Solar Water Heater
A solar water heater is a solar device that heats water using solar energy. It uses sunlight to heat the water during the day. This hot water is stored inside an insulated solar hot water tank for use whenever required. It is among the most cost-effective uses of solar energy.
The solar energy from the sun is utilized for heating water very easily to a temperature of 55-70° C. And hence, if you replace your conventional water heater with a solar water heater, you can save up to 70-80% on electricity. Besides, it operates at low costs and is eco-friendly. This is the reason why thousands of people are installing solar water heaters every year.
How does a solar water heater work?
In the daytime, the sun’s rays fall on the collectors. The absorbers present inside the collectors consume the solar radiation. As a result heat energy is produced. The solar collectors transmit this energy to the water streaming through them. This hot water is stored inside an insulated solar hot water tank for use whenever required. As the tank is insulated, it prevents heat loss. The flow of water from solar collectors to the tank continues due to the thermosiphon principle.
Types of Solar Water Heater
To provide outcomes in different climates and latitudes and to satisfy your budget, a variety of solar water heater configurations are available in the market. The different types allow you to choose the one that matches your preferred efficiency, capacity, functionality, and price. Although choosing the right one is slightly complicated, we are here to help you find out the heater that can serve you with the utmost benefits. The solar water heater comes in two major technologies:
- ETC Solar Water Heater
- FPC Solar Water Heater
ETC Solar Water Heater
In ETC Solar Water Heater, the collector is designed to provide insulation using double-layer borosilicate glass tubes. Each evacuated tube consists of two glass tubes having a vacuum in between which is an excellent insulator. The outer wall of the inner tube is made to absorb maximum solar radiation. And that is why the wall is coated with demanding absorbing material.
An evacuated Tube Collector (ETC) acts as an absorber in the solar water heater. The incident solar radiation falling on the tube passes through the outer transparent tube and strikes the outer of inner tube. It absorbs heat energy and then passes to the cold water flowing in the tube. Hence, the heat gets transferred to the cold water resulting in heating the water.
FPC Solar Water Heater
In an FPC solar water heater, the solar radiation is absorbed by Flat Plate Collectors (FPC) which consist of an insulated outer metallic box covered on the top with a 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.
An evacuated tube technology-based solar water heating system and flat plate technology-based solar water heater both are energy efficient. Hence, both heaters are suitable for home use.