Smart Grid May Benefit Plug-In Hybrids

Mar 21, 2007 9:46 AM

Xcel Energy has announced the results of a six-month study related to plug-in hybrid electric vehicles (PHEVs) and how an increase in their popularity may affect Colorado. The study found that PHEVs may result in a reduction of the overall expense of owning a vehicle and, with the help of smart-grid technologies, eliminate harmful vehicle emissions by up to 50%.

The study looked at how adding PHEVs to the road could affect the electric power grid depending on when and where the cars were charging. It also looked at the overall emission footprint of these vehicles, the decreased vehicle fuel costs and how PHEVs could impact the company’s production and capacity costs.

Xcel Energy’s Utility Innovations group worked with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) on the study. A cutting-edge computer-modeling program was used to measure the impact of a mass penetration of PHEVs and how much energy would be required to charge them.

NREL’s program was able to simulate adding vehicles to the roads in large increments, under real driving conditions, simulating an increase in the market penetration of these vehicles. The study revealed that these cars, each equipped with a 9 kWhr battery, could reduce overall CO₂ vehicle emissions by half. They could also save owners more than $450 in fuel costs each year compared to a traditional combustion engine vehicle.

How much would be saved in vehicle emissions depends on when drivers charge their cars. Incentive programs may induce customers to charge their PHEVs at certain times and will help Xcel Energy minimize emissions and operating costs. It will also enable incremental utility infrastructure investment.

Plans are in place to work towards a more intelligent utility grid. While the specific impact has yet to be studied, technology already exists to allow customers to feed excess power from their own PHEV, back onto the grid. This can potentially lead to better use of renewable energy sources and improved reliability. Future studies will include PHEV field tests and evaluate the ability to manage the charging process in conjunction with the availability of renewable energy sources.