Solar Power Definitions

This refers to the output power achieved by a solar module under set standard test conditions. This standardised test for panels across all manufacturers ensures that the values listed are capable of comparison.

In South Africa, 1 kWp of solar panelling will generate approximately 1 710 kilowatt hours per year.

This is a measure of energy and is used to define the amount of energy used over a one-hour period. This is conventionally the unit of power referred to on your electricity bill.

How large an area is required for a 2 kWp system?

A rooftop solar area of roughly 15m2 will enable you to produce approximately 3 420 kWh of electricity per year.

While there are a number of factors involved in calculating the perfect photovoltaic system size, most homes tend to install systems between 2.450 and 4 kWp, which are capable of generating 4 190 – 6 840 kWh per annum.

To find the ideal PV system size for your needs, Contact REGENERGY today.

A Grid tied system is where most people start, but soon desire the versatility of an Off-Grid or Hybrid System with battery storage capabilities, to maximise your savings.

Grid-Tied (No Battery) – Lowest Cost, cannot store energy generated therefore less overall efficiency, and if main grid goes down, your system shuts down and you cannot generate or use Solar energy while load shed.

Hybrid (Incl. Battery) – Higher initial cost but can store energy generated for later use (specifically at night), therefore highly efficient. If grid goes down, The Island inverter allows you to select and prioritize between preferred power sources, ie. your PV panels, Battery or existing generator.

General Solar Power Questions

Our typical residential solar power job takes us about 20-40 hours of installation time on the roof and about 10+ hours inside the house. We send highly competent technicians, so most jobs are completed in 2-4 days. That said, our installation queue can reach 2-3 weeks out, sometimes longer, so contact us as soon as you’re interested if you have a sense of urgency about your solar project.

Our qualified representatives conduct installations daily! We are a Customer-Centric Company and take pride in supplying high functioning solutions, irrespective of technology selected. This means you have a consistent experience with one company, all aligned on making sure you are delighted with your solar experience every step of the way. Our install crews are friendly, professional, and well-reviewed from Joburg to Cape Town.

Yes. Many customers feel that the pride and peace of mind of solar ‘pays for itself’ as soon as the system powers on. From a financial point of view, solar will recoup the outright cash investment in roughly 3 – 9 years in Johannesburg. (Grid-tied or Hybrid Technology respectively)

The Hybrid Technology will payback in less than 5 years if you are running a Generator daily. A Solar system can potentially provide a 10-fold saving in the first 25 years, if installed correctly with utility scale use in mind. Financing your renewable energy solution could work out to be immediately cash-flow positive (or neutral) (see: Regenergy Finance Solutions).

Currently, company tax in South-Africa is 28%. With this incentive, you can deduct the value of your new solar power system as a depreciation expense from your companies’ profits. This means that your companies income tax liability will be decreased by the same value as the value of the installed solar system. The Income Tax Act, No 58 of 1962 (Act) allows a taxpayer (ie a person subject to tax in terms of the Act) to claim a deduction on the costs incurred in respect of plant, machinery, implements and articles owned by it.

In respect of photovoltaic solar energy of more than one megawatt, a taxpayer is allowed a deduction of the costs to the taxpayer, of the asset producing the electricity on a 50/30/20 basis. In other words, one is allowed a 50% deduction of costs in the first year of use, 30% in the second year and the balance in the third year of use. Where the photovoltaic solar energy system produces less than one megawatt of power, then the taxpayer is allowed a 100% deduction in the first year of use.

While we’re supportive of all forms of renewable energy, small-scale wind power is generally not cost-effective in the interior of a Country, nor easy to site. In other words, you’ll get more electricity, Rand for Rand, by investing in solar instead of wind.

As a rule, solar electric systems need little maintenance since they do not have any moving parts. During solar system lifespan (which is expected to last between 25 and 40 years) the following components have to be replaced:

  • Inverter and/or charge controller (if any) – every 10-15 years of operation – Extended warranty available up to 25 years.
  • Panels – Every 25 – 40 years of operation.
  • AGM Batteries – every 5 years of operation.
  • Lithium Batteries – every 7-10 years of operation.
  • SuperCap Batteries – Every 45 years of operation.

