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The Best Solar Water Heaters

Exploring what you should expect from a solar water heater investment, and best options

Last updated:
Reviewed by
Carlos Huerta

Water heaters are a crucial part of any home. Typically water heaters range from a 30-50 gallon tank that is either natural gas or electricity powered. The temperature of the water heater is set to around 120 degrees Fahrenheit (give or take) and through copper piping, the water is circulated throughout the home for on-demand hot water.

Over the years, water heaters have evolved to become tankless to now solar water heaters. In this guide, we will discuss what exactly is a solar water heater, FAQs, buying guide, and finally features, pros, and cons of the best solar water heaters in the market today.

Solar Water Heater Benefit to a 24/7 Clean Power Grid

TheEnergyFix’s mission is to provide information to help get to a 100% clean power grid dominated by renewables. Solar water heaters are a paramount technology to get there. Note that water heaters account for about 17% of the home’s energy use. Therefore, any efficiency gains in this sector goes a long way. Here are the benefits of solar water heaters:Carbon Emissions ReductionTraditional water heaters utilize gas or electricity. This energy comes directly from the power grid. Depending on how clean your grid is, most likely it’s from coal which emits CO2 into the atmosphere. Therefore, using your solar water heater instead results in direct savings on carbon emissions.Improved Consumer BehaviorOnce people understand and see the actual savings obtained from their solar water heater, they start to change their behavior for the better. Instead of using hot water whenever desired, they time their activities. Instead of taking a hot shower at night, shifting to the morning will reduce your bill even further. These types of behavioral changes lead to more changes that help the power grid become cleaner.

Best Solar Water Heaters: Top Picks

Rheem SolPak Review

Rheem is a well-known American brand based out of Atlanta, GA developing water heaters for decades now. Most likely you have lived in a home or apartment with a Rheem-based water heater already.

Under the Rheem umbrella of products is the SolPak water heaters. The specifications are as follows:

  • Ranges from 80 to 120-gallon water capacity
  • Comes a storage tank, solar collectors, controller, speed pump, mixing valve
  • Energy Star qualified for maximum energy savings
  • Backup heating source either Electric or Gas from the grid
  • Can be installed indoors or outdoors
  • 6-year manufacturer warranty
  • Size
    • Height: 62 inches
    • Width: 2.81 inches
    • Depth: 28.25 inches
  • Requires 66 square feet of roof space for the solar collectors

Duda Solar 50 Gallon Active System Review

Duda is well-known in the solar water heating industry as being a quality brand based out of Alabama.

  • ~50-gallon capacity (200L)
  • Active (indirect)

The Duda system heats water on the rooftop and then stores the water in a storage tank. The solar collector comes with twenty 14mm solar tubes. Thes tubes are at a 45-degree angle to be mounted to a rooftop slant (37-degree angle also available). Due to the setup of the Duda system, it is perfect for a colder climate zone. It also comes with an 8-liter expansion tank to ensure that if there is an overflow due to too much water, there is backup to capture it.

Other Companies selling Solar Water Heaters

  • SunEarth offers a range of solar energy solutions for residential and commercial customers
  • Sunbank Solar produces different parts for domestic solar water heating systems
  • Apricus is also a very popular solar water heaters manufacture



We covered the best solar water heaters and answered many of the FAQs. Solar water heaters, if installed at the right locations with enough sunlight, can be both beneficial to you financially and the goal of reaching a 24/7 100% clean energy powered grid.

If you are interested in exploring further, reach out to your local manufacture such as Rheem. They have local representatives in every state that can answer any detailed questions you may have.

FAQs on Solar Water Heaters

Domestic Solar Water Heaters (DSWH) are becoming more and more readily available due to their reduced costs and reduced emissions.

What is it?

Solar water heating technology is the process of transforming sunlight into heat using a solar thermal collector device. This device collects heat, retains it, and then uses it to heat liquid stored in the tank.

