backuppowercalc
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Use case

Backup power for an off-grid cabin

A weekend or seasonal cabin usually needs the essentials plus a water pump. The well or sump pump is almost always the surge driver here.

Running
2,060W
Peak surge
4,060W
Recommend
5,000W

The well pump (1/2 hp) drives the peak here, surging when it starts. Sizing for the running total plus that single largest surge — not the sum of every surge — gives a realistic 5,000W (5.0kW) recommendation.

Typical loads for an off-grid cabin

LoadRunningStarting
Refrigerator160W480W
Household lights (LED)200W200W
Well pump (1/2 HP)1000W3000W
Furnace blower fan600W1560W
Phone/laptop charging100W100W

Size your exact setup

Common questions

What size generator do I need for an off-grid cabin?

For this typical load set, about a 5,000W (5.0kW) class covers it — that's 2,060W running plus the largest startup surge (from the well pump (1/2 hp)), with a 20% margin.

Can I run more than this?

Yes — this is a representative set. Add or remove loads in the load sizer to match your exact situation and get an updated number.

Other scenarios