How Much Solar Do You Need to Run a House

31 Mar 2023

How Much Solar Do You Need to Run a House?

The amount of solar power you’ll need to power your home is probably one of your first questions if you’re thinking about going solar. The answer depends on a number of things, including your daily energy usage, the size of your house, and the climate where you live. Everything you need to know about how much solar power you need to run a house will be covered in this post.

Learn everything you need to know about solar panels and how they can benefit you by reading our solar panel guide.

Key takeaways: How Much Solar Do You Need to Run a House

  • First understand your energy consumption
  • The size of your solar system will depend on your monthly energy consumption
  • Solar power production can be affected by weather conditions, panel orientation and tilt, shade, and appliance efficiency.
  • To maximize solar power generation, optimise panel placement, use energy-efficient appliances, and install a solar battery.
  • Choose trusted brands when selecting PV panels and refer to irradiation charts for accurate calculations.
  • Work with a reputable supplier and installer to ensure you get a solar system that is the right size for your needs.

Understanding Your Energy Consumption

Understanding your energy consumption is the first step in calculating how much solar power you need. Looking at your electricity bills will give you an idea of how much energy your home uses. You are able to see on the bill how many kilowatt-hours (kWh) in total you consume each month. As an alternative, you can monitor and track how much power your appliances are using with a wattmeter.

Home solar monitoring app showing power consumption

Hybrid system in Johannesburg during March 2023

Sizing Your Solar System

You can calculate the size of the solar system you require after you are aware of your monthly energy consumption. The number of solar panels you have will determine how much energy you can produce; solar panels are rated by their output in watts.

You must know your monthly energy usage in kilowatt-hours (kWh) in order to determine the size of your solar system. South African homes typically use roughly 900 kWh per month, though this can change depending on your location and way of life.

If your monthly energy consumption is 900 kWh, you would require a solar system that can provide about 10 kW of power. Depending on the size and efficiency of the panels, this might require anywhere between 16 and 25 solar panels.

How many PV panels do you need?

In South Africa, trusted brands for PV panels include Deye, Sunsynk, Hauwei, SolarEdge, Canadian Solar, JA Solar, LuxPower, and more. It is not recommended to buy no-name brands as their output is not guaranteed.

If you have a 5.6 kW PV array consisting of 16 x 350Watt PV panels, and it receives 5 hours of irradiation (not sun hours), it can produce up to 28 kWh of energy per day. However, radiation levels vary in different areas of South Africa, so it’s important to refer to the irradiation chart for more detailed information. During winter, irradiation may be as low as 3 hours, while in summer, it may be as high as 6 hours.

map of the photovoltaic potential of South Africa

Photovoltaic Power Potential of South Africa

Factors Affecting Solar Power Production

It’s important to note that solar power production can be affected by several factors, including:

  • Weather conditions: Solar panels generate less energy on cloudy days or during winter months when there is less sunlight.
  • Panel orientation and tilt: Panels facing North with a tilt angle between 30-40 degrees will produce the most energy.
  • The Types of solar panels used in your solar system.
  • Shade: Shading from nearby trees, buildings, or other obstructions can reduce the amount of energy your solar system generates.
  • Maximizing Your Solar Power Generation
  • To maximize your solar power generation, there are several steps you can take:
  • Optimize panel placement: Install your solar panels in a location that receives the most sunlight and has minimal shading.
  • Use energy-efficient appliances: Energy-efficient appliances use less power, which means you’ll need a smaller solar system to meet your energy needs.
  • Install a solar battery: A solar battery can store excess energy generated by your solar system, which can be used when your system is not producing enough power.


In summary, to make sure you can match your energy needs, generating clean, renewable energy at home or for your business requires a solar system that is the right size. We hope this post has given you useful information on how much solar energy you need to operate your home. Please do not hesitate to contact us for a free quotation if you have any queries or need more help.