Frequently Asked Questions

Super Capacitor batteries are the Rolls Royce of storage technology with 200 times more cycle lifespan than Lithium batteries, previously the best battery technology available on the market. Lithium allows for 5000 recharges while SuperCaps allow for 1,000,000 Recharges. Expensive Lithium batteries need replacing every 8 – 10 years.

Typical Solar Deep cycle batteries like Lead, Calcium or other AGM batteries only provide 1500 – 2500 recharges. These batteries require replacing every 3 – 5 yrs.

We supply SuperCaps with a 10 year Swop-out warranty to prove the trust we have in this technology through our applications and accelerated tests. The projected Lifespan of our Super Cap batteries is 45 years, allowing you to truly maximize your returns from your Energy Asset without needing frequent battery replacements as with other chemical battery alternatives.

A standard PV system is made up of Photovoltaic (PV) panels and a solar inverter.

The PV panels transform the energy from the solar rays into Direct Current (DC), while the inverter converts the DC into Alternating Current (AC), which is the type of energy required for the traditional functioning of appliances.

Hybrid Photovoltaic Systems are composed of PV panels, an Island inverter and a solar battery, while a Grid-tied system excludes batteries and uses the Grid as the storage vehicle. The Hybrid system stores excess energy in the battery, which can then be used in the evenings, during bad weather and in cases of load shedding.

Solar power installation is a long-term investment. Depending on the size of your solar system, it can take between 5 and 8 years to pay for itself. After this period, it will save you money for the remainder of its productive life.

One of the main ways you can save with solar is by cutting energy costs. Making use of solar power will also help shield you against changing utility rates. Rooftop solar installation also plays a role in allowing your property value to prosper.

While a PV panel can generate power for over 40 years, the expected lifetime of a panel is between 20 to 25 years of optimal rated production.

Solar panels are made from small solar cells. The cells absorb the sunlight energy and turn it into DC (direct current) electricity. The DC electricity is then converted into AC (alternative current) electricity, by a device called the inverter, and is fed to your internal power grid which operates on AC electricity.

Most manufacturers give 20-25 year warranty but If solar panels are installed and maintained properly, you can expect them to last and produce a good amount of electricity for up to 40 years. Approximately 80% efficient after 25 years.

The size of the system you need depends on several factors: how much electricity you use, how much money are you willing to invest and what is the size of your roof. You should also consider if you want solar energy to meet all your energy needs or just a portion of them.

Typically, solar panels require very little maintenance. If rain doesn’t do the job, you can spray them with a hose a few times per year. You should make sure that there is nothing piled up on top of the solar panels which could block them from the sun. Ideally you should check with your installer about maintenance requirements, if any.

Roof mounted solar panels are generally less expensive because they do not require support structures. You also make use of otherwise unutilized space on your roof. On the other hand, ground mounted panels are a good option if your roof is not suitable for solar panels. Plus, solar panels installed on the ground can be tilted and adjusted to the sun which may increase efficiency.

The price will vary depending on the size, brand and type of solar panels. On average, a household needs a 3kW solar array and then 3KVA Inverter System. This will cost between R150,000 – R180,000. If you want to purchase a system of 4kW, it could cost you from R180-000 – R270,000. The dramatic drop in the cost of solar photovoltaic (PV) modules has fallen by 99 percent over the last four decades, is often touted as a major success story for renewable energy technology.

Given that you have a 3,3kW solar system, installed on a North facing roof, it can generate 5400kWh – 6400 kWh annually. This means that you will receive an instant reduction in your bill due to tariff demand charge reductions. On top of that, you can save over R1,000 to R1,200 per month on your electricity bill. Of course, the savings will vary in different households due to specific factors, but if we follow the example of this 3,3kW system, you could be saving over R13,000 per year increasing at 15% per year.

There are three types of solar panels and they differ in efficiency and price. Monocrystalline solar panels are the most efficient. Some models can convert 25 per cent of the sunlight they receive into electricity. Polycrystalline solar panels are second in efficiency and some models can reach up to 20 per cent. Thin-film solar panels have the lowest efficiency (around 10 per cent) but are also the least expensive panels.

