Hey, presto!

It has been in the news, rubbing shoulders with Sachin Tendulkar’s two tons and controversial Twitterspeak! The magic energy box that generates power for a few thousand homes from a small fuel cell box.

Several major companies, including Google, eBay, and Walmart, have already bought Bloom Energy's technology, and in the few months these fuel cells have been in operation, they've generated 11 million kilowatt hours of electricity (about enough to power 1,000 homes for a year).

The technical details of it is still unknown besides the fact that this is a kind of fuel cell. According to Bloom, the technology is based on planar solid oxide fuel cells that Sridhar developed as a professor at the University of Arizona. A type of solid-oxide fuel cell (SOFC), which unlike hydrogen fuel cells, can operate at high temperatures (typically well over 600 ºC) and can run on a variety of fuels, these are more efficient than conventional turbines for generating electricity. Cost and reliability problems associated with these have been tackled by the company.

Bloom sells 100-kilowatt modules. They're made of small, flat 25-watt fuel cells that can be stacked together. A complete 100-kilowatt module, with multiple stacks and equipment for converting DC power from the stacks into AC power to be used in buildings, is about the size of a parking space. The company says each module can power a small supermarket.

A 400-kilowatt system powers a building at Google that contains an experimental data center.

The company's founder and CEO, KR Sridhar, says the technology--when it's powered by natural gas--can cut carbon dioxide emissions in half compared to the emissions produced conventional power sources, on average..

The long-term goal is to use the technology as both a way to generate electricity and to store it. It's possible to run the fuel cells in reverse, pumping in electricity to generate fuel. The system could then be used to store solar power generated during the day as a fuel for use at night. More work is required for this.

Definitely things looked poised for renewable power. Time to invest more there, right?