Electricity in a Box: Bloom Energy Servers

Lots of publicity over the past few days about the new BLOOM BOX ‘Energy Server’ – an on-site source of electricity powered by a natural gas burning fuel cell. Details are awfully sketchy, but Bloom Energy CEO K.R. Sridhar paints a tantalizing vision of an off-grid future built around his energy server concept. A couple of things seem clear:

1. The Bloom Box appears to be a Solid Oxide Fuel Cell, technology that has been in the commercial sphere for close to a decade. A number of companies claim some commercial SOFC expertise; WIKI has a good intro to SOFC.

Sridhar implies the Bloom version of SOFC makes substantial improvements over current products, but here the details from Bloom fade out. Have they achieved a breakthrough in conversion efficiencies and waste heat recovery? In manufacturing costs? In maintenance and longevity?

If you assume that the 100kW unit spec’d on the Bloom Energy website is the same as the $800k commercial unit they discuss, then the per-kW installed cost of the Energy Server system would be more expensive (but not too far out of the same ballpark) as a fully installed, grid-integrated (but much smaller) residential solar electric system. Not bad for the first shot out of the box, but still a long way to go before Energy Servers will replace your local electric company.

2. Bloom’s primary energy source is a hydrocarbon gas – natural gas in the demonstration cases, but LPG, syn gas or their bio-derived equivalents would also do. In any case, it’s a 2-step chemical process:
– Catalytically ‘burning’ the gas with atmospheric oxygen to produce Hydrogen and CO2
– Electrolytically combining the hydrogen with more oxygen to produce electricity and water
One potential but real advantage of Bloom’s modular SOFC approach is its ability to conveniently recover waste heat, at a usefully high temperature.

The inconvenient detail that prevents this from being a totally green technology is, of course, CO2, the unavoidable result of using a carbon based primary fuel. Hydrogen fuel cells provide the dream-world answer, but until we have a huge, economically viable of source of Hydrogen that doesn’t depend on a carbon-based source, the hydrogen economy will remain just that – a pleasant day dream.

3. Bloom Energy and its venture capital backers have lined up an impressive array of corporate demonstration projects and high profile supporters, and they’re orchestrating an effective publicity blitz – which will surely boost an IPO somewhere (probably not too far) down the road.

They deserve some applause: Bloom, along with the rest of the SOFC community, have been working at the this for a decade, and the R&D cycle is beginning to yield results that the marketplace can put through the economic feasibility wringer.

But they deserve some skepticism, too. We will need a lot more experience – and a lot more solid data from Bloom – before we can start to sort the real story from the hype.

So the best advice is patience. Even if we assume that Bloom truly has made some startling breakthroughs in cost, efficiency and practicality, moving the technology from gee-whiz demonstrations to day-in day-out commodity will not be a quick or easy exercise.

NOTE: Most of the current news stories – including the CBS 60 Minutes clip – have a flavor of ‘Hey, guys, look at this cool press release!’ Here are a couple that dig a little deeper – the Guardian article is especially good.



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3 Responses to “Electricity in a Box: Bloom Energy Servers”

  1. Wallace Brand Says:

    I agree with you that CO2 will remain in significant quantities. But I used the word “toxic” pollution advisedly. There is nothing toxic about CO2 unless you breathe too much of it to the exclusion of oxygen, but by that standard pure water is toxic also. In fact I am advised that CO2 is artificially generated for use in some greenhouses because it is good for the plants.

    The only reason that many are down on CO2 is because they believe that silly theory about global warming based on fudged data. But if you are concerned about CO2, fuel cells will reduce the CO2 significantly. The amount of CO2 emitted is a direct function of the weight of the fuel consumed. If fuel cell efficiency is twice as great as that of conventional generation, the amount of CO2 emitted, per kWh will be half as much.

  2. Wallace Brand Says:

    The FCE and Versa advantage.

    The Bloom fuel cell is reaping the benefit currently of major publicity.

