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Another Step Forward In Small Scale Electrical Generators
NicknamesAreStupid writes "Product Design & Development reports another breakthrough in small scale solid oxide fuel cells. This methane-fueled cell achieves about 50% efficiency at around 2kW, enough to power an average home. It does so by efficiently recycling its heat to perpetuate the process. Of course, this is not practical for most homes, which only have natural gas that contains nearly one fifth impurities. However, that could change if gas suppliers refined their product."
Could it be used on board an electric vehicle to provide power in lieu of a battery?
It must have been something you assimilated. . . .
It makes all the machinery frail and brittle. I'll settle for a few percent less with a Stirling engine running off the natural gas we have now. And most likely it will run on anything I throw into the 'boiler'.
“He’s not deformed, he’s just drunk!”
If there's already a gas supply in place, why use electricity for heating?
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
A classic problem with fuel cells is extreme intolerance to contaminants. Even trace amounts of contaminants tend to damage fuel cells. Hydrogen fuel cells need cleaner hydrogen than is normally available commercially. Research continues on making fuel cells more tolerant of contaminants, but it's hard. Fuel cells are surface chemistry systems. 40 years of research hasn't solved this problem.
Reverse osmosis water purification systems once had the same problem. Today they routinely take in raw seawater and pump out clear water. They just need a backflush cycle once in a while to flush the crud off the membranes. Fuel cells aren't there yet.
I can just picture explaining to my wife that she has to unplug the refridgerator before she can turn on her haid dryer.
I already have a home source of methane. I just need a nice way to capture it.
now we need to go OSS in diesel cars
I can just picture explaining to my wife that she has to unplug the refridgerator before she can turn on her haid dryer.
Green Acres is the place to be...
Unfortunately, air conditioning does not work as well off natural gas as a heater. My boat needed more than 2.5kw for the air conditioners. In Houston, most of the standby generators in case of hurricanes are 5kw to 7.5kw, and some larger houses have 15kw.
I have a 2.9Kw solar, so let me explain how this works.
My bet is that this device does not switch on and off real fast, nor does it modify it's out put much.
And for most systems, like the solar, that produce DC, you need an AC converter. The most efficient ones take the "heartbeat" of the grid to time themselves and makes sure you are not out of sync with the grid power.
That means while you are using .5 or 1Kw steady, you are pumping power out to the grid, running the meter backwards.
When it comes time for a peak surge, you draw from the grid to provide the peak.
So my solar that puts out 22 to 26KW a day during the peak months of May to September roughly half that energy goes back on the grid, I pull some back for peak usage, and pull the rest back at night.
The GRID is my battery, and it is better than free, I get 3.2c credit for producing at peak and pulling at night.
Never answer an anonymous letter. - Yogi Berra
Electricity can be more than 100 % efficient if you use a heat pump ( http://en.wikipedia.org/wiki/Heat_pump ).
The average American house consumes about 1.5KW electricity average across the days (and nights) through the weeks of a year. But they not infrequently peak demand in spikes over 2KW. A hairdryer or space heater draws about 1.5KW. A dishwasher (especially with extra washing or drying heat boost) will draw 1.5KW. An electric stove/oven can draw 4KW or even 7KW as it heats up. A vacuum cleaner can draw up to 1.5KW, especially if it's a strong one that gets jammed.
And all of those could happen at once. A couple happening at once is pretty likely at least once a year. Plus the rest of the 1KW regular demand, which is closer to 2KW max, averaged against quiet times closer to 0.1KW.
A home power supply should be close to half the 100A 120VAC panel, which is 6KW. A 5KW max supply is probably just fine. A 2KW fuelcell would need a battery that can output 5KW for at least a few minutes, perhaps while an alarm goes off warning the battery will drain down shortly and circuit breakers will snap.
Really all the residential fuelcells I've seen talked about are 5KW. A 2KW fuelcell seems like a good device for a yacht.
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make install -not war
The standard numbers that are tossed around for the average US suburban home (where a bit over 50% of the population lives these days), is 30 kWh per day, with a peak hour usage as high as 6 kWh, depending on location. IIRC, the peak hour tends to occur in the late afternoon and early evening, and varies somewhat between households: people coming home from school/work and turning on lights and A/C, parents firing up the washer/dryer, electric cooking, etc. We looked at converting to NG for cooking at one point; current code requires venting to the outside, which would in turn require some structural work. A contemporary single-family house in the US suburbs will be equipped with at least the equivalent of 125-amp 120-volt service (supports 15 kWh per hour max); the equivalent of 200-amp 120-volt service (24 kWh per hour) is not unusual.
Obligatory "Get off my lawn you damned kids!" anecdote. When my kids were in their early teens, I swear they could come through the front door and within 60 seconds, turn on 500 watts worth of assorted load each. Ever since, and after comparing notes with colleagues, I've claimed that one of the defining characteristic of dads who've had teenagers is a compulsive urge to turn things off and sit quietly in the dark.
Electricity can be more than 100 % efficient if you use a heat pump ( http://en.wikipedia.org/wiki/Heat_pump ).
You're forgetting that power plants have efficiencies of 30% or less. So add a heat pump with a typical COP of 3 and the overall cycle is no better than burning the gas directly. Now if the 50% efficiency figure quoted for this fuel cell is really just for the electricity generation side (i.e. does not take into account heat generation), then that may be more interesting. It would actually be a step up from standard power plants too so if it can be scaled up it should be.
You may "need" air conditioning, but there are ways and ways. With decent insulation, you need a lot less air conditioning. I don't know what your understory is like, but in many places you can store heat there in summer, and withdraw it in winter (using some sort of heat pump). That's not enough on it's own, but combined with decent insulation, it get's you quite close to reasonable. Then you need only a quite small amount of either air conditioning or heating.
That said, I'd expect that in Houston the most reasonable alternative would be solar. (And since you're in town, it's not reasonable to even try to get off the grid.)
But the first step is GOOD insulation. With good enough insulation, you could overheat a house just by living in it, even during a blizzard, but that much is unreasonable. It does, however, imply that you'll need some air condition, and air circulation, too, but the air circulation system could go via a heat exchanger, so not too much heat transferred via that pathway.
OTOH ... you won't see me investing in that kind of system. Yes, it would work, but it's too complex, and would probably require lots of maintenance. But with proper design, 2 KW should be plenty. It's just that proper design is quite rare. (FWIW, my wife thinks that we have good insulation. It is to laugh. The wind blows through the house, even with the doors closed. But it suffices for our environment [SF Bay]. Elsewhere I'd be much more interested in better insulation.)
I think we've pushed this "anyone can grow up to be president" thing too far.