How many solar panels to run a pool pump?
About 6 panels at 400 watts under national-average sun, working from 8 kWh a day. The count runs from 4 in desert sun to 7 in the cloudiest states. That answers the energy question; the timing question (this load at night, panels at noon) is the part most listicles skip, so it gets its own section below.
Panels by sun figure
400W panels, 0.77 derate, count rounded up; the right column shows what the rounded-up count actually produces against the load's 8 kWh day.
| Peak sun hours | Panels | Daily margin |
|---|---|---|
| 4.0 h | 7 | ~8.6 kWh vs 8 needed |
| 4.5 h (US avg) | 6 | ~8.3 kWh vs 8 needed |
| 5.0 h | 6 | ~9.2 kWh vs 8 needed |
| 5.5 h | 5 | ~8.5 kWh vs 8 needed |
| 6.0 h | 5 | ~9.2 kWh vs 8 needed |
| 6.5 h | 4 | ~8 kWh vs 8 needed |
Where the 8 kWh figure comes from. A 1.5 HP single-speed pump draws about 1,600W and typically runs 5 hours a day in season: 8 kWh. Variable-speed pumps doing the same turnover at low RPM use a third of that or less.
The part after the panel count
Six panels at average sun for the single-speed pump, and here the honest advice costs us a page view: don't solve this with panels. A variable-speed pump replacement turns the 8 kWh day into 2 or 3, pays for itself in a couple of seasons at most utility rates, and is required by federal efficiency rules for most new pump sales anyway. Solve the pump first, then panel the remainder (two panels instead of six).
If the pump stays, the load is at least solar-shaped: pumps run on timers, timers can run midday, and a pool pump is one of the few household loads you can schedule entirely inside production hours, no battery involved. Grid-tied owners with time-of-use rates should do that scheduling regardless of whether a single panel ever goes up.
Questions people ask
How many solar panels does it take to run a pool pump?
About 6 400-watt panels at the national-average 4.5 peak sun hours, from a planning figure of 8 kWh a day. Strong desert sun brings it to 4; cloudy states need 7. Those counts cover daily energy; running the load at night takes a battery or a grid connection, covered below.
How many panels for a variable-speed pool pump?
Two 400W panels at average US sun, from the 2.5-or-so kWh a day a variable-speed pump uses doing the same turnover a single-speed pump does in 8. The pump swap changes the panel math more than any sun figure in this table does.
Does this count include a battery?
No. The table answers the energy question: how many panels produce what the load consumes over a day. Grid-tied homes need nothing else; the grid absorbs the timing. Off-grid, add storage for the dark hours (the page discusses sizing for this load) and an inverter rated for the start-up surge where the load has one.