Bloom Energy Corporation staged a high-profile event announcing the availability of the Bloom Energy Server, a patented solid oxide fuel cell (SOFC) technology for distributed power generation. The event was hosted at eBay Inc., featured California Governor Arnold Schwarzenegger, General Colin Powell, and early customers including Bank of America; The Coca-Cola Company; Cox Enterprises; eBay; FedEx Express; Google; Staples; and Walmart.
|Diagram of a solid oxide fuel cell. The electrolyte is a ceramic. Click to enlarge.|
Each Bloom Energy Server—comprising thousands of ceramic solid oxide fuel cells packaged as stacks—provides 100 kW of power in roughly the footprint of a parking space. For more power, customers deploy multiple Energy Servers side by side. Bloom’s customers have deployed the solution to lower and/or fix their energy costs, while significantly cutting their carbon footprints and enhancing their energy security by reducing their dependence on the grid.
SOFCs differ in many respects from other fuel cell technologies: they are all solid state, being made from ceramic substances; they operate at temperatures up to 1,000 °C; and the cells can be configured either as rolled tubes (tubular) or as flat plates (planar).
At the high operating temperatures, oxygen ions are formed from air at the air electrode (the cathode). When a fuel gas containing hydrogen is passed over the fuel electrode (the anode), the oxygen ions migrate through the crystal lattice to oxidize the fuel. Electrons generated at the anode move out through an external circuit, creating electricity.
With the high heat generated by the process, reforming hydrocarbon fuels—liquid or gaseous, fossil or renewable—to extract the necessary hydrogen can be accomplished within the fuel cell, eliminating the need for an external reformer.
With low cost ceramic materials, and extremely high electrical efficiencies, SOFCs can deliver attractive economics without relying on CHP. SOFCs operate at high temperature (typically above 800 °C). This high temperature gives them high electrical efficiencies and fuel flexibility, both of which contribute to better economics, but it also creates engineering challenges.
Numerous companies are working on SOFC systems for a wide range of applications in addition to distributed generation, including residential power and heat generation (earlier post); aviation (earlier post); and APU systems (earlier post).
Customers who purchase Bloom’s systems can expect a 3-5 year payback on their capital investment from the energy cost savings. Depending on whether they are using a fossil or renewable fuel as fuel for the SOFC, they can also achieve a 40-100% reduction in their carbon footprint as compared with the US grid.
Since the first commercial customer installation in July 2008, Bloom’s Energy Servers have collectively produced more than 11 million kilowatt hours (kWh) of electricity, with CO2 reductions estimated at 14 million pounds.
Founded in 2001, Bloom Energy can trace its roots to the NASA Mars space program. For NASA, Dr. KR Sridhar, principal co-founder and CEO of Bloom Energy, and his team were charged with building technology to help sustain life on Mars using solar energy and water to produce air to breath and fuel for transportation.
In addition to CEO Sridhar, the company’s board members include John Doerr, partner, Kleiner Perkins Caufield & Byers; General Colin Powell, former US Secretary of State; Scott Sandell, general partner, New Enterprise Associates (NEA); T.J. Rodgers, chairman, SunPower; and Eddy Zervigon, managing director, Morgan Stanley. Bloom Energy’s investors include Kleiner Perkins Caufield & Byers, representing the firm’s first clean tech investment, as well as Morgan Stanley, NEA, and Northgate Capital.