Sun, heat wave, record temperatures, bushfires and sunburns, it’s definitely summer in Australia. But at least, hot sunny summer days mean great solar production, right? Well not exactly.
- Panels will underperform in the heat.
Just as any other electronic equipment, solar panels don’t perform as well in extreme heat. Think that your panels are on the roof and experience greater temperature than the ambient ground temperature.
Manufacturers test the panels at 25 degrees Celsius. As the temperature increases, the panels’ production decreases. Depending on the panels and conditions, production can drop by 10-25% in case of extreme heat. This loss is measured by the temperature coefficient, specific to each model. This coefficient tells you by how much the panel will underperform when the temperature rises by 1 degree Celsius above 25 degrees Celsius. Most of the temperature coefficients range between -0.2 and -0.5. The closer this figure is to zero, the better the panel will perform as the temperature increases.
Let’s take for example a panel with an efficiency rating of %19.96 and a temperature coefficient of -0.34%. For a temperature of 30 degrees Celsius., the efficiency will drop to %19.62, %19.28 when the temperature of the cells is 35 degrees Celsius.
- How to reduce this effect?
The way the panels are installed will also impact the temperature of the panels. If the installation allows for a gap between the roof and the panels, the air flow will cool the panels down. Panels that are mounted paralleled to the roof with no or very little airflow allowed between the roof and the panels experience a greater rise in temperature.
The colour of the panels can also impact its temperature. Light-color materials reduce heat absorption.
Remember that on the other end, the panels will produce more energy in temperatures below 25 degrees Celsius. The gain of efficiency in colder days will help balance the efficiency lost in hot weather. The designer team take into account the summer heat and the winter weather (Read our article Solar in Winter: here) and will give you a yearly daily average production of your system.
If you are considering commercial or residential solar, call Energis on 1300 782 217 or at sales@energis.com.au, one of our solar consultants will talk you through the best option and give you a free quote.
