A discussion in another thread brought this question to me. We are caught in a very bad part of the SW Missouri Ice Storm power outage. We were fortunate in having a wood stove backup (never be without one). Our biggest problem is water. Our well pump runs on electricity and we have none. I was about to buy a generator in the 5000 range. Someone suggested that 2000 is enough to get by and burns half the fuel.
Question; will 2000-2500 run a well pump, and a few lights in the house?

Any advice is appreciated.

Jon,
Wentworth, MO

Check the electrical labeling on your water pump and see how many watts the pump requires to start and how many watts it requires to run. I like having a significant amount of power capability in reserve. Generators can power many useful things.

Your water pump should be labeled as to the voltage/current/wattage it needs.
Then start cutting down your loads as much as you can, switch ican bulbs for cf for example. Eliminate as much as you can and then you can run more from a smaller genset.

I thought this company had a good approach to gathering the data you are looking for.
http://www.generatorjoe.net/store.asp.

also over on the "long Term preparedness" thread, you might find the recent thread "Getting Well Water" to be interesting.
Looks like the cost of the generator is only part of the equation, and getting electrical transfer switches also a significant expense.

like others said, check the pump wattage and keep in mind that a 2000 w generator may be 2000 w peak. i have a honda eu2000i and i think it's 1600 w sustained, 2000 w peak. also be sure to check how many amps you'll need and what the generator can put out.

Rather than asking a bunch of folks who aren't sure, you might want to call the company who installed the pump. Start up can require significantly more amps/watts than continuous.

You are absolutely right. Thanks to everyone who answered. I am checking the rating on the well pump and will get the generator sized accordingly. I was basically concerned about long term fuel consumption if, as seems likely, we are without power for 3 weeks or more.

Thanks again;

Jon Davis

One thing to keep in mind is that ALL generators consume fuel based on the (Watts) power they produce.
While larger sized generators do consume relatively more fuel at low power than a generator that is smaller near it's maximum.
Remember a generator is a device that transforms mechanical power from a power-plant (engine typically) into electrical power.
1 HP mechanical is 746 Watts (US). The efficiency will be less than 100 percent of course. The only difference between a large sized generator and a large sized as far as fuel consumption is the additional frictional loads of the mechanism.
Most are fairly efficient actually.

All this being said, I would never consider anything less than 5000 watts for home use. The smaller ones are fine for camping, but 2000 watts is very small for a number of other things than your pump.

Remember you are buying flexibility (options for unseen things that might pop up).

Really a 6000 to 7000 watt generator (around 10 to 15 HP engine) will be even better. Also the larger generator have other features such as regulation (really nice, required for things like electronics).

While 2000 watt gen-sets are nice for camping and intermittent use (perhaps) in outdoor functions, it's just too small for ANY kind of sustained use.

One final thought, engine life will be much shorter if you are loading the generator near it's maximum.
You wouldn't expect to have a car last long if you ran it at 120 MPH right ? Even if the speedometer goes to 120.

I have installed/specified a many a Gen-Set both personally and professionally ( an Electrical Engineer/Designer), and unless you want it for this one application only (water well) then your money would be better spent on something that has maximum versatility .

One other note about generator sizing:

You WILL fry your jennie if you are NOT running it to _at least_ 75% of its capacity when it is running.

It must have a load.

Some submersible well pumps require 220V. Most, but not all,
generators provide 220V.

Thanks again to everyone for the feedback on this issue. I had to pick one by noon yesterday to deal with a long term outage. In large part due to the feedback received here I went with a 5000 watt generator. It is running everything I need including the well pump very well. I shutdown my electric water heater, electric stove, and microwave but everything else runs easily.

Jon