More and more homeowners are looking up to the sun as a source of renewable energy. We have space on our roof. Why not use it?
Some hesitate because of the fear of heat associated with solar panels. Here’s the truth about the technology taking leaps and bounds towards a green future and lower energy bills.
What makes a solar panel hot?
Solar panels soak up all that juicy energy from the sun and convert it into electricity, or so we’re lead to believe. The sun exudes visible and invisible wavelengths of light, and our solar panels’ photovoltaic cells absorb the visible portion.
The invisible wavelengths of energy bring heat to the system. Full sunlight also hits panel parts like the glass and metal, heating them up and anything they contact.
How hot do solar panels actually get?
They range between 59-95°F, or 15-35°C usually, but can get much hotter. Factors like geographical location, the air temperature, how much direct sunlight they get and roofing material impact their temperature. It depends on many things, but as a base, remember that they are hotter than the ambient temperature.
What is the optimal solar panel temperature?
We test at 25°C, or 77°F, while 1,000W of light/m² shines on them for a maximum output rating. Most of the solar panels you can buy today yield 250-350 watts of power per panel.
The maximum output rating decreases because of factors other than the temperature, such as cleanliness and amounts of direct sunlight. The closer to that optimal temperature, the more the solar energy panels collect.
Are solar panels hot to the touch?
Panels will be, on average, about +36°F hotter than the surrounding air temperature, but they’re built to withstand high temperatures. Death Valley reaches temperatures over 125°F, bringing their solar panels to 161°F.
The panels are dark by design to absorb the visible light, and dark colors simply absorb more heat. Consider cleaning your panels early in the morning or early evening when they have cooled down a bit.
What is the ‘temperature coefficient?’
High temperatures decrease a panel’s power output, and the temperature coefficient is the expected percentage decrease/°C over 25°C (77°F).
For example, a solar cell temperature of 55°C is 30°C over 25. If its temperature coefficient is -0.25%°C we get this:
30°C x -0.25%/°C = -7.5%
It functions at -7.5%, or 92.5%, of its max output.
The lower the temperature coefficient, the more solar energy your panel will convert.
Why does high temperature reduce the efficiency of solar panels?
Electrical processes function more efficiently at lower temperatures, according to the laws of thermodynamics. When sunlight hits the silicon in photovoltaic cells, the silicon transmits and converts sunlight to electricity, putting it simply.
Are heat-resistant solar panels more expensive?
Heat-resistant solar panels have lower temperature coefficients, and that comes at premium prices. The truth is that you probably don’t need to go with a premium model unless you are in a state that is hot and dry.
These heat-resistant premium brands might have other appealing factors like a smaller size and higher energy production efficiency.
Can heat destroy a solar panel?
Yes, there is a maximum temperature recommendation most manufacturers assign to their solar panels, around 185°F. You’ll be dancing with danger around this temperature, but most will never experience this issue unless they have extreme conditions.
How to control the temperature of your solar system
Shade is not an option, but there are other ways to beat the heat.
1. Space and airflow
Keep space between your panels and your roof. This is crucial to allow air to flow all around your panels to keep their temperature down. The more surface area, the more heat dissipation.
Also Read: How Heavy Are Solar Panels
Professional installers will space the panels properly for you. DIY enthusiasts should keep about six inches of space between the panel and the roof.
2. Using water as a coolant
Water irrigation systems keep solar panels cool in extremely hot environments by applying water to the panels’ surfaces. It works the same way as our sweat does; the heat energy leaves the system by evaporating the liquid.
3. Thin-film solar panels
Recent developments in solar panel technology have led to thin-film panels. They have a lower temperature coefficient, but they also have lower energy production than similar-sized traditional panels.
Many fear the heat associated with solar panels. However, the takeaway message is unless you live in a place with extreme temperatures, you should be fine.
More and more people will be capitalizing on solar panels as the technology improves and becomes more accessible. It is an exciting time of innovation, and as more and more interest builds, we will see more and more developments.
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