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In the last ten years, there has been a progressive improvement in rural electrification indexes in developing countries, and renewable energies are progressively being integrated into electrification programs. In Cuba, the government has set a target of 700 MW in solar photovoltaic energy by 2030, including rural electrification and off-grid systems. Within this framework, 10,000 modular systems of 300 Wp are being installed in isolated communities. Nowadays, previously diesel-electrified settlements are migrating into renewable energy technologies projects in rural Cuba. The objective of this research is to evaluate the sustainability of these changes in order to identify the implications for other developing countries, taking four different dimensions into account: environmental, technical, socioeconomic, and institutional. For this purpose, the rural communities of Yaguá (diesel-based) and Río Abajo (solar-based) in the province of Sancti Spiritus are visited and studied. Results show that the institutional dimension of sustainability is positive thanks to improvements in energy security and promotion of the Cuban national plan goals. Moreover, results confirm that the energy transition from diesel-based to solar PV is environmentally sustainable in Cuba, but improvements are still necessary in the power capacity of solar modules to strengthen the socioeconomic and technical dimensions.

In recent years, solar price drops and regulations have helped residential users to invest in grid-connected photovoltaic (PV) facilities. In Spain, a novel law promotes self-consumption by discounting electricity fed into the grid from the utility bill. However, the performance of PV-based facilities depends on diverse factors. The contribution of this paper is to evaluate the techno-economic performance of such installations for different considerations linked to the Spanish law. A simulation model is used to examine different representative cities, load profiles and alternative objectives: maximising profitability and self-sufficiency. For profit maximisation, results show that load profile variations entail PV size changes up to 5 kWp for the same location, together with huge economic and self-sufficiency differences. In contrast, the solar radiation and compensation rate have a more limited influence. For self-sufficiency maximisation, the economic performance drops close to EUR 0, as benefits are used to double the PV size, buy batteries and reach close to 70% self-sufficiency. Finally, a sensitivity analysis shows a limited impact of the utility tariff and the technology cost on the PV size, but a relevant influence on the benefits. These results can help investors and families to quantify the risks and benefits of domestic self-consumption facilities Peer Reviewed Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.2 - Per a 2030, augmentar substancialment el percentatge d’energia renovable en el con­junt de fonts d’energia Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant

The paper assumes that, at the end of the operational period of a Spanish nuclear power plant, an Independent Spent Fuel Storage Installation will be used for long-term storage. Spent fuel assemblies are selected and transferred to casks for dry storage, with a series of imposed restrictions (e.g., limiting the thermal load). In this context, we present a variant of the problem of spent nuclear fuel cask loading in one stage (i.e., the fuel is completely transferred from the spent fuel pool to the casks at once), offering a multi-start metaheuristic of three phases. (1) A mixed integer linear programming (MILP-1) model is used to minimize the cost of the casks required. (2) A deterministic algorithm (A1) assigns the spent fuel assemblies to a specific region of a specific cask based on an MILP-1 solution. (3) Starting from the A1 solutions, a local search algorithm (A2) minimizes the standard deviation of the thermal load among casks. Instances with 1200 fuel assemblies (and six intervals for the decay heat) are optimally solved by MILP-1 plus A1 in less than one second. Additionally, A2 gets a Pearson’s coefficient of variation lower than 0.75% in less than 260s CPU (1000 iterations).