Exergy and exergo-economic analysis of a hybrid renewable energy system under different climate conditions

Abstract

The building sector has a great potential to accelerate the decarbonisation by using high efficient and 100% renewable energy production on-site. This allows also increased energy autonomy to protect building owners against increasing electricity prices. The key solution is to apply micro combined heat and power (micro-CHP) systems to form a domestic hybrid renewable energy system (HRES) which supports fluctuating solar energy production by the controllable biomass-fuelled micro-CHP. However, despite the market availability of the technology, the initial investment of such a system is assumed to be a barrier to penetration. In this study, dynamic exergy and exergo-economic analyses of the HRES are conducted in Matlab/Simulink to define the specific costs of energy products when the market available system is applied to the European building stock under different climate and economic conditions. The overall exergy efficiency of the system is 13%–16%. The specific costs have high variation on a monthly and location basis. On a yearly basis, the lowest specific cost of electricity is 0.29 €/kWh in the southernmost location and of heat products 0.319 €/kWhex (0.034 €/kWh). The comparative results show that the HRES is economically viable and reduces primary energy use and costly irreversibility up to 95%.