aegean and Marmara region of Turkey that demonstrate acceptable cross-correlations. The wind data taken with an interval of one hour were measured by the General Directorate of Electrical Power Resources Survey Administration at four different measuring stations, namely, Gökçeada, Foca, Gelibolu, and Bababurnu. The wind speeds of three different stations were used as input neurons, while the wind speed of the target station was used as an output neuron in the artificial neural network architecture. The results obtained with this model were compared with the measured data. Errors obtained in this model are within acceptable limits. Results show that the artificial neural network method can successfully predict the daily, weekly, and monthly wind speed of any target station using the measured data of surrounding stations.
Article
Renewable energies Iran Power plant Solar energy Biomass and biogas Fuel cell and hydrogen Geothermal energy a b s t r a c t Iran as a major oil producing country has increasingly paid attention to the non-fossil energy resources, in particular to renewable energy sources for its longer term energy plans. In this regard, 11 projects pertaining to solar energy are being utilized or carried out by Iran's Ministry of Energy. The total photovoltaic power installed in 2004 was 14,020 MW. This rate reached 67 MW by the end of 2010. Further, two geothermal projects are being constructed in Ardabil Province at present. By the end of 2010, the Meshkinshahr geothermal power plant project revealed a progress rate equal to 50%. Similarly, the package construction project in Ardabil revealed a 32% progress. Due to financial hardship in the Fourth Development Program, the completion of these projects was extended to the end of the Fifth Development Program. The nameplate power of biogas power plants in Iran is 1.860 MW the total installed capacity is 1.665 MW. According to Strategy Document of Fuel Cell Technology Development (Approved by the government in 2004), Iran has revealed good progress in fuel cell projects. Private sectors have already signed contracts to build more than 600 MW of biomass systems and 500 MW of new wind energy developments. The nominal power of the wind parks that can be erected in the available sites with remarkable wind potential in Iran is approximately 6500 MW, employing wind turbines of 60,000 MW nominal power. The estimated mean annual capacity factor of these wind parks is 33%.
Article
The conversion efficiency of geothermal power developments is generally lower than that of all conventional thermal power plants. Confusion can be found in literature concerning the estimation of this conversion efficiency. Geothermal power plants conversion efficiency estimates that is based on the enthalpy of the produced geothermal fluid can be the most desirable for use during the first estimates of power potential of new wells and for resource estimation studies. The overall conversion efficiency is affected by many parameters including the power plant design (single or double flash, triple flash, dry steam, binary, or hybrid system), size, gas content, dissolved minerals content, parasitic load, ambient conditions and other parameters. This work is a worldwide review using published data from 94 geothermal plants (6 dry-steam, 34 single flash, 18 double flash, 31 binary, 2 hybrid steam-binary and 1 triple flash plant) to find conversion efficiencies based on the reservoir enthalpy. The highest reported conversion efficiency is approximately 21% at the Darajat vapour-dominated system, with a worldwide efficiency average of around 12%. The use of binary plants in low-enthalpy resources has allowed the use of energy from fluid with enthalpy as low as 306 kJ/kg, resulting in a net conversion efficiency of about 1%. A generic geothermal power conversion relation was developed based on the total produced enthalpy. Three more specific correlations are presented for single flash/dry steam plants, double flash plants and binary plants. The conversion efficiency of binary plants has the lowest confidence, mainly because of the common use of air cooling which is highly affected by local and seasonal changes in ambient temperatures.
Article
Global exploitation of renewable energy technologies is increasing rapidly due to the concern in global warming and dwindling supplies of fossil fuels. Most of the countries in the world are blessed with two or more renewable energy sources (RES) and hence have formulated policies to boost the utilization of RES for their electricity production. An assessment of renewable electricity scenario is essential for research and development related works in the field of renewable energy technologies in order to further develop the renewable energy industry. Recent developments in installation capacities, costs and reductions in electricity costs of major RES based electricity generation methods are discussed in this paper. It also includes the past growth and future expectations of renewable electricity production. The analysis shows that if the current developments in renewable industry continue, then a major share of global electricity production in the future could be supplied by renewable energy technologies. The analysis further shows that a significant amount of fuel cost and pollutants emission can be reduced by the increased use of RES based electrical power production technologies.