The major difference from conventional water heaters is that electricity or natural gas is not used as the primary source of energy to heat the water in the tank.

What are the different types of Solar Water Heating Systems?

There are two types: active and passive.

Active systems: This is more common in warm climates (e.g., Arizona, California, Florida). An electric circulating pump is used to circulate water through the solar thermal collector device. Coldwater from the pipes is stored in a storage tank. The electric pump takes water out of the tank, puts it through the collector, and then it goes back into the tank. If the temperature of the water tank goes below a certain preset value (i.e., 120 degrees Fahrenheit), then the pump is activated to warm up the water.
Passive systems: most of these systems are installed on rooftops. Collectors hold water in a serpentine-type pipe. Coldwater flows into these pipes and the sun heats it. This then goes into a typical water heater. The sun does most of the work thus the name “passive”. When hot water is taken out of the water heater for daily use, the cycle repeats always using the sun.
The active and passive systems are the backbone of water heaters. Note that passive and active systems also have several categories under them which you can read about here.

Are there economic benefits of Solar Water Heaters?

Yes! Compared to electric water heaters, the savings can be up to 40%. Compared to natural gas water heaters, it can be up to 20% over a typical lifetime.

How is this possible? During the daytime when the sun is out, your solar water heater uses the sun to heat up water. This process is performed throughout the day and the energy costs are zero. The only time you will be billed is during nighttime periods. Therefore on average, your energy costs are significantly reduced.

What happens when the sun is not shining?

Most solar water heaters have a backup system that is powered by electricity or natural gas. This is used very rarely since in both active and passive systems, the water tank is always ready with hot water. Therefore, when its night, the tank is practically full. However, if for any reason, you need more hot water, your backup systems will pick up the slack.

Also, many users have stated that after installing a solar water heater, their behavior has changed significantly. Instead of doing the laundry at night, they do it during the day when the sun is shining. Such behavioral changes can provide even further energy bill savings.

Is a solar water heater right for me?

Whether a solar heater is ideal for you or not depends on the following factors:

– How much sunlight does your rooftop receive?
– How much water do you require daily?
– Your upfront budget for equipment and labor

If you live in a primarily cold climate, then a solar water heater may not be ideal. Reach out to a manufacturer or installer in your local area for more details. They can answer the question of whether you would benefit from such a system.

Are there any federal tax benefits?

Yes! The Solar Tax Credit applies to solar water heaters. The discounts are as follows:

– In 2020, the tax credit is 26% of the equipment and installation costs
– In 2021, the tax credit is 22% of the equipment and installation costs
– 2021 and beyond, no tax credit available

The tax credit is only valid if you install on a home you own and live in. Rental homes are not allowed but second homes are allowed. For further details, refer to this article.

After installing, make sure to hang on to ALL receipts and provide them to your accountant. The accountant will fill our IRS Form 5695. They will claim the costs come tax time each year and provide you with the tax credits toward your tax bill.

Are there any utility rebates available?

Depending on where you are located and if qualify, yes. For example, San Antonio’s electric municipality, CPS, offers a maximum $2,000 rebate if you install such a device. However, you must use a certified installer hand-picked by CPS. Hawaii utility offers a $750 rebate.

If you are deciding whether to buy a solar water heater, make sure to check your local power utility website for any active rebates or even call their customer service line.

Remember rebates are in addition to federal tax credits so it’s worth your time to do some research.

Where can I learn more about these devices?

Here are some other references to help in your research:

Energy.gov – Everything about solar water heaters
Union of Concerned Scientists
Energy.gov – Estimating cost and Energy Efficiency of solar water heaters

If any specific questions, you can also contact us with your questions.

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Author Bio

Carlos Huerta

Electrical Engineer with background in solar PV designs for residential and commercial projects as well as power systems development. Fan of renewable energy topics and projects. Technical writer for papers, articles and research in related topics to sustainability and especially solar power.

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