Hybrid Solar Collectors: How Do They Work?

As the cost of energy production rises and the availability of fossil fuels decreases, the need, demand and benefits of sustainable sources of energy increases. The two most widely used and available forms of sustainable energy are wind and solar. The race is on to improve collection methods in order to make these technologies as efficient as possible. In the case of solar power collection, attempts to increase the efficiency of solar cells have led to the development of hybrid solar collectors. There are two types of hybrid solar collectors, each of which increases the efficiency of the solar collectors, though they accomplish the increased efficiency in different ways.

The first type of hybrid solar collectors works by increasing the amount of solar energy that is directly converted into electricity. The cells of the collectors are made out of two different materials. One material receives the sun’s energy, which causes electron excitation, and the material begins to give off, or donate, electrical particles. For this reason, it is often called the donor material. The particles it donates are transferred to the second material, called the acceptor. The second material acts to diffuse or disassociate the charged particles and distribute them through the system in the form of usable electricity. The interaction of the two materials together results in a larger amount of solar energy being converted into electricity than would occur with only a single material.

There are several combinations of materials used in the donor/acceptor pair, as well as several designs for both how the transfers occur and how the disassociation of the particles takes place. Popular designs are the nanoparticle/polymer composite design, carbon nanotube design, dye-sensitized design and the inorganic nanostructure/small molecule design.

The second type of hybrid solar collector uses a different technique to increase efficiency. Rather than 

attempting to increase efficiency by increasing the amount of electricity the system can produce, it instead makes use of both the conversion of energy to electricity and the collection of heat produced in the process. One popular version of this type of hybrid solar collector is manufactured by Solimpeks Corporation in Turkey.

The Solimpeks Volthik hybrid solar collectors use tubes to circulate water through the panels. The water absorbs heat produced by the interaction of the sunlight with the collector materials. The water is then circulated and stored in tanks, which can be used for hot water or heating in the structures. An added benefit is, as the water circulates through the system collecting the excess heat, the collection materials are cooled, which greatly increases their efficiency.

The most optimally efficient hybrid solar collector system incorporates both of these techniques. However, increased costs and installation difficulty associated with the tubing and other components required for the Solimpeks type of hybrid solar collector may mean that the simpler dual material collectors are more practical in some situations. As the systems become more efficient and manufacturing costs drop, the hybrid systems will be more frequently installed during new construction, which in turn will further lower the costs associated with hybrid solar collector.

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