How Many Watts Does a Well Pump Use?
Well pumps have high startup surges that require careful generator and inverter sizing. Submersible pumps are more efficient than jet pumps for most residential wells.
Typical Power
750W
Power Range
250-2000W
Startup Surge
2250W
Daily Usage
750Wh
(1 hrs/day typical)
Well Pump Runtime Calculator
Range: 250-2000W
Continuous Runtime
1.1 hours
Days at 1hrs/day
1.3 days
Daily Consumption
750Wh
Usable Battery
960Wh
Recommended Equipment
* Calculations assume 85% inverter efficiency and 80% depth of discharge (LiFePO4).
Battery Runtime Examples
| Battery Size | Voltage | Runtime at 750W |
|---|---|---|
| 200Ah | 12V | 2.1 hours |
| 400Ah | 12V | 4.3 hours |
| 600Ah | 12V | 6.4 hours |
* Assumes 85% inverter efficiency and 80% depth of discharge for LiFePO4 batteries.
Well Pump Power Tips
- •Startup surge is typically 3x running watts - size your inverter accordingly
- •A soft-start device can reduce surge by 60-70%, allowing smaller inverter
- •Submersible pumps are more efficient than jet pumps for depths over 25 feet
- •Running the pump into a storage tank reduces how often it cycles
- •Most homes use 1-2 hours of pump runtime per day for all water needs
Frequently Asked Questions
What size generator for a well pump?
For a typical 1HP (750W) well pump with 2250W surge, you need at least a 3000W generator. A 4000W generator provides comfortable margin for the startup surge.
What size inverter for a well pump?
The inverter must handle the startup surge. For a 750W pump, you need at least a 3000W inverter. Installing a soft-start device lets you use a 1500W inverter instead.
Can solar run a well pump?
Yes, but you need to size for the surge. A 3000W inverter, 400Ah battery bank, and 800W of panels can run most residential well pumps sustainably.