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Renewable energy development and more specifically Wind Farm (WF) installation has been increased during the last years by most countries. A discipline that has been studied thoroughly is the impact of wind turbines on installation locations, during energy production or at the end of their life. Citizens' attitudes, social and environmental factors are among the criteria affecting the selection of WFs installation locations. Various machine learning tools have been used in order to analyze the allocation of the Renewable Energy Systems (RES). In this paper a methodology based on computational geometry and Geographical Information Systems (GIS) is proposed in order to cluster the locations of Wind Turbines (WT) and define the boundaries of the areas that are affected by them. Delaunay Triangulation is selected as the main algorithm, since it is appropriate for handling geospatial data and it uses a geometric approach. Furthermore, algorithms based on graph theory are proposed in order to improve the efficiency of the methodology. The proposed methodology was implemented in locations of WTs in Greece and was compared to other known clustering algorithms. It was found that the locations of WTs in Greece are separated into 158 clusters. Some characteristics of the areas defined by the clusters, such as the distance from the protected areas, the distance from the closest airport and the number of residential areas that are within them, were computed and it was shown that these areas can be separated into 4 groups. The application aims to help policy makers to improve the effectiveness of their decisions by understanding in a better way which areas are more impaired or beneficial by the installation of WFs. • This study deals with the Wind Farm installation problem for an entire country. • Wind Farm locations in Greece are clustered into 158 clusters. • The areas that are more beneficial or impaired by wind turbines are determined. • The mean number of residential areas per cluster is equal to 6. • 79 out of 158 clusters do not contain any residential area. [ABSTRACT FROM AUTHOR]

Local renewable energy initiatives, that involve the local population, can help empower the communities, economically, culturally, and socially. In many cases, the ambitions of energy projects go beyond mere electricity production and involve issues of energy justice, environmental awareness, and environmental citizenship. However, these aspirations are often forgotten during project assessments, or they fail to include local voices, especially those of women and other marginalized groups. Gender has been given little attention in the energy scholarship and especially during the post-implementation assessment of energy projects due to the belief that energy technologies are gender neutral and beneficial for the whole community. The present study, with a focus on two local energy projects with mixed ownership, challenges this notion. The two case studies are the islands of El Hierro in Spain and Tilos in Greece. A detailed survey based on a series of indicators drawn from the energy justice framework is used to evaluate women's perceptions. By following a feminist approach, this work draws attention on the difference experiences of women and how these are often not acknowledged during the assessment of renewable energy projects. Local renewable energy does not automatically imply energy justice and pluralism. More effort is needed from policy makers to include women in the decision making and to ensure a fair distribution of the benefits of the projects. • This paper examines the impact of two innovative renewable energy projects through gender lenses • Two case studies from the Global North are presented • Sex disaggregated results from a detailed survey were analyzed • The energy justice framework is the underlying conceptual tool for the analysis • The differences in energy perceptions and benefits/harms from the projects between genders are discussed [ABSTRACT FROM AUTHOR]

The European Union is committed to a 55% reduction in greenhouse gas emissions by 2030, as outlined in the Green Deal and Climate Law initiatives. In response to geopolitical events, the RePowerEU initiative aims to enhance energy self-sufficiency, reduce reliance on Russian natural gas, and promote hydrogen utilization. Hydrogen valleys, localized ecosystems integrating various hydrogen supply chain elements, play a key role in this transition, particularly benefiting isolated regions like islands. This manuscript focuses on optimizing a Centralized Green Hydrogen Production Facility (CGHPF) on the island of Crete. A mixed-integer linear programming framework is proposed to optimize the CGHPF, considering factors such as land area, wind and solar potential, costs, and efficiency. Additionally, an in-depth sensitivity analysis is conducted to explore the impact of key factors on the economic feasibility of hydrogen investments. The findings suggest that hydrogen can be sold in Crete at prices as low as 3.5 EUR/kg. Specifically, it was found in the base scenario that, selling hydrogen at 3.5 EUR/kg, the net profit of the investment could be as high as EUR 6.19 million, while the capacity of the solar and wind installation supplying the grid hydrogen facility would be 23.51 MW and 52.97 MW, respectively. It is noted that the high profitability is justified by the extraordinary renewable potential of Crete. Finally, based on our study, a policy recommendation to allow a maximum of 20% direct penetration of renewable sources of green hydrogen facilities into the grid is suggested to encourage and accelerate green hydrogen expansion. [ABSTRACT FROM AUTHOR]

This article presents an integrated approach for solving the optimization of economic dispatch and commitment EDC problems of hybrid thermosolar concentrating power generating systems using matrix mathematics. The model uses matrices, and is solved by matlab programming. The study case of a hybrid thermosolar system in the north-west of Greece shows the impact of concentrating solar power (CSP) generation on the optimal cost of energy produced: the CSP system increases the operational costs as compared to the fossil fuel thermal systems. To acquire the benefits of cleaner electric energy with diminished emissions versus the minimal cost of electrical energy generation belongs to multicriteria managerial decisions. This approach can be applied to hybrid energy systems with large numbers of thermal and CSP generators. It offers an accurate instrument to energy engineers and researchers, for critical managerial decisions regarding electrical energy economics. [ABSTRACT FROM AUTHOR]

Research activity in the field of combined cooling heating power (or trigeneration) systems with high renewable energy source (RES) contributions has increased rapidly over the last few years, in line with the European Union legislation about energy communities. However, technical challenges arise regarding the synergetic, sustainable and optimal integration of RES in local energy systems. In the present study, the operation of a trigeneration system located in the student residences of Democritus University of Thrace in Greece is examined. The system involves a combination of highly promising renewable and storage technologies, including solar thermal energy and biomass for heat generation, hot water tanks for thermal energy storage, absorption refrigeration for cooling, along with Organic Rankine Cycle and photovoltaic systems for electricity generation. System modeling and simulation have been implemented in Dymola environment with the use of Modelica equation-based modeling language. The accuracy of the model response has been validated against available measurements. Specific design and control measures have been proposed, simulated in a transient fashion and evaluated in terms of (i) RES generation, (ii) solar fraction and (iii) temporal flexibility. The measures examined, including the placement of a Li-ion battery, resulted in an increase of 24.6% in the heating demand solar contribution and of 7.9% in the renewable energy generated for the electricity demand, over the examined periods. [ABSTRACT FROM AUTHOR]

Climate and energy crises are increasing worldwide. Community-led humanitarian engineering interventions for localized sustainable development and disaster resilience could support populations at risk. This article presents findings from a study that investigated flood response and energy needs of two riparian communities in Greece and Nepal. The findings indicate that the co-development of a hybrid unit for hydropower generation and flood warning is most preferred. This prototype could find applications in different riparian areas as either a main or supplementary system. [ABSTRACT FROM AUTHOR]