Solar panels for swimming pools: pump and water heating

A pool has two electric loads: the filter pump and (optionally) water heating. Both overlap perfectly with the solar daytime curve, which makes pools one of the best solar investments.

1. The filter pump

A typical pump for 8,000-16,000 gallon pools runs at 600-1,100 W for 6-10 hours/day in season. That's 5-10 kWh/day. Math: 7,000 Wh ÷ 5 PSH × 1.3 = 1,820 W. You need 4-5 × 410-450 W panels to fully cover the pump in summer.

2. Direct DC solar pumps

Elegant alternative: a DC pump wired straight to 2-3 panels, no inverter, no battery. When sun shines, it filters; otherwise it rests. Plenty for most residential pools. Full kit cost: $900-1,700.

3. Heating the water: thermal vs PV

To raise a 10,000 gal pool by 10 °F you need 12-18 kWh thermal per day. This is covered far better by solar thermal panels (polypropylene mats or vacuum tubes) than by PV + heat pump. Mat cost: $230-450 for 43 sq ft. ROI: 2-3 seasons.

• Polypropylene solar mat: cheapest, simplest
• Vacuum tubes: 30-40% better than mats, 2× the price
• Heat pump with PV: best for constant year-round temperature

Bonus: night pool cover

A nighttime thermal cover cuts heat loss 50-70%. Combined with daytime solar mat or thermal panels, it extends swim season by 2 months at zero extra energy cost.

If you're off-grid, see our complete off-grid system guide. If the pool is just one of many loads, size everything with how many panels for a home.