Based on the aggregated intelligence of 170,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, alternative-fuel provider Clean Energy Fuels (Nasdaq: CLNE) has earned a respected four-star ranking.

With that in mind, let's take a closer look at Clean Energy's business and see what CAPS investors are saying about the stock right now.

Clean Energy facts

Headquarters (Founded) Seal Beach, Calif. (2001)
Market Cap $962.5 million
Industry Oil and gas refining and marketing
Trailing-12-Month Revenue $211.8 million

Co-Founder/CEO Andrew Littlefair

CFO Richard Wheeler

Return on Equity (Average, Past 3 Years) (10.9%)
Cash/Debt $55.2 million / $64.4 million
Competitors Exterran Holdings (NYSE: EXH)

Sources: Capital IQ (a division of Standard & Poor's) and Motley Fool CAPS.

On CAPS, 97% of the 1,080 members who have rated Clean Energy believe the stock will outperform the S&P 500 going forward. These bulls include buffalonate and miffls.

Last week, buffalonate touched on the trends working in Clean Energy's favor:

The economics of natural gas as a transportation fuel are too great for this company to fail. Commercial and government fleets are rapidly switching to natural gas and for good reason. Natural gas is cleaner, cheaper, and abundant.

Over the next five years, in fact, Clean Energy is expected to grow its bottom line at a brisk rate of 30% annually. That's faster than listed rival Exterran (25%), as well as other alternative fuel plays like FuelCell Energy (Nasdaq: FCEL) (10%) and Fuel Systems Solutions (Nasdaq: FSYS) (15%).

CAPS member miffls elaborates on the bull case:

[Clean Energy] should profit as a result of the wide spread in pricing between crude oil and natural gas. Even if/when natural gas prices rise as a result of greater use, it is so much cheaper than crude oil, companies like [Clean Energy] should continue to do well. ...

[G]iven the spread in prices between crude and natural gas, switching is a great way for companies that have freight costs significantly impact their profitability to boost profits now.

Major companies such as [UPS are realizing the value] of switching over heavy trucks to natural gas fuel now which will be a catalyst for the stock.

I keep seeing a continuous stream of positive press releases about new deals [Clean Energy] has for opening fueling stations for fleets, and now for over the road trucks through the deal they have with Pilot Flying J. There seems to be no real competition to [Clean Energy] and with all of their contracts that I've heard of being long term deals, it seems like that will remain the case.

What do you think about Clean Energy, or any other stock for that matter? If you want to retire rich, you need to put together the best portfolio you can. Owning exceptional stocks is a surefire way to secure your financial future, and on Motley Fool CAPS, thousands of investors are working every day to find them. CAPS is 100% free, so get started!

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. The Fool owns shares of UPS. Try any of our Foolish newsletter services free for 30 days.

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