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Italy has reconsidered incentives on Renewable Energy Sources (RES) to implement the EU clean energy transition and Renewable Energy Communities (REC). Legislation on RECs shifted the focus of incentives from production to self-consumptions. In this paper, the REC model is studied in a minor island disconnected from the national grid, with strongly seasonal energy load and water demand. This is a typical Mediterranean scenario where energy demand is covered by Diesel gensets and water supply is provided with tankers. The implementation of RES is investigated, exploiting the current REC model of incentives. Two sub-optimal REC configurations were defined using time-dependent simulations on pyRES, an in-house code for energy systems. Results show the economical unfeasibility of REC when there is a poor mix of users. In contrast, REC can achieve economic profitability including industrial demand of a desalination unit (DES). The increase of self-consumption guaranteed from the DES allows to increase the NPV of the community and results in major cuts in CO 2 emissions (60% of those related to water supply and 10% of those from Diesel gensets) and a reduction of fuel costs of 22%. This method can be applied to investigate the performance of a REC in a local environment and help stakeholders in planning the expansions of RECs on the territory. [ABSTRACT FROM AUTHOR]

In this paper a thermoeconomic analysis of a novel hybrid Renewable Polygeneration System connected to a district heating and cooling network is presented. The plant is powered simultaneously by solar and geothermal sources, producing electricity, desalinated water, heat and cooling energy. System layout includes Parabolic Through Collector (PTC) field, geothermal wells, Organic Rankine Cycle (ORC) unit and a Multi-Effect Desalination (MED) system. Cooling and thermal demands are calculated by suitable building dynamic simulation models, calibrated for Pantelleria Island. Electrical demand is obtained by measured data. A detailed control strategy has been implemented in order to prevent any heat dissipation, to match the appropriate operating temperature levels in each component, to avoid a too low temperature of geothermal fluid reinjected in the wells and to manage the priority of space heating and cooling process. A 1-year dynamic simulation has been performed and results analyzed on daily, monthly and yearly basis. The system achieved an SPB equal to 8.50 and it resulted capable to cover the energy demands of a small community. Moreover, the plant is capable to cover the fresh water demand of the Pantelleria Island. [ABSTRACT FROM AUTHOR]