Here’s what you need to know about how solar panels work, how weather may affect them, and what to do when the weather is less than ideal.
Australia’s recent parkour-like weather conditions have been nothing short of eventful, from sweltering heat and catastrophic bushfires, to flash flooding and cyclones. It’s left Australian homeowners with solar panels on their roofs scratching their heads about what affects this radical weather might have on their solar panels. How are solar panels impacted by extreme temperatures? What happens during a blackout? How does a solar system withstand heavy rainfall, flooding, or even a cyclone?
Australia’s weather in 2020…
How Solar Panels Work
If you’re unfamiliar about how solar panels work, here’s the rundown. Solar panels convert sunlight – not the sun’s heat – directly into electricity through photovoltaic cells that capture the energy of the sun in the form of DC energy and convert this DC energy via a solar inverter to AC energy, this AC energy is what is used in your home.
Your inverter is wired into your main switch board where the AC energy is utilised in your home first and if any excess energy is available it will be sent to the grid in exchange for a ‘feed in tariff’. If a battery is utilised on the home the excess energy will be stored for night time use, oppose to being sold to the grid.
One of the most common misconceptions about solar is that they need direct sunlight in order to work. The way the sun is projected onto a solar cell doesn’t necessarily require direct sunlight, solar cells just need the photons emitted from the sun. Even if it’s cloudy outside, the sun’s photons are still being spread into the atmosphere and absorbed into the panels. This explains why your solar panels still produce energy during overcast days, although the output is impacted.
This is where the efficiency of your panel comes into play. To ensure the best output possible it is important to have a very efficient panel with a high output (check out our Q CELLS G5+ 330W panel) coupled with the most efficient inverter possible (check out our Enphase micro inverter range for the most efficient inverter on the market).
You Aren’t Protected From Blackouts
Let’s just clarify this very quickly, this is a very common – and fair – question that we get asked a lot. The short answer is, no. Having solar does not protect you from blackouts. Let us explain why.
As long as you are connected to the grid, you will still experience a blackout, just like everyone else. Unless you have a solar battery installed or an independent off-grid system, you won’t have any access to power during a blackout. To have power during black outs check out our Tesla Powerwall 2 home battery system.
There are two main reasons as to why you don’t have power during a black out with a solar system installed. Firstly, when the grid drops out the inverter has no AC reference. This means it cannot form a stable grid to supply your home. Basically, the power quality would be very in consistent.
Secondly, your inverter must turn off to protect the grid and personnel that may be working on the grid. Could you imagine working on the power lines in a storm thinking you had turned them off and all of a sudden a big burst of sunlight comes over, the solar systems in the street power up, and you get the biggest shock of your life… literally.
The Impact of Different Weather on Solar Panels
If you can survive summer in Australia, it’s safe to say that you can survive almost anything. But, what about your solar panels?
In the solar industry, manufacturers rate their solar panels for peak temperatures and snow/wind loads. Lower tier panels typically aren’t as durable or efficient as higher tier panels, and this is usually reflected in the cost.
Some companies, like Hanwha Q CELLS, have designed their solar panels specifically for Australian conditions. Hanwha Q CELLS is the industry leader of extreme weather testing and ratings. Q CELLS’ extensive and intense development process involves putting the panels through brutal testing in the Australian outback and replicating cyclone conditions – you’re welcome Queensland.
You can actually check this out in real-time by heading to the DKA Solar Centre website.
One of the key factors impacting the amount of electricity your solar panels produce is the temperature at which they operate. The best panels are designed to handle extreme variations in temperature (also known as thermal cycling) in both hot and cold climates.
You would be surprised to know how many people think that more sun and therefore more heat will produce more electricity, but this is wrong. Different solar panels react differently to the operating ambient temperature, but in all cases the efficiency of a solar panel decreases as the temperature of the panel increases. Which, given that this is Australia, can be a problem for some.
All solar panels in Australia are tested at 25 degrees Celsius. The impact of temperature on solar panel efficiency (the temperature coefficient) will vary between panels and manufacturers. Some manufacturers have engineered their panels for Australian conditions to have a lower temperature coefficient, operating more efficiently in higher temperatures. Even on hot days, Q CELLS solar modules produce reliable yields and lose less efficiency than standard solar modules.
The recent bushfire crisis in Australia has had a dramatic impact on rooftop solar energy output. Solar monitoring devices in the Penrith and Blue Mountains regions of New South Wales recorded up to 30% production loss due to the build up of dust and ash particles on the panels, and the reduction of photons in the atmosphere as a result of the smoke density.
To restore production levels the panels need to be cleaned, you can hire professionals to do this for you but most people will just sit back wait for the rain to wash the panels.
