As we’re in winter, South Africans often find their energy needs and consumption patterns changing. With winter bringing shorter days and lower sun angles, some of our customers – especially new solar owners being their first winter – have questions about solar panel efficiency and how to optimise their systems during this time.
During winter, the Southern Hemisphere is tilted away from the sun, receiving less direct sunlight compared to summer. This results in lower solar panel efficiency and shorter daylight hours. For instance, in a typical 3.6kWp solar PV installation in Durbanville (Cape Town), our engineers have observed a reduction in electricity generation of up to 65% from January (688.9kWh per month) to June (312.9kWh per month).
Graph of Solar PV Generation Over the Year
The drop in solar generation during winter highlights the importance of oversizing your solar solution to ensure adequate output during these months. In many cases, and especially if you have a 3-phase system, excess generation capacity may be used to export to the grid in summer.
How to Maximise Solar Panel Performance in Winter
Despite the reduced sunlight, there are several strategies to enhance your solar PV system’s performance during winter:
1. Install More Solar Panels and add more batteries
In winter, households generally use more power, such as aircons, electric blankets, kettles and heaters. With this, we advise our customers to rather add another battery and some panels to compensate for the lower sunlight hours and increased shading. This is especially useful in areas like Cape Town with high winter rainfall. With panel prices at an all-time low, now is an ideal time to upgrade your system.
2. Utilise Cooler Temperatures
Cooler temperatures actually improve solar efficiency. Panels in coastal areas perform better than those in hot inland regions. Remember, solar panels rely on light, not heat, and they work more efficiently in cooler climates.
3. Shift Energy Usage to Sunlight Hours
Adjusting your energy consumption to align with peak sunlight hours can greatly enhance efficiency. Use high-power appliances like washing machines and dishwashers during the day, and cook meals using slow cookers, gas stoves or other low-power appliances. Be also mindful of using aircons and heaters, as the older types (non-inverter type) consume a lot of energy, very similar to an electric kettle or more. In contrast, the inverter type aircons consumes at least half of the previous generation. Your pool pump can also be used less frequently in winter than in summer… so be sure to adjust your schedule accordingly.
4. Optimise Geyser Usage
Install timers and blankets on your geysers to ensure they operate during the day when the ambient temperature is higher, reducing the energy required to heat water. Nobody wants a cold shower or bath!
5. Energy-Efficient Habits
Adopting energy-saving habits can also help:
- Run washing machines and dishwashers at lower temperatures during the day.
- Wash clothes on sunny days to avoid using tumble dryers.
- Turn off appliances and lights when not in use. Remember your phone chargers.
Once the seasons change again for spring, you can adjust your usage patterns again to utilise the longer sunny days.
Final words
By understanding how winter impacts solar PV efficiency and implementing these practical strategies, you can ensure your solar system continues to perform optimally throughout the year.
At AWPower, we are committed to helping you navigate the challenges of seasonal changes and maximise your investment in renewable energy. A wise move to improve your return on investment could be to subscribe to an AWPower Maintenance and Support Agreement which services will include seasonal adjustments and maintaining the optimum performance of your system.
For more information contact us at info@awpower.co.za