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.
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
On Jan 3, 12:17 pm, email@example.com 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........
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
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
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
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.
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.
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.
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.
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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