Water Heaters, Solar water Heaters - Vijayawada

SOLAR WATER HEATER

Solar Water Heater is a equipment that helps in heating water by using the energy from the SUN.
Solar energy (sun rays) is used for heating water. Water is easily heated to a temperature of 60-80o C.
Solar Water Heaters (SWHs) of 100-500 litres capacity are suited for domestic use.
Larger systems can be used in restaurants, canteens, guest houses, hotels, hospitals etc.
A 100 litres capacity SWH can replace an electric geyser for residential use and may save upto 1500 units of electricity annually.
The use of 1000 SWHs of 100 litres capacity each can contribute to a peak load saving of approximately 1 MW.
A SWH of 100 litres capacity can prevent emission of 1.5 tonnes of carbon- dioxide per year.

APPLICATIONS OF SOLAR WATER HEATER

Water heating is one of the most cost-effective uses of solar energy, providing hot water for showers, dishwashers and clothes washers.

Solar Water Heaters can be used for Homes, Hospitals, Nursing Homes, Hotels, Restaurants, Dairy Plants, Swimming Pools, Canteens, Ashrams, Hostels, Industry etc.

ADVANTAGES OF SOLAR HOT WATER SYSTEM

By replacing conventional water heater with a Solar Water Heater can save 70-80% on electricity or fuel bills. Use of Solar Water Heater can cut down electricity or fuel bills considerably.

Solar Water Heaters are found to be the most reliable and durable.

Solar Water Heater is backed by 5 years warranty.

Solar Water Heaters are known to have the fastest repayment of investment.


TYPES OF SOLAR WATER HEATERS

FLAT PLATE COLLECTOR BASED SOLAR WATER HEATER

In this system 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 it are blackened metallic absorber (selectively coated) sheets with built in channels or riser tubes to carry water. The absorber sheets absorb the solar radiation and transfer the heat to the flowing water. The flowing hot water is then collected in the storage tank.

EVACUATED TUBE COLLECTOR BASED SOLAR WATER HEATER

In this system the 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. This helps absorption of solar radiation and transfers the heat to the water which flows through the inner tube. The flowing hot water is then collected in the storage tank. The features of Evacuated Tube Collector are as under:-

DESIRABLE CHARACTERISTICS OF A HOT WATER STORAGE TANK
The Hot Water Storage Tank in Domestic Solar Water Heaters is a double walled tank. The space between the inner and the outer tank is filled with insulation to prevent heat losses. The inner tank is generally made of stainless steel to ensure long life. The outer tank could be made of a stainless steel sheet, painted steel sheet or aluminum. Thermostat controlled, electrical
heating elements can also be provided (optional) in the tank to take care of those days when the sun does not shine or demand of water goes up. The capacity of the tank should be in proportion to the collector area used in the system. A commonly used thumb rule is to provide 50 litres of storage for every one sq. m. of collector area.


ESTIMATED REQUIREMENTS OF HOT WATER

CapacityNo. of PeopleNo. of BathroomsNo. of Kitchens
100 LPD3 - 411
150 LPD5 - 621
200 LPD6 - 731
300 LPD8-103 - 42
500 LPD12-145-62


SAVINGS ON ELECTRICITY BILLS
With the use of Solar Water Heaters, considerable savings on electricity bills can be made. In regular use we can save up to 1500 units of electricity per year and electricity rate is Rs. 6 per unit, so we can save 1500 units x Rs. 6 = Rs. 9000/- per annum.

LIFE SPAN OF SOLAR WATER HEATER
Typical Solar Water Heaters made by using materials as per BIS specifications could last for 12 -15 years depending upon the maintenance.

MAINTENANCE REQUIREMENTS
Domestic Solar Water Heater does not need significant maintenance. Occasional leakages in plumbing could be easily repaired by common plumbers. In case quality of water is hard, scale deposition in the collectors may result over the years. This may require de-scaling with acids for which it is best to contact the suppliers. Broken glass may also have to be replaced. If outside exposed surfaces are painted, the paint may have to be redone every 2-3 years to prevent corrosion of the surfaces.

FINANCIAL INCENTIVES FROM GOVERNMENT
MNRE is providing subsidy up to 30% through Nodal agencies. NREDCAP will process the subsidy