The Bloom Box is traditional fuel cell stacks consisting of ceramic and proton exchange membranes separated by metal catalyst plates. However, instead of luxurious platinum, Sridhar has engineered an inexpensive metal alloy substitute. Methane (or other hydrocarbons) and oxygen are fed in, the whole thing is heated up to 1,000 degrees Celsius, and electricity comes out. Bloom estimates that a box filled with 64 ceramic disks can produce enough juice to power a Starbucks.
Bloom Energy is secret sauce that makes it special. It is used to create an ink-coated floppy-disk-size ceramic tile. These are then stacked into small blocks, and multiple stacks are housed in a unit about the size of a refrigerator. The recent cost for each hand-made Bloom Box of the business size is $700,000-800,000. Bloom box ceramic plates are prepared by baking common beach sand and each ceramic plate is coated with a "secret" green ink on one side and another secret black ink on the other side.
According to eBay CEO John Donahoe, who spoke to "60 Minutes”, eBay's five boxes run on landfill waste-based bio-gas and generate more power than the company's 3,000 solar panels. “When averaged out over seven days, the Bloom Box generates five times as much power that eBay can use.” Right now, Google, Fedex, Wal-Mart, Staples, the San Francisco Airport, and the CIA, to name some of the most high-profile companies and organizations are testing the box in California. A four-unit box, using natural gas, has been powering a Google data center for 18 months.