Solar panels love hot, sunny days, right? You might be surprised to hear that this isn’t always true.
Sunny days are great for generating solar energy, but all solar panels lose some performance
capacity when that sunshine is accompanied by excessive heat. This is something to consider when
you’re choosing your solar panels and calculating your long-term energy cost savings.
To express how well a specific solar panel will perform in hot temperatures, solar manufacturers use
a measurement called the “temperature coefficient.” The lower the temperature coefficient, the
better the solar panel will perform on hot days. One of the advantages of using LG Solar panels is
the low temperature coefficients of our different models.
What Exactly is the Temperature Coefficient?
When solar panels are tested for their maximum power output, they are tested at an industry standard
temperature of 77°F1. Generally, solar panels will begin to
generate less power once the temperature rises above 77°F.
The “temperature coefficient” describes the percentage of power output that is lost by a specific
solar panel as the temperature rises above 77°F1. Each solar panel
line (such as LG Solar’s NeON® 2 or NeON® R) typically has a different temperature coefficient.
How is the Temperature Coefficient Calculated?2
To determine a solar panel’s temperature coefficient and the effect of temperature on solar cell
performance, temperatures are measured on the Celsius scale commonly used in countries outside the
United States.
The industry standard of 77°F is equal to 25°C. Starting with the power output at this temperature,
solar panel performance is observed as the temperature rises.
The percentage of power lost at a specific degree measurement above
the industry standard is divided by the number of degrees above 25°C
to provide the temperature coefficient.
For example, 83°F is approximately 28°C. If you’re observing the performance of a solar panel at
28°C, you’re observing it at 3°C higher than the industry standard. If you observe a power loss of
1.08% at that temperature, you divide that power loss by 3 to get 0.36, or a temperature coefficient
of -0.36%/°C Pmax.
To further evaluate the panel’s performance as the temperature rises, you can multiply the percentage
of power lost at a specific temperature by the solar panel wattage to determine how many watts of
power are lost. If the example above is applied to a 320W panel, 1.08% of lost power x 320W = a
power loss of 3.3W. This means that at 28°C (83°F), that solar panel labeled at a maximum power
output of 320W would only generate 316.7W.
The Low Temperature Coefficients of LG Solar Panels
Temperature coefficient is an important aspect of solar panel performance, especially if you live in
a region that experiences excessive heat conditions. We’re proud of the low temperature coefficients
of our solar panels: The NeON® 2 line provides a low temperature coefficient of -0.36%/°C Pmax, and
the NeON® R line offers an even lower temperature coefficient of -0.3%/°C Pmax.
Maintaining Solar Panel Performance on Hot Days
The following considerations can help solar panels generate more power in high temperatures:3
1. Your LG PRO installer will likely make sure there are a few inches of space between your
solar panels and the roof of your home during installation. This will help the solar system
stay cooler due to the airflow beneath the panels.
2. All-black solar panels generally absorb more heat. A panel with a lighter colored
backsheet and/or a silver frame might improve power output in high temperatures.
Your LG PRO installer will also be aware that details such as the angle the panel is installed on the
roof can cause subtle changes in temperature that can impact performance.
Choose a Solar Panel that Does it All
The temperature coefficient is important, but it’s not the only factor to consider when calculating
the long-term performance of your solar system. Solar panel efficiency, maximum power output,
guaranteed degradation rate over time, and energy generation capacity in low-light conditions (such
as in the morning or early evening) are four other factors that come into play. Of course, you’ll
also want to be sure your solar panels are backed by a solid warranty and a trusted manufacturer
with a bankable brand.
LG Solar works closely with your LG PRO installer and serves as a one-stop-shop for any customer
service needs.
At LG Solar, we are proud that our solar panels do it all.
When you go solar, ask for the brand you can trust: LG
