Domestic solar water heating systems

Solar power is often considered the energy technology of the future. In terms of the total amount of energy available, solar power is the single most prevalent form of power in the world, dwarfing the amount of energy available from all other types of renewable and non-renewable sources combined. The amount of power that falls in a hundred square miles of desert is enough to provide for the energy needs of the entire United States. The problem with solar power has always been implementing it. However, there are a number of technologies that have been developed that allow nearly anyone in the right location to take advantage of the sun and reduce their reliance on external power.

Foremost among them is solar heating. This is a technique that uses heat from the sun to warm water for use in a home. Instead of using gas or electric methods to heat water for home use, this allows a homeowner to tap into the free energy from the sun to reduce their heating costs. Solar water heating is a distinct form of solar power, not related to the more familiar solar panels that rely on a photovoltaic cell to produce electricity. Instead, solar water heaters use lenses and dark material to collect heat from the sun to warm water, which is then moved as necessary to provide heat. The heated fluid can be used to provide underfloor heating or shower water. Properly installed solar heaters can be part of a comprehensive solar environmental management system, even allowing for cooling as well as heating.

The heart of the typical home solar heater exists above the house, in the form of a series of solar collectors which focus the heat of the sun on a fluid medium used to transfer that heat. When weather conditions are right, the sun provides enough energy to heat a given volume of fluid, which then stores the heat for release when the temperature decreases. More advanced models include pumps and energy storage systems and can even be used to generate electricity. Great strides have been made in producing industrial scale systems that reduce the energy costs of factories.

In general, solar heating systems are split into passive and active families. Active water heaters are essentially the same as the system above, with the addition of electronic systems to regulate temperature control. Both active and passive systems can be startlingly effective in reducing energy expenses related to heating or cooling. In addition to their financial advantages, solar heating is the single most green way to produce heat for a home, with no emissions at all.

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