A solar hot water heater uses the power and heat of the sun to provide hot water to your home or business. Solar water heaters are especially effective in warmer climates and can be much more simple in design and cheap to produce. Solar water heaters are becomingly increasingly popular in the United States are have already been used for years in places like China, Japan, Europe and even India.
Solar water heaters can be broken up into two distinct categories, active and passive systems. Active systems will pump a fluid (other than the water you will be using in your home) through a solar energy collector. Passive systems use the natural power of convection to power the working fluid inside the water heater.
Most solar collectors are made from a simple insulated box with a glass top and a piece of sheet metal below painted black that’s attached to copper pipes. In large commercial or industrial applications parabolic mirrors (shaped like a satellite dish) are used to concentrate sunlight to power a solar water heater. The heat generated by the sun is stored in a hot water tank, which is typically much larger than a standard tank found on a gas or electric water heater. The tank is extra big to make up for any bad weather or lack of ability to heat the water. The massive volume of the water keeps it warm for much longer. The working fluid that’s used to transfer the heat from the collector to the storage tank is typically some kind of anti-freeze that contains a corrosion inhibitor to prevent damage to the copper pipes carrying the fluid.
Solar Water Heater Pros
- Environmentally Friendly – Solar energy is a renewable resource that doesn’t produce any greenhouse gases like CO and CO2. This makes solar energy a clean resource that costs almost nothing once operational.
- Free Power – Once your solar water heater is setup properly, aside from occasional maintenance you will have hot water for almost nothing at all. This can be a huge impact on your power bill which can be from 15%-30% water heating.
- Can be Used Year Round – Solar water heaters may work best in the summer time, though they can also collect energy from the sun on sunny winter days. Snow can even reflect sunlight onto your water heater or other solar energy devices during winter months.
- Financial Incentives – This is especially true for people living in the USA, Canada and parts of Europe. The government wants people to go green, so they incentivize new technologies to help subsidize the purchasing of equipment. This can mean free power and money back in your pocket to cover the cost of installation.
Solar Water Heater Cons
- Initial Investment – Solar water heaters are far more expensive than any type of traditional water heater including gas, electric and various tankless systems. There may be government programs to help offset the costs of a new solar installation, so research is important before installing any system.
- Limited by the Sun – If the sun isn’t shining, you won’t be saving much energy. Most solar water heaters have built in gas or electric heating elements that are activated when temperatures drop below a certain level. They help to heat your water on cloudy days.
- Outdoor Maintenance – Unlike traditional water heaters, solar water heaters are typically placed outdoors for maximum results. Like anything left outdoors, regular service and maintenance are required to keep things in tip top shape.