Natural gas generators running full time...

[powerplay]

I was asked what pros and cons of using a single phase 150kw natural gas generator full time? any ideas on used equipment? .. reliability? Thanks again!

[K8MHZ]

I was asked what pros and cons of using a single phase 150kw natural gas generator full time? any ideas on used equipment? .. reliability? Thanks again!

I know they use NG generators 24/7 in Alaska. I guess it depends on the design. I sure would get some info from the manufacturer first. Plus, all generators need periodic maintenance that requires shut down, so for uninterrupted service you will need two generators or some other power source.

[rcwilson]

If the generator is fixed or permanent, an enviromental air permit may be required, depending on the local regulations, type of facility, etc. Cost of the permit could be more than any savings.

NG driven generators are typically a little less repsonsive to load changes than gasoline or diesel units. Depending on what loads are starting/stopping, there may be power quality problems that would not be present on a 150 kVA utility fed transformer.

[iwire]

Regardless of the fuel you would want to select a genset rated as 'prime' or contiuous vs one rated as 'standby'.

[stevephillips]

Ive seen a caterpillar genset (IIRC, it was 500kva) with the ability to have its oil changed while running. The setup was rather clever, the oil filter had a isolation valves and a bypass valve. There was also a drain valve for the oil pan. Basically you put the filter valves into isolation/bypass, remove the old one, install new(pre-filled), drain then add 2 quarts 10 times then put the valves in normal position. Never really gets all the old oil out but its enough to keep the engine happy for over 2 years now. Air filters are changed by opening and closing the air box. Visited a cousin in Alaska that serviced a generator that ran 24/7 and that is how they did it.

Each of the fuel supplies had a similar filter setup (it could run on diesel, biodiesel, propane or CNG)

This was the primary power source for the island until the POCO brought in a UW cable. The power from the POCO is very expensive so now its a co-generation plant and is community funded/operated.

The site has 8 of these generators that pretty much ran 24/7 until there is a major failure (blown head gasket, thrown rod, etc) or taken down for overhaul. Every 3 months, the generator with the highest hours is taken down for overhaul. From what I remember, the generators handle the baseload and anything over that comes from the POCO. When the loads are under the capacity, power goes back to the POCO. The generators are governed to always run at 92%.

[conmgt]

Check out Capstone NG turbine generators. Turbine engines are much more reliable mostly because there's really only one moving part...the turbine...as opposed to a reciprocating engine with a crank, rods, pistons, valves, etc. That's why you see turbines in tanks, planes, ships, etc.

Also, the heat from the turbine can be used for building heat/hot water. The Four Season's Hotel (5 star) in Philadelphia has several and uses them for power plus building heat, hot water, pool heat, laundry, etc.

[kwired]

Can you generate electrical energy from natural gas for less cost than you can purchase it from a utility? Some places maybe you can, but most places you probably can't, especially if the prime mover is internal combustion engine.

If reliability is an issue there is still risk of losing gas service, though maybe not as high as losing service from a electric utility.

[ramsy]

There is an interesting analysis of Sterling generation at the bottom of this page:
https://en.wikipedia.org/wiki/Sterling_engine


See photo of 55kw Sterling generator
https://en.wikipedia.org/wiki/File:S...erator_set.jpg

[fmtjfw]

Can you generate electrical energy from natural gas for less cost than you can purchase it from a utility? Some places maybe you can, but most places you probably can't, especially if the prime mover is internal combustion engine.

If reliability is an issue there is still risk of losing gas service, though maybe not as high as losing service from a electric utility.

Some places in WV there is a gas "royality" -- free gas -- from the well drilled on your property. Then the question is the return on investment for the genset.

you might be able to co-generate: use the waste heat to heat the house in the winter. There was such a scheme years ago in MA but I'm not sure it was economical. Depended on the price of Nat gas, heating oil, and electric power.