How many panels do I need for solar power in South Africa? A quick guide

how many solar panels

Finding out how many solar panels you need involves many things. You should think about how much energy you use normally. Look at your kilowatt-hour (kWh) use from before.

Also, consider the climate and how sunny it is where you live. The type and size of solar panels matter too. For the best advice, ask a pro to look at your home. They can tell you just how many panels you need.

Key takeaways

  • Calculating the number of solar panels needed involves considering average energy requirements, current energy use, climate, and panel efficiency and size.
  • Consulting a professional solar installer for a free home solar evaluation is recommended for accurate panel calculations.
  • Solar panel quantity calculators can help estimate the number of panels needed, but professional evaluation is still advised.
  • Considering the peak sunlight hours in your area is crucial when determining the number of panels needed.

Step-by-Step guide to calculating total panels needed

Step 1: Analyse Your Power Bill
Review your monthly and yearly power bills to determine your energy consumption patterns in kilowatt-hours (kWh). This establishes a baseline to understand your solar energy needs. Average SA households use between 600 kWh and 1,000 kWh per month.

Step 2: Consider Your Power Usage
Calculate your average monthly power usage over the past 12 months in kWh to estimate how much energy your solar panels need to generate.

Step 3: Set Your Solar Production Goal
Most experts suggest aiming for 80% of your current power usage to determine the required solar power output.

Step 4: Assess Average Daily Sunlight
Calculate the daily average hours of direct sunlight in your region. South Africa generally has an average of 6.8 hours of direct sunlight daily, you can use this value for the calculations below for a rough answer.

Step 5: Calculate Your Solar Panel System Size
Divide your average monthly energy usage by the product of daily sunlight and 30 days. This calculation will provide the required system size (kW).
kWh per month usage / (avg daily sunlight x 30) = kW solar system

Example Calculation:
If your average monthly consumption is 1,250 kWh:
1,250 / (6.8 x 30) = 6.12 kW solar system

Step 6: Obtain Quotes for Ideal System Size
With the calculated system size, request quotes from solar installers for the specific kW system. It’s advisable to round up to the nearest kW.

Step 7: Calculate the Number of Panels Needed
Multiply the desired system size (kW) by 1,000 to convert it to watts. Divide by the wattage of the panels to determine how many panels are required.

Example Calculation:
For a 7 kW system (7,000 W) using 450 W panels:
7000 / 450 = 15.56 (rounded to 16 panels)

Different panel types will give you different efficiencies and watts. We’ve assumed a 450 W panel in this calculation but read more about this below under Monocrystalline vs Polycrystalline Panels.

Step 8: Check Your Roof Space
Ensure you have sufficient roof space to accommodate the required number of panels. Each standard panel covers approximately 1.7 square meters. For 16 panels, you’ll need around 27 square meters of roof space. It’s a good idea to add another 25% onto this as a safety factor.

Working out your energy needs and the solar panels’ wattage is vital. Doing this ensures you pick the right amount of solar panels for your house. With these steps, you can set up your solar system well and take full advantage of solar energy.

Monocrystalline vs Polycrystalline panels

The panel you chose for your system directly influences how many you’ll need to service your power demand and it also affects how much roof space you’ll need. Here’s a table summary of the differences:

Feature Monocrystalline Panels Polycrystalline Panels
Efficiency Higher, around 15-20%, 300 to 400 Watts Moderate, around 13-16%, 250 to 350 Watts
Cost More expensive Generally more affordable
Space Efficiency More efficient, fewer panels Less efficient, more panels
Appearance Uniform black color Bluish hue with crystal patterns
Longevity Slightly longer lifespan Slightly shorter lifespan
Temperature Tolerance Better at high temperatures Less efficient at high temperatures


Factors that influence solar system performance

Finding the right solar panels is key to boosting your system’s power. You need to think about efficiency, quality, and size. This choice greatly influences how well your system works.

Solar panel efficiency

Solar panel efficiency is about how much sunlight they turn into power. Panels with higher efficiency turn more sunlight into power. This means they do more with the same amount of sunlight.

Solar panel quality

Choosing quality panels is essential. These panels are built well with advanced technology. They last a long time and can deal with different weather types. This ensures your panels work well for years.

Solar panel size

Panel size affects how much energy they can produce. Bigger panels capture more sunlight, making more power. But, you also need to make sure they fit in the space you have.

Knowing what affects solar panel efficiency helps you make smart choices. By looking at efficiency, quality, and size, you can get the most out of your solar system. This lets you enjoy clean, renewable energy.

Factors Affecting Solar Panel Output Efficiency Description
Solar Panel Efficiency The percentage of sunlight a panel converts into usable electricity.
Solar Panel Quality The overall manufacturing quality, advanced technologies, and longevity of the panel.
Solar Panel Size The physical dimensions of the panel, which directly influence its wattage production.

solar panel efficiency

Sunlight hours and location considerations

When figuring the right number of solar panels for your home, sunlight hours matter a lot. More sunlight means your solar system will produce more energy. Here’s a list of the approximate yearly sun hours per province in South Africa:

  1. Limpopo – 3,100
  2. Gauteng – 3,050
  3. North West – 3,175
  4. Mpumalanga – 3,125
  5. Kwa Zulu Natal – 2,475
  6. Eastern Cape – 3,025
  7. Free State – 3,175
  8. Northern Cape – 3,600
  9. Western Cape – 3,125

Thinking about sunlight hours and where you put your solar panels can make your system work better. Places with more sun not only need fewer panels but also make more energy daily. This higher output helps you power your home better.


When you’re looking into getting solar panels, it’s key to figure out how many you need. You must consider how much power you use, the amount of sunlight you get, and the size of the panels. All these factors decide the right number of panels for you.

To get the best advice on this, talking to a solar expert is a smart move. They can look at your home’s individual situation and suggest the best solution.

Using solar energy means you’re helping the planet and saving money. Solar power is both good for the environment and your wallet. It offers a way to generate energy for your house that’s affordable and green.

Want to know more about how solar panels work and what they can do for you? Check out Wikipedia. It has lots of detailed info on solar technology, how to install panels, and why they’re good for the earth.

FAQ:  How many panels do I need for solar?

How do I determine how many solar panels I need for my home?

To figure out how many solar panels you need, think about your daily energy use, the local weather, and the sun’s availability. Also, consider the quality and size of the panels you plan to use. It might be best to get input from a solar expert for the most precise answer. We provide a rough guide for you to do this yourself at the top of this article.

How do I calculate my home’s energy requirements and solar panel wattage?

Look at your power bills to see how much energy your home uses. Figure out your average daily use from that info. Then, factor in the sunlight your area gets to work out how many panels will meet your needs.

The solar panels’ power (wattage) is also crucial. You need to match the panel size and quality to your energy needs. This step helps determine the right number of panels for you.

What factors should I consider when determining the number of solar panels needed for my home?

When deciding on solar panels, your energy needs and the local sunlight hours are key. Think about the efficiency and size of the panels too. For the best advice, it’s wise to talk to a pro who can give you a detailed assessment. They’ll look at all these factors to get your solar system just right.

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