PacB Group // Using Solar Power via Photovoltaic Arrays as a Back-Up Supply

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Using Solar Power via Photovoltaic Arrays as a Back-Up Supply

The need for more widespread use of renewable energy sources is becoming increasingly crucial if we wish to maintain our customary living standards. The ultimate result of the combination of shrinking reserves of fossil fuels and the escalating demand for electricity are all too obviously a matter for urgent concern. Consequently, current projects to harness, instead, efforts to leverage the more sustainable energy provided by the elements, such as the wind, the tides and the sun, need to be intensified. Many households and businesses have already adopted the use of solar power as a back-up for the mains supply, the continuation of which has, for so long, been taken for granted.

Focus an image of the sun on to a piece of paper with a magnifying glass and, within seconds, it will first char, then smoulder and finally burst into flames. This is ample proof of the unlimited power to be harnessed and, indeed, this simple technique has been applied to heat pipes in order to provide hot water or, by means of heat exchange technology, cooling for various purposes. Though an economical and eco-friendly option, this type of application is strictly limited and is not designed to provide the sort of back-up supply from solar power that is needed to meet the needs of even the average domestic consumer.

Thanks to the invention of the photovoltaic cell, instead of merely harnessing the heat of the sun, it is now possible to convert a portion of its radiant energy into an electric current which may then be stored for future use. In addition, and depending upon the nature of the installation, the electrical power generated in this fashion may, instead, be used to operate various electrical items directly or, at least, to augment the mains supply. So how does this work? What precisely is the so-called photovoltaic effect that offers the means to leverage solar power in order to provide a back-up supply of electricity?

When the photons that make up sunlight strike the surface of certain materials, this can act to dislodge negatively charged electrons from their atoms, leaving behind a so-called ‘hole’ which will then be filled by other liberated electrons, in turn, creating new holes. If steps are then taken to direct those freed electrons as a continuous stream, a potential difference occurs and a flow of electric current will result. This is the principle behind the photovoltaic cell.

To scale up this principle sufficiently for solar power to serve as a back-up electricity supply, photovoltaic panels, in conjunction with a rectifier, batteries and an inverter will be necessary. Panels are made up of individual cells each of which generates only about 0,5 volts. An individual panel must, therefore, incorporate a sufficient number of these cells in order to produce enough power. Likewise, the greater the power overall requirements, the more panels will be needed.

The completed array functions to produce a direct current, which can then be used to charge a number of storage batteries. Before the stored electricity can be used, however, it must first be converted to alternating current of the required voltage. This is achieved by means of an inverter resulting in a back-up supply from solar power for use during an accidental or planned mains outage.

To guarantee an effective system, arranging for it to be installed by a qualified and experienced specialist will be every bit as important as being sure to purchase high-quality panels and the other components required to complete your system from a reputable supplier.

Satisfying both of these requirements and able to perform an accurate assessment of your needs, the PacB Group is well established as an expert in the design, supply, installation and maintenance of back-up power sources ranging from solar arrays to diesel generators and UPS systems. For information on our products and services, please feel free to contact us.