Electric cars are coming, but how many and when depend on the economics, experts said at an Environmental & Energy Study Institute briefing yesterday.  With today's battery technology and federal subsidies, plug-in vehicles won't be cost competitive with gasoline fueled ones if the dominant fuel is priced between $2-4/gallon, said Rand Corporation's Constantine Samaras.

          Improved battery technology and higher subsidies can cut cost and make plug-ins more competitive with traditional vehicles, leading to mass adoption, he added.  EPRI Director of Electric Transportation Mark Duvall implored the audience of largely Congressional staffers to do a better job on plug-in vehicles than was done for standard hybrids.

          Those subsidies might not only be federal -- as state sales tax exemptions have led to higher percentages of normal hybrid sales where they're available.  The Toyota Prius entered the market in 2000 without any subsidies and slowly began attracting more and more customers.  Now with other vehicles from competitors, hybrids make up 3% of the US fleet and their owners benefit from subsidies.

          Electricity is the best low-carbon fuel option for cars, even with the system as is, plug-ins would offer improved greenhouse gas emissions over standard hybrids, said Duvall.

          Samaras didn't necessarily agree with that assertion, noting that with the average carbon intensity for power, plug-ins would have roughly the same emissions as traditional hybrids.  That obviously varies from region to region, with some presenting much lower emissions than others.

          Duvall doubted that car makers would employ a regional approach to their system as Chevy will be selling Volts all over the country, for example.

          Plug-ins present the transmission grid with opportunities.  They easily fill the role of generators in the regulation services market, said PJM Advanced Technology Manager Kenneth Huber.

          PJM currently uses about 1,000 mw for regulation in its market and it's most needed between midnight and 6 am, when most cars would be idle and charging.

          Aggregators could bid cars into the regulation services market with about 70,000 cars able to take up the entire need in PJM.  The RTO could easily have 180,000 plug-ins by 2015 if President Obama's goal of 1 million for the entire country is met and distributed by population.

          Postal carrier vans present a good potential source of regulation services, if the US Postal Service put 20,000 plug-ins into service in PJM, it could bring about $100,000 a day by using them in the regulation market for five hours when they're normally siting idle.

          Plug-ins present problems the closer one gets to the meter, said Duvall.  A car charged at the highest rate possible would draw about the same amount of power as a house in Arizona.

          Utilities believe plug-ins will cluster in specific neighborhoods and that could cause equipment to be retired earlier than it would have otherwise.

          The goal will be to lessen the costs for incorporating plug-ins since EPRI has found keeping the money spent on fuel in the US can lead to each car creating about $100 of economic benefits.