Solar Water Heaters: Everything You Need to Know - CNET

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Taking a blistery ablution tin virtually mean pouring wealth down the drain.

The mean American household tin walk between $53 and $70 per period utilizing an electrical h2o heater. If you walk a small other clip successful the shower, that outgo tin heap up adjacent higher. 

Turning down your h2o heater's temperature tin prevention you immoderate wealth connected h2o heating costs, which relationship for 14% to 18% of your home's monthly vigor budget, according to the Department of Energy. But replacing oregon supplementing your existent h2o heater with a solar-powered h2o heater could, too.

Solar h2o heaters harness the sun's vigor to supply a sustainable solution for heating h2o successful the home. While star h2o heaters person gained immense popularity successful countries wherever energy costs are high, they've been slower to drawback connected successful the United States, but could beryllium a compelling enactment for cash-strapped Americans. 

Here's what you request to cognize astir the ins and outs of star h2o heaters and however you tin usage them to trim your c footprint and prevention money.

What are star h2o heaters and however bash they work?

Solar h2o heaters alteration successful design, efficiency, capableness and price, but they each regenerate a bully chunk of the state oregon energy utilized to vigor h2o with clean, escaped sunlight. The three basal designs each person a mode to cod heat, a vessel to store blistery water, backup heating for erstwhile your strategy can't support up and a circulation system.

Batch collector h2o heater

Batch collector h2o heaters vigor h2o successful tubes oregon pipes, usually painted achromatic to cod much of the sun's heat. Cold h2o tin beryllium mixed successful periodically to support h2o from getting excessively hot. These heaters are champion suited for warmer climates. Where freezing mightiness beryllium an issue, they'll request to beryllium drained during acold months to debar harm to the system.

Flat-plate collector h2o heater

Flat-plate collectors trust connected a metallic plate, often painted black, to soak up the sun's heat. Heat travels from the sheet to water-filled tubes. The h2o cycles done heating tubes to and from the retention tank, keeping the stored h2o hot.

Evacuated conduit collector h2o heater

Evacuated conduit collectors are the astir businesslike models retired there. Water is heated successful a conduit that's surrounded by a larger, vacuum-sealed solid tube. Very small vigor is mislaid due to the fact that there's nary aerial betwixt the heating liquid and the extracurricular world.

Solar h2o heaters tin vigor h2o straight oregon indirectly. In indirect heaters, the prima heats a vigor transportation liquid (often a h2o and propylene glycol mixture), which transfers its vigor to h2o successful a tank. Because the freezing constituent of the vigor transportation liquid is little than that of water, the strategy tin run successful colder climates. For example, evacuated conduit collectors tin enactment successful temperatures arsenic debased arsenic minus 40 degrees Fahrenheit, according to the US Environmental Protection Agency.

How to bargain a star h2o heater

Buying a star h2o heater is much analyzable than browsing an online marketplace similar Amazon, selecting a h2o heater, paying and logging out, said Jake Edie, an adjunct prof astatine the University of Illinois successful Chicago who teaches a people connected cleanable vigor successful the electrical grid. 

"Solar h2o heaters, overmuch similar different cleanable vigor options, necessitate a important upfront concern successful speech for semipermanent gains and outgo savings passim their utile lifespan," Edie said.


Solar h2o heater connected a extortion successful Spain.

Jose A. Bernat Bacete/Getty Images

Here are immoderate steps successful purchasing a star h2o heater system.

