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Considering sustainable development, technology selection is a multi-criteria decision-making (MCDM) problem that influences the advantages of enterprises or a country. This paper investigates existing wave energy technologies as alternatives to green and sustainable technologies to apply them in the seas and oceans. A framework is presented, and major technologies to extract wave energy are identified. Each technology has been examined in scopes of strategic factors, availability, technical knowledge, technological features, economic, social, and environmental factors as the main criteria. Totally, 20 converters and 52 criteria are considered. The Caspian Sea is considered as a case, and a decision matrix is established by integrating the gathered data and the experts' opinions. By integrating the fuzzy Delphi method (FDM) and preference ranking organization method for enrichment evaluations (PROMETHEE) method, Pelamis is considered the most appropriate technology to harvest wave energy in the Caspian Sea. [ABSTRACT FROM AUTHOR]

Cyber–physical systems (CPSs) are confronted with major problems, such as high proportions of renewable energy penetration and frequent extreme events, which severely restrict the stability of power systems. The key to solve these problems is the construction of a resilient power system. This study expounds on the development background and current situation of resilient CPSs from the perspectives of emerging technology and appropriate energy policy. Based on the foregoing, the importance of modeling in resilience research is highlighted, and the selection principles of different modeling methods are discussed. In addition, the optimal control strategies and methods applied to respond to extreme events in a three–stage power system are summarized, highlighting the application of optimal control strategies or emerging technologies for investigating simulations and actual systems. The study also focuses on the current development status of renewable energy and how variable renewable energy can reinforce power system resilience. Finally, in view of the gaps in the current CPS research, the key problems that must be resolved by future CPSs are identified. • Each power system link attack is classified and summarized. • Measures for variable renewable energy proportions in resilient CPSs are elaborated. • Rationality and validity of resilient control strategies and methods are studied. • Challenges and future directions of resilient CPSs research are discussed. [ABSTRACT FROM AUTHOR]

Examining the dynamics of technological progress in determining energy intensity not only helps in assessing the relative strength of contributing factors, but also beneficial in designing effective energy policies. The effect of technology on energy intensity was widely discussed, as a whole, without narrowing down to the energy field and considering the technological absorption capacity as well as the heterogeneity. In view of the importance of sustainability in Guangdong province to the Greater Bay Area, this study focused on energy-specific technological progress and investigated the effect of energy-specific technology on energy intensity using a panel dataset covering cities in Guangdong Province for 2005–2017. The empirical evidence shows that energy-specific technology is beneficial in reducing the energy intensity. However, the energy intensity reduction effect is primarily from energy-saving technology rather than the alternative energy technology. From the sources of energy technology, enterprises, rather than from higher education institutions and independent research institutions, are more effective in cutting the energy intensity. In addition, utility-type energy-specific technology shows a stronger reduction effect on energy intensity compared to creation-type. Finally, the study concludes that technological absorption capacity is an important determinant for the effectiveness of energy-specific technology in reducing energy intensity. • Effect of energy-specific technology on energy intensity is investigated particularly. • The total energy-specific technology reduces energy intensity in Guangdong Province significantly. • Reduction effect mainly comes from energy-saving technology of enterprises. • Technological absorption capacity is important to energy intensity mitigation. [ABSTRACT FROM AUTHOR]

A multi-criteria analysis of alternative energy technologies based on sustainable livelihoods framework is presented. A time bound development predicting model derived from a modified heterogenous mean field approach is proposed. The time bound development predicting model and time unbound development predicting model were validated as well as compared. A decision-makers' weighting model for the VIKOR technique was also proposed and compared with the existent weighting models. For the case of Uganda, the results revealed that the development predicting models have statistical errors in the range of 0.2–13.7% when validated with the historical data for human development indices. The multi-criteria analysis revealed that rooftop solar PV is the best-choice technology to implement. By using the time bound development predicting model, development forecasts by the time unbound development predicting model for rooftop solar PV would be achieved between 8.8 and 16.7 years. The study predicts that Uganda would attain a development level of 0.756 in a period of 50 years from its current status of 0.401. The VIKOR technique gap distance recorded statistical errors in the range of 0.64–0.74% when the proposed decision-makers' weighting model was used in comparison to both the interdependent weighting and entropy weighting models. [ABSTRACT FROM AUTHOR]

The development of alternative energy is considered as one of the ways to reduce the environmental pollution and carbon dioxide emissions. In Russia, the current level of development of alternative energy is not high. Russia requires the regulatory mechanisms that would contribute to the development of this energy sector. The objective of the article is to analyze and determine the directions for improving state influence by creating regulatory mechanisms for the development of alternative energy. In this work, the following scientific research methods were used: data analysis, study of statistical data, and analysis of literary sources. The role of alternative energy has been determined since it helps to reduce greenhouse gas emissions and prevent climate change. In the world, this determines the development, considering international agreements and the implementation of the national policies of many states in this regard. Alternative energy has not been sufficiently supported in Russia, many researchers have doubts about the effectiveness of supporting such projects. Prospects for further research are related to further study of the dynamics of the alternative energy development, as well as the study of government decisions in this area. • Alternative energy share in world energy generation has increased significantly. • The largest investor in the development of renewable energy in the world is China. • Most of all the use of renewable energy is in Europe. • In Russia, emissions growth is ahead of generation growth. • Alternative energy is just beginning to develop in Russia. [ABSTRACT FROM AUTHOR]

