Wednesday, February 24, 2010

Bloom box mania - behind the hype

Lot of fuss in the States about the 'Bloom Box'. Wild claims and fantasy. Let's just set it straight:

What is it? = a solid oxide fuel cell

What does it do? = convert one type of energy - hydrocarbon chemical - into another - electricity

Is it renewable? - Depends what you charge up the fuel cell with. As with electric cars, think beyond the battery. It runs on ethanol, biodiesel, methane or natural gas. At least one of these (the last) is not renewable. Ethanol can be distilled from plants. Methane can be tapped from landfill/sewage etc. Whether the first two are sustainable (the real question) depends on the original bio-material - plenty of controversy about biofuels right now. Indonesian palm oil? No thanks. Displacing food-growing? Also no. High fertiliser and pesticide input? (ie fossil fuel and pollution) Also no.

Is it efficient? = The unit is not even a mini-chp (combined heat and power) plant - so the heat output is wasted. Solid oxide fuel cells have an efficiency of around 50% - better than a conventional power plant (32%) but CHP is over 90%.

Should I buy one? = You're better off with a mini-CHP and using the heat. These're also fridge-sized, will heat your building a well as power it, are more efficient when grid-connected, and will be mass market in a couple of years. They are already fairly big in Japan.

2 comments:

Steve (Energy Savings through the use of window film) said...

Why is it not under consideration to provide CHP heat and electricity from a central location to private residences?

I am sure it would be far more efficient and cost effective.

I cannot wait until micro CHPs are available for homes. Any idea of likely capital investment compared with a condensing boiler?

DavidKThorpe said...

See my latest post Renewable domestic heating.