Article
The global demand for energy is currently growing beyond the limits of installable generation capacity. To meet future energy demands efficiently, energy security and reliability must be improved and alternative energy sources must be investigated aggressively. An effective energy solution should be able to address long-term issues by utilizing alternative and renewable energy sources. Of the many available renewable sources of energy, solar energy is clearly a promising option as it is extensively available. Solar power, especially as it reaches more competitive levels with other energy sources in terms of cost, may serve to sustain the lives of millions of underprivileged people in developing countries. Furthermore, solar energy devices can benefit the environment and economy of developing countries. This paper illustrates the need for the utilization of alternative energy sources, evaluates the global scenario of installed generation systems, reviews technologies underlying various solar powered devices, and discusses several applications and challenges in this area. In addition, this paper addresses the costs of deployment, maintenance, and operation, as well as economic policies that promote installation of solar energy systems.
Article
In Turkey, there is a much more potential for renewables, but represent about 37% of total energy production and 10% of total energy consumption. This share is not enough for the country and the governments should be increase to this situation. Renewable energy technologies of wind, biomass, hydropower, geothermal, solar thermal and photovoltaics are finally showing maturity and the ultimate promise of cost competitiveness. With respect to global environmental issues, Turkey's carbon dioxide emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Certain policy interventions could have a dramatic impact on shaping the relationship between geological, geographic and climatic conditions and energy production. This study shows that there is enough renewable energy potential in Turkey for fuels and electricity. Especially hydropower and biomass are very well.
Article
Fossil fuels cover most of the energy demand in the world, and this creates significant social, economic and environmental problems. Many countries have taken measures to increase the share of renewable energy sources (RES), especially in electricity generation, and the review of literature shows that the success of a country in RES diffusion depends on a comprehensive renewable energy policy which combines political commitment with stable and long-term support measures that stimulate technological innovation. As the largest economy in the world, EU has also taken steps to increase RES usage in electricity generation in member states. Similar to other developing countries, Turkey is learning lessons from EU experiences regarding RES policies, and Turkey is also reforming its legal framework in line with acquis communautaire as a candidate country. As a result, EU has a multiway impact on Turkey's renewable energy policy. An overview of Turkey's renewable energy policy showed that EU has significantly contributed to Turkey in shaping its renewable energy policy, and Turkey should increase cooperation with EU in order to utilize its renewable energy potential.
Article
Since the energy crises in the 1970’s, public and private decision makers are considering how to achieve a sustainable transition from fossil fuel based energy to sustainable and clean energies – namely renewable energies. Combined with the improvement of energy efficiency and the rational use of energy, renewable energy can provide everything fossil fuels currently offer in terms of heating and cooling, electricity generation and transportation. Renewable energy technologies posses many long term benefits including energy security, job creation, business opportunities, sustainable development and prevention of global warming.Turkey’s population is growing at an annual rate of 1.04%. If Turkey uses only traditional energy sources, it simply will not have enough energy capacity for its population. Renewable energy sources have the potential to make a large contribution to Turkey’s sustainable and independent energy future.Turkey aims to utilize its energy potential, including from renewable sources in a cost-effective manner. Turkey targets the share of renewable resources in electricity generation to be at least 30% by 2023 has in its 2009 Electricity Market and Security of Supply Strategy. Positive achievements have been obtained in renewable energy development and manufacturing in Turkey over the past decade. The renewable energy related legislation has been intensified. To meet its 30% target, the current promotion mechanism for renewable sources of electricity relies on feed-in tariffs for different renewable energy sources. Large hydropower is already competitive to conventional fossil-based electricity, so feed-in tariffs in the new RE Law are set to facilitate expanding the deployment of other, less mature renewable energy technologies.
Article
The necessity of minimizing environmental impacts of energy use, particularly those with potentially worrisome global effects, is perhaps the greatest challenge resulting from the twentieth century's energy advances. The renewable energy technologies of wind, biofuels, solar thermal and photovoltaics are finally showing maturity and the ultimate promise of cost competitiveness. Turkey's demand for energy and electricity is increasing rapidly and heavily dependent on expensive imported fossil energy resources that place a big burden on the economy and environmental pollution is becoming an important concern in the country. With respect to global environmental issues, Turkey's carbon dioxide emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. This study shows that there is huge potential for renewable energy in Turkey, especially hydropower, biomass, geothermal, solar and wind.
Article
Thermal energy storage is an expanding field within the subject of renewable energy technologies. After a listing of the different possibilities available for energy storage, this paper provides a comparison of various materials for High Temperature Thermal Energy Storage (HTTS). Several attributes and needs of each solution are listed. One in particular is using the latent heat as one of the most efficient ways to store thermal energy. The mixture of phase change material (PCM) embedded in a metal foam is optimising the thermal properties of the material for latent heat energy storage. The results of previous studies show that mechanical and thermal properties of foam were extensively studied separately. This paper highlights the potential for an advanced study of thermo-mechanical properties of metal foams embedded with PCM.
