Does hotter weather mean more energy?

More sun, more heat, more power? We look at what impact hot days have on your solar system.

As we kick back and continue to enjoy the warmest months of the year, it’s easy to assume that that Australia’s summer months are the most lucrative when it comes to generating solar energy. We know that sunshine plays a central role in solar energy production, but does the heat of the sunshine at this time of year help us generate more power?

Solar panels use sunlight and convert it into electricity by a chemical reaction. An inverter then converts this electricity into the type we use around the house. So on a bright, hot day in February, is this system working at double speed?

Soeren Lange, AGL solar expert, says surprisingly, that’s not the case.

“Generally speaking, excessive heat is not good for a solar panel,” he says.

“A panel converts light into electricity, not heat into electricity. So a very hot day doesn’t necessarily mean it’s a great solar day.”

Hotting up.

In fact, he explains, the cells in the panel will lose efficiency in too much heat, reducing output. That’s because as the temperature of a solar panel increases past its optimal range, its efficiency starts to slightly decrease – meaning less energy from the same amount of sunshine. So if a very hot summer’s day is not the most beneficial of weather conditions, what is?

“A very bright but cool winter day could be a much better day for solar production than a very hot summer day,” says Lange.

“There are many factors that can impact the solar generation,” he adds.

“Generally you can cluster them into the three areas: weather, system and location. The weather has a major impact, of course. The most obvious one being sunshine hours – the longer the sun shines, the more electricity the system will produce.”

As well a location – with some states experiencing more sunshine hours than others each day, and thus affecting solar outcome – other factors, such as humidity, the angle of the sun, strength of the sunshine as well as heat, can impact solar generation. The type of solar system that you use will also have an effect on the output.

“Type and wattage of panels and inverter will directly impact generation,” says Lange.

“For example, one panel with 260 watts will usually produce more than a 175-watt panel. Location and set-up conditions will also impact the possible output of a solar system.”

Panels mounted on a roof with around 25-degree roof pitch and perfect north orientation, explains Lange, is the ideal condition. Every angle deviation from this will impact the generation of solar power.

But high temperatures during this time of the year shouldn’t mean your solar system isn’t otherwise working to its full efficiency. So what’s Lange’s advice for making the most of your solar energy in warmer months?

Storage for success.

As solar only generates power during the day, he advises shifting your energy consumption from evening into daytime. This could mean shifting the use of your high-electricity consuming appliances – i.e. washing machines, pool pumps and air conditioning – to daylight hours.

Another way, he says, is to incorporate a battery.

“This enables you to store electricity during times when you don’t need it, and consume it later, for example when you’re watching TV after sunset.”

Whilst hot temperatures may not have the maximising affect on solar output that we may have previously assumed, summer, with its long sunshine hours, is still a good time for producing solar energy.

And of course, knowledge is power: while bright and cool winter days may provide the perfect conditions for producing solar energy, understanding what makes our solar system tick, and adjusting accordingly, means we can make the most of all seasons.