Solar power has been helping bushfire afflicted communities to access power in areas that have been cut-off from access to electricity. The team at Gippsland Solar and Tesla have been doing a lot of incredible work for their community. The Macarthur, Penrith, and Blue Mountains were lucky enough to contain most of the fires, minimising the damage. Unfortunately, Gippsland and surrounds were battered by bush fires, to the extent of destroying hundreds of homes and other structures, eliminating power and water supplies, and claiming the life of 67-year-old Mick Roberts, who died trying to defend his farm.
If you would like to make a donation to the Gippsland Emergency Relief Fund, you can do so here.
Cloud and Rain
We know that our solar panels still produce energy during cloudy or rainy weather, but the amount of electricity generated is dependent on the density of cloud cover and efficiency of the solar cells. Rain even helps wash away dust on panels to keep them operating efficiently.
The output of your panels is still determined by the angle of the sun and its intensity in conjunction with these other factors. Sun intensity refers to the amount of incoming solar energy that reaches the Earth’s surface. The angle at which the rays from the sun hit the Earth determines this intensity. Regardless of latitude or time of year, the sun’s angle reaches closest to 90 degrees – and is therefore at its most intense – at midday (noon). At this time, the sun is said to have attained its highest point.
Snow and Hail
So long as the panels aren’t covered in snow, winter climates are just fine. In fact, cold temperature can actually be more viable for solar energy production, and white snow can reflect light and improve photovoltaic performance. Although, in winter we do produce significantly less. This is largely due to less peak sun hours than in summer (shorter days) and the sun sitting lower in the sky. These graphs into solar irradiation levels between seasonal climates in Victoria are quite interesting and worth taking look at.
Hail, on the other hand, can be very problematic for the Australian homeowner. You aren’t going to find something indestructible, but you can get panels pretty close to it. And while every solar panel manufactured is required to undergo testing for extreme weather conditions, unfortunately, these certifications only designate that a solar panel manufacturer has met the minimum requirements. It’s up to you to do a little extra probing.
If a cyclone rips through town and blows the roof off of your house, then obviously your solar panels are going with it. There’s no guarantees with extreme weather like this and it’s difficult to predict the damage it may inflict. Even extra secure mounting on your panels sometimes isn’t enough and flying debris could range from a bottle cap to a car. All you can do is minimise your losses by having insurance and be sure to keep photos and documentation of your panels for such a situation.
Remember to check the wind load and extreme weather rating on your panels, it will give you a good idea on how durable your panels are in conditions like this – it might just give you the peace of mind you need. The panel itself often isn’t the main issue in extreme weather, high wind will have a direct impact on how your panels are mounted.
There are six main variables that affect a solar panel’s performance in high wind:
- The panel itself (type, weight, size)
- Mounting that fastens it to the roof
- Roof type
A good installer will take all six of these variables into consideration during the design and install of your system to ensure that it will be safe, secure, and efficient on your roof. Cheaper doesn’t mean better, you shouldn’t sacrifice safety for a few bucks.
Durability of Solar Panels
Most inclement weather won’t have a huge impact on your solar panels, so long as they are high quality and boast durability as one of their main attributes. Many top-rated solar panels like the ones we use, have a proven track record of durability, degrading at a slower rate than others. In fact, Q CELLS guarantee a minimum power output of 83% after 25 years.
Another thing that’s pretty great about durable solar panels is that they also protect the roof of your home from harsh weather conditions. Solar panels are built to hold a certain weight and snow/wind load, so the more durable your panels, the better they can withstand snow or hail.
And while snow isn’t that big of an issue in Australia, hail most certainly is. And of course, in good-old Australian style, it can’t just be hail. Because… Australia.
The Importance of Proper Installation
We’ve mentioned this a few times already and can’t express the importance of it enough.
The most important factor when choosing a solar panel installer is to ensure that they are Clean Energy Council Accredited. This means you can be confident the installer has been trained in the safe installation of solar power systems.
Choose the best quality solar panels and look for an installation company that can properly install panels so that they are secure and ready to face any weather condition. If your solar panel installer doesn’t install your system and say to themselves “that’s not going anywhere” in the same proud and confident tone as a man who just strapped something down in the back of his ute, then I’m sorry… But you’ve chosen the wrong installer.
We aren’t saying to go out there and drop stacks of cash on the absolute best product on the market, just choose something that is reliable, durable, and covered by a good warranty. You have to think about solar the same way you would if you were purchasing a car.
If you’re considering rooftop solar, do the research. We also recommend reading this beginner’s guide to solar. It pays to make sure that the panels are suitable for the weather conditions your home or business will experience. The performance and durability of the panels are invaluable to your investment and you will thank yourself for doing the research. The same goes for the installer you choose, make sure that they are certified and look at their previous work, what do other people have to say about them?