On the Mars project, he focused on using electricity to fuel chemical reactions among elements found on the Red Planet, even creating dirt capable of germinating a seed. Figuring that he should be able to reverse the process, he founded Bloom and worked on converting chemical energy to electricity using readily available fuels and conductors.
Eventually, he and his team hit upon a version of the current design of roughly 5-inch-square fuel cells fused together in stacks — each about the size of a half-loaf of bread and capable of powering an average home. The stacks are loaded into tubular metal casings before being enclosed in banks about the size of a refrigerator that can then be arrayed on the ground or a roof to run large facilities.
The equipment, produced at the company headquarters here with final assembly at a factory in Delaware, is simultaneously high- and low-tech. Each cell is made from a thin ceramic wafer that is mainly zirconia — a relative of the diamond substitute. In a process reminiscent of high school art class, the wafers are screen printed with chemical inks on each side in an automated sequence and then fired in kilns. They are sandwiched between metal plates, and the resulting structure is a solid oxide fuel cell that can operate at very high temperatures, about 800 degrees Celsius, or 1,472 degrees Fahrenheit.
At that temperature, when natural gas mixed with steam flows over one surface of the cell while oxygen flows over the other, a reaction results in the release of electricity, steam that is recycled through the process and carbon dioxide.
Equinix tested the Bloom cells at a data center in San Jose for 18 months before committing to the current arrangement, in which it will buy the energy under a 15-year power purchase agreement. The company, which runs more than 185 data centers on five continents, serves as a kind of cloud and network broker. It builds and operates facilities that provide space, power and cooling as well as work rooms, showers and a security system featuring a series of locked chambers like something out of “Get Smart.” The client companies bring their own servers and other hardware to plug into more than 1,000 networks that connect them to customers and to each other.
The Southern Company, based in Atlanta, comes into the partnership because it has unregulated businesses that sell power nationwide. In this case, Southern buys the fuel-cell generators from Bloom and then, through a subsidiary called PowerSecure, sells the output to Equinix under a 15-year agreement.
The Bloom deal with Equinix and Southern is among the largest ever for a fuel-cell business, but Bloom faces competition from other providers, like Fuel Cell Energy, which is based in Danbury, Conn., and has a partnership with Exxon Mobil. It has won a number of recent contracts, which include installing and operating three fuel-cell projects for the Long Island Power Authority and one that will supply power for the Navy submarine base in Groton, Conn.
Indeed, the United States government has had a hand in the technology’s development through grant programs at the Energy Department and a federal tax credit that expired at the end of last year.
The natural-gas fuel cells provide some environmental advantages over traditional power plants that run on fossil fuels: They use little water and release almost no harmful smog emissions. The Bloom cells can also run on biogas or hydrogen, which would make them even more environmentally friendly, given a steady supply of those fuels.
The usefulness of natural-gas fuel cells in reducing greenhouse gas emissions is a matter of some debate, however. Some environmentalists and public-utility officials say the fuel cells’ emissions may be understated and question whether their carbon reductions are sufficient to warrant public subsidies.
Still, their emissions are well below the average for coal-fired plants. Bloom puts the emissions of its natural-gas cells in the range of 679 to 833 pounds of carbon dioxide per megawatt-hour, while coal plants released 2,252 pounds of carbon dioxide per megawatt-hour in the second quarter of this year, according to the Power Sector Carbon Index, an analysis published by the Scott Institute for Energy Innovation at Carnegie Mellon University. They are much closer to those of natural-gas plants, which, according to the index, averaged 938 pounds per megawatt-hour during the same period.
Though companies looking to power energy-hungry data centers have often sought out hydroelectric power, which does not depend on fossil fuels and is generally inexpensive, fuel-cell technology is gaining traction, especially for customers who need an extremely steady power supply even during storms. For Tom Fanning, chief executive of Southern Company, the partnership with Bloom is part of a bid to take advantage of the technological advances that are upending the electric industry by allowing customers to make their own power, known as distributed generation.
“For 100 years, we have had a business model predicated on the notion of making, moving and selling electricity, essentially up to a meter,” he said in a telephone interview. “We started seeing this make-move-and-sell model moving to the customer premises. And so we decided to become involved in this space.”