RICHMOND—Dominion Virginia Power’s more than 18,000 customers in Western Tidewater will see a $4.86 increase in electric bills starting today.

The utility is also asking for an additional 14-cent monthly increase to pay for converting three power plants, including one in Southampton County, to biomass-generating facilities. If the Virginia State Corporation Commission approves the request, the increase would go into effect on April 1. The plants currently use coal to fuel the power stations.

The average residential customer’s monthly bill, effective today, will increase from $103.91 to $108.77 to cover the utility’s costs for fuel, said David Botkins, spokesman with Dominion Virginia Power in Richmond.

“We have a number of commodities to generate electricity,” Botkins said. “Coal, uranium for nuclear plants, natural gas that power our gas generating stations and oil.”

Converting plants in Southampton County, Altavista and Hopewell will cost a total of $165 million, or $55 million per station. Set to be completed in 2013, the conversion will increase Dominion’s renewable generation capacity to power 37,500 homes.

The switch to fueling the plants with waste wood left over from regional timber operations would reduce nitrogen oxides, sulfur dioxide, mercury and particulate emissions and meet emissions standards established by the state Department of Environmental Quality and the U.S. Environmental Protection Agency.

Dominion claims the rate adjustment will allow the utility to collect financing costs over time as projects begin, lessening the larger rate impact that could occur when power stations go into service.

Once construction is completed, it’s unknown if the 14 cents will be removed from bills.

“It should decrease or go away completely,” Botkins said. “I can’t say that with complete certainty.”