3. Bloom Energy

Cleaner energy

KR Sridhar, co-founder and CEO of Bloom Energy
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KR Sridhar, co-founder and CEO of Bloom Energy

Founders: KR Sridhar, Jim McElroy, Matthias Gottmann, John Finn, Dien Nguyen
Date launched: 2001
Funding: $1.1 billion
Industry disrupted: Energy utilities

In the world of disruptors, where the most common denominator among companies is their relative youth, Bloom Energy is practically a senior citizen. The fuel cell company, headquartered in Sunnyvale, California, was started in 2001. It uses fuel cells to convert natural gas into electricity and then places those power-source units in office buildings, retailers (IKEA just signed a deal for one of its stores in Emeryville, California), data centers and other customer locations. Once the fuel cells are in, the company signs long-term contracts to supply electricity to its customers.

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The company's goal, it said, is to "lead the industry away from a centralized 'hub and spoke' energy network to a clean, distributed, and more reliable energy future." Plenty of investors are sold on the benefits of cleantech—and fuel cells as a way to get there.

The company has raised a mind-blowing $1.2 billion of funding from the likes of venture heavyweights Kleiner Perkins Caufield & Byers and New Enterprise Associates (NEA). However, the biggest question marks hovering over the company are: Why it hasn't gone public yet, and Is it making any money?

Bloom investor and board member Scott Sandell of NEA told Reuters in 2012 that the company would likely do an IPO in late 2013 or early 2014. Instead, it has continued to raise more private capital, the latest round totaling $130 million in December. The betting now is that investors will see an IPO in 2015 or otherwise some likely executive changes.

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