“Bloom Energy’s 3 main selling points are: “lower energy costs, clean power, and reliable power.”

The first will obviously depend on many things, especially how low they can get production costs for Bloom Box fuel cells. K.R. Sridhar, the founder of Bloom Energy, claims that costs could be brought down as low as $3,000 for a stack, but I’ll believe it when I see it. In the developing world, decentralized power generation has the benefit that you don’t have to build expensive transmission lines, so it might take off faster there.

The second point depends on what you compare it to. If you take the current U.S. grid average, then a Bloom Box running on natural gas would indeed be clean and produce about half the CO2. But compared to cleaner sources like hydro, wind, solar, nuclear, biomass, etc, you’d probably still produce more CO2. But if these fuel cells are deployed first in states that are very dependent on coal and that have access to natural gas (or even better, biogas), they could make a pretty significant difference.

The most promising use of the Bloom Box, in my opinion, is as a backup for a wind or solar power system. The natural gas/biogas fuel cell would be your backup for when the sun or wind doesn’t shine. If Bloom Energy really can bring the price down low enough, it could be more affordable than large battery packs.

The third point, reliability, will be entirely dependent on how good the technology is. Fuel cell membranes can be contaminated in various way, so the robustness of the design will be key.”