Optimal sizing of hybrid solar micro-CHP systems for the household sector

• The importance of optimal sizing of renewable microgeneration systems is addressed.
• A hybrid system made up of solar and micro-CHP devices is considered.
• Both Photovoltaic and high concentration PV technologies are analysed.
• Optimal sizing enhances savings in dwelling sector applications.
• Electricity grid constraints can have the potential CO2 emissions reduction.

The present paper addresses the importance of optimal sizing hybrid microgeneration systems for dwelling applications. Indeed, the parameters, the constraints and the criteria which must be considered in the sizing phase are several: i) energy prices, ii) ambient conditions, iii) energy demand, iv) units' characteristics, v) electricity grid constraints. The hybrid renewable system under analysis is made up of an electrical solar device and a micro-Combined Heat and Power, micro-CHP unit coupled to a cooling device. In addition to traditional PhotoVoltaic, PV, technology the work considers a High Concentration PhotoVoltaic, HCPV, device, with the aim of understanding its potential application in the countries of the Mediterranean. Results point out the importance of optimal sizing hybrid renewable energy systems, in particular the micro-CHP unit, in order to maximize the economic and the energy savings with respect to conventional generation. Furthermore results point out the critical nature of electricity grid constraints, which can halve the achievable energy savings.