Practical Ways To Maximise Your Solar Panel Performance In Winter
As South Africans transition into the colder months, so too do their energy needs and consumption patterns – as well as their solar panel efficiency.
11/06/2024
As the country transition into winter, so too do energy needs and consumption patterns – as well as solar panel efficiency. “The change in weather, specifically the length of day in winter versus summer, has a direct impact on your solar performance,” says Ross Mains-Sheard, Co-Founder and CEO of Versofy SOLAR.
From the length of day to the angle of the sun in the sky, there are many factors that affect solar panel performance in winter. It is important that we, as consumers, also understand how our energy needs and behaviours shift through the different seasons so that we can implement practical steps to maximise our solar systems at this time of year.
According to Mains-Sheard, regardless of your geographic location, the simple fact that the sun is just not up for as long in winter as it is in summer has the biggest impact on solar systems. “It should be kept in mind that the angle of the sun plays an important role in solar panel performance,” he says. “During winter, the angle of the sun is lower in the sky, which greatly affects performance when it starts hitting your panels at optimum angles, as well as an increased chance of shading occurring.”
Interestingly,
cooler temperatures are actually better for
solar efficiency. “Solar panels at the coast
perform better relative to those in hot areas
like the Karoo, due to the cool sea breeze. It
is important to note that solar panels rely on
light, not heat. For example, in Europe and the
Alps there are solar panels in the snow which
work just as well, even though it’s minus five
degrees!”
It might seem obvious, but it
is also crucial to understand how our energy
needs shift through the year, from season to
season. In winter, the days are shorter, and the
nights are longer, meaning lights are switched
on earlier in the morning and evening.
Naturally, you heat more in winter with oil and
bar heaters, electric blankets and you even boil
the kettle more frequently for hot drinks. Your
geyser works harder because your ambient
temperature is much lower, and the geyser must
be on for longer periods of time to reach and
maintain a temperature. Location, too, plays a
part in your seasonality impact. If you live in
Cape Town, for example, you are likely to use
tumble dryers more because of high winter
rainfall, whereas in Johannesburg it’s sunny
almost every day.
So how can we optimise
our solar efficiency and mitigate the impact of
season changes on our systems? “There are
several practical steps that can be made
including shifting your loads to sunlight
hours if you have solar and installing timers on
your geysers, so they work during the day when
the ambient temperature is higher,” says
Mains-Sheard. “Our solar app is a great tool as
it takes weather conditions and historical usage
into account. For example, it knows that if it
is going to be a sunny day tomorrow, you can
drain the battery more today (and use less from
Eskom). The app applies technology that takes
the myriad of variables into account, so that
you don’t need to.”
Installing more solar
panels and batteries would assist with
resilience to cloud cover and rain in areas like
the Cape during winter. “We encourage more
panelling in these areas, and now is a good time
to upgrade, as panel prices are at an all-time
low due to the high levels of demand.”
A few other practical ways to optimise your solar efficiency in winter
Use high-power electric
appliances when solar panels are generating the
most (in the middle of the day); run washing
machines and dishwashers at lower temperatures
and during sunlight hours; where possible, cook
evening meals during the day (using a slow
cooker on low power rather than the stove or
oven during the evening); wash on sunny days to
avoid using the tumble dryer; turn off
appliances and lights when not in use; install
timers and blankets on geysers.