Eco-economic optimal sizing and operation of PV-battery systems in buildings The Role of CO2 price signals

CO2 pricing enables building owners to benefit from reduced emissions. Changing power plant mix leads to dynamic CO2 factors and price signals that PV-battery systems can exploit. The system's size and CO2 prices influence profitability. So far, no study exists assessing CO2 pricing's influence on PV-battery system optimal sizing and operation. We, therefore, investigate the interaction of PV-battery sizing and operation with CO2 pricing and combine Design of Experiments with model predictive control. For a CO2 price of 100 Euro/t, the cost-optimal design decreases emissions by 79.7 %. Furthermore, high CO2 prices yield large PV and medium battery sizing. The results prove that CO2 pricing is a valuable instrument to encourage CO2-reducing investments of building owners. We recommend future studies to include the effect of CO2 pricing on the power plant mix and thus the CO2 factor. We assume a change in the merit order due to a shift in marginal costs of the respective power plants.