Waterheater Articles

Solar Water Heater

Solar Water Heater: Gaining Worldwide Recognition And Usage

Solar water heaters are made up of a collector that collects solar energy and an insulated storage tank that stores hot water. Depending on the collector system used, the solar water heater may be of either one that is based on Flat plate Collectors or based on Evacuated Tube Collectors.

Two Main Types

The Flat plate Collector solar water heater allows solar radiation to be absorbed by the flat plate collectors that are made up of an insulated outer metallic box that is covered on the top with a glass sheet. Within the box are blackened metallic absorber sheets that have built-in channels or rise tubes to carry water. The flowing water is heated when the absorber absorbs the solar radiation and transfers heat to the flowing water.

The solar water heater that is based on Evacuated Tube Collectors has the collector made out of double layer of borosilicate glass tubes that are evacuated to provide insulation. The inner tube’s outer wall is coated with selective absorbing material and thus helps to absorb the solar radiation and transfer the heat to the water that flows through the inner tube.

The technology used in solar water heaters has matured, and with widespread utilization, will help to reduce significantly the conventional energy that one uses to heat water in the home, factories as well as commercial and institutional establishments. The international market too is growing, and it is believed that approximately more than 107 million square meters of collector area has been installed thus far throughout the world for the heating of water.

By using a solar water heater of hundred liters capacity, one can replace an electric geyser used in residences and affect savings of 1500 units of electricity each year. In addition, using a thousand solar water heaters of one hundred liters capacity each will result in saving peak loads of one megawatt of electricity. With a 100 liters capacity solar water heater, it is also possible to prevent one and a half tones of carbon-dioxide emissions each year.

The solar water heater is also a better bet, and one can expect it to pay back its cost in two to three years after it replaces electricity driven appliance and takes four to five years to payback when replacing a furnace oil appliance. To replace a coal driven appliance, it will pay back its cost in six to seven years. No doubt, the initial investment may be high compared to other available conventional alternatives, but the return on investment is becoming more attractive given the increase in prices of conventional energy.