Demand for solar energy is increasing day by day due to various reasons. Even though using solar energy is popular among many people still, knowledge about this technology is lacking in society. Some even assume that solar-powered products are only for the countries in the Sun Belt. But it is a wrong assumption. Solar panels and solar-powered devices work better in cold temperatures if they get enough sunlight.
In this article we hope to discuss, why do solar panels work better in cold temperatures? According to the literature, solar panels work better in colder temperatures. Most solar panels lost their efficiency after 25 deg C. Not just the panels but the solar battery are also affected at temperatures over 30 deg C.
Rechargeable batteries lose their lifetime at increased temperatures. The reason for these incidents is changes happening in the atomic levels of the solar panels and the battery at higher temperatures.
How does a solar panel work?
Before trying to understand how the temperature affects the solar panel’s efficiency let’s see how solar panel works. Many assume that solar panels work from the heat of the sunlight. But that is not true. Solar panel only needs the sunlight to work. The energy of the sunlight is consist of sunlight photons. These photons are the particles that carry the energy of the sunlight.
Solar panels are made up of a material called crystalline silicon. When the solar panel is exposed to sunlight, sunlight photons are absorbed by the atoms of the solar panel. Because of the increased energy of the solar panel atoms, they tend to be ionized. This ionization results in free electrons. These free electrons flow in one direction in the solar panel and the direct current is generated in the opposite direction.
This direct current can be stored inside a rechargeable solar battery and use later. You can use the current directly to powerup appliances that work from DC supply or you can convert it by an inverter to use for appliances that need AC supply.
What happens to solar panels at higher temperatures?
Like any other electronic equipment, the output of the solar panels decreases with the increased temperature. Usually, solar panels are tested at the temperature of 25 deg C or 77 deg F. Above this temperature the resistance inside the solar panels to the produced current flow increases.
This decreases power output. Also when the panels get hotter the existing number of free electrons inside the panel increases, so this reduces the voltage that the panel can generate when the photons hit the panel. This also decreases the power output of the solar panel.
This power reduction is presented by the value named temperature coefficient/ Pmax. You can find this value by referring to your solar panel’s manufacturer’s datasheet. This value presents the amount of efficiency reduced when the temperature of the solar panel rises above 25 deg C by one degree.
For example, if your solar panel’s temperature coefficient is -0.5% the efficiency of your solar panel will be decreased by 5% if the temperature increased above 25 degC by 1 degC.
The temperature coefficient is different for the different modules.
What happens to batteries at higher temperatures?
Not just the panels but solar batteries also get affected by the increased temperatures. At the increased temperatures, the efficiency of the rechargeable battery increases. But this reduces the lifetime of the battery due to the increase of various unwanted chemical reactions inside the battery.
Excessive heat can make the battery fluid to be evaporated faster. This causes damages to the battery’s internal structure. Also, other chemical reactions can cause corrosion and gassing which reduce the lifetime of the battery.
These chemical reactions can also create sparks which can lead to a fire. Not just that but sometimes these chemical reactions can blow up your whole system. So exposing batteries to extreme temperatures will be very dangerous.
Why cold temperatures are better for solar panels?Solar panels are work very efficiently on sunny cold days than warm days. As we said earlier only sunlight is needed to get power from solar panels, not the sun heat. The optimal temperature for the solar panels is 25 degC. Above this temperature solar panels loses their efficiency according to the temperature coefficient of the modules.
After the peak temperature solar panels drastically lose their efficiency. But if the environment is cold it is unlikely the temperature of the solar panels exceeds the 25 deg C. Inversely temperatures below 25 deg C increase the efficiency of the solar panels. The amount of efficiency that will be increased for one degree of Celsius also depends on the temperature coefficient.
But the extreme cold temperatures are not suitable for the operation of the solar system as it will decrease the efficiency of the battery.
How winter and snow affect the solar panels?
Even though the solar panel efficiency increased by the cold temperatures winter season or the snow will decrease the efficiency of the solar panel. Even though the solar panels work better in cold temperatures during the winter season the daytime is very short.
So this will decrease the amount of sunlight received by the solar panels. Also, snow accumulation on the solar panels is very problematic as they block the sunlight. So this will also reduce the amount of sunlight received by solar panels. During winter seasons solar panels require lots of maintenance to be able to work effectively.
What you can do to reduce the effects of higher temperatures on a solar panel?
If you are living in a very heated area with temperatures above 25 deg C then these tips are for you.
- As many of us know mono and polycrystalline modules have the highest efficiency. But they also have the highest temperature coefficient which makes them a profitless investment. So you have to consider getting modules with a low-temperature coefficient. Now there are hybrid modules that have a low-temperature coefficient.
- It is better if you can install the batteries, inverters, and other electrical components inside a shaded area to avoid any damages to those components from excessive heating.
- Then when fixing the panels on the roofs make sure there is a space of few inches between panels and the roof. This permits airflow between the panels and the roof and cools off the panels quickly.
- Even though many solar panels are constructed in dark colors it is better if you can use light color solar panels. As the light color solar panels absorb less heat they may heat with less speed than darker panels.
| Conclusion |
As you see even though the panels need more sunlight it does not need sun heat. So they work better in sunny cold areas rather than in sunny warm areas. But even though you are living in a very warm area you can get the most suitable solar system by consulting a good solar system provider.