Abstract
Heat pump water heater (HPWH) for household has been focused as a controllable load to compensate power fluctuation of renewable energy (RE) sources like photo voltaic (PV) cells, wind turbine (WT) and so on. HPWH should be operated without loss of user's convenience during power compensation. In this paper, HPWH model has been mode by use of a commercial HPWH with small change. The HPWH used in the study can be control the rotation speed of compressor by external signals, and it almost operates under the normal conditions as the HPWH without any change. Simulation studies have been done to evaluate loss of hot water demand by use of measured 60 hot water demands with power compensation control, and to evaluate the LFC capacity of the model gird with battery energy storage system. From simulation results, it is shown that The LFC capacity of the grid becomes large according to the capacity of HPWH, and loss of hot water demand under power control is relatively small and if several start-up/shutdown operation is allowed, the loss of hot water may be negligible small. The required energy for the hot water demand is almost the same value as mid-night operation.