Sustainable livelihoods approach is progressively being applied in feasibility assessment for implementation of alternative energy technologies in developing countries. In this study, an evaluation model for assessing the sustainable livelihoods capitals, namely, social, natural, financial, physical and human capitals by utilizing interpretive structural modeling approach and MICMAC analysis is proposed. The study's emphasis was centred on evaluating the current status of the community's sustainable livelihoods capitals and predicting the impact of implementing alternative energy technologies on the community's capitals. The proposed model was used for the case of Uganda, a developing country in Sub-Saharan Africa and the modeling results revealed that currently social capital and financial capital at 0.482 and 0.460, respectively, are the most developed sustainable livelihoods capitals in Uganda. The evaluated average value of 0.401 for the predicted current status of capitals by the proposed model is in close agreement with previous studies' findings. Also, of the evaluated alternative energy technologies for implementation in Uganda, rooftop solar PV systems emerged as the best option followed by ground-mounted solar PV systems. The proposed model is replicable and applicable for any location with the utilization of the appropriate datasets of that location under consideration. • Linked interpretive structural model, MICMAC and sustainable livelihoods framework. • Identified key community capitals' enablers and their interdependence. • Implemented the model to assess the alternative energy technologies in Uganda. • Found out that rooftop solar PV is the best alternative energy for Uganda. • Proposed a general model that is replicable and applicable for any location. [ABSTRACT FROM AUTHOR]

The cross-flow turbine is an attractive technology for small-scale hydropower generation thanks to its low capital cost and relatively high efficiency even under partial discharge operating conditions. It has been proposed that this kind of turbine can be manufactured from standard steel pipe sections given its simple geometry, an alternative that would further decrease the turbine's capital cost compared to highly engineered cross-flow designs. This article explores the trade-offs encountered during the design of cross-flow turbines under the constrains imposed by the discrete set of dimensions available for commercial steel pipes. First, the computational model is presented, analyzed in terms of its convergence behavior, and validated with experimental data. Then, a parametric analysis is performed to understand the relative importance of the design variables and their optimum value in regard to the turbine efficiency. Based on the design guidelines derived from the parametric analysis, an example cross-flow turbine design is presented and thoroughly characterized, demonstrating that it is possible to engineer a cross-flow turbine of competitive efficiency out of commercial steel pipes. These guidelines may encourage the use of cross-flow turbines as an appropriate technology for off-grid regions. • A cross-flow turbine design methodology is presented. • The numerical model is characterized and then validated with experimental data. • The influence of the main design parameters on the efficiency is investigated. • Design guidelines and insight are drawn based on the parametric analysis results. • A cross-flow turbine design example is characterized throughout its operating range. [ABSTRACT FROM AUTHOR]

Keeping track of field performance and degradation rate of photovoltaic panels in regions with diverse environmental exposures is critical. The objective of this paper is to determine two and half year performance characteristics and degradation rate of poly-crystalline and heterojunction with intrinsic thin layer roof-top photovoltaic units under prevailing weather conditions in the Central Anatolia region. Degradation rates of the photovoltaic units were determined through analysing the effective peak power, and the temperature corrected performance ratio of each technology. Processing of the measured data covering the test period reveals that the thin film technology offers lower degradation rate with nearly −0.1% than the poly-crystalline based technology within the range of −0.67% to −0.83%, respectively. The study allows a better understanding of variations in performance and behaviour of the output power of poly-crystalline and heterojunction with intrinsic thin layer roof-top photovoltaic units after 2.5 years of outdoor exposure. • Degradation analysis of crystalline PV modules in Turkey is performed. • The p-Si modules demonstrated higher degradation rate. • The HiT modules are distinguished as the well-suited technology for the region. • The assessment procedure seems convenient as performance ratios are corrected. • Findings are beneficial in contemplating climate specific degradation mechanism. [ABSTRACT FROM AUTHOR]

The OBREC is an overtopping structure which is integrated into a traditional rubble-mound breakwater to convert wave energy into electricity. The relatively simple geometry of this overtopping device, with a single frontal ramp and a reservoir, makes the technology suitable to be fully combined also with existing structures. OBREC has been deeply investigated over the last years with physical and numerical model tests, and it is still under development with the ongoing monitoring activities at full-scale in real environments focusing on the wave-OBREC interaction. A comprehensive review of the research studies during the last ten years is here presented. The paper contains some unpublished details on OBREC geometry and power take-off strategy. A special attention is also directed to the description of the full-scale prototype of OBREC at Naples harbour, where an experimental campaign is still continuing. • Innovative rubble mound breakwater for wave energy production. • Physical and numerical model tests. • Formulae for preliminary design. • Full-scale prototype. [ABSTRACT FROM AUTHOR]

