(By Bruce Henderson, bhenderson@charlotteobserver.com) Piedmont Natural Gas said today it will soon open Charlotte's first publicly-accessible compressed natural gas fueling station.A $79,000 grant from the N.C. Solar Center helped Piedmont expand an existing station at its Charlotte operations center at 4301 Yancey Road. The expansion, to be completed in two to four weeks, will allow public access to pumps that are now behind a fence.