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In the know

The ins and outs of photovoltaic (PV) power generation

Photovoltaic (PV) systems make use of the sun to generate electricity during daylight hours. And because solar is a technology and not a fuel, there are no ongoing costs after installation as is the case with gas for example. Right now, solar delivers between an 18-25% return on investment each year based on electricity savings, far outstripping any other investment vehicle where you could place your money.  Investing in solar to save on your electricity costs is a no-brainer, and the very best investment you can make right now for your business or home over the next 20-25 years.

What is rooftop PV?

A rooftop photovoltaic (PV) system has its electricity-generating solar panels mounted on the rooftop of a building or structure. Solar panels are exposed to sunlight or solar radiation and generate electricity which is called a photovoltaic effect. This solar power flows via cable to a device called an inverter which converts the direct current (produced from the panels) to alternating current. With the inverters synchronising the solar power and the Eskom grid, that power can be fed directly into your internal electrical network and save electricity. So every KWh generated by the solar system is a kWh less required from Eskom or local municipality.

Analysing your electricity needs – No shooting in the dark

Calculating your electricity needs is the first step towards getting PV ready.  A thorough examination of your electricity needs helps you determine the following:

  • The size and cost of the system you will need
  • Fluctuations in your energy usage during the day and night and over the months to manage peak demands.
  • Energy saving measures you can implement to reduce your electricity use before installing PV so that you save on the costs of a bigger system simply by being more efficient.

By conducting a load analysis, One Energy will record the wattage and average daily use of all of the electrical devices that are plugged into your central power source such as refrigerators, lights, televisions, PCs, power tools, machinery and computer equipment. Some loads, like your refrigerator or electric fencing, use electricity all the time, while others, like power tools or large format printers, use electricity intermittently, known as selectable loads.

Some providers will ask you only for an electricity bill and attempt to provide a PV solution based on this, but the approach is fundamentally flawed and inaccurate since your bill cannot reveal day and night usage, selective loads or peak demands which need to be factored into your PV solution. A thorough load analysis is a must.  That’s why with One Energy, we’ll visit your premises, set-up loggers on your electricity distribution board for at least a week to ten days, and provide you with a comprehensive view of where your electricity usage is going, and what steps we can take to help you reduce it.  We will also be able to provide a very good indication of what your savings will be depending on what size system and the solutions we specify for you, so there is no shooting in the dark.

Implementing energy efficiency measures before you buy your PV system will reduce your electricity use and allow you to buy a smaller and less expensive system.  For example, converting geysers which are usually your biggest electricity users to solar or heat pumps, installing LED low energy lighting, using gas for cooking, putting movement and day/night sensors on office lighting and so on.

Types of PV Connections

A solar PV system typically comes in three configurations:

  • System 1 Grid Tie – No batteries, grid connected system (read the case study of a family that radically slashed their electricity bill using this config). This system supplements your grid energy usage during daylight hours. This is a highly practical solution to dramatically reduce your electricity bill by producing all your daytime energy requirements, free from the sun, and avoiding the additional expense of a battery system.
  • System 2 Hybrid – Batteries and a grid connection, and is commonly referred to as a hybrid system and with the correct installation will act as a UPS (uninterrupted power supply) in the event of a power outage. The PV system will charge up the batteries first and then the excess production will supplement your household/ business energy needs.
  • System 3 Island – Only batteries, no grid connection, useful for areas where no grid exists, such as farms or remote areas. The energy produced will charge up the batteries which should allow for 3 days’ worth of energy needs and these batteries will feed the power requirements of the property.

What is the cost to install PV?

Many people believe renewable energy is too expensive without actually doing their homework. When we take them through the costs versus the savings, most are stunned at how absolutely affordable it is.  If we look at a typical PV system, your initial capital layout would be in the beginning when you purchase the equipment and on average takes between 5-7 years to offset the costs, but then for the expected 25 years of the lifespan of your panels, you will get free electricity.  The initial upfront cost is the only cost involved with solar. After that, because there are no moving parts, the maintenance on the system is very low.  Once fully paid, you have an incredible investment and asset for your property that keeps saving you thousands of Rands each year, for many years to come. Another advantage of PV is that it is entirely scalable and can be ramped up as your requirements demand and, more importantly, your budget allows.

To give you an idea of indicative cost of a grid tie-system* (no batteries), fully installed, for a household*** you’re looking at around:

Inverter Panels Electricity produced Cost **
4kW 8 9kWh/day R52 900
4kW 12 14kWh/day R65 900
4kW 16 19kWh/day R79 900

*Tier 1 panels – this is important as it means these are top quality components from a fully bankable manufacturer that has the balance sheet to carry the warranties for many years to come!

**Indicative costs for a standard installation.  All quotes subject to a site inspection and needs analysis.

***Typical sizes used for residential applications.  Pricing on larger and commercial solutions available on request.

Financing sorted

Many people put off making the switch to alternative energy sources because they don’t have the upfront cash.  That’s why One Energy offers you competitive finance options.  With every Eskom increase that comes each year, you’ll be saving more and more and protecting your pocket against the impact of hyperinflationary increases.  So, instead of paying exorbitant electricity bills for absolutely no return, you’ll be investing your money into your new resources, saving thousands over the long term and increasing your property value by up to 15-20%.