Clean Energy Fuels Corp. completed 18 refuse truck natural gas fueling stations in 2011.

The waste projects were among a total of 68 fueling station projects in 16 states that Seal Beach, Calif.-based Clean Energy completed in 2011, the company said in a news release.

 “We increased the number of station projects completed during the year by 50 percent over 2010,” said Andrew J. Littlefair, Clean Energy president and CEO. In addition to stations for waste management, Clean Energy also opened seven facilities serving transit, 28 for airport/taxi/shuttle operations and 15 to support local and regional trucking and small fleets.

In the second half of the year Clean Energy received total investment commitments of $450 million, which it intends substantially to fund more fueling station development going forward, Littlefair added.