How Does a Solar Water Heating System Work?


Solar water heaters are probably the most used and understood solar systems anywhere on the globe. Easy to install and economic, solar water heaters can find its place in our daily lives easily. It works on the simple fundamental: trapping sunlight to heat water. The question is why do we need a Solar water heater? For one, with Solar water heater helps us go green since it uses the renewable source of Sun’s energy to operate. Secondly, water heating is a huge expense. Domestic consumption aside, there are industries and factories that need hot water in humongous quantities. Fossil fuel derived heat sources are pollutants and depleting rapidly. Hence, the need for a solar water heater. Using a solar water heater is economical too along with being, an extremely low maintenance deal. Here is a description of how a Solar heater works.

How does a solar heater work?

The primary requirement of a Solar heater, like any other solar equipment, is Solar power or Sunlight. Hence the solar heater panel for water is mounted on the rooftop, where it receives the maximum Sunlight. The set up consists of a water storage tank and pipes connecting the storage tank to heat box. The heat box or the insulated box is coloured black from inside and fitted with copper pipes. These copper pipes are also coloured black for heat absorption. This box is then covered by a glass cover so that the heat from the sun is trapped inside.

When sunlight hits this insulated box, the heat gets trapped inside due to the glass cover and the black colour of the box. It is the same as parking a car in the heat, with the glass windows closed. Once the heat is trapped, the copper pines inside the insulated box, heat up. These copper pipes are also coloured black. In the meanwhile, water from the source flows into these copper pipes. The heated copper pipes heat up the water in the pipes. At this point in time, the hot water rises up as it is lighter in density as compared to cold water. The hot water thus gets collected in the connected tank, ready to be used.

However, solar heaters work on two technologies for water heating: Passive and active. The active solar heaters pump the hot water out of the storage tank using a small pumping system. An active solar heating system will also pump in anti-freezing fluids, which helps the water heating systems in extremely cold weather.

The passive systems, on the other hand, use the hot water’s ability to rise high. This water is then collected in the tank, which is connected to the household water supply taps and faucets. These systems are less expensive. However, passive systems lose the warmth of the water quickly and the heat transfer is n not as effective.


Like with any device, solar water heating systems its advantages. Here are few good-to-know advantages before opting to install a solar water heater.

  • Solar water heating installations use Sunlight so you do not have to worry about huge electricity bills
  • For extremely cold weathers, where water¬†freeze and pipes burst, Active solar heaters, has the facility of ensuring that water does not freeze
  • In many parts of the world, using solar energy systems and giving the surplus back to the state grid, gets you a handsome credit on your electricity bills via the net metering solar systems
  • They help cut down on fossil fuel usage.
  • Solar water heater panels are cost-efficient and sturdy.

One may argue that solar heating systems do not work at nights. It is in fact right. However what one needs to understand here is that, through the installation of net metering solar systems, you can only get stored solar power without interruption but can also give back the surplus electricity and earn credits on your power bill.

Conclusion –

Solar water heaters are the need of every household. Hot water, used for utility purposes use a lot of power and for a longer time period, may it for bathing or washing. One of the best reasons for using solar powered energy is the government’s push to avail of the abundant renewable source of energy.