Solar Water Heaters

Solar water heaters have been in use for more than a century and today there are tens of millions of units in use around the world. While solar water heating is not very common in the United States, it's popularity is growing. The technology is in widespread use in other countires such as Israel, China, and Germany, and in recent years the market has begun to grow in the United States. Many people mistakenly think that solar water heating can't work in Kentucky because of our climate. In reality, Kentucky's solar energy resources are quite good and enable us to heat 50 - 80% of a home's annual hot water needs with solar energy. 

Solar water heating systems that are used for year-round water heating in climates like Kentucky, where freezing temperatures are common for half of the year, require freeze protection. In places like south Florida and the Carribean, where temperatures never reach freezing, solar water  heaters do not require  freeze protection. This allows these systems to be simpler and requires fewer components. The two freeze protected system designs recommended for Kentucky are known as Pressurized Glycol and Drainback systems. Both systems work very effectively and reliably.

Solar water heating systems are durable, low-maintenance, and reliable. Systems are generally expected to last for 25 and if properly maintained, can continue to run for many years beyond that. Systems include a back-up water heating system to ensure that hot water  is always available. The back-up heating system can use electric, natural gas, or  propane and is controlled by a thermostat. Since solar  water heaters normally have large water storage tanks, families often find that they have more hot water available after installing a solar heater.

Solar water heaters need a sunny location where the solar collector can be mounted, whether on the roof or on the ground near the house. The collectors must be mounted in a spot that faces south and is unshaded at a minimum from 10 am to 2 pm throughout the year. It's preferable, of course, for the collectors to be unshaded as much as possible. It is not  necessary for the collectors to face precisely due south. If the collectors face within 45 degrees of due south they will still function effectively.

Financial Benefits of Using Solar Water Heaters

A solar water heater can reduce the cost of heating water by 50 to 80% or more, saving a family hundreds of dollars per year (see Table ). A solar water heater fixes the cost of energy needed to heat water, providing security against rising fuel prices, and may also increase the equity value of your home.

Environmental Benefits of Solar Water Heating

Solar water heaters use a free renewable resource, without producing pollution . Their use reduces our demand for energy from coal, natural gas and propane, all fossil fuels whose use causes significant environmental harm. When you install a solar water heater, you will not only save your family hundreds of dollars per year on utility bills, but you will be helping to create a cleaner, safer environment for your children and grandchildren.

• Annual Pollution Prevented by Using a Solar Water Heater in Kentucky

Solar water heaters are used for:

• Residential water heating
• Heating swimming pools
• Space heating, including radiant floor heating and other space heating systems
• Hotels
• Laundromats
• Fire Stations
• Apartment complexes
• Restaurants
• Food processing facilities
• Facilities that have a high demand for hot water

To learn more about solar water heaters, read the following chapter from The Kentucky Solar Energy Guide :

• Chapter 6 - Introduction to Solar Water Heating Systems

Efficiency and Conservation First!

Before investing in a solar water heater there are many things you can do to use hot water more efficiently and reduce your demand for hot water. These steps will not only lower your monthly utility bills, but may allow you to install a smaller, and therefore less costly, solar water heater. Remember, saving energy is generally cheaper than producing energy, so start with conservation and energy efficiency.

Some simple ways to conserve hot water include installing low-flow showerheads, lowering the thermostat on your water heater to 120 oF, adding insulation to your existing water heater, replacing an old washing machine with a high-efficiency Energy Star-rated washer, installing a timer on an electric water heater, and learning ways to use less hot water. To learn more about conserving hot water, read Chapter 9 of The Kentucky Solar Energy Guide.