Honda Co-Generation Unit

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Hi,
I was just wondering if in the USA anyone has one of these units? What it is is a small One Cylinder engine, with electrical power generation (1kw) and hot water heater heating (2.8 kw).
It is sort of efficient in that it unlike normal standby power generation, alot of the heat is used for heating and hot water, just line he Steam heat supplied in Manhattan New York.
Best, Mike.
http://world.honda.com/news/2004/c041020.html
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its a interesting concept. but how practical is it other than for emergencies?
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I'm not even sure how this widget is even designed to operate. They talk about it being used an average of 10 hours a day in a typical Japanese home, which makes it sound as if it's there to supplement the normal electric demand. It only produces 1KW, which is very small. The traditional emergency stationary backup units for homes are many times that. Plus, Japanese homes are typically much smaller than a US home.
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On Jan 3, 12:17 pm, snipped-for-privacy@optonline.net wrote:

i wonder if it includes a sychronous inverter allowing the meter to turn backwards? selling power back to the utility company.
certinally coal nuclear and oil fired plants with thoise big cooling towers waste lots of heat........
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snipped-for-privacy@aol.com wrote:

I'll wager their overall thermal efficiency is higher than these units. You can't escape the 2nd law...
--
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Sure... 100% is the theoretical limit for cogen. The Intelligen 5 kW unit got a combined 93% efficiency ((heat+elec output)/fuel heating value.)
Nick
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snipped-for-privacy@ece.villanova.edu wrote:

It must be something else than a single-cylinder engine generator then that the posting I saw said it was...
--
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A thermal power plant's useful output is electricity only. It's hard to generate electricity from heat, and a lot of the heat ends up being dumped by the cooling tower in order to create a larger temperature differential to boost the efficiency of the turbines.
With a cogeneration unit, the heat output is counted as useful output instead of waste heat when calculating efficiency. But that's fair only if you actually need the water heating.
So the cogen unit is almost certainly less efficient at generating electricity than the large utility unit, if that's the only output you count. The cogen unit is also probably less efficient at heating water than a high-efficiency dedicated water heater, if you only measure water temperature rise as useful output. It's only when you count *both* water heat and electricity that you end up with the high quoted efficiency.
    Dave
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Dave Martindale wrote:

Not necessarily, some of them use waste heat as well or process steam albeit not a tremendous number.

It isn't heat that is used (directly) to generate the electricity; the heat is used to make steam.
The use of a cooling tower is simply one alternative--other plants use water exchangers.
But in the end, yes, there has to be an ultimate heat sink and the colder it is, the better.
But, just as a central generating unit uses the best ultimate temperature sink, they also pull vacuum on the turbine exhaust.
Plus, it might even operate the boiler side at supercritical. All of these features far exceed the thermal efficiency of any little generating unit.

Precisely my point -- when posting that the cooling towers indicate that the central generating station is less efficient, that implied the comparison to the generation. Ain't no little pos generator such as this going to come close for the generation side efficiency which is all I was referring to. --
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true,
another thing people living off grid in rural places may have a gas well, around here they are pretty common.....
sometimes they wqere drilled for oil many years ago, when production decreases the original property owner pays a fee to buy the well, for its natural gas.
i met a guy that did just that, he heated his home etc off free natural gas, although he wasnt off grid. around karns city pa.
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snipped-for-privacy@aol.com wrote:

Very few any more that still allow a free tap if the well is in production at all. Totally abandoned and expired lease, but how many of those are there...
Until about 10 years ago or so, we had an uncharged tap off the main cross-country pipeline that was a condition grandfather made when negotiating right-of-way. That lasted for 60 years or so, but no more. At least we weren't cut off entirely which is what most of the lease-holders have done for the single-well taps. It's been a major problem for those who relied on it for irrigation wells, grain driers, and other agricultural needs even more than simply household heating.
--


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It probably does. Then again, the $1K EU2000 can probably do that as well, since it can be paralleled with another EU2000 with no special sync wiring. We might recover exhaust heat (about 4X the electrical output power) by running the exhaust into a gas water heater or using some sort of hookah.
Nick
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At 85% total efficiency, a 90+ furnace extracts more useful energy from the gas used.
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If you were off the grid it would be interesting try alt.energy.homepower for off grid people that know about these things. I believe it is very expensive.
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ransley wrote:

If it has the Honda name, it's inherently expensive.
I believe at lest some of the folks on the a.e.h. group are in northern "heat all the time" climates and do similar homebrew co-gen setups.
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wrote:

How many people off-grid have natural gas?
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Bob F wrote:

Many have LP, and an engine that will run on natural gas will also run on LP with minimal changes.
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They get propane
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hobbes wrote:

I am not sure if co-generation is that useful with internal combustion engines. Usually it seems to be used with steam turbine power conversion where the process necessarily has a lot of waste heat which normally goes to a cooling tower or to a river. The cooling tower portion of the power plant is replaced by the space heating and water heating needs of a local town or city.
Does anyone know if internal combustion engines produce as significant portion of waste heat as steam turbines?
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M Q wrote:

Thermal efficiency of ICEs is worse than steam turbines. As was noted further up in the post, the electrical output is 1kW while the thermal output is 2.8kW on the unit in question.
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