Solar Water Heaters

Best Solar Water Heaters In India. Everything You Need To Know

We all need hot water in our daily life but it is a little bit expensive as it loads a lot of energy. More than 18% of the total domestic energy is used in hot water. But in most homes and in many commercial buildings this energy is generated from fossil fuel which is very harmful to the environment. Nowadays people are very aware of nature and so they are finding an alternative the fossil fuel. So, solar water heaters are a great alternative for commercial water heaters.

The main usage of the main use of solar water heaters is to heat the water by using the solar radiation which is collected in the solar water heaters. Solar water heaters are a new invention which is done by modern science. They grab the attention of the users as they are eco-friendly and also easy to use. The solar water heaters are used in both residential well as commercial uses.

So if you want to install solar water heaters in your house then you must have a brief knowledge about it. In this blog, I tried to give a brief idea about solar water heaters, their benefits, types, advantages and disadvantages, and many more. Before going to the article let’s have an idea about solar energy and its future impact.

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What Is Solar Energy?

Solar energy which is radiation generated from the sun is capable of producing heat or else generating electricity. The individual particles of the sunlight which is known as protons carry a huge amount of solar energy. The solar energy which is collected from the PV panels converts that energy into electricity so that it can be used in various ways.

These panels are made of various small silicon particles which helps in absorbing the excess solar power from the sun and then converting it into electricity for usage in households as well as in organizations.

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Future Impact Of Solar Energy In India

Prime Minister Narendra Modi has generated the goal of installing 450 GW of renewable energy by the year 2030. To achieve it means that India will be able to generate about 6y0% of the total electricity from non-fossil fuel by the year 2030.

According to IBEF, in October 2021 the capacity of the Indian renewal energy stood at 149GW representing approximately 38.27% of the overall installed power capacity and thus providing an amazing opportunity for spreading the renewal of the green data centers. In October 2021, India’s renewable energy capacity increased by 1,522.35 MW.

As of September 2021, India had 101.53 GW of renewable energy capacity and represents approximately 38% of the overall installed power capacity. The country is targeting about 450 Gigawatt (GW) of installed renewable energy capacity by 2030 about 280 GW (over 60%) is expected from solar. As of September 2021, India had 101.53 GW of renewable energy capacity and represents approximately 38% of the overall installed power capacity. By December 2019, 15,100 megawatts (MW) of wind power projects were issued, of which, projects of 12,162.50 MW capacity have already been awarded. Power generation from renewable energy sources in India reached 127.01 billion units (BU) in FY20.

With a potential capacity of 363 GW and with policies focused on the renewable energy sector, Northern India is expected to become the hub for renewable energy in India.

What Is Solar Water Heaters?

Solar water heaters are an alternate solution for commercial water heaters. This device is mainly used for heating the water using solar power. The solar energy is converted into heat and then is transferred into the water tank which is very effective for warming up the water. Solar water heaters are eco-friendly and also energy efficient hot water heaters this is because they are operated with renewable energy.

The solar water heaters are made up of a solar collector mounted on the roof of a building and connected to a water storage tank. On the basis of the system, the cold water is calculated from the tank through the collector and then to be heated directly or by the high capacity of heat exchange fluid which is then warmed in the solar collector and then transfer the heat of the fluid through the tubes in the water in the tank. While exchanging the heat from the solar collector the cold water is then assisted passively to the solar heaters to use the electricity to calculate the heat exchange fluid and then operate to the pumps and the controllers.

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How Do The Solar Water Heater Work?

The solar water heater working principle is to trap the thermal energy from the sun and then it is used to heat the water. These systems are made up of the devices such as collectors, a storage tank, a heat exchanger, a controller system, and a backup heater.

Collectors: The solar collectors are mainly installed on the rooftop of the building. These collectors generate heat with the help of solar energy. The solar radiation passes through the collector which has a glass covering which is designed with a coating that captures the solar energy and converts it into heat. This heat then circulated to the transfer fluid which is consists of small pipes in the plate.

Heat Exchangers And Storage Tank: After the transfer field heats up by the collector then is circulated to the heat exchangers which is placed in the storage tank. when these pipes are filled with the heated transfer fluid then it circulated from the pipes and makes them hot for various usage.

Controller System: Lots of heaters have a controller system within them which helps in maintaining the temperature of the water present in the tank. it also helps in preventing the cold water to move through the system when it is extremely cold outside and transfer the fluid which is not being warmed sufficiently.

Backup Heater: If it is too cloudy then, the backup heaters help in heating the water through the gas or electricity. The backup heaters will account for roughly 20% of the hot water usage throughout the year.

