Working of Solar Water Heater

A solar water heating system is a device that uses solar energy to heat water for domestic, commercial, and industrial needs. Heating of water is the most common application of solar energy in the world. A typical solar water heating system can save up to 1500 units of electricity every year, for every 100 litres per day of solar water heating capacity.

Working:

• The system is generally installed on the roof or open ground, with the collector facing the sun and connected to a continuous water supply.

• Water flows through the tubes, absorbs solar heat and becomes hot.

• The heated water is stored in a tank for further use.

• The water stored in the tank remains hot overnight as the storage tank is insulated and heat losses are small.

There are actually two types of Collectors. They are:

Flat-plate collectors

Flat plates are the simplest collectors: at their most basic, they're little more than water pipes running through shallow metal boxes coated with thick black glass. The glass collects and traps the heat (like a greenhouse), which the water running through the pipes picks up and transfers to your hot water tank.

Evacuated tubes

These are a bit more sophisticated. They look like thicker versions of fluorescent strip lights but work more like vacuum flasks. Completely empty (hence the name "evacuated"), they collect and trap the heat from sunlight. This flows to a collecting device (sometimes called a manifold) at the top (or at one end) through which water or another fluid flows, carrying the heat to the hot water tank. Unlike flat-plate collectors, they don't let as much heat escape back out again, so they're more efficient. However, since they're a bit more hi-tech and sophisticated, they are sometimes more expensive.

Uses of Solar Energy:

• SWHs can be used at homes for producing hot water that can be used for bathing, cleaning, and washing. Solar water heaters (SWHs) of 100-300 litres capacity are suited for a domestic application. Larger systems can also be used for a variety of industrial applications. Hot water at 60-80oC could be obtained through use of solar water heaters.

• Fuel Savings: A 100 litres capacity SWH can replace an electric geyser for residential use and saves 1500 units of electricity annually.

• Saves cost on power generation - The use of 1000 SWHs of 100 litres capacity each can contribute to a peak load saving of 1 MW.

• Environmental benefits - A SWH of 100 litres capacity can prevent the emission of 1.5 tonnes of carbon-dioxide per year.

• Payback period - SWHs have a lifespan of 15-20 years. The payback period is about 3-4 years when electricity is replaced, 4-5 years when furnace oil is replaced and 6-7 years when coal is replaced.

Advantages of Solar Water Heater:

• Solar thermal panels take up less space than solar PV panels.

• They are efficient. Approximately 80% radiation is turned into heat energy.

• They are cheaper to install than solar PV panels because you only need 2-3 panels.

• You save money on electricity bills.

• They lower your carbon footprint.

Next time you get a really big electricity or gas bill, your thoughts may turn to solar panels. Wouldn't it be good if you could catch all the power you need from the Sun? Hurry up!!! Move to solar…Install a solar water heater in your building soon.

For more details: Soura Natural Energy Solutions