Strategies for Reducing Peak Demand in Net-Zero Energy Solar Homes

Abstract

This paper investigates strategies to reduce peak loads in net-zero energy solar homes through the coordination of different design and operation strategies. The concept of net-zero energy homes, roughly defined as grid-tied houses that supply their energy needs with renewable energy sources over a period of interest, has gained in popularity in recent year. In spite of the clear advantages of this design approach, it is necessary to address the issue of peak loads and their impact on utility grids. Even if the net-zero energy goal is achieved during the period of assessment (e.g., one year), significant imbalances may be observed at smaller time scales. For instance, in northern latitudes, the generation of PV panels typically exceeds the energy use of the house during the summer months, while in winter the energy use of the house is larger than the generation of the PV system. Fluctuations of the ratio generation/use are also registered during the daily cycle. If a net zero energy house draws energy from the utility grid during peak periods, its impact on the grid will be similar to that of a conventional home, with the subsequent need for increased generation and transmission capacity.