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Types Of Solar Water Heaters

Nowadays solar water heaters are very reliable when it matches perfectly with the climate and also load. There are different types of solar water heaters available in the market in order to match the efficiency, capacity, functionality, and price. It is very touching to choose the right solar heaters. First, you have to know the different types of solar water heaters which are present in India. There is a total of three types of solar water heaters. Now let’s look at them.

ETC Solar Water Heaters

ETC Solar Water Heaters
ETC Solar Water Heaters

The Evacuated Tube Collector is the solar thermal solution that is ideal for solar water heaters and also designed in such a way that it fulfills the water heating needs for the domestic needs. It is consists of double-layered borosilicate glass tubes. It is also made up of two glass tubes that have a vacuum in between them which act as insulators. The outer wall of the inner tube is designed in such a way that it helps on absorbing solar radiation.

The ETC acts as the absorber in the water heater. The solar radiation falls on the tubes which then go through the outer tube and then strikes the outer of the inner tube. It absorbs the energy and then moves towards the cold water flow in the tube. through this process, the water gets heated and ready to use.

FPC Solar Water Heaters

FPC Solar Water Heaters
FPC Solar Water Heaters

The Flate Tube Collector is made up of the insulated outer metallic box which is layered by the glass sheet. Inside of it, there are blackened metallic absorber sheets with build-in channels which helps in carrying the water. The absorber helps in absorbing the solar radiation and then transfers the heat to the flowing water. The flat-based solar heater is very efficient and also has a long shelf life. This is also very cost-effective and eco-friendly in nature.

Pressurized VS Heat Exchanger

Based on the capacity the solar water heaters have certain other types based upon the functionality.

Heat Exchanger Water Heater:

The heat exchanger solar water heaters use the heat exchanges in order to heat the water. The water can be heated through another medium which can be air or liquid. After the solar collectors trap the solar energy, the heat exchanger transfer the heat to the liquid or the air. Through this process, the heated liquid runs inside the water tank through pipes to unheated water. The medium flows inside the cold water and the heat starts to exchange from the medium to the water.

Pressurized Solar Water Heater:

Pressurized Solar Water Heater is also called the High-pressure Direct Pressure Solar Water Heater. It helps in heating the water through pressure. The water available in the tank should be under high pressure so that it can work properly. The pressure of the water tank should be equal to the pressure of the tap water.

Prssurize with the heat exchanger:

This device is the combination of the pressurize heater and the heat exchanger heater. Like the heat exchanger heater, it runs by the copper tubes which are connected to the tank. The solar power heats the medium which is present inside the copper tube and then it starts to transfer the energy to the unheated water which makes it hot with the temperature around 60 degrees. Similar to the pressurized heater, the heating process is done by pressure.

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Benefits Of Solar Water Heater For Home

Solar water heaters have developed in the past 100 years which makes them more reliable. It not only helps in heating up the water but also reduces the global carbon footprint. If you are thinking about the initial installation cost then let me clear to you that, if you think about it as a long time investment then it will be much more beneficial for you. Also, there are lots of benefits of solar water heaters that you must be aware of. Let’s have a look at them.

Zero Cost: The solar collectors which are attached to the solar heaters trap the energy from the sun which means that you do not have to pay a single amount to the power grid for using the electricity. As it is a renewable source of energy so it is available in ample amounts.

Low Maintenance: Solar water heaters do not need a huge amount of maintenance cost as it demands simply cleaning. It does not consist of any moving parts so there will be no tear and breaking up of the appliances which are needed to repair on the daily basis. If you maintain it properly then it can be last for almost 20-25 years long.

Choice Of The Size: Proper size of the solar water heater is essential. If the homeowners have enough storage to meet 90-100% of their hot water needs then the store density must be huge. A to-60 gallon of the storage tank is great for the usage of three people whereas an 80-gallon tank is great for four people.

High Efficiency: About 80% of the total solar radiation is turned into electricity which is needed to obtain hot water at home for the usage of various purposes.

Eco-Friendly: The solar water heater is not dependent on any fossil fuel and also has zero-emission and lower carbon footprint which is very eco-friendly in nature.

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Types Of Solar Hot Water System

Solar water heating is the most effective energy to generate hot water for household purposes. The prime energy of the solar heater is solar energy which is trapped in the collecter and then convert into heat energy for heating up the water. Nowadays solar water heater is trendy it is eco-friendly as well as it needs a limited amount of maintenance. So, it grabs the attention of the consumers. If you are planning to install solar water heaters then you must have an idea about different types of solar systems.

