The science of winter solar panel output
One of the prevailing myths about solar panels is that they do not work well in winter. This is not true. Depending on where you live in Australia, solar panels might even perform better during the cold compared to summer. In Darwin, for example, solar efficiency improves when the sky is cool and clear compared to when it’s cloudy and stormy. Even in below-freezing weather, solar panels are able to convert sunlight into consumable electricity for your home.
How is it possible that solar panels can work well in cool weather?
Solar panels work by allowing particles of light called photons to remove electrons from atoms, which generates electricity. This process is called ‘exciting’ an electron. When solar panels get hot, numerous electrons get too ‘excited’ which decreases the solar panel’s overall voltage. During winter, solar panel temperature is not hot enough to over-excite these electrons.
Cold weather will not impact your solar panels because they rely on light and not heat. During winter, solar panels get the same amount of UV light from the sun as they do in the summer. Cool weather and clear skies are optimal weather conditions for converting sun rays into electricity. In fact, heat can work against you – the hotter the solar panels, the worse they perform. Excessive heat can reduce energy output in any solar panel system.
However, cloud cover and shorter days in the winter do affect solar power production. In addition, the sun sits about three degrees lower come winter, so your panels are getting less quality light. But you can still expect around 55 – 75% of the energy production during the summer months.
This is why the installation positioning is vital. If you live in a cold city, your installer should place the solar panels at an angle that is optimised to the reduced hours of sunlight come winter.
How much energy do solar panels generate in winter?
The optimal temperature for solar panels is 25°C – anything higher than that, and they begin to lose efficiency. The overall efficiency of solar panels decreases by 0.5% every time the temperature goes up a degree. This means that when the air temperature is at 35 degrees, the efficiency of your solar panel drops by 5%. Given that the average winter temperature in Australia is 17°C, it is unlikely that solar panels will get too hot.
However, days are shorter, and there is more cloud coverage during winter – which means less sunlight. Solar panel performance can drop by 2 – 15% in the cold months, depending on where you live, how your panels are tilted, and how much dirt has accumulated on the panel surface.
On average, a 5kW system can generate 20kWh a day in summer and 13kWh a day in winter. Solar panel performance is at its peak when the temperature is cool, and there is minimal cloud coverage.
Can solar batteries help?
In some cities, heavy cloud coverage can go on for weeks – leaving you with little to no sunlight at all. The perfect solution for overcast days is the solar battery.
Solar batteries are a great way to store solar energy and ensure optimal efficiency in winter. Any excess power that the panels generate during summer is stored in a solar battery, so cloud coverage does not affect solar energy output. With the appropriate solar battery, your property has the potential to become a self-sufficient ecosystem that is entirely independent of grid power.
Some Australian homeowners opt for feed-in tariffs where any excess power generated by the solar system is sold back to the power company. Unfortunately, many households end up purchasing that same power back from the grid at a higher price than when they sold it.
On the other hand, solar batteries not only store solar energy from your sunny days in preparation for cloudy ones but also provide backup power for your home in case of a blackout.
How to save solar power during winter
There are many ways to save solar power during winter, such as the ways listed below – apply these strategies to help reduce your reliance on solar batteries and ensure a continuous power supply throughout winter:
- Make a list of the power rating of all your household appliances so you can adjust your energy consumption.
- Change high-wattage bulbs to LED lights.
- Repair or replace inefficient devices.
- Shut down electronic devices when they are not in use.
- Recharge your electronic devices during the day when the solar panels generate more energy.
- Stagger the use of high-energy appliances so as not to burn through the power supply.
So, should you worry about solar panel performance during winter?
While overcast skies can reduce the amount of sunlight your panels are getting, solar power remains an effective and sustainable energy source even in rainy, cold climates. However, if poor weather conditions are frequent in your area, you should consider investing in solar battery storage.
The best way to effectively save solar power during winter is to monitor your energy consumption and implement power-saving measures in your home. Take note of the times when the sun is out and when household consumption is at its peak. In addition, keeping your solar panels free from dirt and dust also increases their overall efficiency. As long as direct sunlight hits your solar panels with an outdoor temperature lower than 25°C, then expect your system to operate at maximum efficiency.
Get your solar panels set up correctly, with Aztech Solar
Apart from reduced daylight hours, the lower solar output during winter is due to the sub-optimal angle of the sun. This is where a creative and meticulous solar installer comes in. Here at Aztech Solar, we consider the weather conditions in your area when sizing a solar panel system for your needs to ensure that your family has enough electricity when it starts to get cold in June. Talk to one of our solar installation experts today so you can discuss your solar requirements for winter or check out our extensive range of solar options. Call us on 02 4067 2634, visit us at aztechsolar.com.au, or click here to send us an online message and we will contact you right back!