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Solar water heaters use the free heat energy from the solar rays to heat up the water which can be used in homes, offices and other commercial uses.
Solar water heaters have the capability to fulfill 80-90% of heated water needs of homes (saving electricity, more on this ahead).
How do Solar Heaters Work?
Solar water heaters work mainly by using heat energy from the sunlight to heat water by using the solar thermal collector.
The solar energy collector heats the fluid inside the pipes in the heater which then flows actively (active systems) or via gravity/natural convection (passive system) through the pipes which run through the water storage tank thereby heating up the water in the storage tank.
The hot water storage tanks are usually large to store adequate amount of hot water in case of bad weather and to ensure that there is more hot water than required. The larger size is because the optimum final temperature of hot water in the storage tank is lower than conventional water heater.
Types of Solar Water Heaters
Solar water heaters are of two types, mainly Active and Passive. Both need an additional source of heat energy such as an electricity-based water heater or a fuel oil central water heating system which gets activated once the temperature falls below a set-point. This is to make sure that you get hot water even when the sun is down.
Providing the solar water heaters with a passive backup heat source like a wood stove chimney can ensure that the solar water heaters provide hot water even in winters without the use of any fossil fuels or electricity.
Passive Solar Water Heaters
Passive Solar Heaters are more adapted to hot weather climates. They don’t need electricity or fossil fuels at all and you can easily set them up yourself.
To move the heat around, it depends on convection or heating up the fluid in pipes of solar water heater.
Although, passive solar water heaters are cheaper than the active ones and need almost no maintenance once you set them up, they have very low efficiencies as compared to active solar water heaters.
Here is an example of a passive solar heater if you’d like to try one out!
Active Solar Water Heaters
Active Solar Water Heaters are much more suited for moderate and cold climates.
The active solar water heaters use electricity, but the ones customized for cold climates have special heat collectors that can be used in remote locations and places/homes that are entirely off-grid, with the right kind of setup.
They need at least a single pump to make heating fluid flow actively in the internal pipes of the solar water heater system.
The type of solar water heater that suits you best depends entirely upon the climate that you live in.
Why Solar Water Heaters are Preferred as Compared to Conventional Water Heaters?
Solar Power Heaters save a lot of a electricity and therefore, money. These water heaters typically pay themselves off within 3 years.
Solar Water Heaters have a good lifetime of around 20 years, and have low maintenance cost since solar energy is free.
When using systems solely dependent upon solar energy, it eliminates the need of fossil fuels to heat up water. This will reduce the carbon footprint of your home and indirectly, yours.
They add to the value of the property. A report suggests that homes dependent upon solar power generate greater value than those dependent upon conventional sources of energy.
You stay protected if the electricity costs increase in future, at least for the next 20 years.
If you install passive solar water heaters, you have hot water even if there is no electricity (for example, a blackout).
There might be some incentives available in your area that will reduce the cost of equipment or installation. Check with your municipality or local energy company to find out if you are eligible for such grants.
If you’d like to save money you can install solar water heaters yourself (especially the passive ones), or hire professional help.
The newer models of solar water heaters have varieties best suited for almost any weather around the world.