Bloom Energy, Kleiner Perkins' first cleantech investment, has raised another $150 million, according to VentureWire, as reported in the WSJ. 

Bloom, founded eleven years ago, builds and sells fuel cells of the solid oxide fuel cell (SOFC) variety. The devices run on natural gas and produce electricity with fewer emissions than a diesel gen-set.

This Round G brings the VC total for Bloom to approximately $800M on a reported valuation of $2.7 billion, a figure which brings it near the 'Solyndra line' of VC totals. At a certain point, the necessity of having to raise more VC becomes looks more like a liability and an indication that something is wrong with a business model.

Previous investors in Bloom have included Advanced Equities, Apex Venture Partners, DAG Ventures, GSV Capital, Kleiner Perkins Caufield & Byers, Mobius Venture Capital, Madrone Capital, New Enterprise Associates, SunBridge Partners, and Goldman Sachs.

Years ago, I obtained some communications from Advanced Equities, believed to be one of the largest investors in Bloom, that predicted a Bloom IPO in 2009.

There is still not a single, pure-play, public fuel cell company that has experienced anything close to profitability. It's difficult to believe that Bloom is anywhere close to being profitable despite the plundering of the Self Generation Incentive Program (SGIP) they enjoyed. Bloom also sells its fuel cells as a service -- a fuel cell PPA, as it were -- to take some of the pain out of the initial investment.

Bloom does have a stellar list of high-profile customers, including Apple, Adobe, and Google.  

Bloom's high headcount, high burn rate, and presumably negative margins, along with a less-than-open IPO market, indicate a rocky road ahead. I would also suggest that Bloom's green credentials are debatable.

Last year, I spoke with Mike Bangs, Adobe's Director of Global Facilities, about his Bloom installation. The firm's two 200-kilowatt units installed at the company's San Francisco site are Bloom's next-generation design and put out twice the power of the previous 100-kilowatt model -- in the same footprint. Those two units provide about a third of the power for Adobe's San Francisco operation. Although Bloom does have a Power Purchase Agreement (PPA) option, Adobe owns these boxes and qualified for the federal 1603 Investment Tax Credit, as well as the Self Generation Incentive Program (SGIP). Between those two generous programs, Adobe estimates that power costs it about $.085 per kilowatt-hour after the incentives. The company has also locked in its price for natural gas for a 10-year term.

Jeff St. John recently posed the question, can Bloom’s fuel cells compete with the natural gas-fired power plants that now serve the grid?

That’s a complex question, involving differences in cost per watt (gas turbines are still cheaper); the cleanliness of emissions (Bloom’s fuel cells are arguably cleaner, though they still emit CO2); the potential to capture waste heat for extra benefit (Bloom’s fuel cells don’t, while other gas-fired systems do); and the extra-complex question of whether or not Bloom’s natural gas-fueled devices are truly a “green” energy source.

Bloom has been working on a 30-megawatt project in Delaware, which could grow to as much as 50 megawatts, and is an order of magnitude larger than Bloom’s biggest projects so far with its California customers.   

Other stationary fuel cell makers like ClearEdge Power and FuelCell Energy make use of their combined heat and power characteristics, while Bloom does not. 

So far, Bloom has been able to ship its product into subsidy-rich regions. The big question is if Bloom can survive when those subsidies recede.