HomeGreen Technology7 Best Solar Water Heaters In The U.S.

7 Best Solar Water Heaters In The U.S.

The best solar water heaters are somewhat like choosing your holiday destination – it’s all about personal preference and what best matches your needs!

As many of you reading this have decided it’s time to go solar with your household water heating, you may be wondering what the best systems on the market may be.

This all depends on brand preference, system design, and needs such as how much hot water you need.

This article takes a look at seven of the best solar water heaters you can buy in the United States.


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How Does A Solar Water Heater Work?

Mechanism Of Action

The basics of how a solar water heater works all start at the source – solar radiation.

The sun rays reach and heat (this is solar thermal energy) an absorptive surface that heats the fluid passing through strategically placed pipes. This fluid can be the water itself, which will return to the tank until needed. In more complex systems, the fluid is a heat-transfer fluid that flows back to a heat exchanging mechanism and warms up the water.

A depiction of the basic mechanism of solar heat exchange in water heating systems. Source: U.S. Energy Information Administration

While the basic concept remains the same, there are an array of technologies that allow you to do this.

Related Reading: How much do water heaters cost in the U.S.?

Types of solar water heaters

There are two primary types of solar water heaters.

These are active or passive, and have various subtypes of their own which look like this:

Solar Water Heater Type Subtypes
Active Solar Water Heater Direct Circulation
Indirect Circulation
Passive Solar Water Heater Thermosyphon
Intergral Collector-Storage
Table depicting the various solar water heater types and subtypes.

Active Solar Water Heaters

Direct Circulation

These are the best solar water heaters for warmer climates!

In these systems, cold water pumps from storage units to a collector (solar absorptive surface) when the sun is out, and back into your home.

They generally work to maintain warmth by constantly recirculating the heated water and simply flushing the hot water down as it is used within your household.

Indirect Circulation

Image showing the basic mechanism of an indirect circulation solar water heater.
Source: Valentine Eastern Sierra Reserves

These are known as closed-loop water heaters and heat water by pumping an anti-freeze heating fluid to the collector solar absorbing surfaces and back down into a heat exchanger.

The heat exchanger absorbs the transferred energy effectively because of the thermal conduction materials it is made of. These include copper (most popular), bronze, steel, and other metals.

Passive Solar Water Heaters


This type of system is very popular and works by storing water up on your rooftop and allows the water to flow through solar energy collection tubes. The hot water then flows directly into your household plumbing system as you open the hot water faucets for use.

Integral Collector-Storage

The integral collector-storage system works similarly to the thermosyphons. However, in this case, the cold water first flows into a solar collector which works to heat it in an integrated box-like structure containing tanks and tubes.

Thereafter, water flows into a conventional heater to ensure a constant source of hot water.

What Are The 7 Best Solar Water Heaters In The U.S.?

Now that you know what type of solar heaters there are and how they work, it’s time to take a closer look at the best solar water heaters for your household on the market today:

1. Sunbank 40 Gallon Solar Water Heater

  • System type: passive
  • General price: $2500
  • Capacity: 40 gallons
  • Collector: borosilicate & nickel-plated copper heat pipe collectors
  • Working fluid: water
  • System certification: SRCC OG-300

The Sunbank is certainly one of the best solar water heaters on the market!

It is a reputable heating system that prides itself on easy installation, efficiency, and affordability. Moreover, it comes with a 10-year warranty and a one-year warranty on separate components.

One of the latest developments making this heater stand out is the new and improved corrosion resistance in its stainless steel tank.

It also utilizes nickel-plated copper heat pipes and the best thing about this solar water heater?

It can be used as a pre-heating function as an entirely independent system!

2. Duda 300L Solar Water Heater System

  • System type: active
  • General price: $3601,83
  • Capacity: 80 gallons
  • Collector: borosilicate glass and tri-metal coated glass
  • Working fluid: inhibited propylene glycol
  • System certification: SRCC OG-100

According to DudaDiesel, their Duda active solar water heater systems are one-of-a-kind in absorption efficiency, with a whopping 93-96% rate!

This system is the most popular type in North America and has the advantage of allowing you to store your hot water anywhere you please, as well as the option of gas assistance heating too.

