While solar water heaters cost more than conventional water heaters, their tendency to harness solar energy can produce massive savings. Additionally, they also yield great environmental benefits.

According to research, heating water constitutes 18% of a household’s electricity consumption bill. However, a solar water heater can significantly reduce up to 50-80% of the water heating bills.

Further in the article, you’ll learn about the electrical components, working, and types of solar thermal water heaters. Moreover, along with their many advantages, you’ll also learn the process through which a solar water heater aids in cutting costs.

Components and Working of a Solar Water Heater

Most solar water heating systems are typically made of various basic components such as:

  • Solar collectors
  • Thermal storage
  • System controls and controllers
  • A conventional water heater (as backup)

Solar water heating is a dependable, sustainable, renewable energy technology used to heat cold water. Sunlight strikes an absorber surface within an actual tank or solar collector and heats it. Then, potable water flows through the tubes attached to the absorber and catches its heat.

Solar water heating systems consisting of a heat-transfer-fluid loop possess a heat exchanger that transfers heat to the potable water. The heated water is kept in a distinct preheated water tank. At times, conventional solar storage tanks that store water are used instead. If extra heat is required, it’s provided by electricity or natural gas through the conventional water heating system.

Thermal storage is usually needed to sync the timing of the intermittent solar resource with the timing of the hot water load. Generally, a couple of gallons of water per square foot of collector area is enough. This water can be potable or non-potable if a load side exchanger is used.

In conclusion, a solar water heater works by preheating the water to the conventional heating system. They are engineered to deal with 41% to 70% of the water heating load. Nonetheless, a backup conventional water heating system must meet 100% of the peak hot water requirement.

These backup heating systems provide you with water during cloudy days or when the solar panels are down.

Solar Thermal Water Heater

How Should You Choose a Solar Water Heater?

There are several kinds of solar water heaters available on the market. But, purchasing a solar heater without considering your needs and circumstances isn’t the best idea. Surprisingly, the costliest solar water heater system might not suit your house either.

The right solar water heater for you will depend on the following factors:

  • Free space
  • Availability of sunlight
  • Capacity requirements
  • Residence codes and regulations
  • Budget

What Kind of Solar Water Heaters are best?

These hot water systems are divided into two categories, namely active and passive. The significant difference is: active water heating systems need circulating pumps to circulate water, while a passive hot water system relies on the gravitational pull to do the same.

In addition to pumps, active systems require electrical energy to function and may contain an antifreeze in heat exchanging fluid form. Water gains heat in a tube and is piped directly through a faucet within the most fundamental passive solar collectors.

Below are different types of passive and active systems and how they can benefit you.

Active Solar Water Heaters

Although these water heaters are pricier than passive systems, they make up in their efficiency. There are a couple of types when it comes to an active solar water heater.

Active Direct Solar Hot Water Heater

Inside active direct systems, household water goes through the solar collectors into the useable water-storing unit. They’re most appropriate for warmer regions where temperatures don’t go under the freezing point very often.

Active Indirect Solar Hot Water Heater

An anti-freezing liquid circulates through the tubes present in solar collectors in an active indirect water heating system. Subsequently, the fluid’s heat is shifted over to the water. Consequently, the heated potable water is poured into a storage tank meant for homely purposes.

Active indirect solar water heating systems are essential during cold climates, frequently dipping below the freezing point. In the absence of an active water heating system, pipes are susceptible to freezing.

Passive Solar Water Heaters

These water heater systems are less expensive and less efficient than active systems. Nevertheless, they’re more reliable, last longer, and are a cost-effective option if you’re on a tight budget. A passive system uses pressure and gravitational force to move water properly and comes in a couple of variants.

Integral Collector Storage Systems and Batch Heaters

Integral Collector Storage systems are one of the most easily operable among other solar water heating systems. Although they’re adequately efficient, they don’t function in cold weather climates with a chance of freezing temperature.

These hot water systems are either as standard as a massive black water tank or several smaller copper tubes welded to a ceiling. Besides, copper tubing units heat quicker because of the larger surface area and emit heat faster due to the same.

An ICS heating system is typically used for preheating water for domestic systems. Once water is required, it exits storage tanks to enter the conventional water heaters.

The most crucial element to consider in an ICS solar water heating system is its size. They’re enormous and heavy since storage tanks are themselves the collectors. As a result, your wall’s structure should be sturdy enough to enable the functioning of such a system.

Thermosyphon Water Heating Systems

Thermosyphon systems depend on solar heating and thermal circulation instead of natural circulation. Water moves once cool water goes under, warm water goes up, and heat transfer occurs. A Thermosyphon system possesses a tank similar to ICS systems.

