Solar water heater or domestic hot water systems are water heating systems that use sunlight to heat water. Although they are expensive to install, they are pretty efficient, eco-friendly, and they can be used in almost any climate. Aside from that, they can help reduce your power bills significantly.
How a Solar Water Heater Works
A solar water heating system comes with solar collectors and a storage tank. There are mainly two types of solar water heaters: active and passive.
Active water heaters use active pumps to circulate water throughout the system, while passive water heaters use pressure.
Active solar water heaters
With active solar water heaters, cold water is sent to the bottom of the storage tank, and when there is sunshine, a solar-powered pump pushes the water to the solar panels, where it gets heated. The heated water flows back to the storage tank but stays at the top of the tank, ready to be used, and since the storage tank is insulated, the hot water stays hot.
But during the cold months or when there is no sunshine, a thermostat turns on an auxiliary heater in the tank, fueled by either gas or electricity to heat the water. The system comes with two pressure relief valves that prevent the buildup of pressure in the tank.
Passive water heaters
Passive solar water heaters, also referred to as thermo-siphon systems don’t use pumps as active solar heaters do; instead, they use pressure, which is why the storage tank sits above the solar collectors.
These water heaters use a pressurized storage tank that pushes the cold water into the vacuum tube collectors, where it is heated and ready for use.
How to choose a solar water heater
If you are planning to install a water heater for home use, there are a couple of factors you need to consider, and they include:
Type of Solar Water Heating System
As mentioned, there are active and passive water heating systems. Active water heating systems require space for the storage tank, while passive water heating systems don’t need much space because they sit on the roof of the house.
So if you have ample space, you can go with an active system. If you don’t have much space, a passive water heater would be more suitable.
The climate in your area
If you live in an area where temperatures drop to freezing during the cold season, it would be ideal to get an active water heating system. Active systems come with an inbuilt secondary heater, which is fueled by electricity or gas to heat water when there is no sunshine.
Passive water heaters do not come with this option. They rely entirely on sunshine to heat water and, therefore, are not suitable in areas that experience extreme cold for months at a time.
Active water heating systems are generally more expensive than passive water heating systems. However, they are more efficient, and they can operate in any climate.
If budget is a priority and you live in a place where sometimes it gets super cold, you could install a passive water heater if you have a backup water heater. If you don’t have a backup water heating system but have ample space, consider investing in an active water heater.
Although maintenance should not be much of a priority when choosing a solar water heating system, it is essential that you select a system that you can afford to maintain. Passive water heaters are easier to maintain than active water heating systems but prioritize other more important factors.
No matter what type of solar water heating system you install, the goods news is that your power bill will go down significantly. Besides that, since solar systems harness the sun’s energy to heat water, there are no carbon emissions to deal with or toxic fumes. It is one of the most effective and environmentally friendly solutions for heating your water and even powering your home.