BLOG
search

Solar panels can handle the heat

Jason RothmanJune 25, 2018 905 0

Solar panels can handle the heat

People everywhere want solar power but many people are afraid that solar panels only work in the perfect climate, and that is simply not true. Due to advancements in solar technology, today’s panels are more durable, efficient, and can handle even the hottest days.
 

A hot day does not always mean more solar power

It seems logical to think that the hotter the day, the more power the solar panels can generate, but that is not always true. Solar panel efficiency is actually reduced in high temperatures. There are two basic reasons for this. Heat and heat. The solar panels are getting blasted by so much energy, they cannot take it all in, and secondly, when electric things heat up they don’t work as efficiently because more of that electricity gets lost as heat. The optimum temperatures to run solar panels is 77 degrees Fahrenheit, or 25 degrees Celsius. When you move 10 or 15 degrees away from that optimal temperature, either way, the efficiency starts to drop. They are still efficient enough to completely power a home on the hottest day, they just aren’t as efficient.
 

How hot do solar panels actually get?

Home solar panels are tested at 25 degrees C  or 77  degrees F, and thus solar panel temperature will generally range between 15 degrees C and 35  degrees C during which solar cells will produce at maximum efficiency. However, solar panels can get as hot as 65  degrees C (149  degrees F) at which point solar cell efficiency will be hindered. Install factors like how close the panels are installed to the roof can impact the typical heat of your solar system.

The majority of solar panels are composed of silicon photovoltaic cells, which are protected by a sheet of glass and held together with a metal frame. Those materials are comparable to the materials that make up the windows and frame of a car. When you want to understand how hot solar panels can get, think about a car that’s been sitting in a hot parking lot on a summer day. The windows and frame will be hot to the touch, but there’s little danger of burns or fire. The actual temperature that your solar panels will be at a given time varies significantly depending on air temperature, how close you are to the equator, level of direct sunlight, and roof material.
 

The effect of temperature on solar panel efficiency

Homeowners considering solar often wonder, can solar panels overheat?  Just as with any other electronic equipment, solar panel performance does decline as they get hot. The laws of thermodynamics tell us that with increased heat comes decreased power output, and this applies to solar panels. Thus, warmer temperatures will always mean less output for solar cells, and this loss is quantified in a “temperature coefficient" by panel manufacturers, which varies from model to model.

How can you know what kind of output losses your panels are experiencing? Manufacturers rate their products’ susceptibility to a temperature in the form of the temperature coefficient, which is expressed as a percentage per degree Celsius. It is standard practice to test solar panels for power output at 25 degrees C. So, if a panel is rated to have a temperature coefficient of -0.50 percent per  degree of Celcius, that panel’s output power will decrease by a half of a percent for every degree the temperature rises about 25 degrees C (77 °F). Although that number sounds small, the surface temperature of a dark colored roof in the summer can be significantly higher than 25  degrees C (imagine the surface of an asphalt road on a hot summer day). The small percentage of output power loss for each degree of heat compounds.
 

The drop in solar panel efficiency is actually quite small

Here’s an example: if you have solar panels with an efficiency rating of 17 percent and a temperature coefficient of -0.45, they will lose 0.45 percent of their efficiency for every degree above 25 degrees C. If the surface temperature of your roof increases to 30  degrees C (86 degrees F), your solar panel’s efficiency will fall to 16.7 percent. If it increases to 35 degrees C (95 degrees F), efficiency falls to 16.3 percent.

If you want to move into the future and join the solar revolution, or if you want to find out what solar panels are right for you, go to HahaSmart.com and try our price checker tool. You can see how much a system will cost, and how much you can save over the next 20 years.

For more information relating to going solar, don't forget to visit our solar blog section for more handy guides and articles.

 

Solar system price checker

Comments

Design Your Solar Home

START

12 3

Input your address to see if it is solar friendly and how much you can save with solar.

Great. Your address is perfect for solar. Solar incentive is still available. Select monthly utility cost and calculate the size of solar system you will need now.

Whoa ! Going solar is definitely a smart decision.

kw System size years Payback period Lifetime savings

No money down, 100% finance is available.

Looking for certified solar installer? Sign up now and we will find them for you.

Do not show this information again.