Providing power to rural communities, which are far from the grid and suffer from lack of energy access in Africa, especially in Benin, in a sustainable manner requires the adoption of appropriate technology. This paper aims at analysing the techno-economic feasibility of hybrid renewable energy system (HRES) for sustainable rural electrification in Benin, using a case study of Fouay village. HOMER software is used to perform optimization, simulation and sensitivity analysis. The analysis showed that hybrid solar photovoltaics (PV)/diesel generator (DG)/battery (of 150 kW/62.5 kVA/637 kWh) is the least cost optimal system. This system ensures a reliable power supply, reduces battery requirements by 70% compared to PV/battery system and achieves 97% CO 2 emissions reduction compared to a conventional DG. Moreover, the study demonstrated that the most economical HRES depends strongly on the potential energy sources available at a location and power plant's remoteness from the beneficiary. In summary, as solar radiation is an abundant resource across the country, this hybrid PV/DG/battery system can be a suitable model to power remote areas in Benin, and we recommend it for future electrification projects in the country in place of the current widely deployed PV/battery system. • PV/DG/battery is the least costly system with a COE of $0.207/kWh. • HRES (PV/DG/battery) reduces battery storage requirements by 70%. • PV/DG/battery system has a short payback period of 3.45 years and a high IRR of 33.3%. • The robustness of the system is discussed by performing the sensitivity analysis. • Optimised HRES (PV/DG/battery) is economically more viable than grid extension. [ABSTRACT FROM AUTHOR]

The adoption of appropriate waste management strategy has been considered as a lasting solution to part of the environmental problems facing Anambra State of Nigeria. Implementation of spatial information technologies such as Remote Sensing (RS) and Geographic Information System (GIS) in addressing the issue of waste management has been identified as an appropriate technology. The limitations of the use of GIS alone or only location mathematical models in effective suitability analysis has been observed by many researchers, therefore this study adopted the integration of geospatial technology with Set Cover Location Model (SCLM) and facility location allocation modelling as a holistic approach to the problem. The result of the study shows that a minimum of three biogas processing plants is needed to maximally process all the wastes in the study area. The output of the allocation and location model shows that a processing plant with about 5.6 Tons, 1.7 Tons and 57 Tons capacity is best located at Ajali, Ihiala and Abagana towns respectively in the study area. It is recommended that strategic waste management approach as used in this study will be a veritable tool for energy solution in the study area. • Development of suitable waste collection radius based on GIS criteria. • Problem Formulation for Set Cover Location Problem from GIS Data. • Determination of minimum number of biogas plant for the study area. • Location allocation modelling of wastes generation sites to processing sites. • Installation of two small scale and one large scale biogas plant. [ABSTRACT FROM AUTHOR]

In this paper, a case study applied to an animal farm in Iran, covering both technical and economic aspects of biogas production using manure from livestock to replace fossil fuel used for heat and electricity generation is presented. The mentioned farm has 3058 dairy cows. Biogas production followed by small-scale combined heat and power (CHP) units based on a new dual fuel internal combustion engine (ICE) have replaced conventional technology used today, namely electricity from the grid and diesel fuel for heating via boiler technology. Results from the techno-economic studies reveal that alternative technology using biogas as fuel are superior compared to the conventional one, both from economic and environmental point of view. By evaluating the proposed model, the annual cost saving, percentage of system profitability index, and payback period are calculated as 73,159.31 $, 60.99% and 28.5 month, respectively. Replacing the conventional technology by biogas based technology results in 529.65 tons per year annual CO 2 emission reduction for this typical animal farm. Finally, a sensitivity analysis is elaborated in order to show how the profitability of biogas CHP plants would vary due to changes of some key parameters such as prices of diesel fuel, electricity and electricity buyback. [ABSTRACT FROM AUTHOR]

This paper presents the results and lessons learned from four and a half years of implementing low cost tubular digesters in Bolivia. The selection of this technology is justified in comparison with other popular technologies such as fixed dome or floating drum digesters. The highlighted weakness of the tubular model (its short life expectancy), is transformed into a strength, making the low cost tubular digester an appropriate technology for widespread application. The experiences in Bolivia show that the success of biogas programs depend more on socio-economic factors than on the validated technology selected, suggesting that local circumstances are a critical, and often underestimated, factor to be taken into consideration in the praxis. Finally, some testimonies of the use of biol (bio-slurry or effluent) are reported, identifying the high potential of this anaerobic digestion product that provides a food sovereignty approach, reduced expansion of the agricultural frontier, increased agricultural productivity and hence family income, that other household energizing systems do not have. A brief report of lessons learned is also included. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports author’s experiences of technical assistance for developing countries. The authors proposed a curved-plate bladed rotors based on the design concept of an appropriate technology. From the wind tunnel test, the highest power coefficients both 3-bladed and 5-bladed rotors are around 0.35 as the same value for high performance solid propeller type bladed rotor. Thus, the proposed curved-plate bladed rotors will have good prospect not only for developing countries, but also for educational materials. [Copyright &y& Elsevier]