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Can solid-oxide fuel cells like the Bloom box remake the energy landscape?

The views expressed are those of the author and are not necessarily those of Scientific American.

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The fuel cell has a long history. Various types of fuel cells have been part of the NASA space program, and the basic science of how fuel cells work—an energy carrier comes in, creates a flow of charge in the anode, which migrates to the cathode creating a current, and separated by some form of electrolyte—has been known for more than a century. Yet, Bloom Energy believes the time is finally right for one of the more promising fuel-cell technologies—solid-oxide fuel cells, so-called because the electrolyte is a solid rather than the more common liquids—to produce electricity on a grander scale.

The company, featured in a 60 Minutes segment on February 18, has developed a version of the solid-oxide fuel cell that relies on natural gas to generate 100 kilowatts of electricity, all for $800,000. Even at that price, the company has sold 30 of them to customers such as eBay, Google and Wal-Mart, primarily so that those companies can ensure dependable electricity even in a situation where the supply from the traditional grid is interrupted. The expensive technology would replace the more typical diesel generator often employed by hospitals and the like, which can cost as little as $25,000 not counting costs associated with the petroleum-derived fuel.

In fact, the Bloom box makes no economic sense whatsoever without various government subsidies, particularly a federal tax credit paired with incentives from the state of California. According to Bloom’s CEO K. R. Sridhar that means electricity from his box costs as little as nine cents per kilowatt-hour, or three cents less than California’s average electricity price.

But solid-oxide fuel cells have run hot and cold over the years, literally. That’s because the technology relies on operating temperatures of as much as 1,000 degrees Celsius and, perhaps because of those high temperatures, remains acutely vulnerable to breaking down, particularly all the extra bits required to make the fuel cell run: fans, heaters and devices to process the natural gas fuel. Plus, microscopic defects in the materials that compose the anode, cathode and electrolyte can shut the whole thing down and the cell must warm up to operating temperature before it can produce electricity, making it slow to start.

Bloom claims to have surmounted these problems for its "Energy Server," but they are far from the only ones working on it, as evidenced by research from the recent ARPA-E summit. Physicist Gunter Luepke and physicist-in-training Erik Spahr at the College of William and Mary are developing such a fuel cell that uses infrared light to enable faster start-up and longer lifetimes, potentially suitable even for cars. And materials scientist Eric Wachsman of the University of Maryland has successfully dropped operating temperatures to as low as 400 degrees Celsius.

Of course, since such solid-oxide fuel cells rely on natural gas, they are not exactly the zero-emitting electricity source of tomorrow—producing roughly one-third less CO2 per kilowatt-hour than an internal combustion engine. But plants can be gasified to form the fuel, making the process at least carbon neutral. Whether such solid-oxide fuel cells can live up to the hype is another question. After all, just a few years ago it was Plug Power or Ballard Power Systems and proton exchange membrane fuel cells that were going to be the force for home electricity and car propulsion.

Image: Bloom Energy Server being installed. Courtesy of Bloom Energy

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  1. 1. sethdayal 9:33 pm 03/5/2010

    When you add the 25 times more potent methane from natural gas leakage in the delivery system, natural gas actually emits more GHG’s than coal.

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  2. 2. paradox715 1:23 am 03/6/2010

    sethdayal, you have no idea what you’re talking about. Coal produces up to 65% more CO2 than natural gas when burned for electrical generation. Fugitive emissions from the natural gas industry are incredibly small relative to the horrendous emissions coming from coal.

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  3. 3. paradox715 1:31 am 03/6/2010

    To add to that, you can see the entire methane release in the US is relatively minor – 10% of GHGs – the vast majority which come from agriculture, rotting food in landfills, and cows. Wheras almost 40% of the entire USA emissions come from coal based power generation.

