What Direction Should My Solar Panels Face?
Ideally, solar panels should face north. In Australia, solar panels facing north generate the most energy. But there’s more to it than just direction. The placement, tilt, and time of day you use electricity can all play a role in maximising your solar power benefits.
To make sure your solar system works at its best, it’s important to consider your roof’s orientation and how much power you use during the day. If your roof faces east or west, we can still make it work to suit your energy needs.
The goal is to optimise your system to reduce your electricity bills and increase your savings, regardless of your roof’s orientation.
Key Takeaways:
Optimal Panel Orientation – In Australia, solar panels generate the most energy when facing north, especially in winter when the sun is lower in the sky. The tilt can be adjusted based on seasonal energy needs, but flat panels with a slight tilt work well for flat roofs.
Panel Placement Based on Energy Usage – If a home has an east-west roofline, panels can be installed on either side based on when the household consumes the most power. Western-facing panels are ideal for homes using more energy in the afternoon.
Splitting Arrays for Efficiency – Using Enphase microinverters allows solar arrays to be split across multiple roof sections. This helps distribute solar power generation throughout the day and minimises shading effects.
Time-of-Use Tariffs & Peak Output Considerations – Time-of-use electricity rates can impact solar placement decisions, especially in areas like Sydney. Additionally, a 5kW system rarely reaches full capacity, but strategic placement can extend energy production into peak pricing hours.
What is the Optimal Orientation for Your Solar System?
Technically, the panels should be tilted north to match the angle of the sun. However, tilting panels just pushes output from summer to winter.
So, if you have a flat roof and you use more power during summer it makes more sense to leave the panels close to flat with just a little tilt to ensure that rain flows off the panels and doesn’t pool on the surface. If you have a pitched roof, then we will always install the panels in line with the roof.
Designing a System to Match Your Energy Needs
If your house has a north-south roofline with the option of installing the panels east or west, we can install panels on either roof section depending on what time of the day you use the most power.
Many families will use more power in the afternoon when the kids are home from school and the air conditioner and pool pump are running. If this is the case we would recommend installing your solar panels on the western roof, or we could do a split system with most of the panels west and a few east.
Split Solar Arrays = Greater Efficiency
We can split your array by using Enphase microinverters. This can also help avoid shade later in the afternoon as pictured below. You can see in this image we are using 3 sections of roof where each string of panels will output power at different times across the day.
By splitting the panels like this, the output of solar power gets distributed across the day, making it easier to use more of the solar power because there isn’t such a big peak in the middle of the day
Peak Output & Time of Use Tariffs
The other point that can influence the decision of where to install panels is that time-of-use tariffs can sometimes be charged by your energy retailer (ask us for help if you are not sure about this). This typically will only apply to households in the Ausgrid distribution area (roughly the eastern half of Sydney):
A solar system will peak when the sun is shining directly onto the panels, so for an array facing north, this will be for approximately 4 hours during the middle of the day.
The graph below shows a system that is installed on a roof facing northwest where there is a bit of early morning shade. This is a great orientation for a solar system in Sydney, especially if you have time-of-use billing where power is most expensive after 2 pm on weekdays in summer.
You can see in the graph how even in autumn the system will continue operating until 7 pm if you have the panels installed on a roof that catches the late afternoon sun:
The other important point to take away from this image is that a 5kW system will rarely reach its peak output. This system reached a maximum output of 3.84 kW and yet produced 29.1 kWh of power across the day:
For a 5kW system to output close to 5kWs at any one time, it has to be the right time of the day and the right time of the year, which is very rare. In this example, the system is installed on a tile roof with a normal pitch of about 20 degrees.
There are 19 panels all facing north-west. This helps extend the output into the late afternoon, as seen in the graph above. In Sydney during summer, panels that are installed flat will be working closer to their peak efficiency because the sun is so high in the sky.
The peak output on this system during a sunny March day is only 3.84 kW, however, even in March, this 5kW system will typically produce around 30 kWh a day, much higher than the Clean Energy Council guideline of 19.5 kWh.
Strategically placing your solar panels can significantly impact their output and how well they match your energy usage patterns. But there's more to consider when optimising your solar system for maximum benefit.
To explore all the factors influencing the perfect system size and layout for your home, head over to our comprehensive guide to help you make an informed decision.
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