Can a power station run a well pump?
Short answer
Only some can. Most deep well pumps run on 240 V, and most portable power stations only supply 120 V, so check that first. A typical 1/2 HP pump draws about 1,000 W running and around 2,100 W to start. With a 240 V capable unit of 3,600 Wh, the pump alone can run for about 1.5 days of normal water use, or about 3 days if you use water carefully.
Check the voltage first
Look at the pump's control box or the breaker that feeds it. A double breaker (two switches tied together) means 240 V. Deep submersible pumps are almost always 240 V. Shallow-well jet pumps are sometimes 120 V, which makes them much easier to power.
For a 240 V pump you need a power station that offers 240 V output, either built in or by linking two compatible units. Most portable units only offer 120 V outlets.
The startup surge
A pump motor pulls roughly two to three times its running watts for a moment when it starts. A 1/2 HP pump needs about 2,100 W; a 1 HP pump can need 4,000 W or more. The power station's surge rating on its 240 V output must cover this, or the pump will not start.
A soft-start kit, installed by a pump professional, can cut that surge substantially and make a smaller power source workable.
Runtime by power station size
A well pump only runs when the pressure tank needs refilling, usually for a total of 30 minutes to 2 hours a day. The columns assume a 1/2 HP pump at 1,000 W, 85% usable battery energy, and a power station with 240 V output. Water use drives everything, so conserving water stretches the battery directly.
| Power station | Normal use (2 h/day) | Careful use (1 h/day) | Essentials only (30 min/day) |
|---|---|---|---|
| 2,048 Wh 240 V output | 20.9 hours | 41.8 hours | 3.5 days |
| 3,600 Wh 240 V output | 36.7 hours | 3.1 days | 6.1 days |
| 7,200 Wh 240 V output | 3.1 days | 6.1 days | 12.2 days |
For your exact appliance and power station, use the runtime calculator.
How the pump actually uses energy
The pump does not run all the time. It refills the pressure tank when pressure drops, then shuts off. A 1/2 HP pump moving roughly 10 gallons per minute uses about 1 kWh per hour of running, so a family that is careful with water during an outage can get by on well under 1 kWh a day for the pump.
Connecting the pump
Well pumps are hardwired. Powering one from a portable source requires a transfer switch or interlock installed by a licensed electrician. Never backfeed through an outlet.
Before a storm
- Fill bathtubs and large containers with water. A few gallons stored can cover drinking and flushing without running the pump at all.
- Top up the power station and know where your pump's breaker is.
- If you rely on your well for drinking water, consider a generator with a 240 V outlet as your main backup and a power station for everything else.
Frequently asked questions
Can a 120 V power station run a well pump?
Only if the pump is a 120 V model, which is common for shallow-well jet pumps but rare for deep submersible pumps. Most deep well pumps need 240 V.
How many watts does a well pump need to start?
A 1/2 HP pump typically needs about 2,100 W to start and 1,000 W to run. A 1 HP pump can need 4,000 W or more to start and about 2,000 W to run.
What size generator do I need for a well pump?
For a 1/2 HP pump, a generator with at least 3,000 running watts and a 240 V outlet is a reasonable minimum, more if other appliances run at the same time. Our generator size calculator can add up your full load.
Sources and method
Runtime figures assume 85% of battery capacity reaches AC appliances and typical US appliance ratings. See exactly how we calculate. Found a mistake? Tell us and we will fix it.