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  4. 4. BONSOLAIRE 4:04 am 03/6/2010

    I believe SETHDAYAL’s comments were based on the fact that the methane contained in the Natural gas (IF BIOGAS ESPECIALLY) the methane, not having been combusted is thus released into the atmosphere. Your calculation of 10% of GHG’s is not relevant as the comparison should be made on GHG released per KW/h of energy produced. AS such, Coal would release marginal levels of Methane and substantial levels of CO2, while this fuel cell device, not apparently not combusting the methane, would theoretically release 30% the CO2 of traditional energy sources as stated in the article and substantial levels of methane from the natural gas. Since methane is a more potent GHG than CO2 is, you could then assume that a 10MW facility of these fuel cell systems would produce 30% of the CO2 of a typical coal plant of the same power generating capacity and substantially more methane resulting in a net increase in GHG assuming the analyst was intelligent enough to include both GHG’s in the equation.

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  5. 5. JamesDavis 7:34 am 03/6/2010

    Sethdayal: You are more right than you are wrong and you are on the right path. Natural gas extraction’s waste water contains a larg amount of radioactivity caused by its fracking, which makes it more harmful than coal, but a little bit less, about 1%, polluting to the atmostphere. Both coal and natural gas should be completly eliminated from our energy producing systems. This technology is too expensive and too unstable to be an affordable or practical source of energy and never come to market. It is not worth wasting tax payers money on.

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  6. 6. dbmccauley 8:18 am 03/6/2010

    So why is bloom getting so much press if it creates more GHG, is expensive, has a slow start-up and is less reliable than diesel? Especially diesel on natural gas.

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  7. 7. j.quasimodo 9:19 am 03/6/2010

    BONSOLAIRE believes that the methane "is not combusted". Natural gas is mostly methane, and using it in the fuel cell is equivalent to combustion, in that it s converted to CO2 and water in order to get energy from it. So no, it does not inherently release methane as such to the atmosphere. As to JamesDavis’ contention that waste water from methane extraction contains radioactive material, perhaps some NG waste does, but NG comes from a range of different technologies and any radioactive waste could be managed. Yes we’ll eventually phase out all fossil fuels but NG is a better stopgap than coal while we get our act together.

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  8. 8. sethdayal 11:05 am 03/6/2010

    As much as 5% of natural gas pumped is leaked into the atmosphere along the pipeline/production system. That methane is 25 times as potent a GHG as CO2.

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  9. 9. Crucialitis 11:35 am 03/6/2010

    …I lost so much money on Ballard.
    Thanks for depressing me, SciAm. lol

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  10. 10. leelarsen 6:03 pm 03/6/2010

    I wish SciAm and other somewhat "mainstream academic" journals/mags would do an article on Vanadium flow redox batteries. I think these are much more important to the future of energy storage and solving the intermittent down-time problems associated with wind and solar options and can help make them more cost-effective to install.

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  11. 11. paradox715 12:11 am 03/7/2010

    While you’re correct that methane is 25x more potent than CO2…

    CO2 emissions from the USA were 6 Billion tons in 2007. Methane emissions (including those from natural gas) were only 30 million. Adjusting that to GHGE warming equivalent brings it to 700 million tons of CO2E from methane.

    Of that 700, 215 is from cows, 195 is from landfills, 177 is from natural gas systems, 71 is from coal mining.


    So even if you doubled the amount of natural gas and halved the amount of coal mining you’d be adding only 140 million metric tons of GHGE to the atmosphere from methane – while you’d be reducing coal CO2 emissions by up to 65% -> meaning 0.65*2,162 = 1,405 saved.

    Makes sense to me to spend 140 to save 1,400

    While issues like water are a huge deal and should be regulated & monitored by state governments – the amount of radioactive materials (uranium, thorium) and other poisons like mercury are phenomenal from coal.

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  12. 12. paradox715 12:28 am 03/7/2010

    Also note that the net emissions savings by using gas would be about 21% of current emissions, making it a feasible way of meeting the entire US emission reduction goals without resorting to incredibly expensive technology right away. Then we just phase in renewables and high tech stuff over time to keep beating the tougher targets.

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  13. 13. RADScientist 9:13 am 03/7/2010

    There are many benefits to Bloom’s solid oxide fuel cell technology if it succeeds. The distributed nature of the device could help foster adoption of electric vehicle since it could help offload some of the stress on the national grid.

