Home Sized Combined Heat and Power Plant

[peakbagger]

https://granitegeek.concordmonitor....ater-air-conditioner-and-emergency-generator/

Nice concept but the devil is in the details, lot of moving parts to get it down to that price range. I think he had connection with a politician that helped him get New England Wood Pellets started.

Interesting to note he refers to Dean Kamen's project, to date despite occasional mentions in the press no actual commercial system has been produced.

 

[Dune]

Actually there was a set up for sale at one time.

• It was a small diesel genset which started on call from a thermostat.

I think it was ahead of it's time.

Meanwhile, any liquid cooled genset could be used for residential cogen.

 

[begreen]

I'm bullish on scavenging waste heat, especially where it does not affect the primary function. A fuel cell can also be used for co-gen. Not sure how well using this will work out using a Brayton cycle engine but I am glad they are researching it.

 

[twd000]

Not far down the road from me. I'm a bit confused as to the use case. They mention taking the house off-grid, but then say that it will initially run on natural gas. Isn't that the very definition of the grid?

 

[peakbagger]

I do CHP plants on occasion. There are incentives if the plants exceed a baseline combined thermal and electrical efficiency (electrical output is converted to btus) so we track efficiency continuously. We also track the the fuel input. Some of the plants can run at or slightly above 80% efficiency. They are generally set up to being able to run "islanded" off the grid so if the grid goes out the plant keeps running. On more than a couple of occasions the grid went down and the plant operators do not realize it for several hours as everything keeps running.

 

[begreen]

Not far down the road from me. I'm a bit confused as to the use case. They mention taking the house off-grid, but then say that it will initially run on natural gas. Isn't that the very definition of the grid?

They also discuss grid-tied systems supplying the grid with power while generating heat and providing the home with services during power outages.

 

[twd000]

They also discuss grid-tied systems supplying the grid with power while generating heat and providing the home with services during power outages.

most people around here have propane generators for that purpose.

I can't imagine these would be oversized enough to provide the grid (your neighbors) power in excess of your own consumption

 

[peakbagger]

There are new inverter standards that have come out called 1741 SA which allows small systems to do grid support https://aeesolar.com/wp-content/uploads/2017/08/UL-1741-SA-What-You-Need-to-Know_Webinar.pdf. Prior inverters like mine were designed to monitor the grid for disturbances and shut off if they detected them. The inverter then waits until the grid is back and stable for five minutes before turning back on again. This is not a problem if there is only a little bit of solar on a grid circuit but if there is lot of it, the act of all these solar systems changing their output when cloud goes by can cause a ripple on the circuit that causes all the solar to shut down. The power company then sees a big demand increase and has to crank on additional generation until the 5 minutes are up and then they see all the solar come back on line and have to shut it down. In many cases all the solar coming back on line causes another ripple and they all shut down again.

The new SA inverters have wider operating range and if they see a condition on the grid that they can help with they stay on the line (assuming these functions are enabled). The same concept is being built into home battery standards. if the utility enables the function, the batteries can export to the grid to help stabilize it.

Its a brave new world with respect to the grid and how distributed generation is going to play in it. Hawaii is the current guinea pig and California is next. I expect power quality and reliability will actually reduce over the next few years and strongly urge folks to have a very good surge suppressor on their incoming power line.