In this segment, Motley Fool analysts Joel South and Taylor Muckerman discuss companies 15 thru 11 of their Top 20 energy companies to watch. Companies 20 thru 16 can be found here.

Be sure to follow the energy sector on Twitter as well.

For Clean Energy Fuels (NASDAQ:CLNE), long haul trucks and fleet vehicles appear to be the future. Natural gas is currently price competitive with diesel and many companies like Waste Management and UPS (NYSE:UPS) are transforming their fleets to run on natural gas. UPS has its sights set on running the largest private fleet of natural gas trucks in the United States. This aggressive plan involves the likely purchase of more than 1,000 natural gas powered trucks over the next two years. 

For more on partnerships and recent deals that have our analysts convinced Clean Energy Fuels is one to watch, take a look at the video below. 

Natural Gas Has To Be Produced By Someone

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, United Parcel Service, and Waste Management. The Motley Fool owns shares of General Electric Company and Waste Management. 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.