Solar panels work by turning sunlight into electricity using the photovoltaic (PV) effect. More sunlight means more power. However, if the panels get too hot, they produce less electricity.

High temperatures can lower the efficiency of solar panels, reducing how much sunlight they can turn into energy. Keep reading to find out how temperature impacts solar panel performance and how to manage these effects.

What is Solar Panel Efficiency?

Solar panel efficiency refers to the ability of a solar panel to convert sunlight into usable electricity. It is expressed as a percentage, indicating how much of the solar energy hitting the panel is converted into electrical energy. For example, a panel with 20% efficiency converts 20% of the sunlight into electricity, while the rest is lost as heat or reflected.

Efficiency is influenced by various factors including:

• Temperature: High temperatures can reduce efficiency by increasing the electrical conductivity of the panel materials, which lowers voltage and power output. Cooler temperatures can enhance efficiency by increasing voltage output.
• Sunlight: The amount and quality of direct sunlight are critical. More sunlight means higher efficiency.
• Panel Quality: The design and materials of the panel affect its efficiency, with higher-quality panels generally offering better performance.

How Hot Do Solar Panels Actually get? 

Solar panels are usually tested at 25°C (77°F), but their temperatures can range from 15°C to 35°C while operating at their best efficiency. However, they can heat up to as much as 65°C (149°F), which can reduce their efficiency.

Solar panels are made of silicon cells covered by glass and supported by a metal frame. This setup is similar to a car's windows and frame. To get an idea of how hot solar panels can get, imagine a car parked in the sun on a hot day. The windows and frame will be quite warm but won’t pose a fire risk.

How to Counteract Solar Panel Overheating?

To mitigate the effects of overheating in solar panels, several strategies can be employed. Regardless of the type of panel used, some energy loss due to heat is inevitable. However, mounting the panels a few inches above the roof allows for airflow beneath them, helping to dissipate heat from the solar modules. Additionally, it's important to note that solar panels achieve their maximum conversion efficiency at a temperature of 25°C.

Factors That Affect Solar Panel Efficiency

A variety of factors can impact solar performance and efficiency, including:

• Temperature: High temperatures will directly reduce the efficiency of a photovoltaic panel. 
• Sunlight: The amount of direct sunlight a PV panel receives is typically the most significant determiner of how much electricity it can produce. Even the most efficient solar panel can’t generate electricity at night, and production is diminished on overcast days.
• Orientation and Tilt: Orienting panels towards the sun (facing south if you are in the Northern Hemisphere) to maximize sunlight exposure is best. Depending on your latitude, you can optimize their efficiency by angling them directly toward the sun’s path — around 30-45 degrees. 
• Dust, Snow, and Debris: Dirt, leaves, snow, and other debris can block sunlight from the panels. Be sure to clean your solar panels regularly to keep them efficient. 
• Panel Age: As photovoltaic panels age, their efficiency will slowly decrease year after year. Having said that, high-quality solar panels can last 25 years or more — longer than an asphalt roof.
• Shading: If shadows from nearby trees or structures block your panels, they won’t reach maximum efficiency. This issue also goes for partial shading — if one cell in a monocrystalline or polycrystalline PV panel is in the shade, the cumulative electricity generation capacity of the panel will be adversely affected.  

Comparing Solar Panel Efficiency in Hot and Cold Environments

Solar panel efficiency varies significantly between hot and cold climates:

• Hot Environments: High temperatures can reduce solar panel efficiency by causing the materials in the panels to become too conductive, leading to lower voltage and power output. For every degree above 25°C (77°F), efficiency can drop by 0.3% to 0.5%.

• Cold Environments: In contrast, cold weather can enhance solar panel performance. Lower temperatures increase the voltage output, making panels more efficient. However, sunlight is still crucial, so cold climates with ample sunlight can see better overall efficiency than hot, sunny regions.

Ultimately, while cold environments generally boost solar panel efficiency, the amount of sunlight remains the most critical factor in determining overall performance.

The Relationship Between Temperature, Humidity, and Solar Panel Efficiency

Temperature and humidity both affect solar panel efficiency:

• Temperature: High temperatures can lower solar panel efficiency by increasing the conductivity of the materials, which reduces voltage and power output. Efficiency typically decreases by 0.3% to 0.5% for every degree above 25°C (77°F). Conversely, cooler temperatures can improve efficiency by increasing voltage output.

• Humidity: High humidity can decrease efficiency by causing more clouds and moisture in the air, which blocks or absorbs sunlight before it reaches the panels. This reduces the amount of direct sunlight hitting the panels, diminishing overall energy production.

In summary, while low temperatures can enhance efficiency, high humidity can have a negative impact by limiting sunlight exposure. Both factors need to be considered to understand and optimize solar panel performance.

Conclusion

In conclusion, solar panels are an effective and sustainable way to generate electricity, whether for a home or business. They work well in various weather conditions, have a long lifespan, and require minimal maintenance. To maximize their efficiency, it’s important to choose the right type of panels, ensure proper installation, and consider advanced cooling technologies for hot climates.