Solar Water Heaters Are Pretty Cool
No one likes a cold shower. Maybe you should look into solar water heaters. They are becoming more popular and more available. They can lower the cost of electric bills about 30%-50%. A typical solar water heater can cost from under $1,000 to over $3,000. They may be a little more than electric water heaters, but you will save money in the long run. The savings are definitely worth the cost over time. If your budget is limited, consider taking out a home equity loan to cover the cost.
If you're building a new home or refinancing, the economics are even more attractive. Including the price of a solar water heater in a new 30-year mortgage usually amounts to between $13 and $20 per month. The federal income tax deduction for mortgage interest attributable to the solar system reduces that by about $3–$5 per month. So if your fuel savings are more than $15 per month, the solar investment is profitable immediately. On a monthly basis, you're saving more than you're paying.
Solar water heating systems include storage tanks and solar collectors. The two types of solar water heating systems are active or passive. Active systems have circulating pumps and controls, and passive do not.
Active solar water heating system
There are two types of active systems: Direct and Indirect circulation systems. With direct systems the pumps circulate household water through the collectors and into the home. They are better in climates where it rarely freezes. With indirect systems the pumps circulate a non-freezing, heat-transfer fluid through the collectors and a heat exchanger. This preheats the water before going into the home. They are popular in climates prone to freezing temperatures.
Passive solar water heating system
Passive solar water heating systems are typically less expensive than active systems, but they're usually not as efficient. However, passive systems can be more reliable and may last longer. There are two basic types of passive systems: integral collector-storage passive systems and thermosyphon systems. Integral collector-storage passive systems are best where the temperature rarely falls below freezing. They are also work better in large households. In thermosyphon systems the collector is installed below the storage tank so the warm water will rise into the tank. These are usually more expensive that the integral collector-storage passive systems.
Solar water heating systems almost always require a backup system for cloudy days and times of increased demand. Conventional storage water heaters usually provide backup and may already be part of the solar system package. A backup system may also be part of the solar collector, such as rooftop tanks with thermosyphon systems. Since an integral-collector storage system already stores hot water in addition to collecting solar heat, it may be packaged with a demand (tankless or instantaneous) water heater for backup.
Use the Sun. It's there for a reason.
If you have the resources and you are the Ultimate DIYer, you can try to make your own solar water heater for under $5.
Note: Much of the information on this webpage was gathered from the U.S. Department of Energy: Energy Efficiency Renewable Energy website