Reducing CO2 Emissions for PV-CHP Hybrid Systems by Using a Hierarchical Control Algorithm

National targets for CO2 reduction in the German building sector have stagnated due to low refurbishment rates. This paper proposes an alternative approach using highly efficient, decentralized energy systems. By combining photovoltaic (PV) systems and combined heat and power (CHP) plants controlled by a modified hierarchical control algorithm, CO2 emissions can be reduced. Results from a single-family home show a 13% CO2 reduction with only 11% higher operational costs on heating days. On summer days, up to 50% CO2 emissions can be avoided without additional costs. The control algorithm easily adapts to changing input parameters, making it suitable for different countries and business cases. Overall, with its modified control, the PV-CHP hybrid system can effectively reduce CO2 emissions and adapt to varying conditions. The control can be easily used for other energy systems, like fuel cells or heat pumps.