A system which turns cold water into hot water with the help of heat contained in the Sun's rays is called a solar water heating systems (SHWS)

Around 60o to 90o C. The rise in temperature depends on

  •   Solar Radiation
  •   Weather Conditions
  •   Solar collectors' system efficiency.

Yes, it can be installed on Rooftops, Building terrace, Open ground

There should be : - No shading, - South orientation of the collectors, - Collector Tilt = Latitude or + 10o thereof , - Over head tank with its bottom water outlet at least 8" above the hot water tank of a solar water heating system.

It generates hot water on : -Clear sunny day (Max.), - Partially cloudy day: Moderate,

- Rainy or heavily overcast day -Nil, - Average 300 days in a year (330 days in Gujarat & Rajasthan)

Only soft and potable water recommended - Hard water can reduce efficiency over time & damages collectors

Stainless Steel or copper for small tanks, Mild steel tank with anti-corrosive coating inside for large tanks

Galvanized steel pipes of class B or C are normally used. Copper pipes can also be used. Heat resistant plastic piping, if available, can also be used.

Yes, the best collectors are those with

  •   high quality material for long life, say 10-15 years,(check out our page on Solar Water Heaters)
  •   good workmanship to make collector water-proof and dust-proof,
  •   high efficiency

SHWS can be provided with back up heating system by

- Electrical heater or - Boilers run on furnace oil/fire wood/coal or one bathroom should have elec. heater.

Maintenance is minimal :

-Periodic glass cleaning, -Check for leakages and valve functioning


  •   Soft loan from IREDA & some banks repayable over 5 to 8 years at low interest.
  •   100% depreciation tax relief for profit making companies
  •   Limited subsidy on innovative solar systems.
  •    Domestic System (100 LPD at 60o C )
  •   Rs. 17,000/- to Rs. 22,000/- as per quality
  •   Non domestic System ( Range 60o to 90o C ): Rs. 130/- to 170/- per unit(100 lpd)

The chart explains all!