PNNL

Abstract

Pacific Northwest National Laboratory conducted a study on the impact of wide-scale implementation of net zero-energy homes (ZEHs) in the western grid. Although minimized via utilization of advanced building technologies, ZEHs still consume energy that must be balanced on an annual basis via self-generation of electricity which is commonly assumed to be from rooftop photovoltaics (PV). This results in a ZEH having a significantly different electricity demand profile than a conventional home. Wide-spread implementation of ZEHs will cause absolute demand levels to fall compared to continued use of more conventional facilities; however, the shape of the demand profile will also change significantly. Demand profile changes will lead to changes in the hourly value of electric generation. With significant penetration of ZEHs, it can be expected that ZEHs will face time of day rates or real time pricing that reflect the value of generation and use. This will impact the economics of ZEHs and the optimal design of PV systems for subsequent ZEHs.