SEMINAR ON SOLAR WATER HEATER SUBMITTED TO: Mrs. Kavita Sharma SUBMITTED BY: Raghav Garg 5234/15 Electrical Engg. 6 th Semester

What is Solar Water Heater?  A Solar Water Heater is a device which provides hot water for bathing, washing, cleaning, etc. using solar energy.  It is generally installed at the terrace or where sunlight is available and heats water during day time which is stored in an insulated storage tank for use when required including mornings.  The electrical energy can be saved upto 80%. The solar water heater can produce hot water upto 50 ° C to 70 ° C.

Schematic diagram

What are different types of Solar Water Heaters?  Two types of Solar Water Heaters are available; one based on flat plate collectors and the other based on evacuated tube collectors. Flat plate collector (FPC) based systems are of metallic type and have longer life as compared to Evacuated tube collector (ETC) based system because ETCs are made of glass which are of fragile( can be easily broken or destroyed)in nature.  Both these systems are available with and without heat exchanger. They can also work with and without pump. Systems without pump are known as thermo syphon systems and those with pump are known as forced circulation systems.

Flat Plate Collectors (FPC) based Solar Water Heaters  The solar radiation is absorbed by Flat Plate Collectors which consist of an insulated outer metallic box covered on the top with glass sheet.  Inside there are blackened metallic absorber (selectively coated) sheets with built in channels or riser tubes to carry water.  The absorber absorbs the solar radiation and transfers the heat to the flowing water.

Evacuated Tube Collectors (ETC) based Solar Water Heaters  Evacuated Tube Collector is made of double layer borosilicate glass tubes evacuated for providing insulation.  The outer wall of the inner tube is coated with selective absorbing material.

How does it work? The sun light is observed by the solar panels and due to the photovoltaic effect, the heat energy heats the cold water passing through the collectors. The water flowing through the collectors get stored in the storage tank and they are either utilized for future use or supplied to the house via the pump.

Advantages  Simple to construct and install.  No or negligible running cost.  Almost maintenance free.  Cost is low and economically competitive with electric water heating system.  It saves time and high grade form of electric energy.  Required low temperature up to 100 o C can be achieved by simple flat plate collector.

Disadvantages  Freezing problem  Solar thermal panels can only heat water.  A new hot water cylinder will need to be installed so space is required to Install this.

Applications  Swimming Pools  Residential  Houses  Textile Industries  Boiler House  Hospital And Nursing Home  Dairies And Food Processing Industries  Textile Factory  Hotels And Restaurants

THANK YOU