Grid impact of a net zero energy building with BiPV using different energy mangament strategies

A net-zero energy office building with Building-integrated photovoltaics (BiPV), a heat pump with cooling functionality and TABS as a heat distribution system is simulated in dynamic thermohydraulic simulations in Dymola. The focus of the evaluation is the electricity exchange with the grid. The temporal mismatch between local electricity production and electricity consumption is evaluated using established indicators such as the autonomy and self-consumption. Moreover, it is analyzed during which times electricity is consumed from the grid, and how high the fraction of Wind and PV in the energy mix is during the time of consumption. The latter is quantitatively expressed using the Grid Support Coefficients GSCabs and GSCrel proposed by the authors. HVAC operation accounts for roughly 43% of the total electricity consumption of the considered building. With a conventional HVAC control concept based on heating and cooling curves, an annual autonomy rate of 42% and a self-consumption rate of 43% are achieved. In an alternative control scheme, the trajectory of heat and cold delivery to the zones is altered such that the self-consumption of the locally produced electricity is maximized. The remaining electricity demand for HVAC operation, which has to be covered from the public grid, is shifted to times of a high availability of Wind and PV power in the energy system. With this energy management scheme, the autonomy and the selfconsumption rate are increased to 50% and 53%, respectively. The fraction of Renewables in the electricity consumed from the public grid is increased by 15% (relative). Thermal comfort in the offices is only moderately affected by the shifting of the heating and cooling loads.