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Back in 2008 I ran across an interesting little company and decided to give it the old green thumb in CAPS. Since then, Clean Energy Fuels (Nasdaq: CLNE) has performed quite admirably, scoring over 100 points. Had I been working here back then maybe I would have done something more with it. But better late than never, as they say, so today I'm adding it to my Real Money portfolio.

Keep it simple
In line with my investing philosophy, there are four things I look for when considering any investment:

  1. I want management I can trust. They need to be in it to win it, and they need to be honest.
  2. I want something that is understandable and that I can enjoy following.
  3. I want a catalyst -- a short-term event or long-term trend that will help create value.
  4. I want a fair price. Enough said.

Management I can trust, in it to win it
When T. Boone Pickens founded Pickens Fuel Corp. in 1997, I'm relatively certain it was with a greater vision in mind. Fast-forward to 2001 and he and co-founder and current CEO Andrew Littlefair founded Clean Energy Fuels with the goal of building out a national infrastructure to support natural gas as a viable fuel for transportation.

Given that Pickens owns about 23% of the shares outstanding today, he is well-tied to the success of the company. And it's not like this is his first rodeo, either. His grass-roots movement the Pickens Plan continues to gain traction with the support of more than 1.7 million Americans, and his primary focus on fleet vehicles and the trucking industry should keep Clean Energy Fuels from becoming too distracted.

Understandable and interested
Clean Energy Fuels isn't the simplest business in the world, but at the end of the day its mission is still clear in growing the natural gas movement. Clean Energy Fuels operates, maintains, and/or supplies approximately 300 natural gas fueling sites in 26 states and Canada and serves over 530 fleet customers operating somewhere in the neighborhood of 25,000 natural gas vehicles. Some of the company's customers include Waste Management (NYSE: WM), Republic Services (NYSE: RSG), and a multitude of large-scale airports around the nation as well as a significant number of U.S. transit agencies and government fleets.

A long-term trend
For all of the alternative fuel options out there today, natural gas remains the most widely used, and this trend is growing. Here's the breakdown of 2010 data from the U.S. Energy Administration:

There are two keys to Clean Energy Fuels' success. First is the actual adoption of natural gas for transportation. The other is the completion of America's Natural Gas Highway, a network built to accommodate trucking from coast to coast through 150 natural gas fueling stations slated for completion in phase one of the project. Many of these stations will be co-located with existing Pilot-Flying J Travel Centers, which are already serving the trucking industry.

All at a fair price
I recently said that sticking a valuation on Clean Energy is about as easy as changing a baby's diaper on a roller coaster, and I stand by that statement. While the company has delivered a couple of profitable quarters since its IPO in 2007, investors in Clean Energy Fuels must be prepared to deal with losses over the next year or two as the build-out continues.

Clean Energy has increased revenue at a 20% annualized rate over the past five years, and average estimates have the company reaching profitability in 2014 on revenue of around $700 million, which is reasonable as long as ANGH stays on schedule. Considering that Class 8 trucks alone consume approximately 20,000 gallons of fuel each year, it doesn't take much for the per-station economics to start looking attractive. While Clean Energy's stock price has been volatile, it's equal to about four times sales, which is on the lower end of the historical range. If the company reaches profitability in 2014, I think the stock could be worth closer to $30 per share. It's a riskier proposition but one that I think has a very bright future, so I'm adding $750 worth of shares to my portfolio.

Start me up
Clean Energy Fuels is a fascinating story and a company that I believe holds a lot of potential. If management is able to successfully build out America's Natural Gas Highway, then this company will have a formidable moat that will be very tough to match, making it one very valuable fuel provider with a lot of open road ahead.

Want to stay informed on the future of nat-gas transportation? The Fool's got a low-cost way: our premium research service covering Clean Energy Fuels. For less than the cost of your average trade, you'll get a full year's worth of updates on CLNE's major behind-the-scenes moves. Click here -- Clean Energy Fuels -- to get started.