    However the Fuel Cell Energy of Danbury, CT Molten Carbonate fuel cell and Versa Power Systems of Littleton, CO Solid Oxide fuel cell appear to be far ahead of Bloom. Bloom also has a Solid Oxide fuel cell.

    FCE targets loads from 300 kW to 3,000 kW. FCE has already cut its costs so that its largest model can now be manufactured so as to sell margin positive. It currently has 60 installations around the world. FCE owns 42% of Versa Power Systems. Versa Power does not yet market a commercial product but has already gotten the cost of its smaller fuel cell down to $700 per kW through its participation in the billion dollar SECA program. By continuing to participate in that cost reduction program it expects its fuel cells to cost only $400 per kW by 2012. Bloom predicts its fuel cells will be commercial in about 10 years.

    Neither FCE nor Versa use platinum catalysts and neither need to be fueled with hydrogen. These are advantages that Bloom implies are exclusive to its product. The FCE fuel cell, in addition to using natural gas as a fuel, can also use propane, mine mouth methane, bio-gas and byproduct gases from industrial processes such as sewage effluent, methane from beer brewing and baking, and even paint fumes from the painting facility of an auto manufacturer.

    Most American houses have a peak load of 10 kW. The Versa Power Solid Oxide fuel cell is suitable for that use but can also be scaled up to 100,000 kW plants.

    Bloom’s 100 kW fuel cell weighs 100 tons or 200,000 lbs according to its spec sheet. That is 2,000 lbs per kW. But the Versa Power fuel cell weighs only 200 lbs per kW, an order of magnitude lower. Versa Power has been cooperating with the US Airforce on developing power supply for military drones and with the US Navy on developing power supply for mobile underwater platforms. At 2,000 lbs per kW, Bloom fuel cells are far too heavy for this purpose.

    FCE’s stationary fuel cell has an efficiency of 47% after its DC output (efficiency 54%) undergoes losses due to its conversion to AC. Its efficiency in small sizes permits it to be located near its loads so it does not have to provide for losses over transmission and distribution lines. Conventional coal fired steam turbine generation must get up to sizes of some 500,000 to 600,000 kW to reach an efficiency of 38% (or 43% for supercritical units). Power from these giant units when adjusted for transmission line and distribution line losses to the customer’s meter, may only have an efficiency of 29%.

    FCE can also be used as a combined cycle or hybrid. When its exhaust is fed into a turbine, its electrical efficieny increases to 56%. It can be used with backpressure turbines at gas transmission pressure step down stations where it can develop efficiency of 60%. It claims that with much larger units of 40,000 kW it can achieve an electrical efficiency of 78%

    It can also cogenerate because the units is on site, the heat will only have to travel a few yards. Heat energy can’t travel for long distances. When there is a need for domestic hot water, space heating or air conditioning at the site of the electrical load, the fuel efficiencly can grow as high as 90%+ as it has at one installation in Germany.

    FCE has partnered with POSCO Steel Co. of South Korea. It is one of its best customers. POSCO has built a factory to manufacture the mechanical and electrical portions of FCE’s fuel cell leaving the stack elements to fCE. FCE is currently manufacturing at a rate of 30,000 kW per year and will be raising its capacity to 50,000 kW per year.

    The FCE and Versa Fuel Cells can eliminate transmission and distribution lines and also 99% of the toxic pollution emitted by base load coal generation that provides for more than half of all kilowatt hours generated by conventional generation today.

    • Bob Brothers Says:

      Very nice, informative run-down, Mr Brand. Thanks for the citing some efficiency data (sources?)

      My only real quibble is with your last paragraph – the “can eliminate … 99% of toxic pollution” statement. While this may be true of sulfur and metals like Hg, it is certainly incorrect to imply that the fuel cell is 99% polution-free. As long as the hydrogen source is organic – even bio-gas, paint fumes, ag waste – CO2 is the inevitable by-product. Even if H2 is ultimately sourced from non-fossil electricity (ie solar, nuclear, wind), the carbon footprint will still be considerable, due to the equipment / facilities infrastructure.

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