Silicon Valley start-up Bloom Energy has unveiled the Bloom Box, a domestic fuel cell system that it says is simple and cheap to run. But it's not expected to be available for up to ten years.
There's an enormous amount of hype around the launch. On 60 Minuteslast night, founder KR Sridhar held up a brick-sized device that he claimed could power at least one home. He suggests that Bloom Boxes could eventually replace the electricity grid altogether.
But with the official launch not until Wednesday, technical details are thin on the ground.
The Bloom Box's catalytic plates consist of a stack of ceramic plates interspersed with an unidentified 'cheap metal alloy' - other similar cells require expensive metals such as platinum.
It can run on any fuel, says the company, from fossil fuels to biomass, which is combined with oxygen to create electricity, with carbon dioxide and water as byproducts. There's no word on the efficiency of the thing - other similar fuel cells can manage up to 90 percent - or of the running costs.
Sridhar says that he came up with the idea after working on a device for NASA that would be able to create oxygen for a Mars mission.
The company already has larger-scale versions - costing upwards of $700,000 - in use at eBay and Google datacenters, where it claims they've saved the companies hundreds of thousands of dollars in energy costs.
It says the domestic models should cost as little as $3,000 and be available within five to ten years. But with dozens of other companies working on similar technologies, it's entirely possible that Bloom could be beaten to market.
Bloom Energy has taken eight years to get this far, and has received $400 million in venture capital.