Dominion Virginia Power plans to begin a pilot program this fall that would charge electric vehicle owners less to “fill up” during off-peak periods.

The pilot, which customers will be able to sign up for beginning Oct. 3, was approved earlier this month by the Virginia State Corporation Commission.

“This pilot program will allow us to gauge the impact of EVs on our system, from the power station to the house,” Kenneth D. Barker, vice president of Customer Solutions and Energy Conservation, said in a statement.

In its application, Dominion estimated that more than 5,000 electric vehicles will be on the roads in its service area by 2013, growing to more than 86,000 by 2020.

The rates are intended to discourage users from charging vehicles during peak times “to minimize the potential adverse impacts on utility infrastructure,” according to the order granting approval for the pilot.

Dominion said the pilot will offer participants two rate options:

• Electric vehicle only: Customers would have a second meter installed to measure energy used just to charge an EV at a lower rate. Dominion estimates it would cost about 43 cents to charge an EV overnight, compared to 94 cents using the standard residential rate.

• Whole house: The price for electricity would change during the day to encourage off-peak use for charging vehicles. Dominion estimates wit would cost 41 cents to 49 cents to charge an EV.

Each option will be limited to 750 participants under the pilot, which is scheduled to end Nov. 30, 2014, Dominion said. Participants would enroll for at least one year.