Article
Thermal applications are drawing increasing attention in the solar energy research field, due to their high performance in energy storage density and energy conversion efficiency. In these applications, solar collectors and thermal energy storage systems are the two core components. This paper focuses on the latest developments and advances in solar thermal applications, providing a review of solar collectors and thermal energy storage systems. Various types of solar collectors are reviewed and discussed, including both non-concentrating collectors (low temperature applications) and concentrating collectors (high temperature applications). These are studied in terms of optical optimisation, heat loss reduction, heat recuperation enhancement and different sun-tracking mechanisms. Various types of thermal energy storage systems are also reviewed and discussed, including sensible heat storage, latent heat storage, chemical storage and cascaded storage. They are studied in terms of design criteria, material selection and different heat transfer enhancement technologies. Last but not least, existing and future solar power stations are overviewed.
Article
A looming energy supply crisis in sub-Saharan Africa (SSA) raises concerns about a long-lasting energy shortage. This energy crisis is expected to persist for an indefinite period in the region unless immediate actions are taken to reverse the trend. Although global aspiration to reduce greenhouse gas (GHG) emissions into the atmosphere is high, such desire is low in SSA. Regional stakeholders are more worried about increasing power generation capacity to enhance better access to different sorts of development. To progress in line with advanced patterns of energy development globally, to increase the availability of electrical energy and to sustain emissions reductions, exploitation of local renewable energy (RE) resources is inevitable. Consequently, this paper presents a comprehensive review of RE integration for expanding access to electricity in SSA. The review covers the sustainability of RE resources in SSA, the regional status of RE applications and the necessity of RE power generation integration planning from a management aspect. Finally, the benefits of RE integration into the power sector of SSA and some conceptual challenges affecting its integration in the region are highlighted.
Article
In Turkey, where there is no nuclear power, electricity is generated from the thermal, hydro, wind and geothermal power plants. While the installed capacity of Turkey's electric power plants was 4,187 MW in 1975, it increased to 40,777 MW in 2007. For the total installed capacity of 40,777 MW, the share of wind power plants is only 0.36%. On the other hand, Turkey has the highest share of technical wind energy potential in Europe. It is estimated that Turkey's technical wind energy potential is around 83,000 MW; the economica potential is approximately 10,000 MW. But, by the end of November 2008, the installed wind capacity of Turkey was only 3.33% of Turkey's total economical wind potential. The strong development of wind energy in Turkey is expected to continue in the coming years. In this article, wind energy potential and wind power installations in Turkey are investigated in detail.
Article
The paper explores the biomass based power generation potential of Africa. Access to electricity in sub-Saharan Africa (SSA) is about 26% and falls to less than 1% in the rural areas. On the basis of the agricultural and forest produce of this region, the residues generated after processing are estimated for all the countries. The paper also addresses the use of gasification technology – an efficient thermo-chemical process for distributed power generation – either to replace fossil fuel in an existing diesel engine based power generation system or to generate electricity using a gas engine. This approach enables the implementation of electrification programs in the rural sector and gives access to grid quality power. This study estimates power generation potential at about 5000MW and 10,000MW by using 30% of residues generated during agro processing and 10% of forest residues from the wood processing industry, respectively. A power generation potential of 15000MW could generate 100terawatt-hours (TWh), about 15% of current generation in SSA. The paper also summarizes some of the experience in using the biomass gasification technology for power generation in Africa and India. The paper also highlights the techno economics and key barriers to promotion of biomass energy in sub-Saharan Africa.
Article
In this study, wind energy density in the southern and southwestern region of Turkey was investigated by using the Weibull and Rayleigh probability density functions, and the wind atlas analysis and application program (WAsP). Hourly wind speeds and directions collected by the General Directorate of Electrical Power Resources Survey Administration were used. Before the construction of the wind turbine generator in these locations, several fundamental properties of the site such as wind behavior, availability, continuity, and probability should be carried out in order to provide the necessary information to the potential investors about cost and economical aspects of planning the wind energy project. The dominant wind direction, probability distribution, Weibull parameters, mean wind speed and power potential of all stations were determined by the Weibull and Rayleigh models, and the WAsP program. The results obtained with these models were compared with the measured data. Finally, it is found that these regions have a reasonable wind power potential and they are suitable for planting wind energy turbines. However, Belen is the most promising and convenient site for production of electricity from wind power.
