There is no such thing as a "fuel cell battery." A battery stores and releases electrical energy. A fuel cell turns hydrogen gas or methane or other hydrocarbons into electricity. The Bloom Box is a generator based on fuel cells instead of an internal combustion engine. It is "legit." Fuel cells are "legit." They work. The problem is that they are much more expensive than ICEs and don't last as long. As I said in the other thread on this same topic, this box is good if you need a generator and you are willing to pay a considerable premium for quiet operation. There's nothing earth-shattering about it. It is not a new source of energy. It's not even the only generator based on fuel cells. It might be a small improvement over earlier fuel cells.
Actually it is a very large step forward in fuel cell technology. To the original question, yes it is legit, as companies are already using them. Unlike eestor and many others, these are actually in use in the real world. Companies like Google, Ebay, Coke, Staples, Fedex and others are on board as we speak. The longest have been in operation being tested for about 18 months. The fuel cells are warranteed to 10 years. The advances are that they are much much cheaper to make and operated at fairly normal temperatures. You can find data sheets at www.bloomenergy.com. Currently they only have the commercial sized energy boxes (100kW). They say they plan on a residential sized box which will cost about $3000. They use oxygen and a fuel source. The fuel source is flexible, but the most commonly used one is natural gas. Google is currently switching over from nat gas to biogas. So yes, this looks like it is 'for real'. We will have to see how durable these things are, but barring big issues there, this looks like a very useful device in a number of situations.
I suppose you might consider 800 degrees Celsius to be a "fairly normal" temperature, but I consider it to be rather on the warm side.
I would consider that to be rather warm as well. Where did you hear/read that their fuel cells operate at that temperature? From what I have read at their site, the have resolved both the high cost and high temps in their Solid Oxide Fuel cells. edit* Hmmm, nothing really about a lower temp that I can find. Just something from engadget showing one of there guys with a hand on one showing it is running 'cool' and a description of cool air coming out the vents at the bottom. Could be they do run at a high temp and reuse that internally? Or somehow shunt of the heat through the ground? By their description of 'solving' the engineering issues they may be talking about making the fuel cells last longer even though they run at higher temps?
Well, they claim that running natural gas through their fuel cell is twice as efficient as burning it to produce electricity. Which, if true, would be ... not unreasonable. But ... They list it at 0.77 lbs C02/KWH, using natural gas. The only DOE figure I could find for the existing installed base of generation was 1999, 1.3 pounds CO2 per kilowatthour. So, definitely more efficient than the average natural gas fired generator in 1999. However, it's essentially no different from a modern combined-cycle gas-fired electric generator, which I see listed in several places as producing about 0.8 lbs C02/KWH. So it's not twice as efficient as the next best currently available technology for converting natural gas to electricity. It's modestly better, and can be had in small sizes. And both are less efficient, overall, than using natural gas to heat your home with any type of modern furnace. But that's apples and oranges, I guess. They list a 100 KW generator at $800,000. A diesel unit would cost about $25,000. Same thing in propane, about the same price. Less efficient, obviously, dirtier, obviously, but 3/4 million buys a lot of fuel. Download the specs, quick calc: Uses 8 gallons diesel/hour fully loaded. Assuming price of diesel is about the same as natural gas per unit of energy, and this cuts your bill in half, then it would pay for itself in just under 8 years of continuous use at full load. That's not bad. Second quick calc. A therm of natural gas generates 11.7 lbs C02 when burned. So their .77/KWH = 0.066 therms/KWH. Currently, a therm, wholesale, is about $0.50. So, yeah, that's some cheap electricity, other than the capital cost.
Their site gave 800 C. as the operating temp of this type of fuel cell. They also talk about how the natural gas must be reformed at high temperature before it goes into the fuel cell stack. When they claim to be more efficient than an ICE-based generator, they're probably assuming the waste heat is wasted, As Jayman pointed out in the other thread on this same topic, modern systems that utilize the waste heat are extremely efficient. (An ICE must be continually cooled, thus the waste heat, which your car dumps into the environment, but which a stationary system can utilize. This type of fuel cell requires heat to reform the natural gas, but presumably this heat is essentially a catalyst which need not be dissipated.) I still say the principal advantage of this thing is lack of noise. If you need quiet, and are willing to pay, it's a good gadget.
If a residential-sized system could be designed with CHP the efficiency and savings could be enormous But so would the installed cost, I fear
Isn't it wonderful? With only 5 decades, billions in research, we've managed to create a device that wastes either natural gas or electricity in a way that (had it simply been used as its original energy) only decreases efficiency by a factor of 4. Hell, the fuel cell car, is supposed to be down under a half million dollars in less than a decade now (never mind that they've been saying that for 5 decades). Won't someone help me wipe the smile off my face? Well, now you know how THIS member feels about it. And don't even get me started on how far battery research would be right now if those billions had been put to better use. .
