A new eBay data center in South Jordan, Utah, enables the e-commerce giant to keep its goods flowing, but it is remarkable for another reason entirely. The center is the first facility of its kind to generate all its electricity on site from fuel cells, which are provided by Bloom Energy.

The data center is one more sign that fuel-cell energy companies are in the early stages of a rally. After nearly 10 years of spiraling stock prices, recent technological innovations and improved balance sheets are attracting Fortune 500 companies, both as customers and partners. Now, an industry known for operating in the red shows signs of achieving profitability.



"The market is more and more becoming aware of the attributes of fuel cells and buying into them and all of that is leading to large annual production of fuel cell technology," said Scott Samuelsen, director of the Fuel Cell Research Center at the University of California at Irvine.



Revenue from stationary fuel cells grew 55 percent last year, to $1.3 billion, according to Navigant Research's Fuel Cells Annual Report 2013.



Fuel cell systems convert fuels such as natural gas, methane and biogas into electricity via an electrochemical process with minimal emissions. While wind and solar provide intermittent power, fuel cells operate continuously.



"In the early 2000s there was a lot of hype around the sector," said Kerry-Ann Adamson, a Navigant fuel cell analyst. "The technology was in the grip of trying to find where the problem in the market was. At the time, it was a solution without a problem."

But Samuelsen at the Fuel Cell Research Center said two developments have emerged since to lay the groundwork for this rally.

The first is the rise of high-temperature fuel cells. Much of the technology popular 10 years ago required expensive rare earth, such as platinum. But the fuel cell systems from companies such as Bloom and FuelCell Energy are made from cheaper and abundant ceramics.

(Read more: Natural gas: Risks and rewards for Gazprom boss)

