Appliance Wattage & Running Cost
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What size generator or power station for a heat pump? (3,750+ W)

To run a heat pump, choose at least
3,750 W running · 5,000 W startup surge.

A heat pump draws about 3,000 W while running, but its motor can spike to roughly 5,000 W at startup, so size for the surge. Pick a generator, inverter or power station rated comfortably above these numbers.

Battery runtime calculator

Estimated runtime

Assumes about 85% usable capacity. Motors need extra headroom for startup surge.

How long a power station lasts

Power stationEstimated runtime
300 Wh0 h 5 min
500 Wh0 h 9 min
1,000 Wh0 h 17 min
2,000 Wh0 h 34 min
3,000 Wh0 h 51 min

Sizing guide

Minimum running watts3,750 W
Minimum starting watts5,000 W
Suggested inverter5,000 W or higher

See also heat pump wattage and running cost.

FAQ

How many watts does a heat pump use?

Typically 1500-5000 watts while running, with a surge at compressor startup.

Why is a heat pump efficient?

It transfers existing heat rather than generating it, so each watt does more work.