PacB Group // So, You Are thinking About a Rooftop Solar Panel Installation

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So, You Are thinking About a Rooftop Solar Panel Installation

Given the steadily-rising cost of municipal power, the frequency of power outages, the widespread publicity regarding the risk to the environment of the continued use of fossil fuels to generate electricity, and the escalating demand from all sectors of the community, the need for additional, sustainable sources is crucial. While wind-driven generators are a possible option for providers, they are excessively noisy, hugely expensive, and totally impractical for residential use. By contrast, a solar panel installation can provide power that is clean, virtually unlimited, and might even have the potential to generate some income for its owner.

For all intents and purposes, energy obtained from the sun’s radiation can be considered as inexhaustible, and may be captured in one of two ways. Either the thermal energy carried by radiation in the infra-red region of the spectrum can be used to heat water, which may then be utilised for a variety of purposes or, instead, the energy may be sourced from the opposite end of the sun’s spectral band and used to generate electricity. The ability of ultra-violet rays to generate an electric current is made possible by the photovoltaic effect, and relies on the use of a suitable solar panel installation.

Consisting of individual cells with the capacity to generate around half a volt, the total output from a single panel will be determined by the number of individual cells connected in series. This, in turn, will also determine its surface area. For example, to produce an output of between 12 and 18 volts would require 36 individual cells, and is likely to occupy around 65cm by 135cm. It is, therefore, not hard to see that an array consisting of several, interconnected panels will be necessary in order to meet the needs of an average three-bedroom, suburban home.

For commercial purposes, an area of around 25 acres is required to accommodate a solar panel installation with a generating capacity of five megawatts. This, in fact, is sufficient power to meet the needs of around 1 500 average homes, while also offering an important added advantage. By operating without the use of fossil fuels, an array of this size offers the means to prevent the emission of more than 2 000 tonnes of CO₂.

For domestic purposes, the size of the required array will depend on the size of the home and the uses for which the auxiliary power is intended. Although there are methods to determine that requirement precisely, the calculation is probably best left to the engineer who will be undertaking the solar panel installation, and who will first provide you with a quotation based on the calculated requirements.

Interestingly, the intensity of sunlight is not critical. Even in northern climates, daylight is sufficient to keep a system operational. It is, however important that the roof is exposed to daylight, and is not shaded by overhanging trees. It should have a pitch of between 10 and 60 degrees, and should face north, east, or west. If it may be in need of repair, then this will need to be dealt with before proceeding with a rooftop solar panel installation.

Once the panels are in position, the next step is to wire them to the other components and integrate the system into the domestic supply. Because the output from the array is direct current (DC), it must be converted to alternating current (AC), which requires the use of an inverter. This can be conveniently located in the loft. An electrician will then complete the connection to the distribution board along with a meter to monitor power generator. The option to incorporate rechargeable batteries into the system offers a means to store surplus power that is generated during the day for use after dark.  Those living in Cape Town, however, can now sell surplus power from their solar panel installations to the city.