Solar Thermal

SOLAR THERMAL systems concentrate sunlight to provide hot water for a building.  There are several solar-thermal system configurations which employ the sun's energy to heat water:

  • Active solar hot water systems use pumps and controls to circulate heated water; passive systems do not.

  • Open-loop systems heat water directly for use in a home or pool; closed-loop systems heat a heat-transfer fluid (such as food-grade propylene glycol) which transfers heat to the hot water storage tank. Heat-transfer fluids are necessary in climates where water would freeze in the winter.


  • Water or Space Heating
  • Residential
  • Commercial
  • Agricultural
  • Industrial

Solar collecters contain parallel tubes that absorb sunlight and transfer heat to the water storage tank.  On average, a solar water heater can reduce water heating bills by 50% - 80%.  Solar thermal systems can be even more cost-effective if they are integrated in the constuction of new homes.  A conventional natural gas or electric system can be used in conjunction with solar thermal systems to provide additional heating as necessary.

Active, closed-loop solar hot water systems are the most appropriate for Utah's climate, where freezing temperatures are common.

Types of Solar Thermal Collectors:

solar thermal flat plate evac tube cropped
 Flat plate collectors contain a thin absorber sheet made of thermally stable polymers, aluminum, steel or copper (to which a black coating is applied), backed by a grid or coil of fluid tubing. The whole apparatus is placed in an insulated casing with a glass or polycarbonate cover. Flat plate collectors look similar to solar photovoltaic panels, which produce electricity.  Evacuated tube collectors are a series of modular tubes, mounted in parallel, each of which contains an absorber tube. Sunlight passing through an outer glass tube heats the absorber tube contained within it. The absorber can be made of copper or specially-coated glass tubing.

How do I find a solar thermal installer?

There are many solar dealers and installers in Utah who specialize in solar thermal. Contact a solar installer to explore options for your home.

What incentives are available for solar thermal in Utah?

Questar gas offers a rebate program for solar water heating systems, and State and Federal tax incentives for renewable energy installations can be used for solar hot water heaters. Learn more about incentives.

Want to learn more about solar thermal?

Estimate the correct system size for your home, calculate your savings, or learn more about solar hot water components from the U.S. Department of Energy's EnergySaver site.



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