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How do flat-plate solar collectors heat water or air?

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heating In a thermoelectric generating system a heat source—usually fueled by coal, oil, or gas—is used within a boiler to convert water to high-pressure steam. The steam expands and turns the blades of a turbine, which turns the armature of a generator, producing electric power. A condenser converts any remaining steam to water, and a pump returns the water to the boiler.

Flat-plate solar collectors are a key component of active solar heating systems used to provide hot water or space heating.12

These collectors consist of a blackened metal plate designed to absorb sunlight. The plate is insulated on the front by layers of glass and air; the glass allows visible light to pass through while trapping the resulting heat.12

To transfer this thermal energy, a carrier fluid—typically water or air—is circulated past the back of the plate or through tubes in contact with it. As the fluid flows, it absorbs the heat from the plate and is then pumped to a distribution or storage system, such as an insulated tank. This process typically heats the carrier fluid to temperatures between 66° and 93° C (150° and 200° F). The stored heat can then be used immediately or reserved for use during the night or on cloudy days.12