Do Solar Panels Absorb Heat? (Interesting Results)

Solar panel technology is truly marvelous, converting the vast energy provided by the sun into storable, usable forms to power our homes and various appliances.
However, exactly how solar panels work is a mystery to many casual enthusiasts.

Here, we’ll explore the answer to one often-asked question: “do solar panels absorb heat?”

A few of the points we’ll cover include:


• Do solar panels absorb heat?
• How solar panels cool homes
• What convection currents are
• How much savings solar panels can provide on cooling and roof repair costs
• How solar-power air conditioners work

We’ll also discuss similar details about how solar panels work such as their cooling benefits for homes in the summertime.

Solar panels covering a roof

Do Solar Panels Absorb Heat?

Yes. Although the electricity that solar panels generate comes from sunlight, not heat, they do absorb heat nonetheless, as one might expect from an object that relies on absorbing the sun’s rays to function.

Solar panels, by their design, suck up the maximum amount of sunlight possible from the environment.

Think about some time when you’ve made the mistake of wearing a black shirt in the hot sun when you should’ve worn white – it can get quite warm, right?

That black t-shirt is not, of course, generating electricity like a solar panel, but the same principle applies – namely, of sunlight generating heat in an object that absorbs a lot of it (like solar panels, which are blue or black, other dark-colored objects absorb more heat than light-colored ones).

How Solar Panels Cool Homes

The good news for homeowners is that solar panels provide an extra barrier of protection, absorbing heat before it hits the actual rooftop and has a chance to make its way into your home.

One of the under-appreciated benefits of solar panels is the cost-savings they offer to homeowners who would otherwise rely on air conditioners to cool their homes in the hotter months.

If you haven’t ever worked as a roofer, you might not appreciate just how hot rooftops can get under the glaring sun. In fact, rooftop temperatures in July and August can frequently exceed a scorching 160+ degrees Fahrenheit.

Rooftop heat conditions can be so severe that the Occupational Safety and Health Administration (OHSA) sets strict guidelines to protect roofers’ safety on the job. Heat strokes are not uncommon in the profession.

The materials comprising roofs are designed to withstand the heat and repel it upward but, even so, no matter how well insulated your home is, some heat inevitably leaks inside and raises the indoor temperature.

What Is the Convection Current and How Does It Cool the Home?

A significant amount of the heat that solar panels absorb passes into the wider environment (saving your home from exposure) via a process called a convection current.

A “convection current” refers to air movement that occurs between the solar panels and the roof. This air carries away with it a significant portion of the heat from the solar panels so that it never has the chance to make headway into your home.

Solar panels that have tiled arrays, in addition, have even more space separating them from the actual roof for convection currents to do their thing, whisking away even more unwanted heat.

More efficient solar panels translate into greater cooling effects because inefficient conversion results in greater heat buildup on the panels. Higher-quality solar panels that are better at turning sunlight into electricity operate at lower temperatures than lower-quality ones.

Just How Much Heat Reduction Do Solar Panels Achieve on Roofs

To quantify just how effective solar panels can be for reducing roof temperatures, let’s take a look at an impressive study performed by researchers at the University of California San Diego.

They set out to measure the heat reductions provided by solar panels and found that they reduced the surface temperature by as much as 38% — more than one-third.

Several factors affect the actual number on a case-by-case basis such as how the solar panels are positioned on the roof, the surface area that they cover, the type of solar panels, and, of course, the architecture of the roof itself.

The Other Benefits of Solar Panels For Roofs

In addition to keeping roofs cool in the summer, solar panels also protect them from wear and tear.

For example, depending on the climate, your roof may be susceptible to a phenomenon known as a thermal shock that can really do a number on its integrity over time.

Thermal shock occurs when high daytime temperatures cause the materials in the roof to expand. Then, after sundown, the temperature cools considerably, causing the materials to contract. This can eventually result in gaps in the roof as well as warping – obviously not good for your home or your wallet.

Large repair jobs on roofs in the US tend to cost on average between $1,500 and $7,000 – money that you would likely find better uses for than constantly having to invest in roof fixes.

Solar panels protect roofs, at least to a certain degree, from the thermal shock phenomenon by preventing the rooftop temperature from getting too high during the daytime and holding in some of the heat after sundown to stop the temperature from falling too rapidly and contracting the roof materials.

In the long run, this can add several extra years of life to your roof and, as a result, save you potentially thousands of dollars in costly calls to the roofing company.

Solar-Powered Air Conditioners For Even Greater Energy Savings

We’ve already discussed in detail how solar panels eliminate costly air conditioning requirements simply by virtue of their heat absorption. But you can also take your savings to the next level by installing solar-powered air conditioners to potentially fully eliminate your AC bills next summer.

According to data from the U.S. Energy Information Administration, air conditioning represents roughly 12% of all home energy use – and it’s even higher (as high as 27%) in hot climates. That amounts to, depending on the size of your home, many thousands of dollars each year.

In the aggregate, that adds up to roughly $29 billion in AC costs to American homeowners each year – a lot of money.

When we’re talking about such large figures, it’s easy to understand how, over time, solar panels can pay for themselves and then some by chipping away at these costs.

Solar-powered AC systems are now available as either stand-alone units to power single rooms or as system-wide HVAC systems that ventilate your entire house.

In addition to shaving down energy costs, harnessing the natural power of the sun to cool your home is also beneficial for the environment, as it cuts down on your carbon footprint by eliminating reliance on fossil fuels for energy.

Sources

https://www.researchgate.net/publication/251496714_Effects_of_solar_photovoltaic_panels_on_roof_heat_transfer
https://www.osha.gov/news/newsreleases/region7/11102016-0
https://www.eia.gov/todayinenergy/detail.php?id=36692
https://www.energy.gov/energysaver/air-conditioning