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Solar energy is harnessed from the sun by photovoltaic cells that convert sunlight
into electricity. The process of converting the sun’s rays into electricity is called
the photoelectric effect. It presents as a sustainable source of energy that can
reduce carbon emissions and tackle climate change. But with growing extreme
weather conditions what could be the effect on solar panels?
Here is what you need to know about how weather conditions affect the panel’s
operation and efficiency.
Solar panels perform well in sunny weather because with no clouds in the sky
the transmitted sunlight directly hits the panels. Clouds reduce the amount of
sunlight that can hit the panels, so on a cloudy day they don’t produce as much
electricity as they do on a sunny day. A study was done by the University of
Brighton in the UK to investigate how weather conditions affect the efficiency
and operation of solar panels in the southeast of the UK. The effect of weather
conditions on the performance of PV panels was demonstrated through analyzing
the system outputs of two existing solar PV installations. Results revealed that
high humidity and rain particularly have the most significant effects on the
efficiency of the two PV installations [1]. A similar study was done by Shahid
Beheshti University in Iran, for 70 days. Results revealed that after 70 days
without rain dust was accumulated on the surface of the panels, which caused a
21.47 (%) reduction in the power [2].
Solar panels can perform well in colder and sunny weather. In places like
southern Florida, where extreme winds occur every year because of hurricane
season shouldn’t be a concern as solar panels are manufactured and engineered
to withstand winds up to 170 Mph [3]. As for very hot climates, the performance
can drop this happens because the solar panels give maximum power output at
25 ֯ C for every increase in module temperature by 1 ֯ C the efficiency decreases.
This decrease in efficiency varies between -0.3% / ֯ C to -0.5% / ֯ C. This is
known as the temperature coefficient. This can be found in the manufacturer's
datasheet. As for winters, the ambient temperature can help in improving the
performance of the solar panels as long as the panels aren’t covered in snow. In
recent years innovations have been made to develop solar panels to minimize the
effect of weather conditions like for example self-cleaning and hydrophobic
coatings are common methods available when installing new solar panels.
Different weather conditions have an impact on the type of PV cell technologies.
The PV market is dominated by monocrystalline and multicrystalline silicon
wafers, followed by thin-film technology. Studies have shown that different PV
cell technologies have their own merits and demerits in different weather
conditions. This article will focus mainly on monocrystalline and multicrystalline silicon panels. Monocrystalline solar panels are relatively a premium
product compared to their multicrystalline counterpart. Monocrystalline panels
perform better because they are produced by using silicon wafers which have a
single crystal orientation whereas multicrystalline panels are made using chunks
of silicon with different crystal orientations. This is the main reason why
monocrystalline silicon panels have higher efficiency compared to
multicrystalline silicon panels and they are also more expensive to produce.
Another advantage is monocrystalline panels have high heat tolerance.
A study performed by VIT University from India analyzed the performance of
monocrystalline and multicrystalline cell technologies under different weather
conditions. On a sunny day, it was observed that monocrystalline panels
produced more power compared to their multicrystalline counterparts. Similar
results were observed in cloudy weather conditions. It was also shown that
relative humidity has an impact on the performance of the panels due to the
reflective factors which affect the irradiance levels [4]. In all the cases
monocrystalline panels performed better than multicrystalline panels. This
comparative analysis gives a clear understanding of the performance of different
PV modules under varying weather conditions and also gives a good insight into
the selection of the right technology for a particular environment.
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