In the video below, Motley Fool analysts Joel South and Taylor Muckerman take a question from a reader, who asks: "Clean Energy Fuels Corporation (NASDAQ:CLNE), is it a buy? I've got a few shares of Westport Innovations (NASDAQ:WPRT) already and I feel we are in the transition phase of alternate energy and I feel that natural gas will eventually take off, that means I should act now rather than later? Yes or no? Thanks for your time."

Joel South has no position in any stocks mentioned. Taylor Muckerman has no position in any stocks mentioned. The Motley Fool recommends Clean Energy Fuels and Westport Innovations. The Motley Fool owns shares of 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.