Solar Water Heating
Solar water heating is hot water heated by the sun in a collector. This is different from photovoltaic solar panels which produce electricity. Solar heating systems are generally composed of solar thermal collectors, a freeze protected fluid system to move the heat from the collector to its point of usage, and a reservoir or tank for heat storage and subsequent use. Seasonal hot water tank systems are also available for off the grid use.
The system may be used to heat water for domestic home or business use, for hot tubs, or as an energy input for space heating applications. Solar heating installations are most commonly used to supplement existing domestic hot water systems. Domestic hot water is used for laundry, showers, dishwashers, and normal everyday use.
Typically a domestic hot water system includes a hot water holding tank with an electric heating element or connection to a fuel oil boiler that is activated when the water in the tank falls below a minimum temperature setting such as 50°C. Hence, hot water is always available. The addition of a solar hot water heater can significantly reduce the need for energy you pay for in fuel oil or electricity.
In some cases with additional plumbing the excess hot water available from solar heating can supplement space heating. Typically a hot water heating system that is more than fifteen years old may be a good candidate for replacement with a new high efficiency solar assisted system.
In our climate, a solar heating system can provide a very high percentage (up to 50%) of annual domestic hot water energy. In many northern European countries, combined hot water and space heating systems are used to provide 15 to 25% of home heating energy.
Additional Resources
1. http://www.enerworks.com/ - Alascorp sells and installs Enerworks residential and commercial products.
2. http://www.heliodyne.com/ - Alascorp uses heliodyne products bought locally and installed by local experts.
3. http://www.radiantsolar.com/ - this site has one of the clearest explanations of solar heat on the web.