Article
The current world status of geothermal electricity production, including installed capacities, number of units and energy produced by exploitation technology, is presented in this paper. Four geothermal model plants based on different modes of high enthalpy technologies are analyzed from energy, environmental and economic points of view for specific reservoir characteristics. Once process parameters are optimized for the best plant operation, a cost and financial analysis is performed within a given economic frame. This analysis shows that Dry Steam power plants are the most efficient. Flash steam power plants increase their exergy efficiency with increasing reservoir temperature. Double Flash technology raises the energy produced with respect to Single Flash between 17 and 25%, and economic parameters become better. An additional third flash process increases power production by 10%, but economic parameters are not improved unless a reservoir of very high temperatures is considered. The energy and economic study conclude that the choice of the best flash technology depends on the resource characteristics, the financial frame and the technology costs.Highlights► Four high enthalpy geothermal power model plants are defined and analyzed. ► Double flash technology raises energy produced respect Single Flash between 17 and 25%. ► An additional third flash process increases power production in 10%. ► Double flash technology improves economic parameters, but Triple Flash do not necessary improve them any more.
Article
The development of wind power installations globally and in Turkey is reviewed here. Firstly, the growth of global installed wind power capacity between 1996 and 2007 is reviewed, and the top countries in terms of total installed wind power capacity by region are identified. Then, wind power installation and its development in Europe are discussed. In addition, the current status and development of Turkey's wind power plants are investigated in detail.
Article
a b s t r a c t Today, there are 1.4 billion people around the world that lack access to electricity, some 85% of them in rural areas. Without additional dedicated policies, by 2030 the number of people drops, but only to 1.2 billion. Some 15% of the world's population still lack access, the majority of them living in Sub-Saharan Africa. The number of people relying on the traditional use of biomass is projected to rise from 2.7 billion today to 2.8 billion in 2030. Addressing these inequities depends upon international recognition that the projected situation is intolerable, a commitment to effect the necessary change, and setting targets and indicators to monitor progress. A new financial, institutional and technological framework is required, as is capacity building in order to dramatically scale up access to modern energy services at the local and regional levels. In this paper, we discussed the energy situation of the developing countries for sustainable development.
Article
Global environmental concerns and the escalating demand for energy, coupled with steady progress in renewable energy technologies, are opening up new opportunities for utilization of renewable energy resources. Solar energy is the most abundant, inexhaustible and clean of all the renewable energy resources till date. The power from sun intercepted by the earth is about 1.8 x 1011 MW, which is many times larger than the present rate of all the energy consumption. Photovoltaic technology is one of the finest ways to harness the solar power. This paper reviews the photovoltaic technology, its power generating capability, the different existing light absorbing materials used, its environmental aspect coupled with a variety of its applications. The different existing performance and reliability evaluation models, sizing and control, grid connection and distribution have also been discussed.
Article
The objective of this paper is to briefly review the state-of-the-art in the harnessing of marine energy and study the positions and features of the boundary and domestic seas and lakes of Iran from energy point of view and the possibility of using these energy resources. Generally, the energy potentials in the seas and oceans are classified in five groups: wave energy, tidal energy, ocean thermal energy, ocean current energy, and salinity gradient energy. Due to the variety of Iran's bodies of water, other than ocean current energy, it is possible to use the rest of these energy resources. Each body of water of Iran is suitable for a specific kind of marine energy. There are great sources of tidal energy in the Persian Gulf coasts. For thermal energy, the ideal sites are located in the Caspian Sea coasts, and wave energy can economically be extracted in the Gulf of Oman coasts as well as in remote islands which are off-grid. Finally, Urmia Lake is the best location for salinity gradient energy. This study shows that more investment is required in this area for research and small scale pilot plants in order to exploit such renewable resources.
Article
Renewable technologies are considered as clean sources of energy and optimal use of these resources minimize environmental impacts, produce minimum secondary wastes and are sustainable based on current and future economic and social societal needs. Sun is the source of all energies. The primary forms of solar energy are heat and light. Sunlight and heat are transformed and absorbed by the environment in a multitude of ways. Some of these transformations result in renewable energy flows such as biomass and wind energy. Renewable energy technologies provide an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting conventional energy sources. In this article a review has been done on scope of CO2 mitigation through solar cooker, water heater, dryer, biofuel, improved cookstoves and by hydrogen.