Optimization and operation of integrated homes with photovoltaic battery energy storage systems and power-to-heat coupling

Renewable energies from residential photovoltaic systems can be used in the electricity sector as well as in the residential heating sector. Therefore, sector coupling, for example by using heat pump systems, is mandatory. Integrated homes use photovoltaic energy for space heating and domestic hot water to contribute to the decarbonization of the heating sector. The economics are a key to increasing the market penetration of integrated homes. Combined operation strategies for the electricity sector as well as for the heating sector can enhance the economics of these systems. This paper analyses different operation strategies for both electrical and thermal systems and examines the gain in efficiency by combined strategies. Furthermore, the dimensioning of the different system components heavily influences the economics of the integrated home. Capital-intensive components, such as photovoltaic generators, battery storage systems, heat pumps, and thermal storage units, play a major role for the profitability. Therefore, the optimization of component sizing is necessary in order to enhance the economics of the system. This paper presents optimization results based on the covariance matrix adaptation evolution strategy. The results of the paper indicate that combined operation strategies as well as the optimization of the component sizes strongly influence the economics of photovoltaic battery energy storage systems with power-to-heat coupling. The impact of the optimization on the economic efficiency is higher compared to the influence of advanced combined operation strategies. The optimization indicates that relatively small storage units are more economical. The use of the heating sector as additional storage for excess photovoltaic energy is only economical to a minor degree, because it reduces the coefficient of performance of the heat pump.