Many investors were wondering which area would buy into the idea of natural-gas-powered vehicles first: the infrastructure companies or the user base. Well, Clean Energy Fuels (NASDAQ:CLNE) put that debate to rest in 2012. Building out its infrastructure became a key initiative in the last year, and it finally appears to be paying off with a growing customer base. Some of the biggest company names in the world are seeking to increase their exposure to this technology in 2013 after slowly entering the market in 2012.

To find out some of the well-known companies using this technology, check out the video below. 

Taylor Muckerman has no position in any stocks mentioned. The Motley Fool recommends Clean Energy Fuels, Cummins, United Parcel Service, and Westport Innovations. The Motley Fool owns shares of Cummins, General Electric Company, and Westport Innovations. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.