PacB Group // Install Backup Solar Power for a More Sustainable Option

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Install Backup Solar Power for a More Sustainable Option

Although providing the sole energy source, rather than providing backup, solar power has bathed our planet since long before it finally merged from a glowing globe into its solid state. Later, that same energy would act on the so-called primordial soup, over the course of millions of years, to spawn the first self-replicating molecules we now know form the basis of all life on the earth. Located in what cosmologists term the ‘Goldilocks’ zone, our planet still relies on the sun to sustain the life it gave rise to. More recently, however, its human tenants have applied their characteristic ingenuity to exploit the sun’s rays for other purposes, in particular, to generate electricity.

Both as a primary energy source and for backup purposes, solar power holds the offer of electricity that is not only cheaper than when generated by other means, but a source that should be sustainable for as long as the sun remains active. The potential energy in its rays has long been evident. Scientists have learned how it drives the chemical reaction known as photosynthesis in which, with the aid of the pigment chlorophyll, carbon dioxide and water are transformed into the carbohydrates necessary to sustain the life of green plants and algae. That same energy promotes the melanin production responsible for tanning, while, in excess, it can cause mutations that result in tumours.

In order to provide a backup electricity source, the solar power must also be used to drive a photochemical reaction. In this case, the reaction occurs, not in living cells, but in specially formulated, man-made materials known as semiconductors. While earlier attempts to harness this energy leveraged that in the infra-red region, focussing the sun’s thermal energy to boil water and perhaps generate steam, attention later shifted to the opposite end of the spectrum and the photovoltaic effect produced by light in the ultra-violet region. Effectively, the technology for capturing the sun’s energy has evolved from boiling a kettle with a magnifying glass to converting light directly into electricity.

To be more precise, the reaction required to provide backup electricity from solar power is the result of the release of electrons from atoms upon collision with photons. Two layers of semiconducting materials are sandwiched together to form a single solar cell. The upper layer has an excess of electrons, and is exposed to sunlight, while the lower layer has an electron deficit. When a wire is used to connect the two, the subsequent flow of liberated electrons results in an electrical current. The current, in turn, can be used to perform work.

In a domestic installation, for example, the combined output of one or more panels, each made up of multiple cells, could be used to supplement the municipal supply, and help to reduce monthly electricity bills. Recently, however, rather than resorting to a petrol or diesel generator, more consumers are recognising the value of backup solar power to cope with the ongoing threat of mains outages.

When not being consumed, the surplus electricity generated from sunlight can be stored in batteries, allowing it to be called upon as and when required. An inverter is used to transform the stored DC current into AC when required, while sensors detect irregularities in the main supply in order to initiate the switch to battery power automatically until mains power is restored.

Apart from its obvious convenience, there are many good reasons for choosing this type of installation. It does not consume costly fossil fuel with its unavoidable carbon footprint, and operates silently, while its lack of moving parts also tends to limit the need for servicing and repairs. The natural choice of those with concerns for the eco-system, and the need for more sustainable energy, backup solar power can also form part of a hybrid, uninterruptible power supply to protect computers and digital data.