CHARLESTON, W.Va. -- Kanawha County leaders are ready to receive bids on a natural gas filling port to fuel the county's natural-gas-powered Chevrolet Tahoe SUV.Installation of the port, which will allow the county to fill the vehicle's tank at the courthouse downtown, is just one step in a plan to convert county vehicles to alternate fuel sources."I would like a good portion of the fleet to go toward natural gas," Kanawha County Commission President Kent Carper said.In September, the county bought its first natural-gas-powered vehicle, which can be filled up on compressed natural gas for the equivalent of less than $2 a gallon of gasoline.The Kanawha Valley Regional Transportation Authority has meanwhile agreed to buy eight natural-gas-powered buses, and the Kanawha County Commission voted to buy 20 natural-gas-powered vehicles in coming months if a local business owner installs a natural gas filling station.Although an entrepreneur has yet to step in with a commitment to build the station, "I'm absolutely convinced that's going to happen," Carper said. "It's just a question of when and where."Recent exploitation of the vast Marcellus Shale gas field that extends beneath much of West Virginia has convinced Carper that vast supplies of cheap, locally produced and refined natural gas will soon be available. County officials want to be ready if that happens."[The gas] is already there," Carper said. "You don't even have to process it. You just take it out of the ground and compress it."The county's SUV will run on either gasoline or natural gas at the flip of a switch.Matt Thomas, in charge of the natural gas project for the County Commission, said the fueling port is expected to cost between $14,000 and $18,000 and would fill a vehicle over the course of several hours. County officials hope a commercial natural gas filling station, that will pump gas as fast as a gasoline pump, will be built in the area soon."The time frame I thought originally was six to nine months," Carper said. Now, county officials are hoping a natural gas filling station will be up and running within a year to 18 months.Carper said the county likely next will buy a natural gas-powered vehicle to transport mental hygiene patients to and from the courthouse annex. Those vehicles make a lot of trips, and are a logical choice to convert to natural gas, he said.Converting a vehicle to run on compressed natural gas costs about $10,000 to $15,000, but the extra cost will be made up quickly in savings on fuel, county officials believe. Carper thinks natural gas will only get cheaper as more local gas reserves are tapped.County officials are also looking at converting vehicles to run on liquid propane.Carper and Kanawha County Commissioners Dave Hardy and Hoppy Shores are expected to talk about the alternate fuel vehicle program at a regular commission meeting on Jan. 10.Reach Rusty Marks at email@example.com or 304-348-1215.