Bloom Energy Solid Oxide Fuel Cell

Bloom Energy is the company that develops, builds, installs Bloom Energy Servers. The company, started in 2002 by CEO .
The Bloom Energy Server consists of solid oxide fuel cells (SOFC). This technology has the advantage that it can be made out of low-cost materials with high energy efficiencies. The cells can run on a variety of fuels, including traditional fuel, natural gas, biomass gas, landfill gas, and ethanol.

Some other [[|fuel cell]] technologies have tried to overcome these limitations by offering combined heat and power (CHP) schemes to take advantage of their wasted heat. While CHP does improve the economic value proposition, it only really does so in environments with exactly the right ratios of heat and power requirements on a 24/7/365 basis. Everywhere else the cost, complexity, and customization of CHP tends to outweigh the benefits.

According to Bloomenergy solid oxide fuel cells (SOFCs) hold the greatest potential of any fuel cell technology. With low cost ceramic materials, and extremely high electrical efficiencies, SOFCs can deliver attractive economics without relying on CHP. But until now, there were significant technical challenges inhibiting the commercialization of this promising new technology. SOFCs operate at extremely high temperature (typically above 800°C). This high temperature gives them extremely high electrical efficiencies, and fuel flexibility, both of which contribute to better economics, but it also creates engineering challenges.

Bloom believes it has solved these engineering challenges. With breakthroughs in materials science, and revolutionary new design, Bloom's SOFC technology is a cost effective, all-electric solution.

Bloom Energy Server provides 100kW of power, in roughly the footprint of a standard parking space Bloom Boxes Servers are now (March 2010) in use at eBay, Google, FedEx, Staples, WalMart, Coke, Cox and Bank of American. Cost is between U.S. $700,000 and $800,000. At eBay, Bloom Energy is maintaining the machines under a ten-year maintenance contract. eBay CEO John Donahoe told 60 Minutes that the five Bloom Boxes installed seven months ago at the company's campus in San Jose, California, running on natural gas now provide almost 15 percent of eBay's electricity needs with a seven month energy savings of $100,000. At that rate, the Bloom Boxes should pay for themselves within three years.

ES-5000 Energy Server Specifications


Natural Gas, Directed Biogas

Input fuel pressure

15 psig

Fuel required @ rated power

0.661 MMBtu/hr of natural gas

Water required (for startup only)

120 gallons municipal water

Rated power output (AC)

100 kW

Electrical efficiency (LHV net AC)

> 50%

Electrical connection

480V @ 60 Hz, 4-wire 3 phase


10 tons


224" x 84" x 81"

Noise @ rated power

< 70 DB @ 6 feet

ES-5000 Emissions are suppose to be around 50% of grid Electricity


< 0.07 lbs/MW-hr




< 0.10 lbs/MW-hr


< 0.02 lbs/MW-hr

CO2 @ specified efficiency

773 lbs/MW-hr on natural gas,

carbon neutral on Directed Biogas

A smaller 1 kilowatt unit is planned for the next 5 to 10 years with enough energy for one home. Cost may be as low as $3000, plus fuel (natural gas). CEO K. R. Sridhar claimed it will be the size of a brick. That is the fuel cell plates only. The whole unit should be the size of a small refrigerator with efficiencies of twice the grid electricity.