Thermosiphon Systems

Thermosiphon Systems are the method of passive heat exchange that is based on the natural convection that circulates the fluid from the collector and then to the storage tank. In a thermosiphon system, the fluid gesture is done in such a way that helps in transferring the heat. These systems are very systematical with the high levels of solar radiation.

Direct-Circulation Systems

The direct circulation systems are used to pump out the water from the storage to the collector. The circulation of the hot water from the storage tanks provides the device protection from freezing. The recirculating system increases the energy usage whereas the flushing decreases the hours of the operations. The direct circulation system is mainly used in places where the freezing temperature is infrequent.

Drain-Down Systems

Drain Down Systems are basically indirect water heating systems. The treated or untreated water is passed through the closed-loop and then the heat is circulated to the portable water by the heat exchanger. If there is no heat then the collector fluid is drained out by gravity to prevent freezing. The convection loops help in reducing the temperature of the preserved water.

Indirect Water-Heating Systems

Indirect Water-Heating Systems help in circulating the freeze-protected fluid by a closed-loop and thus the heat is shifted to the portable water with the help of a heat exchanger with 80-90% efficiency. Water-ethylene glycol solutions and water-propylene glycol solutions are mainly used for freeze protection.

Air Systems

The collector which is present in the device helps in heating up the air and then it is moved by the fan to air to the water heat exchanger. Then this water is used for various purposes. The efficiency of this heat exchanger is 50% range.

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Advantages And Disadvantages Of Solar Water Heaters

Solar water heaters have gained a lot of popularity nowadays. These are not just cost-effective but also very eco-friendly to heat the water for various purposes. The solar water heaters are composed of solar controllers and also strong tanks. So if you want to install solar water heaters then you must know about the advantages and the disadvantages of solar water heaters.


  • Save the water heating bills: By installing the solar water heaters you can able to save a lot of energy bills. Like regular water heater the solar water heater give the same efficiebncy with savings added in the overtime.
  • Little to no maintanace: Once you have install your solar water heater then you dont have to worry about the maintanance. As the active maintanace is very minimal. A well solar heaters can last for over 20 years and also work efficiency if heating the water with the help of the solar power.
  • Environmenr Friendly heating option: with the ehlp of the solar water heaters you can able to use 100% of the renewale energy without hamper the environmet. As the main sourse of the device is solar energy so while using this device there is zero emission of any harmful substances.
  • Easy installation: The solar water heaters are easy to install.

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  • Additional space: The solar water heater needs an aditional roof space to install it.
  • Performance is dependent on the climate: One of the most important factor is that the solar heater is totally weather related. If the weather is a little bit cloudy then the solar heater unable to work properly. So you need sun every day of he year for the solar water heater to work properly.

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How To Select The Solar Water Heaters?

There are many different types of solar water systems available in the Indian market. So it is very demented to choose the right one. Here are the steps which help you to choose the right solar water heater for your household.

  • Work on the economics of the solar water heating system.
  • Evaluate the solar resousce which means that the availability of the sun, the direction in which the sunlight is available and also the location where it should be installed.
  • Then decide the perfect size of the solar heater.
  • Gain the knowledge about the local codes, regulations and subsidies,tax extempyion etc.

Also, have the look at the various components which is needed for the solar water heating system are:

  • Heat exchanger for the solar water system.
  • Heat transfer fluids for the water heating systems.

How To Install And Maintain The Solar Water Heater System?

The proper installation of the solar water heater depends on many factors. The factors include the solar resource, climate, local building code requirements, and safety issues.
After installation, it is very essential to maintain the system in order to run the heater smoothly. Regular maintenance on the system can be as infrequent as every 3-5 years which is preferable as an insulator. the system replacement is required after 10 years to maintain the solar water heaters. To install the solar water heater properly you have to follow this step:

  • Mount the solar collector on the roof.
  • Then install the solar vstorage tank and the heat exchange next to the coventional water heater.
  • Install the piping and the pump for the glycol loop.
  • After insatll it then establish the water piping.
  • Install the controls
  • Fill the system
  • Then insulate the water and glycol lines.

Now, your solar water heater is ready for usage. You can enjoy the service of the water heater without hurting the environment.

The solar water heaters require little amount o maintenance. If you take good care of it then the system can be last for 50% – 100% longer. there are the following steps about how you can maintain the solar water heater.

The devices which are attached to the solar water heaters which are needed to be monitored are mentioned below.

