With the ever-increasing cost of electricity and an ongoing push for sustainable living, many homeowners are turning to solar as an effective solution. When homeowners start to think about installing solar, one of the most common questions we get asked is “How much solar power do I need?” The answer will vary based on a few different factors and requires some calculations to figure out. We’ll walk you through this process, so you’ll know how many panels are needed for your household.
Find out your household’s energy consumption
The first step in determining how many solar panels you need is to calculate how much electricity your household uses. This is typically measured in kilowatt-hours (kWh) and can be found on your past electricity bills. An average Australian household consumes between 15 and 20 kWh per day. However, this can vary based on factors like the size of your home, the number of occupants, and your energy usage habits. It’s best to look at your electricity usage across multiple months, as you may use more energy at different times of the year (e.g. Winter). Identifying your typical usage is critical to estimating the number of solar panels required.
Learn your location’s peak sun hours
Peak sun hours are a simplified way to measure how much solar energy a location receives. It’s essentially an hour where the sun’s intensity is at its strongest, averaging 1,000 watts per square metre. This measurement helps you estimate the performance of your solar panels. Geraldton enjoys numerous sunny days, making it an ideal location for solar power. According to the Australian Bureau of Meteorology, Geraldton receives an average of 4-7 peak sun hours per day. This means your solar panels will produce their rated peak output for this duration.
Deciding on solar panel size
Solar panels vary in levels of efficiency and output. A panel’s efficiency is determined by its ability to convert sunlight into usable electrical power, while its wattage (W) is the maximum power output it can produce. If you know the exact type of solar panel you want, find out its wattage and use that number. If you haven’t selected a specific model yet, most modern solar panels have a wattage of around 400 watts (0.4 kW).
Calculate how many solar panels you need
If you’re comfortable with some basic maths, you can estimate how many solar panels you need using this simple formula:
Number of panels = (Your monthly energy consumption (kWh) / Monthly peak sun hours in your area) / Solar panel wattage
For example:
Monthly energy consumption (1320) ÷ Monthly peak sun hours in your area (200). The resulting number is your estimated system size (kW).
1320 / 200 = 6.6 kW system.
6.6 kW system / 0.4 kW panel = 16.5 solar panels.
You would need approximately 17 solar panels to meet your energy needs.
Remember, this is just a rough estimate. You should consult a qualified solar installer for a more accurate figure. They can assess your needs and recommend the right system size for your home.
Other Factors to Consider
- Roof Space and Orientation: North-facing roofs capture the most sunlight in Australia. A home with a north-facing roof will get more out of the same system than a shaded roof and therefore needs fewer panels.
- Battery Storage: A solar battery can store solar energy for use during non-sunlight hours. This could alter the number of panels needed. Battery storage allows for greater energy independence and less reliance on the grid.
- Future Energy Needs: Consider any future changes in energy use that could increase your energy demand. This includes starting a family, getting an electric vehicle, or installing a pool.
Consulting a Solar Specialist
While you can make calculations yourself, we strongly recommend talking to a professional solar system installer. They can provide a more accurate assessment based on a thorough analysis of your location, roof orientation, shading issues, and your specific energy needs. Geraldton Solar Force specialises in tailored solar solutions and can help you find the perfect system for your household. If you’re considering installing a solar panel system for your home, contact our team for a free quote.
