Solar energy is widely recognized as a significant player in the field of alternative energy. The use of solar power as a substitute for fossil fuels allows individuals and businesses to generate environmentally friendly electricity.

However, effectively harnessing the energy from the sun requires a comprehensive understanding of various factors. One of these factors is temperature. The temperature coefficient of solar panels plays a vital role in determining their efficiency in different climates and conditions.

Solar Panel Temperature Coefficient: Definition

The solar panel temperature coefficient refers to the rate at which a solar panel’s efficiency decreases as its temperature rises.

Solar panels operate optimally when exposed to direct sunlight, but excessive direct sunlight can cause them to become too hot. As a result, their efficiency decreases due to the functioning of photovoltaic cells.

It’s important to note that most solar panels have a negative temperature coefficient, meaning that as the panel’s temperature increases, its efficiency decreases. It’s unlikely to find a solar panel that performs better at higher temperatures. The actual percentage of efficiency drop varies based on the brand and type of solar panel.

The majority of solar panels have a temperature coefficient ranging from -0.3% / °C to -0.5% / °C. The closer the temperature coefficient is to 0, the better.

The operating temperature range for solar panels generally falls between 59 degrees Fahrenheit and 95 degrees Fahrenheit, with 77 degrees Fahrenheit being the optimal temperature.

While the operating temperature can reach as high as 185 degrees Fahrenheit, solar panels absorb the heat from the sun and function at a hotter temperature than the surrounding air.

3 Factors That Determine the Temperature Coefficient

There are several factors that can influence the temperature coefficient of solar panels. Let’s take a closer look at them.

Panel Technology and Design

The technology and design of the solar panels, including their structure and arrangement, can impact their temperature coefficient.

Both monocrystalline silicon panels and polycrystalline silicon panels typically have a temperature coefficient ranging from -0.44% / °C to -0.50% / °C.

In comparison, thin-film solar panels generally have a lower temperature coefficient. According to Freedom Solar Power, panels with thin-film solar cells usually have coefficients closer to -0.2% / °C.

Roofing Material

The roofing material used can also affect the temperature of solar panels. Different roofing materials have differing abilities to absorb heat.

When it comes to roofing materials, the following types are commonly recommended for solar panel installation:

– Asphalt shingles: These don’t absorb much sunlight.
– Metal: Metal roofs are excellent at reflecting sunlight.
– Tile, tar and gravel, and wood (such as synthetic cedar): These materials work well for ground-mounted systems or community solar farms.

In general, having a lighter-colored roof is advantageous. It’s important for the roofing material to possess high solar reflectance to keep the roof cool and prevent an increase in the panels’ temperature. Remember, panels lose efficiency when they exceed their ideal temperature coefficient.


The location where you install solar panels greatly affects their temperature coefficient. Climate and average temperature play the biggest roles in this.

For example, if you live in hot and humid places like Texas or Florida, your roof or panel placement may not be cool enough for optimal performance. In such locations, it’s crucial to take necessary measures to keep your panels cool.

Aside from the type of roofing material used, other factors like shading from trees and buildings, the orientation of your system, and other details also contribute to the temperature coefficient’s impact on energy production.


To optimize your solar panel efficiency, your solar panel temperature coefficient should be as close to 0 as possible. Some of the best ways to do this include buying thin-film solar panels, using light-colored roofing materials, and placing solar panels in the shade (if you live in a hot climate).