    Bloom’s energy server can also help reduce the amount of fresh water used to generate electricity at centralized coal-fired plants especially for arid climates such as in the southwestern US.

    I think it is important that we look at the big picture of the value of technologies such as this instead of just focusing on whether its claims of GHG reduction are accurate.

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  14. 14. YukonJack 5:02 pm 03/8/2010

    Communication is clearly difficult, especially when people don’t READ what others write. Let me quote from Sethdayal: "When you add the 25 times more potent methane from natural gas LEAKAGE in the delivery system…" [EMPHASIS MINE] Sethdayal’s point is that methane, if leaked, is a much more potent GHG than carbon dioxide produced by combustion. This lies at the base of concerns about melting of methane clathrates in the permafrost zones and on the seabed.

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  15. 15. sofistek 2:33 am 03/9/2010

    Will Scientific American articles about alternative energy systems save the planet?

    We see so many of the "save the world articles" (nearly always asking the question, "will/can xyz save us") that there must be a major energy problem facing the world. I wonder if conservation and powering down are in the minds of anyone but a few knowledgeable folk.

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  16. 16. Forlornehope 8:51 am 03/9/2010

    Rolls-Royce, the gas turbine company not the car maker, has been working on SOFC’s for some years. That’s a $10bn plus sized global company that is quite strong in various areas of energy generation. It’s difficult from the reporting to understand what is special about the Bloom box, apart from the hype!

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  17. 17. dwbd 10:26 pm 03/9/2010

    The DOE is using EPA numbers of 1.4% leakage from NG production, in the USA. Higher values have been reported by Keeling of 6-10% & Crutzen of 4%. Using the EPA #’s or 1.4% X25(by weight) X 16/44 (to vol)=12.7% GHG contribution.

    DOE numbers for USA electricity generation are Coal: 960 gm CO2/kwh, NG 597 gm CO2/kwh

    So adding in Methane gives Coal: 1009 gm CO2 equiv/kwh, NG 672 gm CO2/kwh.

    The NGas emissions are elevated by raw NG containing up to 20% heavier (higher CO2 release) hydrocarbons, and up to 8% CO2.

    The increasing use of LNG will greatly increase Methane emissions from NG usage, as LNG storage must be vented. And less developed nations will have a much higher percentage release of Methane from NG usage.

    So, the improvement of NG over Coal is quite simply not significant enough to justify all the hype being pushed about it in the press. As a-matter-of-fact it is an INEXCUSEABLE, STUPID AND IDIOTIC IDEA TO USE NG FOR BASELOAD POWER GENERATION.

    The #2 priority use of NG should be to replace imported Oil – which is rarely used for power generation, by converting it to Methanol/DME and using it as a transportation fuel.

    The #1 priority use of NG is to supply peaking & standby power generation, and to supply the very high winter peak heating energy needed in Northern regions.

    Also of course as feedstock for the chemical Energy.

    It is INCREDIBLE, that in one breath, renewable advocates are willing to spend huge amounts of capital, like $400 per kwh, and $2k per kw for energy storage (like batteries or pumped hydro) and in the next breath want to throw away our already cheap NG Chemical Energy storage (5-8 cents a kwh) on baseload power generation – which can much better be done with Nuclear.

    NG supplies are highly limited. The USA has to import 14% of it’s NG. And the latest EIA forecast is a 13% increase in NG production by 2035. While Total USA energy consumption will increase by 15%. So NG won’t even be able to keep up with Energy Consumption Growth, never mind replacing Imports, Never Mind doing replacing Filthy Coal.

    WE MUST USE NUCLEAR & HYDRO EXCLUSIVELY FOR ALL BASELOAD POWER GENERATION. USE OF NG IS A CRIMINAL ACT that will cause NG prices to explode, shortages to become frequent, and real pain for the consumers WHO ACTUALLY NEED the NG, like homeowners in Northern regions, for their Winter Heating Peak Load.

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