20 November 2023

With the international trend towards renewable energy, folk are looking to solar power as an alternative to plugging into the main grid — especially in South Africa. If you are thinking of doing the same, then here’s what you’ll need to know…

What is solar power?

Solar effectively means from the sun, so solar power systems harness the light and heat energy that comes from the sun. At the beginning of the 21st century, the technology was both expensive and less advanced. The most common application for solar energy was for heating water with many households moving to solar geysers as a way of both saving electricity and coping with load shedding.

Solar water heaters versus photovoltaic systems

Solar water heaters use panels to capture the sun’s heat to warm the water in an insulated metal cylinder – the geyser. These systems, like all the solar-related technologies, have improved over the last few years so that — although it’s preferable that they face north and have full sun — they still work when the weather is overcast.

Photovoltaic systems, on the other hand, convert sunlight into energy – electricity. As an explanation: Photo comes from the Greek word that means light and volt is the name for the unit of electrical force. This comes from the name of the inventor of the battery, Alessandro Volta. The two together form photovoltaic.

How do photovoltaic solar cells and panels work?

Photovoltaic panels contain semiconductor materials which are usually silicone. When light hits the semiconductor, it releases electrons that generate electricity. This is known as direct current (DC) which must be converted to alternating current (AC) that you can use in your household.

Individual solar panels can generate between 200 and 350 watts of power when they are in strong sunlight and, as we have noted, can even work on cloudy days but will generate less power. This means that even homes that are off the grid might need to have backup systems for those “darker” patches during winter when there is constant rain and clouds.

Why should I consider going solar?

Perhaps the most obvious reason for going solar is the long-term cost savings coupled with the security of the electricity supply. In South Africa, the threat of load shedding is ever-present, coupled with the increasing frequency of extreme weather events that can result in protracted periods without electricity.

Although investing in solar energy is a major capital expense, it will both add value to your property and reduce your carbon footprint, helping to save the planet.

Note: For the purposes of this article, we’re confining the remainder of this discussion to freestanding houses. Blocks of flats or apartments will have different considerations that must usually include all the residents, the body corporate, and/or other management structures.

Working out how much power my household uses

Before taking the plunge, you need to size up what you’ll need. Here’s a list of questions to guide you:

  • How big is your household – the house itself and the number of people who live in it?
  • What is your average electricity usage?
  • How big is your roof, how many solar panels will fit on it, and will it support their weight?
  • What are the compliance and regulatory requirements related to installing solar power within your local municipality?

Let’s look at how to answer these questions.

Household electricity usage

Most people have a good idea about how many units of electricity they use a month. One unit of electricity translates into 1 kilowatt hour (KWh). If you’re confused, this is a measure of consumption versus the measure of power – in kilowatts – that your toaster, kettle, hairdryer, or TV will use. To work out the specifications for your solar power system, it’s your consumption that you need to work out. Here is a formula:

  1. Work out your average monthly usage by recording how many units of electricity you use over a 12-month period (a year): add up the readings and divide by 12.
  2. Take this number – your average annual usage – and divide that by 30 (days in the month).
  3. Divide that number by 5.5 which is the average number of sunny hours per day in South Africa.

Your final answer will determine the size and rating of the solar panel array you will need. Typically, an average household will need roughly between six and fourteen 455W solar panels. Of course, you must still get expert advice from a professional before making the final decision.

The roof of your house – the base for your solar system

The bottom line is that solar panels all need to face the same direction to harvest as much of the sun’s rays as possible. In South Africa, the best direction for your solar array to face is north.

When it comes to a house, your roof is the foundation for your solar system. If you have a simple, pitched roof, as opposed to a complex one e.g., a U-shaped design, it should be quite straightforward. While it may seem that a flat roof is the obvious ideal choice, that isn’t always so: like with a complex roof, you may need to build structures or mountings to ensure the best position for your solar panel array.

In addition to the pitch of the roof, you need to consider the materials from which your roof is made. In South Africa, most suburban houses have tiled roofs with corrugated iron roofs running a close second. These are the best possible materials on which to install solar panels unlike a thatched roof because the dried grass used for thatching is highly flammable, making a solar installation potentially dangerous.

Regulatory compliance

As more and more households are installing solar, local authorities and/or Eskom are introducing mandatory registration and other procedures. This might seem like overkill, but given the safety considerations associated with electricity, complying with these regulations is smart. In addition, installing a solar system could have an impact on your homeowner’s insurance and if it doesn’t meet the standards for Small Scale Embedded Generation you might end up being penalised and/or losing your cover. The City of Cape Town is leading the way in this regard and has already put steps in place to regulate the installation of solar systems.

Selecting your solar system supplier

Simply selecting a supplier is not enough. Because of the regulatory and safety issues we’ve mentioned, installing solar is not a DIY job. It’s best to go with a registered installer whose track record you can verify (ask for references). In addition, reputable installers should also offer a Certificate of Compliance from an independent inspector. A good contractor will also ensure that your equipment has the relevant guarantees and warranties to give you peace of mind.

Costs and Pricing

As we mentioned, converting to solar involves significant capital outlay which goes beyond just the panels. You will also need to fork out for –

  • An inverter
  • Roof mount kit
  • Other components associated with electrical installations
  • A registered and qualified electrician (with labour)
  • Certificate of Compliance

The final cost, with the panels, will obviously depend on the size of your system, the brands you select and your installer. In general, final costs could be anything between R58,000 and nearly R130,000.

Is going solar right for you?

Ultimately, only you can answer this question. Either way, we recommend that you carefully research what you need. If you are interested in going ahead and want to know how much value you might be able to recoup in terms of the home’s resale value, contact your nearest RE/MAX office and seek some insights from one of our local experts.

Have more unanswered questions? Here are some related questions – and answers – that might help…

Do I need permission from Eskom to install solar panels?

Yes, you do need to apply to Eskomif you plan to install solar panels and generate your own electricity.

Can I self-install solar system?

Installing your solar system is not a DIY job unless you are a qualified and registered electrician.

How long do solar panels last?

Solar panels are designed to last at least 15 to 25/30 years on average. However, various factors, such as the installation technique, the quality of the panels, and the operational environment, might affect how long solar panels really last. Remember that the solar panel's life expectancy doesn’t necessarily indicate that it will cease to generate electricity at that point. It simply implies that they will produce less energy than what producers of solar panels deem ideal.

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