The Feed-in Tariff is a governmental program encouraging the adoption of renewable energy sources. You will receive payments from your energy supplier for the electricity you generate, even if you do not use it in your household. However, to qualify for the feed-in tariff you firstly need to pay Eskom a generation tariff of R500 per month. For the relatively small amount of electricity that you intend to offload into the grid, it does not easily recover this initial monthly payment to qualify. Improvements in Legislation will enhance the benefits of the feed-in Tariff.

Grid-tied solar electricity offers a way to fix your electricity rate for more than 25 years. The maintenance-free panels come with a 25-year production warranty and the expected useful lifespan is up to 50 years (output starts to slow down over time but is still significant). A grid-tied PV system can protect you from electricity price increases for decades. That’s a feeling of energy security that is hard to duplicate.

Simply put – the sooner you get solar, the sooner you will enjoy its benefits! If you wait for some unproven technology down the road, you will have missed the opportunity to generate and use your own power now. Solar Panels have already dropped 99% in price over the last 4 decades as exports double, so efficiencies of scale have already been met. (https://www.sciencedaily.com/releases/2018/11/181120073818.htm)

Solar is like saving for retirement – the sooner you start doing it, the better. If you want to benefit from future technologies, ensure your system is well designed by professionals to allow for expansion and modifications to your system over time.

In South Africa, the ideal roof orientation is Solar North, but can be placed North East or North West, with slight reduction in power generation. Within this range, power output stays within 10 or 15 percent of maximum. Even more easterly and westerly roof installations are viable, especially on shallower roofs. For example, a flat roof that is due east or due west still achieves 77% of a system’s potential performance. More important than angle, generally, is shading. We don’t want to see any shading on a solar roof from 9 am to 3 pm, year-round. Technological improvements such as micro-inverters can compensate for shading issues to some extent. The best way to know for certain if your roof is viable for solar is to contact us for a free solar evaluation.

We mount solar panels on a purpose-built aluminium rail system that is fastened about every four feet by penetrations into roof rafters. On a standing seam metal roof, these attachments are made directly to the standing seams, with no roof penetrations. On asphalt roofs, each mount is sealed with a 50-year Tripolymer sealant to prevent any leaks. We guarantee all roof work will be free from leaks. As for the weight of the array, it is less than 5 pounds per square foot, so a typically framed roof is more than adequate to carry the weight.

Every kilowatt of the solar array takes about 7 – 8 m2 depending on roof angle and spacing requirements. Therefore, a typical 3kW array (consisting of twelve panels) will take a roof area about 22m2 – 24m2, or 4m tall by 6m wide (two rows of six).

That varies from home to home (or business to business) based on energy usage, solar exposure, and the size of the building, alongside a few other factors. For a very quick estimate of your particular need, send us your electricity bill for an estimation. For a more exact estimate, follow that up with a chat with one of our System Design Specialists.

As people have converted more aspects of their life to solar (e.g. running heating, cooling, and electric cars) the number of panels we install in the typical system has increased as well. In 2018, the average # of panels installed for residential systems was 25.

At Regenergy, we can also pole-mount photovoltaic panels or ground-mount panels on a concrete base.

Today nearly all inverters come with built-in monitoring that varies based on manufacturer. By reconciling your production with your electric bill, you can get a good idea what your household’s electric load is and how much of a difference the photovoltaic system is making.

Solar energy systems are sophisticated pieces of equipment and not suitable for DIY type projects. With grid-tied solar electric, you need to contract with a professional company to meet most rebate program requirements, as well as to perform the interconnection with the utility. With solar hot water, while you can do the plumbing yourself, the cost and risk associated with a poor installation greatly outweigh the cost of hiring a professional.

That number varies depending on how much, and when you use your power. For a very quick estimate of your specific need, please contact Regenergy for more info. For a more exact estimate, send us your electricity bill and we will have one of our system specialists call you to give an indication. In 2018, the average installed residential project cost (prior to tax rebates or any feed in tariff incentives) was approx. R 200,000.

