Solar panel temperatures can range from 15 °C ( 59 °F) and 35 °C ( 95 °F) during which they are considered to be operating at their most efficient.
But, the maximum temperature could reach as high as 85 °C ( 185 °F) on a hot summer day at which the efficiency of the panel can start to drop.
In this article, I’ll discuss the temperature range of solar panels, how they get so hot, and why this can be a problem.
- The solar panel performs at its peak at a temperature of 25°C (77°F).
- The higher the panel temperature above 25°C (77°F), the less efficiently it performs.
- The temperature coefficient of a solar panel determines how much the energy production decreases for every 1ºC above 25ºC.
- When the solar cells get very hot, the electrons inside the cells start to bounce around more, resulting in a reduction in the solar panel voltage.
- Providing space between the panels and the roof can help cool the panels.
What Is the Optimal Solar Panel Temperature?
The optimal temperature for a solar panel is around 25°C (77°F).
At this temperature, the solar panel performs at peak efficiency.
But on hotter days, when the temperature of solar panels rises above 25°C (77°F), the efficiency of the solar panel decreases due to thermal losses.
This loss of performance is quantified as the temperature coefficient which is expressed as a percentage.
It states how much of the panel’s rated power will be lost for every degree Celsius increase in temperature above 25°C.
For example, if a solar panel has a temperature coefficient of -0.45%/ºC, this means that its efficiency decreases by 0.45% for every 1ºC above 25ºC.
We can calculate the power loss it would incur:
40ºC – 25ºC = 15ºC x -0.45%/ºC = -6.75%
This means that at 40ºC (104ºF) this particular solar panel will produce 6.75% less energy than its maximum rated output.
What Makes a Solar Panel Hot?
This might seem like a silly question, but there are actually many factors that influence the temperature of a solar panel.
Solar panels get hot due to the exposure to direct sunlight, but isn’t that what they’re designed to do?
Of course, then what’s the problem?
The sun releases light energy at many different wavelengths and the solar panels only absorb energy from certain wavelengths.
The rest of the radiation is converted to heat and raises the solar panel’s temperature.
The PV cells only use light energy, not heat.
So they convert the light energy into an electric current but the rest of the heat just gets trapped in the panel, making it really hot.
Other parts of the solar panel absorb heat from the environment, such as the frame and glass cover.
These materials absorb any heat around them, making the solar panel hot.
Why Does High Temperature Reduce the Efficiency of Solar Panels?
Solar panels are made of semiconductor materials and as their temperature increases, the electrical properties of these materials change.
When the light photons hit the solar cell, they knock the electrons away from their atoms, creating an electric current.
But when the solar cells get very hot, these electrons become more mobile and start to move around within the cell instead of being pushed out into the circuit for electricity production.
This reduces the voltage of the solar panel, causing a drop in power output.
Can Heat Destroy a Solar Panel?
Manufacturers design solar panels to withstand temperatures up to 185°F (85°C).
This is the point where most of the solar panel components, such as PV cells and metal frames, start to fail or become permanently damaged.
But it is unlikely that a solar panel would ever reach this temperature in normal conditions.
So, don’t worry, your solar panels aren’t in danger of getting fried.
How to Control the Temperature of Your Solar System?
1. Provide Space and Airflow
Solar panels can cool down by dissipating heat into the atmosphere via convection.
To do this, it is important to leave some inches between the panels and the roof so it will act as an air gap, allowing airflow beneath them.
2. Use Water As a Coolant
On hot days, we sweat to cool down and to keep our bodies running at an optimal temperature.
The same concept applies to solar panels.
Circulating cold water on the solar panel will absorb the heat from the panels and release it into the atmosphere, keeping them cool.
But after the solar panels cool down you should gently dry the panels with a soft close.
Otherwise, the water drops may reflect the sunlight from the panels and decrease their efficiency.
This technique is mostly used in ground-mounted solar farms, as it’s easier to circulate and dry off the water.
3. Use Thin-Film Solar Panels
Thin-film panels are produced with a thin layer of semiconducting material, making them lighter and less susceptible to heat buildup.
They boast a temperature coefficient of between -0.20 and -0.25 which is less than other traditional panels with a temperature coefficient of -0.26 and -0.50.
But this type of solar panels produces less energy than their silicon counterparts.
In other words, they will lose less energy at higher temperatures but will convert less solar energy into electricity.
Are Heat-Resistant Solar Panels More Expensive?
Solar panels with low-temperature coefficients will lose less power due to increased temperatures, making them more efficient.
This will make these units more expensive as they require additional design and manufacturing processes.
But if you live in a moderate climate, then this may be unnecessary.
On the other hand, if you live in an area with extreme temperatures such as deserts, then it is worth considering an investment in these temperature-resistant panels.
The additional cost will be made up over time with increased efficiency and improved performance.
How Much Heat Do Solar Panels Give Off?
Solar panels give off a temperature range between 15 °C ( 59 °F) and 35 °C ( 95 °F).
Do Solar Panels Get Very Hot?
Solar panels get as hot as 185°F (85°C) in extreme conditions when exposed to direct sunlight.
How Do You Keep Solar Panels from Overheating?
You can keep solar panels from overheating by providing sufficient space to maximize airflow beneath the panels and use cold water as a coolant to absorb heat.
If you ask me, I think it is worth investing in temperature-resistant panels if you live in an area with extreme temperatures. But this should be a last resort as these units are more expensive.
Do you still have questions? If so, leave them in the comments and I will get back to you with an answer.