Question: How profitable is it to run a genset into the grid?

It's useful for heating one house and its hot water, or a small neighborhood. It's harder to distribute heat to 100,000 houses from a large power plant in the boonies :-)

Intelligen's $10K 11 HP Lister-Petter diesel cogen system did exactly that, with a 93.5% combined heat and power efficiency.

It ran less during summertime, merely supplying hot water.

It's close to 100% vs 30% efficient. There's no need for cooling towers nor transmission lines. Nor HR departments...

Nick

So completely disconnect from the power grid. That would cause you some problems in the summer when you don't need heat but want electricity.

Charles Perry P.E.

because I don't care too. I'm only interested in keeping my lights and fridge going. Producing power is not my job, computer consulting is, being my own producer allows me to live off-grid in an area where land is cheap, the forest is beautiful, and the neighbors (deer, fox, lynx, and bear) are quiet. yes, my costs truly do come out to about $0.06 / kWh. I keep a record of every expenditure. how much does your hobby (golf?) cost you?

There are "district heating" schemes where hot water from a power plant is circulated to provide space heating. At least one Northern Ontario community I visited a few years ago used waste heat from the diesel plant to heat the local store - fuel had to brought in over winter roads or by air, so there was a lot of incentive to maximize efficiency. There used to be a district heating plant in Winnipeg that used waste heat from a steam electrical generation station to heat downtown buildings, but it was torn down decades ago. I believe there's a lot of geothermal-source district heating in Iceland, where one hot-water well provides heat for many buildings (but this isn't really waste heat from electric power production).

Of course if you have a district heating scheme then you have *two* grids, one for electricity, one for hot water - and it's a little harder to turn the latter into air conditioning, which is a bigger load in most U.S. cities.

Bill

Not related to power plants per se, but Syracuse NY is talking about running a water line from Lake Ontario to the city and back to form an 'A/C cooling' loop. The lake water, at between 60 and 80 F in the summer will be used as the sink for several large building complex's A/C. Think Syracuse University is one of the complexes (Go Orange!)

daestrom

Some other examples -

the concept is currently called 'micro Combined Heat & Power [mCHP] . at least one purpose-designed system matching such single dwelling service has recently gone into commercial production. check website of New Zealand company 'Whispergen'.

Surely you realize that staying hooked up is more economical.

Nick

Cornell already did that with Cayuga lake. (Go Big Red!) They also took 2nd place today in the DC DOE Decathlon, behind last year's winner, U Colorado. I advised the U Mass/Dartmouth team, who took 18th out of 18 teams :-)

Nick

Nope. The purpose of all this is not to live off the grid, but while heating your house, generate some more valuable electricity to offset the cost. During summer your home heater/generator will be shut down (or only generate a little electricity when making hot water, or used only during power outages as a regular generator). Kind of like those copper mines that as a sideline, recover and sell silver and gold that occurs with the copper. It's not economical to run the mine just to get the silver and gold, but it is to get the copper, and with a little more work you can extract and sell the silver and gold.

Yes, I was pointing that out for you, using sarcasm. You are the one who was extolling the higher efficiency.

Charles Perry P.E.

There's no way any home generator could ever approach the cost-efficiency of a primary grid power plant. That's the reason everyone doesn't have a generator in their back yard. If you sell back to the grid, getting say, 85 cents on the dollar, it's not a real market value for your power production. It's a subsidy in fact, that works on a small scale to mitigate peak loads on the grid without the need for brownouts or costly expansions to primary production capacity.

The minute grid-tie production begins to rival power plant levels, it will all stop. At that point it would be much more feasible to build a new power plant than to keep paying small producers to run their meters backwards.

...unless the "waste heat" is used.

Nick

You've claimed that before, and I don't dispute your figures, but I doubt anyone else could do it for the costs you claim.

If you grow oilseed crops in your backyard, weed them yourself, fertilize it with your own sewage, keep free-roaming chickens to pick off the insects, harvest, press it, and process it yourself at no labour cost...

Then I believe you, but that's not an economic solution for the rest of the world.

We had a few 500KW co-gen units attempt to "break even" on their electric bills by using the waste heat in their office buildings. After being subsidized by the provincail utility and all the massive mechanixcal problems the office manager is just not qualified to fix, they found it a dead loss to even attempt to match the grid prices for energy. What would they do with all that heat in an office building in the winter? They both sit scrapped and never talked about as the "professional installers" hang their heads in shame. Better engineering and more thought outside the sales wallet was in order.

OTOH, we have another customer that has 5MVA of co-gen power they use primarily for steam and it's heat they woul dneed in their processes anyway. The electrical energy is THEIR byproduct and they want to expand with more they find them so profitable.

So from that, I agree with your po>

There are many ways to do something wrong :-)

Nick

I disagree, I'm not the first, or the last to do this. There are many others who live off-grid doing the same.

some of the rest of the world, not everyone in the world. I was not aware that I had to come up with a solution for every single person.