Assessing variability of photovoltaic load supply in Hawai‘i

Abstract

Since 2010, the installed capacity of solar photovoltaic (PV) penetration in Hawai'i has soared due to exceedingly high electricity rates, generous installation tax credits, and net energy metering. The inherent variability of solar resources and changes in customer behavior impose increasing volatility at the circuit level, which poses challenges with grid stability. This study uses a rich and unique proprietary data set to assess the interrelated effects of weather and socio-economic factors on power system operations to maintain a balance between load and supply of solar photovoltaic at the system level. We find that PV penetration, weather and residents on circuit contribute greatly to volatility under varying operating regimes. In the end, Hawai'i shows that “old grids” can tolerate much higher level of penetration than previously understood.