Co-Benefits of Large Scale Plug-In Hybrid Electric Vehicle and Solar PV Deployment

A number of studies have found that plug-in hybrid electric vehicles (PHEVs) will have relatively small grid impacts if charged with overnight off-peak electricity. However the greatest petroleum displacement will occur if vehicles are allowed to charge during the day, maximizing all-electric range. Charging during the day also allows for a smaller, lower cost battery. Mid-day charging will add to peak electricity demands and may occur in locations where it is difficult to construct new generation and transmission capacity. Solar photovoltaics (PV) provide an option to provide mid-day peaking capacity. Mid-day charging of PHEVs also may absorb low value or even curtailed PV generation during periods of low demand. This study identifies possible co-benefits of large scale PV and PHEV deployment by simulating the Texas grid and identifying changes in peak capacity requirements and PV curtailment. A modest deployment of PV is able to avoid most of the increase in capacity requirements associated with very large PHEV penetrations. PHEVs are also able to reduce curtailment at high PV penetration, especially if charging can be controlled to improve the coincidence of consumer charging demand with normal PV generation patterns.