The amount it generates is of little concern - what matters is where the methane (or other fuel) comes from. If the methane is produced from fresh biomass then the box is carbon neutral. But if the fuel comes from oil then it won't be carbon neutral.
I appreciate the idea of getting maximum use from things that have already been produced, but I'm pretty down on scaling biofuels up. I think there are better uses of land and freshwater. In practice, photosynthesis just isn't that efficient, and then the plant takes a big cut for its own growth and maintainence. Finally, there generally multiple inneficient steps for transformation into useful work. It is dismal compared to solar + battery + electric motor.
 unless it also produces carbon monoxide, which is unlikely considering the efficiency claims. Other than H2O, I'm not aware of any other possible byproducts of methane oxidisation.
The same was said for the ICE, and now our cars emit all sorts of crud. Ideally, that's all you get: CH4 + O2 ---> 2H20 + CO2. Practically, you get sulfur and other impurities. Specifically sulfur scrubbers (http://www.duke-energy.com/environment/air-quality/sulfur-di...) are often used to reduce the amount of sulfur, but they raise the amount of CO2 byproduct. It's a no-win situation.
So, fuel for this thing will be cheap in the near future (cheap for NG-fuel power plants too).
Not carbon-neutral though for those who are sensitive to environmental costs. For that, you'd have to set one up near a bio-methane plant or methane-capture facility. But really... there's no way a bunch of these things are going to pollute anything near what an equivalent coal-fired plant does. So adopting them would be a net win environmentalwise.
So, how many Starbucks to a Library of Congress? How about not estimating and giving us some useful metrics, preferable based on this newfangled "watt" unit?
Elsewhere in the article, they say Ebay got 100k USD of electric power from using 5 boxes for 9 months. Assuming 10c/kW.h, that's 1 MW.h in 6408 hours, coming out to about 154 kW for all five boxes.
Adjust for actual utility rates and exact usage.
30kw - can run 300 100 watt light bulbs continuously.
They could even throw in a refrigerator or two.
The problem with comparing a lightbulb or refrigerator, etc. is that the average person has to think... ok, so how many discs are in a box? how many lighbulbs do I have in my house? etc.
In the piece (which I admit is very fluff), the founder shows a box and says 'this is a european house', grabs another box and says 'this is an american house, or 4 asian houses'.
These are methods of explanation that the 60 minutes audience can understand.
The actual company is apparently launching on Wednesday, so I'd expect that on that day we'll hear more details.
Seeing as the device can use a different gases as fuel, wouldn't we expect that the output would be dependent on the fuel supplied?
It depends on where the limits are.
Consider the typical gas furnace. I understand that natural gas varies considerably in energy per gram (or per cubic feet at a standard pressure). Within limits, the system adjusts the amount consumed to account for that and appropriate output. Meanwhile, an electric hair dryer doesn't - it's heat output is determined by the input voltage, current, and wave shape.
The fuel cell we used @ VT in 1999 was 20kW and substantially smaller (it fit within a car's engine compartment).
Then again, that was pure hydrogen, not methane.
You can order a 65-kW microturbine from Capstone Turbine Corp for about $40,000 USD.
Natgas-powered microturbines have commonly been used for distributed power generation in industrial settings (hotels, hospitals, etc...)
See Ingersoll Rand: http://www.ingersollrandproducts.com/IS/Category.aspx-am_en-...
See Captsone Turbine Corp: http://www.microturbine.com/prodsol/solutions/chp.asp
Try Googling for "microturbine".
 Also, "Microturbines: Applications for Distributed Energy Systems" is a good book on the subject. Amazon: http://www.amazon.com/Microturbines-Applications-Distributed...
Microturbines aren't especially quiet either, but it's hard to know how much noise this thing makes without more information.
In the movie there is a statement that it is twice as effective.
How much a natural gas turbine of the same output costs?
Also, where does one get the energy to heat the magic box to 1800 F?
Well. It can't be worse than coal.
Suspend your suspension of disbelief and engage physics 101.
Do we have anyone here on HN who can actually confirm that these devices have been installed at Google?
I've taken an interest in various energy generation ideas over the years, and a fair amount of hoaxing has always gone on. Sometimes the hoaxes are quite sophisticated an investors who like what they see but know little about physics end up being defrauded out of large amounts of money. From what I've seen in this article/video this raises all the classic red flags which you could expect from a hoax operation.
I have a feeling you missed the part where they put hydrocarbons in one end.
“These fuel cells aren’t powering any off-site data centers,” said a Google spokesperson. “Instead, Bloom fuel cells are powering a portion of Google’s energy needs at our headquarters right here in Mountain View. This is another on-site renewable energy source that we’re exploring to help power our facilities. We have a 400kW installation on Google’s main campus. Over the first 18 months the project has had 98% availability and delivered 3.8 million kWh of electricity.”
Seriously, how is methane+heat=>electricity so outlandish?