  • Assess your roof: Ensure your extortion is successful bully information and receives astatine slightest 5 hours of sunlight daily. 
  • Estimate the size of the heater needed: The size of your star h2o heater depends connected the fig of radical successful your household and your location. Depending connected however overmuch prima you get, a 20-square-foot collector sheet is recommended for 2 people, with an further 8 to 14 quadrate feet per person. The h2o vessel should beryllium 1.5 to 2 gallons per quadrate ft of collector plate.
  • Check ratio metrics: The star vigor origin and star fraction of the strategy are the astir important metrics to measurement and recognize a h2o heater's efficiency. A emblematic star vigor origin (the magnitude of powerfulness utilized from the prima divided by the powerfulness utilized from the grid) is betwixt 2 and three, and a emblematic star fraction (the magnitude of powerfulness utilized by the prima divided by each the powerfulness utilized by the system) falls betwixt 0.5 and 0.75.
  • Estimate cost: Consider the system's archetypal cost, the imaginable attraction costs and the savings from the federal taxation recognition for star h2o heaters.
  • Get quotes from installers: Contact star h2o heater installers for quotes and compare.
  • Purchase and hold for installation: Once you've decided, proceed with the acquisition and acceptable up a clip for the installers to instal your system.
  • Apply for taxation credit: In the US, star h2o heaters suffice for a 30% national taxation credit. Be definite to use for this erstwhile you record your taxes.

Types of star h2o heaters

When it comes to star h2o heaters, determination are 2 superior types: progressive star h2o heating systems and passive star h2o heating systems.

Active star h2o heaters

Active star h2o heaters usage a pump to circulate the heated liquid and tin beryllium divided into 2 types: nonstop and indirect circulating systems. Active star h2o heating systems are mostly much expensive, but are the communal benignant installed successful the US, according to the EPA.

  • Direct circulating systems circulate h2o straight done star collectors and are suitable for climates that don't acquisition freezing temperatures.
  • Indirect circulating systems circulate a non-freezing heat-transfer fluid done a vigor exchanger that warms the water, making them perfect for environments prone to freezing. 

Passive star h2o heaters

Passive star h2o heaters don't person pumps to determination blistery and acold h2o around. They travel successful 2 chiseled variations: integral collector-storage systems and thermosiphon systems. Passive star h2o heaters are known for their reliability, cost-effectiveness and durability, but don't let for immoderate of the finer power of progressive systems.

  • Integral collector-storage systems vigor h2o done a transparent screen connected a retention vessel from which h2o is drawn erstwhile a blistery h2o pat is opened.
  • Thermosiphon systems vigor h2o successful a collector connected the extortion and usage the information that lukewarm h2o volition emergence and acold h2o volition descend to support a travel of cooler h2o successful the way of the sun's warming rays.

How overmuch does a star h2o heater cost?

The outgo of a star h2o heater tin alteration wide depending connected the type, size and installation requirements. On average, you tin expect to wage betwixt $2,000 and $5,000 for the system, with installation costs adding $1,000 to $3,000. Despite the upfront costs, star h2o heaters tin supply savings implicit clip done reduced vigor bills.

In the United States, star h2o heaters suffice for a national taxation credit, sitting astatine 30% of the full outgo done the extremity of 2032. So for a strategy that costs $3,877, you would beryllium eligible to person backmost $1,163 erstwhile you record your taxes.

What are the pros and cons of star h2o heaters?

Like immoderate technology, star powered h2o heaters person pros and cons.

"While solar-powered h2o heaters are an fantabulous means to trim your wide energy expenses, it is important to enactment that they person their challenges," said Edie. "For instance, during cloudy days oregon astatine night erstwhile star panels cannot make power, the h2o heaters volition beryllium incapable to nutrient blistery water." 

Here's a further breakdown of the pros and cons.


  • Energy savings:Installing star h2o heaters tin assistance you prevention connected your electrical measure and trim your reliance connected municipal powerfulness for your blistery h2o needs. 
  • Environmentally friendly:By harnessing the sun's energy, star h2o heaters supply a sustainable vigor solution that reduces your c footprint.
  • Long lifespan:Solar h2o heaters person a agelong lifespan and tin past up to 20 years oregon much with due maintenance.


  • Expensive: The upfront outgo of installing a star h2o heater tin beryllium high, though vigor savings tin offset this implicit time.
  • Weather dependent:Solar h2o heaters beryllium connected sunlight to function. Cloudy oregon rainy upwind whitethorn impact their performance, though pairing them with a accepted h2o heater tin support the blistery h2o flowing adjacent during a drawstring of cloudy days.
  • Requires space: Solar h2o heaters request abstraction connected your home's extortion to instal star panels. Small homes oregon shared flat buildings whitethorn not beryllium suitable.
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