In other words, storage can be placed at quite a distance from the collectors that absorb the solar radiation and seasonal changes won’t affect this either (unlike in most passive heater storage systems).

So, this heater might just be the best solar water heater for your household, should you live in a seasonally dynamic environment.

3. HelioMaxx™ 80G Glycol Solar Hot Water Evacuated Tube Collector Kit

  • System type: active
  • General price: $5399,94
  • Capacity: 80 gallons
  • Collector: borosilicate glass
  • Working fluid: inhibited propylene glycol
  • System certification: SRCC OG-100

Looking for a solar heating system but still want the option of a backup electrical connection too?

Then the Heliomaxx might prove to be the best option for you.

The residential solar kits are designed by highly trained engineers who have crafted a product ideally suited to the colder northern climate – infamous for bursting and breaking most solar water systems.

Even better, the company mentions that you can expect a 10-year performance warranty.

The patented parts of this performing piece allow for excellent results and compatibility for almost all retrofitting.

If you find yourself in the icy northern environment and perhaps have some existing structural components you would like to add to – the Heliomaxx is simply perfect.

4. Heliodyne Cool Climate Water Heating System

  • System type: active
  • General price: $6070
  • Capacity: 80 gallons
  • Collector: Not defined
  • Working fluid: glycol
  • System certification: SRCC OG-100

The closed loop design of the Heliodyne Cool Climate water heating system is ideal if you’re looking for a system that offers protection from harsh cold and harsh water chemistry (such as very brackish water).

This product is designed to work in any type of home setup and the heating fluid offers maximum durability within the system.

According to the company, this system will pay itself off in a mere 4-8 years from the start of operation. So if you’re after a system with a relatively quick payback period, as well as a hardy one, this system is a great choice that won’t disappoint.

5. Stiebel Eltron SOLkit SB 300

  • System type: active
  • General price: $4659
  • Capacity: 80 gallons
  • Collector: Copper tubes
  • Working fluid: glycol
  • System certification: SRCC OG-100

If you are somebody who likes a product from a company with a long-standing reputation – Stiebel Eltron is for you.

This company has been actively producing energy products for over 40 years and is dedicated to being at the forefront of advanced water heating technology.

These are one of the best solar water heaters when it comes to federal tax credits too, with a savings and return of around 30%.

The price of this kit is in the middle range of its type, so you need not worry about crazy prices for this level of quality.

6. SolPal Integrated Collector Storage System

  • System type: passive
  • General price: $3793.54
  • Capacity: 51.5 gallons
  • Collector: Copper, aluminum, glass
  • Working fluid: water
  • System certification: SRCC OG-300

The SolPal brand offers one of the best solar water heating systems on the market today.

This brand is all about unique design, aesthetic integration into your home, and easy installation, and it comes with a cherry on top – a 5-year guarantee.

If you’re looking for a sleek design, aesthetic pleasure, and good quality then you have come across the perfect match for you.

And just to top things off, the price is on the more affordable side too.

7. EagleSun DBS-80-40 Drainback System

  • System type: passive
  • General price: $3590
  • Capacity: 51.5 gallons
  • Collector: Not defined
  • Working fluid: Not defined
  • System certification: SRCC OG-300

This product is a drain-back design that prides itself in its excellent reliability and ability to overcome the most common solar water heating system failures.

A simpler design with fewer components means more efficiency and stability in this case.

If it’s consistency that you’re after but don’t find yourself particularly concerned about the smaller capacity, then the EagleSun makes the perfect addition to your house.

Final Thoughts

Choosing between the best solar water heaters is quite a challenge – they all offer unique selling points.

At the end of the day, it depends on the type of system – active or passive – that you are looking for, the cost (although they all fall within close range of each other), brand reputation, and volume.

If you’re after a smaller and simple design, the EagleSun is for you.

If it’s the long-standing brand reputation that you’re after, the Stiebel Eltron is for you.

The good news is there is quite a variety to choose from.

So take your time, do your research, and you’ll soon find what you’re looking for.

If you want to share your thoughts or ask us a question, please feel free to reach out to us in the comments section below! Alternatively, visit our forum or follow us on Twitter!


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