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What Size Inverter Do You Need to Run a Well Pump?
Quick Answer
Short answer: size the inverter to the pump's startup surge, not its running watts. A typical 1 HP submersible well pump runs at roughly 1,100-1,500W but can demand 4,000-7,500W for a fraction of a second at startup. An inverter whose surge rating clears that spike — and whose continuous rating covers the pump plus your other loads — runs the pump without drama. For most residential pumps up to 1.5 HP, a 12 kW-class inverter with 18 kW or more of surge (like the EG4 12000XP) is comfortably sufficient.
Typical Well Pump Power Draw
Figures below are typical nameplate ranges for 240V submersible pumps. Your pump's data plate — running amps (FLA) and locked-rotor amps (LRA) — is the authority: multiply amps by 240V to get watts.
| Pump size | Typical running watts | Typical startup surge | Look for surge rating of |
|---|---|---|---|
| 0.5 HP | 600-900W | 2,000-3,500W | 4 kW or more |
| 1 HP | 1,100-1,500W | 4,000-7,500W | 8 kW or more |
| 1.5 HP | 1,600-2,000W | 6,000-10,000W | 12 kW or more |
| 2 HP | 2,200-2,800W | 8,000-14,000W | 16 kW or more |
The Three Checks
- Surge: inverter surge rating ≥ pump LRA × 240V. This is the check that fails most often — a pump that 'almost starts' is tripping on surge, not on running load.
- Continuous: inverter continuous watts ≥ pump running watts + everything else on at the same time (pressure tank cycles overlap with fridge, lights, and HVAC blowers).
- Voltage: most well pumps are 240V, so you need split-phase output — a 120V-only inverter or power station cannot run one at all.
Inverters That Handle Wells Well
- EG4 12000XP — $2,099.99. 12,000W continuous and an 18kW surge for 5 seconds: enough for most pumps up to 2 HP, and our most popular off-grid choice.
- Sol-Ark 15K — from $5,299. 12,000W continuous with a 24,000W surge for 10 seconds, plus 200A grid passthrough for grid-connected homes.
- Portable option: for outage-only pump backup, a 240V power station with high surge — the Jackery Explorer 5000 Plus (14,400W surge) — can carry a 1 HP pump through an outage.
If Your Pump Still Won't Start
A soft starter on the pump cuts startup surge substantially and is often cheaper than upsizing the inverter. Also check the pressure switch and tank: a waterlogged tank makes the pump short-cycle, which looks like an inverter problem but is not.
Prices checked November 6, 2026 at Renewable Outdoors — an authorized dealer with a Lowest Price Guarantee and financing through Affirm at checkout. Shop the EG4 12000XP or the Sol-Ark 15K — both are in our solar inverters collection
Frequently Asked Questions
Can a solar inverter run a well pump?
Yes, if it is split-phase (240V) and its surge rating exceeds the pump's startup draw. Most residential pumps are 0.5-1.5 HP; a 12 kW inverter with 18 kW+ surge, like the EG4 12000XP, runs them comfortably alongside household loads.
Why does my pump trip the inverter if the watts look fine?
Almost always surge. A pump's locked-rotor startup draw is typically 3-5 times its running watts, and it happens in the first fraction of a second. Compare the pump's LRA (on its data plate) times 240V against the inverter's surge rating, not its continuous rating.
What size inverter for a 1 HP well pump?
Look for at least 8 kW of surge and 3-4 kW of continuous headroom above your other simultaneous loads. In practice, most people land on a 12 kW-class inverter (EG4 12000XP or Sol-Ark 15K) because the pump shares the system with the rest of the house.
Can a portable power station run a well pump?
Only 240V models with strong surge. The Jackery Explorer 5000 Plus (7,200W continuous, 14,400W surge) can run many 1 HP pumps during outages. Smaller 120V stations cannot run a 240V pump at all.
