An Ultimate Guide to Solar Water Heating Systems in India

Solar water heaters are a special kind of geyser that generate hot water using solar energy. Because of their low operating costs and minimal impact on the environment, these are frequently chosen. Water heating systems powered by the sun allow for substantial cost savings due to their low electrical demand.

The term "solar water heating system" refers to any apparatus that uses the sun's rays to supply warm water through specially designed pipes for solar system works to the users for consumption. Solar energy is most commonly used for heating water around the world. For every 100 litres, a day of solar water heating capacity, a typical solar water heating system can save up to 1500 kilowatt-hours of electricity per year.

The solar collectors along with the pipes for solar system works installed in a solar water heating system are typically mounted on the roof. The system is made up of solar collectors that are pointed directly at the sky. The process begins with the cold water flowing into the vacuum collector tube. Here, the collector soaks up the sun's heat and distributes it to the fluid. Hotter temperatures cause water levels to rise. It is then transferred to an insulated tank, where it can stay hot for a long time. Insulation prevents heat from escaping, so water can be used at any time without losing its temperature.

Types:
- Flat plate collector (FPC):
The most common kind of collector is one that focuses on FPCs. They are made out of a square box that has insulation on its inside. This container has a glass lid over it. There is a network of copper pipes that are connected to one another just below the glass that allows water to circulate through the system. This system is more long-lasting than others because it is made of metal. The metal pipes for solar system works in India are the most preferred ones over other materials.
- Evacuated Tube Collectors (ETC):
Glass tubes are used in evacuated tube solar collectors in order to capture solar radiation. The idea that a vacuum might act as an effective insulator is at the heart of this solar system for heating water for use in the home. There are numerous layers that make up a tube known as 3T, and each one traps a vacuum between them. In order to achieve a better level of operational effectiveness, the inner tank of the solar geysers is insulated with PUF material. Magnesium anodes are used in these geysers, which helps to strengthen their durability and ensures that you may have peace of mind for many years to come.

Parts of the SWH System:
● A Solar Water Heating (SWH) system has three main parts: a flat plate solar collector, an elevated storage tank placed behind the collector, and a network of pipelines.
● Typically, the collector is made up of copper tubes soldered to copper sheets, with an insulating material installed at the back as well as a toughened glass sheet installed on top. A flat box is used to store the entire assembly.
● Some types use evacuated glass tubes instead of copper, eliminating the need for a protective cover and insulating box.
Working:
● In most cases, the system is installed on the surface of open ground or a roof, with the collector oriented toward the direction of the sun as well as connected to a source of continually flowing water.
● The water is heated as it passes through the specially designed pipes for solar system works, that are exposed to the sun's rays.
● A tank is used to store the heated water so that it can be used at a later time.
● As a result of the insulated storage tank and the low amount of heat that escapes during the night, the water that is kept there will remain hot in the morning.

Applications:
● Hot water for washing, cleaning, as well as bathing, can be generated by SWHs for use in residential settings. For residential use, a solar water heater (SWH) with a capacity of 100 to 300 litres is ideal. In addition to their potential utility in military settings, larger systems have several practical uses in industry. Solar water heaters may provide hot water between 60 and 80 degrees Celsius.
● When used in place of an electric geyser, an SWH with a 100-litre capacity can save annual electricity use by 1500 kilowatt-hours.
● One megawatt (MW) of peak load can be reduced with the usage of one thousand SWHs with a 100-litre storage capacity apiece.
● One hundred litres of SWH capacity can offset yearly CO2 emissions by 1.5 tonnes.
● The typical lifespan of an SWH is between 15 and 20 years. When the replacement of electricity is done, the payback period lasts around 3-4 years, when the replacement of furnace oil is done, the period lasts around 4-5 years, as well as when the replacement for the coal is done, it lasts around 6-7 years.