The collectors are attached at a descending angle from the tank to enable a thermal circulation system. This system gathers sunlight and returns heated water to the storage tank through a heat pipe or closed loop. Thermosyphon systems are much more efficient than ICS solar hot water heaters, but they can’t be operated in regions with freezing temperatures.

Solar Thermal Water Heaters

Do Solar Water Heaters Work in Winter?

Most solar water heaters are unable to function with optimum efficiency during winters. Passive systems and active direct solar water heaters are examples of such systems. However, active indirect systems are specifically designed to perform during cold weather due to non-freezing fluids.

How Effective is a Solar Water Heater?

The efficiency of solar hot water heating systems is highly dependent on the design and material of the absorber plate. According to the calculations, the collector efficiencies of a solar heating system are 78.5% and 81.7%, while the tank efficiencies are in the range of 71% and 78%. The performance of these systems falls a bit in cold regions due to insufficient solar radiation.

How Much are Solar Water Heating Systems Worth?

Solar water heater systems’ value increases over time with continuous hot water usage. Furthermore, it’s most economical for households consisting of numerous family members.

These water heater costs around 9000$ excluding federal incentives. Additionally, the high-end models cost around 13000$, whereas a smaller solar water heater will incur 1500$.

Prices fluctuate based on various factors, such as:

  • Material of construct
  • System size
  • Maintenance cost
  • Installation cost
  • Weight and size

While passive solar water heaters are the most cost-effective option costing 4000$ per 60 gallons, they don’t function in all weathers. If your house structure won’t support a heavy passive system, it’s best to go for an expensive active solar collector.

You can add the price of a solar water heating system to your mortgage if you’re building a new house. Adding the charge to, say 30-year property loan will cost you less than 30$ a month. After tacking federal incentives, the same amount will go down to 15$ a month.

Apart from the charge to buy and install these systems, you’ll have to consider the annual operating expenses. In a typical passive system, it is negligible. However, in conventional systems working in harmony with solar heaters, you’ll have to pay extra heating costs.

Solar Water Heater

How to Save Money While Buying Solar Water Heaters?

To your fortune, you don’t have to bear the entire cost of this type of water heating system. You can use the federal tax credits system to decrease installation costs and significantly save lots of money.

Federal Residential Renewable Energy Tax Credits or Investment Tax Credits (ITC) are liable to offer a tax credit of 26 per cent on solar water heaters. This benefit is to encourage the use of energy-saving devices. However, there are a few conditions to become eligible:

  • A minimum of 50% of the energy produced from the structure should come from solar heating, through solar panels, or photovoltaic cells.
  • The system should belong to a range of solar water heaters certified by the Solar Rating and Certification Corporation (SRCC).
  • You shouldn’t use solar heating systems to heat water in hot tubs or swimming pools. They should be purely used for business or home purposes.

You might wonder about the cost difference between buying solar water heaters and building them yourself.

Solar Hot Water Heaters vs Domestic Solar System

Solar water heaters are now much more uncommon compared to the past. This decline is primarily because of the significant decrease in solar panels prices. As a result, people have started to install their solar panels to convert solar power into heat or thermal energy.

Property owners who wish to utilize their free space are inclined to buy their personal solar panels. This way, they can generate heat and energy at their will through solar radiation and enjoy their home’s hot water.

Solar collectors are a good investment if space is scarce as they consume much less space than solar panels. Solar water heaters are a wise option for people living in unreachable and remote areas. Besides, they can also serve as an environment-friendly bonus to existing solar energy generators.

Although modern water heaters are highly efficient, solar hot water heating systems yield massive savings and reduce environmental impact. Most systems with similar potential to save the environment are worth buying, and here’s why!

Five Benefits of Buying a Solar Collector

Eco-friendly water heaters, aka solar collectors, might not reduce your water consumption, but they come with the following benefits:

  • It helps fight climate change by reducing the emission of carbon and other greenhouse gases.
  • The use of solar radiation in solar heaters discourages the burning of coal for energy and heat generation, hence protecting the air quality.
  • Dependency on fossil fuel power plants is the leading cause of water intoxication, which is tackled by using solar heaters.
  • It can help you save almost 80% on your water bills every month.
  • Research shows that houses with solar energy-based technologies sell faster and at higher prices than those without.


The sun doesn’t shine all day, so it’s okay to use traditional water heaters as a backup. Habits like doing laundry on a sunny day can help save water and energy. Moreover, you can contact any local solar company to enquire about the rebates they offer for installing solar water heaters.