An intro to solar energy - learn how to benefit from solar energy!  

by Pool Builders on 06-17-2010 in Articles

Often lost in the dazzle of its somewhat more glamorous cousin, solar electric energy, solar thermal energy has actually been around a lot longer than solar electric.

Back in the 7th century B.C., glass and mirrors were used to generate heat to start fires using wood. This was the first recorded application of solar thermal energy, which refers to the conversion of sunlight into heat.

Solar thermal has come a long way since those early applications, but some historical perspective is still in order.

In The Beginning There Was The Hot Box

Up until the 18th century, solar thermal had been used but mostly in primitive ways. That was when Swiss scientist Horace de Saussure formalized the application of solar thermal by creating what became known as a "hot box", with which he was able to generate heat up to an astounding 228 degrees fahrenheit.

This concept was later adapted by one William Bailey in the 20th century when he found a way to store greater quantities of hot water from a solar heating system by separating the heating element from the water tank, thus laying the groundwork for modern day solar hot water heating systems.

The Various Applications Of Solar Thermal

There are several applications of solar thermal today, the most common of which are to heat swimming pools, heat water and for space heating. The common denominator of all these applications is the fact that solar collectors are used to harness the sun's heat to heat air or fluid to be transferred to water stored in a tank for heating (except in the case of pool heating systems, in which the heat is transferred directly to the pool; certain industrial systems also involve no storage).

A Brief Introduction To The Different Applications

Solar water heating systems generally consist of a solar collector (usually a flat-plate collector) and a storage tank. The collector uses the sun's heat to heat either a transfer fluid or water, and hot water is then stored in the tank for later use. About two-thirds of a household's hot water supply is provided by these systems, with the rest supplied by conventional systems.

Medium-temperature collectors are used in active solar space-heating systems to absorb the heat from the sun, which is used to heat either air or liquid. Pumps or fans then transfer the hot air or liquid either into a storage tank and from there into the heating system, or straight into the building's heating system.

Solar pool heating systems are probably the most simple of the solar thermal systems, since they have a ready-made pump in the pool's existing filtration system, which pumps water from the pool through a solar collector to be heated. The heated water is then transferred directly back to the pool. Solar pool collectors are made from materials such as plastic, which means they are generally cheaper.

This introduction is just that, and is meant to give you a glimpse into the power of solar thermal technology. We'll explore the various types of systems in greater detail, but hopefully you're already able to see how beneficial solar thermal energy can be for you in the form of reduced energy bills and the environment in the form of reduced carbon emissions through less burning of fossil fuels.

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