One of the most common misconceptions about solar energy is whether solar panels use heat or light to generate electricity. Many people assume that the hotter the climate, the more efficiently solar panels will work. However, this isn’t entirely true. The key to understanding solar power lies in knowing the difference between solar thermal energy and photovoltaic (PV) solar energy.
Let’s break it down and explore how solar panels actually generate electricity, the role of temperature in their performance, and the factors that affect their energy production.
The difference between solar thermal and photovoltaic solar energy
Solar power can be harnessed in two primary ways:
- Solar thermal energy – This method uses sunlight to produce heat, which is then used for various applications, such as heating water or generating steam to drive turbines for electricity production. Solar thermal systems are commonly used in residential water heating and large-scale solar power plants.
- Photovoltaic (PV) solar energy – This is the type of solar power most people are familiar with. PV solar panels convert sunlight directly into electricity using semiconductor materials, without generating heat as a primary function.
Most home and commercial solar installations use PV solar panels, so let’s focus on how they work.
Do solar panels work better in hot or cold weather?
It’s easy to assume that solar panels work best in hot, sunny environments like deserts, where the sun is blazing all day. However, heat can actually reduce solar panel efficiency.
The role of temperature in solar panel performance
Solar panels are electronic devices, and just like computers and other electronics, they operate more efficiently in cooler temperatures. When solar panels overheat, their ability to generate electricity declines.
To measure performance, manufacturers test solar panels under standard conditions, typically at 77°F (25°C). As temperatures rise above this benchmark, panel efficiency starts to drop. The temperature coefficient of a solar panel indicates how much power is lost for each degree increase above 77°F.
For example:
- On a hot summer day, when temperatures reach 95°F or higher, conventional solar panels can lose 10-20% of their efficiency.
- In contrast, on a clear, cool winter day, solar panels can operate more efficiently and even produce more electricity than in extreme heat.
This is why some of the best locations for solar power generation are in cooler regions with plenty of sunlight rather than in the hottest climates.
How do solar panels generate electricity?
Solar panels work by absorbing sunlight and converting it into electricity through the photovoltaic effect.
Here’s how the process works:
- Sunlight hits the solar panel – The panel is made up of photovoltaic (PV) cells that absorb light energy.
- Electrons get excited – The light energy excites electrons in the PV cells, causing them to move.
- An electric current is generated – The movement of electrons creates direct current (DC) electricity.
- An inverter converts DC to AC power – Since most homes and businesses use alternating current (AC) electricity, an inverter is used to make the power compatible with household appliances.
It’s important to note that solar panels rely on light, not heat, to generate electricity. This means they can still work effectively in cold, sunny conditions and even on cloudy days, as long as enough sunlight reaches the panels.
The impact of sunlight angle and shading on energy production
Beyond temperature, other factors influence how much electricity solar panels can generate.
1. The angle of the sun
The angle at which sunlight hits the solar panels affects how much energy they produce.
- Solar panels work best when sunlight is hitting them directly (perpendicular to the panel surface).
- The position of the sun changes throughout the day and across seasons, which is why solar installers carefully design panel placement and tilt angles to optimize energy production.
2. The amount of sunlight
Naturally, solar panels generate the most electricity when exposed to direct, unobstructed sunlight. Factors that reduce sunlight exposure include:
- Shading from trees, buildings, or nearby structures
- Cloud cover (though some sunlight still penetrates clouds)
- Dust, dirt, or snow covering the panels
3. The spectrum of light used by solar panels
Even when clouds block direct sunlight, some solar energy still reaches your panels. This is because PV cells use different parts of the light spectrum, including:
- Visible light (what we see with our eyes)
- Infrared and ultraviolet (UV) light (which we can’t see but still reaches the Earth’s surface)
This explains why you can still get sunburned on a cloudy day—because UV rays penetrate the clouds. Likewise, advanced solar panels, like those offered by Sunhub, capture more infrared and UV light, allowing them to generate power even in less-than-ideal conditions.
Why high-efficiency solar panels matter
Choosing high-efficiency solar panels makes a big difference in energy production, especially when dealing with real-world conditions like heat, shading, and changing light angles.
Sunhub offers premium solar panels that:
- Are 30% more efficient than conventional panels, meaning you need fewer panels to generate the same amount of energy.
- Have a lower temperature coefficient, reducing energy losses on hot days.
- Feature microinverters that help maximize power output, even in partially shaded conditions.
How solar panels provide long-term value
Investing in high-quality solar panels not only helps lower electricity bills but also ensures long-term performance and durability.
Key benefits include:
- Long lifespan – Many high-efficiency panels, like those from Sunhub, are designed to last 40 years or more with minimal degradation.
- Lower maintenance needs – Advanced solar panels are built with durable materials that resist corrosion and micro-cracks.
- Consistent energy savings – By generating your own electricity, you can reduce or even eliminate utility bills, providing financial stability over time.
Final thoughts
While heat and light both come from the sun, only light is used to generate electricity in PV solar panels. In fact, excessive heat can actually reduce panel efficiency. Solar panels perform best in cool, sunny conditions and are designed to work even on cloudy days by utilizing different parts of the light spectrum.
By choosing high-quality, high-efficiency solar panels, homeowners and businesses can maximize energy production, reduce costs, and benefit from clean, renewable power for decades.
At Sunhub, we help businesses harness the power of solar with top-tier solar solutions. Contact us today!