It will be smaller! With solar, your inverter and your household loads are all “behind the meter,” meaning that if the sun is out and you are in your house and running loads – say a TV, dryer, and electric stove – your solar-generated power will be consumed without it ever being registered by the utility company. So, at the end of the month, your electric bill will say you’ve used fewer kWh than your inverter says you have generated. This is because your home is self-consuming free solar power with a slight top-up from the grid. Though it can be a bit confusing, you can feel good about this situation because every kWh you don’t pay for, avoids annual price increases and saves you a growing amount yearly.

Yes! Several studies demonstrate that solar homes are worth more money and sell more quickly due to the additional value that the home provides. To accurately determine how much Solar has increased the value of your home, will be dependent on many other variables such as price bracket, location etc.

Solar power inverters are relatively quiet – emitting about as much noise as a refrigerator. They are generally installed in utility rooms, Pantry or basements alongside existing mechanical systems, rather than in living spaces.

Solar Panel Manufacturers test their products to ensure that they are capable of withstanding hail storms. The Conclusion: Hail may be an impressive Physical force, but solar panels are well-equipped to withstand impacts even from very large Hailstones.

While hail can damage some types of thin film solar panels, the likelihood is very small, and occurrences are extremely rare. Many solar-electric modules and solar hot water collectors are made with tempered glass. The substrate is a flexible, plastic material and highly resistant to impact damage from rocks or hail.

Our solar professionals design your system to meet your yearly electric use, using the best weather-data available from government sources, as well as our proprietary data-set, having built and monitored 100’s of solar arrays across South Africa. Our design process is based around annual production, not seasonal, so naturally solar panels produce more in the summer and less in the winter. While the build-up of dust and pollen can affect panel efficiency, panels also clear easily (their surfaces are made of hardened glass) so with the typical rainfall in Summer, washing the panels yourself is almost never necessary.

Solar electricity is identical to grid power, so you will never notice that the house is running on solar power. What you will see, of course, is a smaller electric bill!

Most areas in South Africa average more than 2 500 hours of sunshine per year, and average solar-radiation levels range between 4.5 and 6.5kWh/m2 in one day. Receiving over 300 sunny days per year in South Africa will allow you to maximize the benefits of Solar Power. Each Kilowatt of Solar Panels installed will produce upwards of 1350 – 1650 kWh/year of electricity. With our energy auditing software, we use professional solar survey tools to assess if shade or off-axis issues will affect your system performance, and present an independently verifiable production element in your system proposal.

When the grid power goes down, the grid-tied solar electric system goes down, too. This is to prevent any accidental back-feeding of solar electricity to the grid which might endanger line-workers. However, a new generation of battery backup technology is revolutionizing Energy Storage, providing clean backup power in event of a power outage. See Super Capacitor Batteries for more information.

While the idea of cutting ties with the electric company may seem romantic, in reality, it is anything but practical except for very specific cases (generally when utility power is not available to that area and prohibitively expensive to install). To become entirely Off-Grid, requires multiple days of surplus energy stored, in case of extended cloudy and raining conditions. These additional batteries can increase the system cost, whereby you need to tackle it in stages, over time.

We use a variety of top, well-respected solar panel manufacturers depending on the application. We usually carry three options, which we call “Good,” “Better,” and “Best.” Our “Better” option is a panel by electronics manufacturer LG. All reputable solar manufacturers offer a 25-year warranty on their panels, which are expected to live roughly twice that long.

REGENERGY chooses among a variety of top manufacturers depending on the application. Currently the vast majority of systems we install use Victron, Fronius or Goodwe Energy inverter technology. All inverter companies offer at least a 10-year warranty, though the inverter is expected to last 25 years or longer and can have an extended warranty supplied, at a small additional cost.

Solar panels sold today don’t ever stop generating. While some of the wirings may need upgrading in future years, the panels remain useful for over 40 years and generations to come, with a minimal reduction in output in the years after the warranty.

I have more questions!

Understanding solar power can appear complex and can take time to understand. 

If you have any more questions – or are ready to start your solar venture, please fill the contact form below.