Hybrid Renewable Energy Systems: Impact of thermal storage on systems optimal design and performance

Hybrid Renewable Energy Systems (HRESs) can rely on the integration of multiple renewable and non-renewable energy sources. Those are effective means to increase the exploitation of local renewable energy sources in the Distributed Generation (DG) paradigm concept. The design of FIRES is usually performed matching load and production profiles in a long -to medium-term time horizon with the aim to optimize energy performance with respect to costs. In this work, a multi-objective parameter is defined to identify the optimal configuration of the hybrid system. Costs, renewable energy self-consumption and emission factors are included in the functional parameter to be targeted. Production and disposal emission factors are evaluated by means of a Life Cycle Analysis (LCA) for PV and batteries in order to show how this would affect the sizing of the FIRES. Moreover, the effects of a Thermal Energy Storage (TES) system on the performance and the design of a residential FIRES in analyzed when both electric and thermal loads are considered in the energy management strategy. A beneficial effect of the TES inclusion is observed, resulting in system downsizing at same energy and emission performance, as well as in a lower LCOE (Levelized Cost of Energy) and higher PV energy self-consumption.