Solar Panel Design and Orientation

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Which Direction Should My Solar Panels Face?

If you're thinking about investing in a solar system for your home, chances are you're wondering where the panels will need to be installed on your property to maximise their effectiveness, and whether that decision will affect the visual street appeal of your roofline.

We understand this concern, which is why we will educate you on your solar system’s production based on your roof orientation and pitch, to tailor a system you’re happy with.

The good news is that even if you don't want or can't have panels on the north facing roof of your property for any reason, you'll only be losing a small fraction of your annual savings on your solar power bill.

A Real Life Comparison in Solar Panels Orientation

6.6kW Solar System
Facing: North, 22.5 Degree Pitch
Annual Generation: 9,525kWh

6.6kW Solar System
Facing: Split 3kW East & 3.6kW West, 22.5 Degree Pitch
Annual Generation: 8,500 kWh

6.6kW Solar System
Facing: Flat
Annual Generation: 9,000kWh

6.6kW Solar System
Facing: South at 20 degrees
Annual Generation: 7,700kWh

This comparison guide shows that the most you would lose on your power bill savings per year by having an East or West facing roof is around $150 (1,000kWh into grid @ 15c) compared with North!

And the most you would lose on your power bill savings per year by having a South facing roof is around $262 (1,750kWh into grid @ 15c) compared with North!

Check out a recent case study on a 6.6kW solar system install with a split East/West roof orientation which saved $1,750. 

So we can either factor in the slight loss in production to our calculations for non-best performing, non-north facing roof or you can make up the difference by simply adding a few extra panels to your roof.

Optimising Orientation For Maximum Self Consumption

You may have heard that the only worthwhile option is to install your solar panels on a north facing roof, and traditionally, (due to 4 x higher feed in tariffs than we have today), this has been the standard recommended position, as it generates the most energy and was generally the best way to make the most earnings on your power exported to the grid as possible.

However let’s not forget that the original solar systems installed back then were only 1.5kW, so installing a 6.6kW solar system now gets you 4 x the feed in tariff (15c per kWh – 18c per kWh currently on average) that a 1.5kW system gets you, so you are on par (if not ahead) with the early adopters, yet paying thousands and thousands less for your solar system!

Today we are now working with higher electricity rates, so the other way to lower the bottom line on your power bill is to concentrate on optimising your self consumption, (which simply put is power generated and used by your household).

We suggest assessing our guide to panels direction, looking at the time of day the power is generated (and available for household use) for those panels - then compare it to the times of day you're usually at home using electricity. If you can align your panel orientation to the average timing of energy use in your lifestyle you will be able to optimise the benefits for your household.

North Facing Panels

Produce the most energy overall, good for daytime energy usage, generating extra electricity to offset your electricity bill and more importantly, generate more power to charge a battery when the time comes.

West Facing Panels

Produce approximately 12% less energy than north facing panels and still generate in the morning, but generate more power during the afternoon so perfect for those that don’t deal well with the Adelaide summer heat!

East Facing Panels

Produce approximately 15% less energy than north facing panels, generate most in the morning, yet still generate in the afternoon and have best chance of capturing any winter sun more for those that can’t stand Adelaide winters!

South Facing Panels

South facing panels angled at less than 20 degrees still produce really well in Adelaide. In summer the production is on par with a west facing roof, if not better as the sun tracks above the roof all day. In winter as the sun is lower the production does take a hit, but still a great year round production option! In most cases a south facing roof can out perform a shaded north roof space!

Best Adelaide Solar Panel Direction

 

The above compass image shows the optimum solar panel orientation for Adelaide and South Australia. It highlights the fact that solar panels will work in all directions, including south with differing energy yields.

 

Optimal Angle For Solar Panels

Most solar panels are installed straight onto existing roofs, which are usually pitched anywhere from 0 degrees (flat) to 30+ degrees.

Our tilt chart below gives you some indication of the efficiency of solar panels at various angles from flat to 90 degrees, and this table gives you a comprehensive and comparative overview of the efficiency from all angles. Most roofs will end up with solar panels operating at between 90%-100% efficiency.

 
 

A word of warning on optimising the angle of your solar panels for maximum efficiency. Solar panels will operate at 100% of achievable efficiency when placed on a 30 degree angle, true North in Adelaide.

As you can imagine, not all rooflines are pitched at 30 degrees, with the average roof being pitched at 22.5 degrees. So if you want to chase absolute best production you probably think the obvious solution to this issue is installing panels on struts to tilt them to the optimal angle 30 degrees North!

Problem in South Australia is these struts require planning approval from council and engineer sign off, which may not be approved, will incur significant costs into the thousands in many cases and loss of solar savings while waiting for all this. This isn't great for your bottom line, nor will it guarantee that you will make back the extra spend in savings.

What you may not realise is that even a completely flat solar panel will still operate at 87% efficiency, which may work out better for your energy savings in the long run than investing in the supports to tilt your panels to the perfect angle.

Final Thoughts

End of the day your roof is what your roof is, so let us educate you on the options, set clear expectations, design a panel layout you’re happy with and hey, even that south roof could get you an under-4-year payback and 20% return on investment!

Feeling confused? Talk to one of our experts to find the design solution that's right for your property.

To learn details specific to your property, please contact us.


 
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WRITTEN BY

Ben Gordon

Joining Goliath after 10 years as a team leader with Coca-Cola, Ben transitioned into solar sales and customer service, receiving great praise from our customers due to his honest nature.