Design approach for a low carbon energy supply in buildings by combining green hydrogen with thermal and electrical components

Abstract:
Sector coupling technologies are future key technologies to realize CO2 free energy supply of buildings. In this study, a model is presented to analyze and optimize the future supply of electricity and heat using the example of a university facility (Research Center Energy Storage Technologies (EST) in Goslar, Germany). The aim is to realize a low-CO2 energy supply using sector coupling between electrical and thermal energy producers and consumers and to compare the results with the existing energy supply system of the building. Three optimization methods (Simulated Annealing, Bayesian Optimization, Genetic Algorithm) will be used to design the capacity of a hydrogen storage system in such a way that the annual natural gas consumption and CO2 emissions as well as the annual energy costs of the system are minimized. The optimization results show that a hydrogen storage with a capacity of 2500 kWh can meet the economic and ecological goals of this project. However, the analysis of the system's energy balance shows that gas consumption can be reduced by 60%, resulting in 122 tons less CO2 emissions compared to the existing system. The analysis also reveals that the system requires 3.8 times more electricity, 78% of which must be drawn from the grid. Further optimization was carried out to bring the total amount of CO2 emissions to zero. As a result, the system becomes even more dependent on the grid and the annual energy costs of the system increase as the capacity of sector couplers such as the heat pump and CHP plant increases. The analysis of the increasing installed power of the photovoltaic system also shows a significant reduction in annual energy costs.