Does this make sense from an energy conservation point of view? As I see it, the Honda system works like this:
natural gas from the gas main runs an IC engine ( a modified Automobile engine)
the engine runs an alternator, which supplies electricity to the house, and feeds the surplus back into the power grid (your meter spins backwards)
The heat from the IC engine exhaust goes through a heat exchanger, and heats hot water, which heats your house.
So, you get electricity and heat. Is the added complexity worth it? If you simply burn natural gas to get heat, your system has a certain efficiency (stack efficiency) which tells you roughly how much heat is going into your house, and how much is going up your chimney (wasted heat). Is the Honda system better at improving stack efficiency?
What’s the payback period for such a system? Would wholesale adoption of this save a lot of energy (nation wise)? Obviously, the energy that the alternator uses is not available to heat your house-so you have to burn etra fuel to get the same number of heating BTUs.
I heard about this system years ago-the engines were made by FIAT-I don’t remember it being very popular.
You do realize we’ve had 98% efficiancy furnaces for quite a while now, right? That other 2% isn’t even enough energy to get the carbon monoxide up the chimney (this is why HE furnaces have to be power-vented out the side of a house), let alone power your house AND supply enough power to turn your meter backward.
Also, I think most energy companies do not like you sending power back over the wires, as it poses a danger to workers whi might be working on what they beleive is an unpowered line.
The solar power mail lists I am on at work indicate that in California you are required to have a device that senses when the power on the line side goes down and not send power out to the line side. So the problem of powering unpowered lines is more or less solved. It is an added expense for home generation.
One problem is that you’re buying natural gas at retail and using it to generate electricity. Presumably the electrical utility is buying natural gas at a cheaper wholesale rate to run its generators. Also, the IC engine is going to need regular maintenance, probably frequently since it’s running 24x7. The electrical utility has people on staff who are trained to do this, so unless you’re prepared to do this yourself, it’s going to cost you more. And you’re also generating a lot of noise and air pollution in a residential area, which is going to annoy the neighbors.
One idea I heard that did sound appealing was the idea of using a plug-in electric hybrid auto as an temporary emergency generator, in the case of a blackout. I don’t know if this will be available though.
Well, as i say, the idea only makes sense if you get the added electricity for free-presumably, the IC engine sheds so much heat, that you recover the waste heat and use it to heat your house. If this assumption is wrong, then i would say the whole idea makes no sense 9except for HONDA-they get to sell more engines).
Regarding stack efficiency: we recently replaced an old (steam0 furnace that was rated at very low efficiency (75%). the new boiler is about 87%-does this mean we should use 125 less oil? Or is the translation different?
This statement made me wonder just how much electricity is generated in the US using natural gas (not much, I suspected, maybe 5%), the percent was a surprising 20 according to this site with lots of information.
What I can find is this which is a product that uses natural gas to produce hydrogen for a fuel cell vehicle while also heating the house and producing electricity (produced in conjuction with Plug Power). I know that they are also producing natural gas cars that can be “philled” at home. But I can’t find anything like what the op is discussing. Help.
Natural gas can be burned much more efficiently in a Diesel engine (CI) than in a “modified car engine” by which I assume you meant spark ignition (SI) Some of the CI advantage can be reclaimed by raising the compression ratio of the SI engine to take advantage of the high octane rating of natural gas. Conversion of CI engines to natural gas is VERY simple by comparison to SI engines though. CI engines have a large durability advantage as well (though SI engines do last longer burning NG than gasoline, because the later degrades cylinder wall lubrication and fouls the oil faster)
You may well have higher transmission losses. Currently, large generating stations connect to the grid at very high voltage segments. If a significant part of the generating capacity were connected via the typically 650-1300V residential distribution infrastructure, and the industrial loads were distant, then I can see it being worse.
The big issue I see is that Joe Average currently can’t fix his car. Implement this plan, and not only does he need a another reliable mechanic, but one that makes house calls.
That sounds very similar to what ralph124c described, but the press release is about 16 months old and I can’t find anything similar on Plug Power’s website, so I don’t know if this project ever went anywhere.