The Bloom box - doing fuel cells right

Todd Woody at the NY Times has had a couple of stories in the last few days on The Bloom Box, or Bloom Energy Server, a solid-oxide fuel cell designed as an on-site distributed generator. Present costs are still rather pricey - $7 to $8 capital cost per watt (or $7000-$8000/kW - I had this mixed up earlier - see this analysis from Jesse Jenkins for details) plus the cost of natural gas as fuel and any operational and maintenance costs (and they're only claiming a 10-year lifetime). Efficiency is quoted at 50 to 55%. Higher efficiency and lower capital costs would be essential to making it truly useful. Still, I find this a good step forward in the technology. Why?

A few points that distinguish this type of fuel cell from some of the others that have been discussed:

  • it is fueled by natural gas, not hydrogen. I.e. the fuel to run these already has a distribution system, and renewable sources (bio-gas) are possible.
  • it doesn't require precious metal as catalysts (it runs hot, instead, to get the electro-chemistry going)
  • it is stationary - waste heat can be used for local co-generation purposes (and it's at relatively high temperatures)

Right now a simple gas turbine generator would probably be a better choice for local generation (less costly and not much less efficiency), and a combined-cycle gas turbine runs at even higher total efficiency in conversion to electricity. But there is no way to improve the efficiency of those systems, while a fuel cell in principle can get much closer to 100% efficiency. So this sort of fuel cell may be a good choice for further R&D work, if there is real potential for prices to drop further and the efficiencies to improve; it's not very far away from being the first truly competitive large-scale fuel cell technology.

But it's not quite there yet.


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To add to your points in

To add to your points in favour, if the fuel cell technology that this is based on has the potential to switch to other fuel sources in the future (eg hydrogen) then it is an even better step in the right direction. It builds expertise and promotes economies of scale in the fuel cell business which should lower costs for future infrastructure in this area.

Just read the article...

Just read the article... indeed that's the direction they're headed:

One byproduct of fuel cells is water, and Bloom has patented and proved a fuel-cell design that could also tap electricity generated by solar panels and wind farms to electrolyze water to produce hydrogen that could be used as fuel in the cell.

“That’s the killer app,” said Mr. Sridhar, who said such a product probably would introduced within a decade.