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Curated Best-Of List

Best Solar Water Heater

3 expert-curated picks ranked by performance, value, and long-term reliability

Solar water heaters use rooftop solar collectors to heat water directly, separate from the electric/gas water heater categories. The category has shrunk since 2015 as rooftop PV + heat-pump water heater combinations have become cheaper and more flexible than dedicated solar thermal systems.

Solar thermal vs PV-driven heat-pump — the modern decision

Two paths to solar-powered water heating:

Solar thermal water heater (direct heating)

Rooftop collectors heat water (or antifreeze in cold climates) directly. Heated fluid pumped to a storage tank in the house. UEF can effectively exceed 4.0 when sun is available. $5,000-$9,000 installed.

Rooftop PV + heat-pump water heater (modern alternative)

Rooftop PV array generates electricity. Heat-pump water heater (Rheem ProTerra, AO Smith Voltex) uses that electricity efficiently. UEF 3.45 from the heat-pump compounded with free solar electricity. $3,500-$6,000 for combined install (heat-pump + PV portion).

The PV + heat-pump combination is now cheaper, more flexible (the PV produces electricity for other home uses too), and easier to service than dedicated solar thermal. Most new solar-water-heating installs are PV + heat-pump rather than solar thermal.

When solar thermal is still right

  • Existing solar thermal system needs replacement (familiar service ecosystem)
  • Off-grid installation where PV is already at capacity for other loads
  • Very high hot-water demand (commercial laundry, hotel) where dedicated thermal beats PV-driven
  • Specific incentive programs that favor solar thermal over PV (rare in 2026)

Solar thermal water heater picks

Best evacuated tube system: SunMaxx ETC-50 with 80-gal storage

50 evacuated tube collectors paired with 80-gallon storage tank. Effective in cold climates because the vacuum-insulated tubes lose less heat to ambient air than flat-plate collectors. About $7,500 installed.

Best flat-plate system: SunEarth Empire EP-40 with 80-gal storage

40 sq ft flat-plate collectors. Works best in warm climates with strong sun exposure. About $5,500 installed.

Best preheating system: Apricus AP-30 retrofit

30-tube system designed to preheat water entering an existing tank. Reduces the existing tank's heating load. About $4,500 installed.

Solar thermal economics

Federal Section 25D residential clean energy credit (30% of install cost) applies to solar water heaters as well as PV. State and local incentives vary widely. Operating cost typically $5-$15/month for backup electric or gas elements (covering periods without adequate sun).

Payback period 8-15 years depending on local utility rates, sun exposure, and incentive levels. For most US households, the PV + heat-pump combination has shorter payback and more flexible utility.

Solar thermal with backup heating element

All solar water heaters include backup heating (electric resistance or gas) for cloudy periods. The backup element kicks in when the storage tank temperature drops below setpoint. Annual sun-fraction (percentage of water heated by solar versus backup) typically 60-80% in good climates, 40-60% in cloudy climates.

3 products
$949 – $1,795
Updated May 2026

Quick Comparison

# Product Brand Rating Price
1 Rinnai RU199iN Sensei Tankless Water Heater Rinnai 4.8 Check current price Amazon
2 Rheem Performance Platinum 50-Gallon Gas Water Heater Rheem 4.6 Check current price Amazon
3 AO Smith Signature Premier 50-Gallon Gas Water Heater AO Smith 4.5 Check current price Amazon