Impact Assessment of Electric Boilers in Low Voltage Distribution Network

Flexibility from the electricity supply, with high share of intermittent energy sources such as wind and solar, has been offered by combined heat and power (CHP) generation in Denmark for decades. There could be periods where the fuel prices are higher than the electricity prices (even -ve), during high wind production and is idle for electric boilers (EBs) operation. In the future, using EBs, excess electricity from wind turbines can be effectively utilized for heat production, and still meet the thermal demand by decreasing CHP production. Thus, there is need for demand side flexibility that is expected to increase through power-to-heat technologies using electric boilers. This paper aims to assess the potential of EBs, modelled with simple stratified layers in the storage system, and as smaller units of distributed flexible loads in their individual houses in Denmark. The models of EB in LV-residential grids were
simulated to assess the use of EBs to analyze their capacity as well as flexibility as active loads, under various electricity and thermal load profiles of the individual houses during winter. Subjected to high heat and electricity demand in weak grids, flexibility of EBs units with local control incorporated based on grid voltages, restricts the operation of EBs but ensures operation of the distribution system within limits still trying to keep the thermal comfort in the houses.