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Solar Solutions

Solar Solutions to Everyday Problems

 

As human life has continued to overcome the many obstacles to its survival and has made more technological progress over the course of the last century than in its entire prior history, we may have also encountered our most formidable obstacle to date, and it is one of our own making. The insatiable demand for energy, primarily obtained by the combustion of fossil fuels appears to have dug a pit into which civilisation is falling and from which it will be lucky to emerge. Among the options that offer hope is the use of solar energy to provide more sustainable power solutions.

This is the same energy that may have catalysed the chemical reactions required to spawn the first primitive life forms on earth and which continues to contribute to the nutrition of green plants through its interaction with the pigment known as chlorophyll. With all intents and purposes, its power can be considered inexhaustible given that its ultimate demise will end all possibility of life on earth. The energy in question travels nearly 150 million kilometres to reach us and consists of a mix or waveforms and particles. Both the infra-red waves and the particles known as photons are now being leveraged to provide solar energy solutions of two types.

The simplest and the first of these to be applied practically makes use of the sun’s thermal energy, which is emitted in the form of infra-red radiation. It is in this form that the sun’s energy acts to keep us warm or to thaw the winter snow and can even be induced to create a fire when focussed with a lens on to combustible materials. For the more practical purpose mentioned earlier, the thermal properties of sunlight can, with the aid of suitable installation, also be harnessed in order to heat water for use in a domestic hot water system.

Both solar solutions depend on the use of a collector, which in low-temperature thermal systems and in its simplest form, consists of a flat structure made of a dark, absorbent material containing channels for the circulation of fluid. A layer of glass provides protection, and the heat absorbed by the dark material is transferred first to fluid and then to the hot water system. A system, such as this can typically achieve temperatures of around 70°C. In colder climates, a fluid similar to anti-freeze serves as the transport fluid and a heat exchanger is used to transfer the stored heat to the home’s hot water system. In high-temperature systems, parabolic mirrors are used to focus the sun’s rays in order to boil water, creating steam to drive a generator.

The second of the solar solutions is more complex, but it has one big advantage in that it is a far more versatile option for domestic purposes than the thermal alternative. It utilises a property known as the photovoltaic (PV) effect to generate electricity directly. Accordingly, PV systems are able to generate power for many different purposes, including providing hot water on tap, whenever necessary.

The photovoltaic effect refers to the ability of photons to displace electrons from a suitably treated semiconductor, which acts as the system’s collector and is the uppermost of two such layers, As such, it has been doped to contain an excess of electrons while the lower layer has an electron deficit. Electrons released from the collector are carried by a wire to the lower layer creating a potential difference of between 0,5 and 0,6 volts. Effective solar solutions must, of course, be able to produce far more than these tiny voltages and this is achieved by connecting multiple cells to form panels and multiple panels to form an array of the necessary size to meet the power requirements of any given installation.

For effective solar and conventional power solutions in South Africa, look no further than PacB Group.