Miriam Mantegna

Renewable energies diffusion in small and noninterconnected islands is among the main challenges of modern energy systems. Oceania is one of the most populous countries in the world, being composed by several islands and archipelagos. This paper presents an in-depth analysis of the current energy landscape and renewable energy potential of three Pacific Island Countries: Fiji, Tonga, and Tuvalu. The study evaluates local energy demands, existing infrastructure, socio-political constraints, and the feasibility of transitioning to a renewable energy mix. Using data from international and regional development agencies, the paper proposes tailored strategies that leverage photovoltaic, wind, biomass, hydro, and emerging oceanic energy sources to ensure energy independence, reduce greenhouse gas emissions, and foster sustainable development.

Small islands face significant challenges in achieving sustainable energy systems due to isolated grids and areliance on imported fossil fuels. Introducing renewable energy communities in small islands can support the integration of intermittent renewable sources as solar or wave since they aim at locally share the energy production. The study investigates the integration of a renewable energy community on small islands, using Favignana in the Mediterranean Sea as a case study. This research focuses on solar and marine energies, also integrating hydrogen-based technologies and the smart management of local desalination unit. The results show that an isolated energy system can host significan share of renewables since they offer several benefits in terms of economic, energy and environmental aspects. Moreover, energy storage systems significantly enhance renewables integration. Fuel cells can also help the power system as electrical energy storage system and also as freshwater generator.

Small islands face significant challenges in achieving sustainable energy systems due to isolated grids and a reliance on imported fossil fuels. The study investigates the integration of renewable energy sources on small islands, using Favignana in the Mediterranean Sea as a case study. This research evaluates various scenarios for increasing renewables penetration, focusing on solar and marine energies. Two main scenarios are analyzed and compared with the current situation: integration of renewables production up to the limit ensuring the security of the power system and implementation of renewables and energy storage systems. The results show that while the installation of renewables offers several benefits in terms of economic, energy and environmental aspects, the setting of an upper limit leads to underutilization of renewables availability. Conversely, energy storage systems significantly enhance renewables integration but involve high initial investments and varied environmental impacts depending on the technology. Policymakers are urged to consider both economic and environmental factors to develop effective strategies for small islands, ultimately reducing depen-dence on fossil fuels and enhancing energy self-sufficiency.

The recent post-pandemic period has economically affected many business sectors. One of these is the hotel industry. As a result of this economic crisis, it is necessary to act on the economic costs of running energy-intensive buildings such as a hotel. The thermal and electrical energy consumption of an accommodation facility weighs heavily on the economic balance. Governments around the globe have moved to help those activities in need. To improve the sustainability of the hospitality sector from an environmental and economic point of view, the introduction of energy retrofit solutions is mandatory. Following European sustainability laws, the impact and efficiency of the building were calculated using smart readiness indicators. The purpose of this paper is to present a case study of a 5-star hotel located in southern Italy characterized by high energy consumption. Precisely these consumptions are due to air conditioning, lighting, hot water, catering, and all other utilities. The entire building and the systems serving it were characterized by means of software that studies consumption with dynamic models, Trnsys. The same software made it possible to model the case study by replacing the existing air conditioning system with one supplied by renewable energies. Two energy retrofit hypotheses were chosen to obtain the best economic and environmental results. First, the choice was to install solar cooling powered by flat solar panels, and the second choice was solar cooling powered by evacuated tube collectors. This paper reports the technical and economic characteristics of both proposed solutions, quantifying the energy and economic savings to identify the best solution.

In Italy, a large part of the buildings classified as historical–artistic heritage is in a state of degradation and requires urgent interventions. Among the needs, a reduction in the high energy consumption and an improvement of the indoor comfort are mandatory. The case study of the “Ex Institute of Zoology of Palermo” shows how it is possible to achieve a reduction in energy consumption and preserve the building’s historicity through the estimation of energy loads and the subsequent processing. To quantify the energy savings of the structure, it was necessary to follow a few steps, namely an inspection of the building and an evaluation of its consumption. To elaborate a correct energy analysis, the thermal conductance was calculated by considering measurements over a period of 60 days and proceeding with the calculation of the transmittance. The resulting data are imported in the energy model developed with the TERMUS BIM software. In the case study, a potential energy saving equal to 35% of the current energy consumption can be avoided by replacing the lamps with LED ones, installing photovoltaic panels, replacing the heat pumps with a centralized system and the current fixtures with double thermal break fixtures. These interventions are implemented in compliance with the architectural peculiarities.