I work at an ISP. We have wireless repeaters at about 50 locations. We lose power frequently. Power outages can be a major work disruption for us, and a letdown for customers.
We have UPSs everywhere, and Tripplite APS systems with large AGM batteries at places which require a long runtime (8-24 hours). This save us from having to run around like madmen with generators during storms for typical length power outages.
Tripp Lite PowerVerter APS Inverter/Chargers
We have a few small gasoline generators. Honda engines are a good power choice for gasoline. We have a variety of gasoline generators, but the Honda EU2000 is my favorite. It's quite and very efficient. (meaning less refueling trips)
Honda EU2000I Generator - Honda Super Quiet Generators
Our main site where all the servers are has UPSs and a 3-phase
Cummins/Onan generator 35kw diesel to match our 3-phase power. If you need 30+ KW, you probably need 3-phase. We use about 15KW, but want plenty of room to grow. It is on an automatic exerciser, block heater, fireproof room, motorized louver vents, exhaust chimney, 275 gallon heating oil tank indoors for fuel. It's nice. We've had stuff go 1000+ days (it's entire lifespan on the Internet) without losing power.
http://hosting.midcoast.com/otherser...ogenerator.jpg
At my house, which is my personal office when trees and power lines are across the road and I can't get out, I have the old work generator, a kubota gl6500 diesel. It's also very reliable, good on fuel, etc... I keep about 10-15 gallons of diesel in the basement for it, and I can run my whole house on it (including well), as we don't have an electric stove, electric hot water, or electric dryer. No big electrical loads means any 120/240v generator of modest capacity will work fine. It's good for about 12 hours on 3-4 gallons of fuel, and I have run it days at a time nonstop. I could bleed some heating oil if I needed more fuel.