Peak load shifting using a price-based control in PCM-enhanced buildings

Peak load shifting, a load management policy, has attracted widespread attention as it can minimize the impact of load variation on a system's operation and reduce the electricity costs. Phase change materials (PCMs) can contribute to peak load shifting by storing the daytime solar energy in winter/free night cooling in summer or the low-rate energy provided at off-peak hours for use during the high electricity peak period. This study aimed to experimentally investigate the effect of an active PCM storage in combination with a price-based control on peak load shifting. The experiments were conducted using two identical test huts, which were equipped with an electric and solar air heater during cold seasons or an air conditioning unit during warm seasons. But in addition, one of the huts was equipped with an active PCM storage unit charged by the solar heater. A CompactRio data acquisition system, powered by LabView interface, was used to transfer data and communicate with a host computer. Results showed that the proposed system was successful in shifting both heating and cooling demands to the off-peak periods. Up to 47% of daily energy-saving (-0.83 kWh) with a corresponding 65% of electricity cost-saving, in winter, and up to 23% daily energy saving (-0.27 kWh) with a relevant 42% of cost-saving, in summer, were achieved.