Solar Controller: the collector must remain unshaded. The dust and the dirt can hamper the performance of the solar water heater. In the dusty weather, the panels need to be cleaned properly. The collectors should be inspected for cracks and yellowing and the seal should be checked so that they are in the good condition.

Roof And Support: The roof penetration should be checked properly to make sure that there is no problem with the leakage of the water. the nuts and the bolts are also checked thoroughly for tightness.

Plumbing, Pipes, And Valves: All the pipes and the valve should be inspected thoroughly for the drips and the leakage and if there is any leakage then it should be replaced. it is also very essential that the pressure relief valve is not stuck open or shut.

Pump: The pump should be in good condition if it is not then it can cause an overheat to the system.

Sensors: As it is mainly used to control the water heater it is very necessary to maintain them properly. In order to check the sensor, you should apply mild heat. If it is working properly then it can record the temperature rise.

Heat Transfer Fluids: The solar water heater utilizes the glycol solution which should be checked annually to see if it is in good condition.

Hot Water Storage Tank: This should be checked periodically for cracks, leaks.

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Subsidies On Solar Water System

On 3rd August 2011, The Indian National Bank for Ministry of New and Renewable Energy (MNRE) provides subsidies and also motivates the users to install the solar water heaters. These schemes even come under Solar Water Heating Systems (SWHS).

The government through the agencies and also channel partners provide 30% of the total cost subsidies to the consumers in different states, on the other hand, 60% subsidies are available in the states like North-East states, Hilly area states, and islands.

The government provides an interest-free loan which is given to the states like North-East states, Hilly States, Island states, Chhattisgarh, Jharkhand, and Uttrakhand.

The government also passes on the subsidy to the partners which in turn then passes to the consumers and thus the consumers need to do is to go to the right solar water heater company that has the approval of MNRE approval. There are many MNRE approved for solar water heater systems.

Final Word On The Best Solar Water Heater India

Finally, to summarize the whole topic I will try to tell you that solar water heaters are very popular in the Indian market. Nowadays people are concerned about the environment, so they are avoiding using the items which are run by fossil fuels. These devices emit carbon products which are very harmful to the environment. That’s why the solar industry is booming in India, and many companies, are available for producing various kinds of solar products.

Nowadays, people need hot water for various purposes. The commercial heater is not very eco-friendly and also does not help in saving the electricity bills of the consumers. The solar water heater is the best alternative solution for heating the water without damaging the environment. As the major source of energy is solar energy which is trapped in the solar collector and then converts into heat energy which then heats up the water. So, it not only helps in maintaining the electricity bills but is also eco-friendly in nature.

Lastly, thank you for reading my article. I hope this will help you a lot with the solar water heater. So if you have a solar water heater then you can share your experience in the comment section below.

FAQ’S Of Solar Water Heaters:

1. What is an FPC solar water heater?

The FPC solar water heaters are the device that absorbs the sunrays through the place collector. The device is consists of copper tubes that are placed inside which serve to heat the water.

2. How will solar heaters work in winter?

The solar water heaters are designed with inbuilt water heating elements which help the device to work efficiently in winter.

3. Where can I install a solar water heater?

You can install your solar heater anywhere as per your preference. But many people like to install their solar heater on the roof of the house.

4. Do I need to install solar panels for solar water heaters?

Absolutely not, the flat plate collector which is present in the solar water heater helps in heating up the water.

5. What is an ETC solar water heater?

The ETC solar water heater is mainly used to heat the water by double-layer borosilicate glass tubes. These tubes tarps the solar radiation and then heat the water through this energy.

6. How long can water remains hot in a solar water heater?

Approximately 48 hours the water remains hot in the solar water heaters.

7. Can I heat water from a solar heater even at night?

No, you cannot heat the water from the solar heater at night as the main source of the heater is the sunlight. But the heated water is stored in the water tank which can be used at night.

8. What is the approximate life of solar water heaters?

The shelf life of the solar water heaters is approximately 15- 20 years. If you maintain the heaters properly then they can last a longer period of time.

9. What is the warranty period on solar water heaters?

The warranty period of the solar water heaters for 2 years and 10 years for the solar collectors.

10. Is there a government subsidy on solar water heaters?

Yes, there are some subsidies provided by the government for solar water heaters.

11. What are the types of solar water heaters?

There are three types of solar water heaters they are:
1. ETC Solar Water Heaters
2. FTC Solar Water Heaters
3. Pressurized VS Heat Exchanger

12. How do I select the best capacity water heater for my home?

To select the perfect water heaters for your home first you need to calculate the total consumption of the water at your home, then find out the water consumption. After that, you can easily choose the solar water heater.