Some of the newer inverter generators (Honda) will throttle up and down with load so you will use less fuel when just running lights...
If you will run alot, consider a diesel for longevity. Some of the older miltary sets aren't too badly priced if you can find them and will run for weeks on end.
1. Inverter generators get very expensive for higher current loads... They are nice, but you pay for that niceness! Probalby not feasible to run either a compressor or a welder on an inverter generator, at least IMHO!
2. Military generators have shot up in price greatly. They are now in high demand. However, they are built like brick sh?t houses, will run all day, every day, without a worry, have fantastic overload capabilities, and some are quiet. I have a MEP-004 rated at 15 KW which will do about 20 KW full time, and a bit more for short periods. It has a noise reducing enclosure so it is not too noisy, and is mounted on a trailer. Total weight is about 7,000 lb, it is not a light weight toy from Home Depot. Regardless of load it burns about a gallon an hour, plus up to an additional half gallon when loaded (we typically burn between 1 and 1.5 gallons using it as we don't load it heavily.)
Careful there. Most military generators aren't 60hz, and most are 3 phase anyway.
They're great units, but not too efficient, and not too compatible with civilian tools.
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There is a vast array of military surplus generators, some are single phase, some three. Three phase can be used for most applications by using two of the phases in a 120/208 volt configuration. Most are 60 Hz, some are 400. Avoid the 400 Hz units, they cannot be converted to 60 Hz without considerable expense.
All the military generators produce excellent power, generally clean and reliable. They are designed to emulate standard AC power sources, are usually intended to power electronic devices (radios and radar sets, for example) and do very well running tools and equipment in the typical shop.
Efficiency is good for the diesel units... There is not enough difference between a commercial diesel generator and a military generator to really say which is more efficient. Down side is that they usually don't have auto-start, so fully automatic backup systems are a bit more difficult to design.
There are many, many great threads on SteelSoldiers.com (the aux equipment section) and I'd recommend anyone considering a military generator go there and research. And anyone who is in New England is welcome to stop by and take a look at my setup, and have a chance to touch-n-feel a big military generator set.
