The Bloom Energy Server (the Bloom Box) is a solid oxide fuel cell (SOFC) made by Bloom Energy, of Sunnyvale,
hydrocarbons produced from biological sources) to generate electricity on the site
where it will be used. It can withstand temperatures of up to 1,800 °F (980 °C), that would cause
many other fuel cells to break down or require maintenance. According to the company, a single cell (one 100 mm × 100 mm metal alloy plate between two ceramic layers) generates 25 watts.
Bloom stated that two hundred servers have been deployed in California for corporations including eBay, Google, Yahoo, and Wal-Mart.
COMPONENTS
The Bloom Energy Server uses thin white ceramic plates (100 × 100 mm) that are made from components found in beach sand. Each plate is coated with a green nickel oxide-based ink on one side, forming the anode, and another black (probably Lanthanum strontium
manganite) ink on the cathode side.According to the San Jose Mercury News, "Bloom's secret technology apparently lies in the proprietary green ink that acts as the anode and the black ink that acts as the cathode..." but in fact these materials are widely known in the field of SOFCs. Wired reported that the secret ingredient may be yttria-stabilized zirconia based upon US patent that was granted to Bloom in 2009; but this material is also one of the most common electrolyte materials in the field. US patent 20080261099, assigned to Bloom Energy Corporation, says that the "electrolyte includes yttria stabilized zirconia and a scandia-stabilized zirconia, such as a scandia ceria stabilized zirconia". ScSZ has a higher conductivity than YSZ at lower temperatures, which provides greater efficiency and higher reliability when used as an electrolyte. Scandia is scandium oxide which is a transition metal oxide that costs between US$1,400 and US$2,000 per kilogram in 99.9% pure form. Current annual world wide production of scandium is less than 2,000 kilograms. Most of the 5,000 kilograms used annually is sourced from Soviet era stockpiles.
To save money, the Bloom Energy Server uses inexpensive metal alloy plates for electric conductance between the two ceramic fast ion conductor plates. In competing lower temperature fuel cells, platinum is required at the cathode.
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