Off-Grid Septic Pump

[Uniquark]

I'm looking at running my septic pump off grid. The background is that the property has two houses connected to a singled pumped septic system. The old house is closer to the pump tank and currently provides the power. We expect to take the old house down in the near future and would rather not run the wire all the way from the other house. The septic pump has to pump against about 20 feet of dynamic head and is currently a 110-volt Zoeller cast iron pump.

  I would like to set up a small system to collect enough energy and power the pump when it comes on, about once a week. I think I need about 1 KWHr per week and should probably have enough storage capacity for several weeks. I live in Vermont. Solar is a resonable option. Wind might be an option, but it does not look good from the resources online. Microhydro would be a great option, but not for such a small project. The pump is relatively new, so I'm debating between replacing it with a 12-volt pump (is such available?) and including an inverter in the system.

  Any thoughts would be appreciated.

[stephent]

Getting an inverter that's big enough to start the sewage grinder/pump will be costly.

It's not necessarily the amp draw when running the pump--it's the starting surge for it.

Might be possible of course, but it won't be cheap.

Solar + batteries to have a few weeks of backup is pricey too.

Might think of using a smaller (3-5kw) gas/diesel generator for just weekly or bi-weekly pumping. It would be good for a backup system for the house too.

Probably be cheaper in the long run to just run buried UF cable and the grid power from the new house, though.