Altadena, CA

Traditional Roofs Compared to Solar Roofs in the San Gabriel Valley

Don Simkovich

The image shows a lifetime roofing material over a low-slope roof in Altadena. Do you know what would have been used not too long ago?

Hot tar.

The whole neighborhood knew when a low slope roof was being installed or repaired. Not now. Not only is the material durable enough to last for at least a few decades, it also increases the energy efficiency of the home.

Having energy efficient homes is a priority for homeowners around Pasadena, Arcadia and other cities in the San Gabriel Valley since summer temperatures regularly hit 100 degrees. Southern California is awash in sunshine so it would make sense to install solar, especially since California was the first state to make solar mandatory in new home construction.

The expense with solar, though, is greater than with traditional roofing. And even though asphalt shingles and tile are Old School they still create energy savings when installed properly.

A local roofing contractor who partners with solar installation companies, Thomas Garvey of Garvey Roofing in Monrovia, says the cost of installing a new roof with traditional roofing techniques is about one-third the cost of solar roofs.

“I call it a triple stack with proper ventilation,” says Garvey.

Roofing materials, including the underlayment, are made to reflect the sun’s ultraviolet rays.

Take a closer look at the materials and why they work, then compare with the many available options with solar roofing.

Heat Transference

Heat seeks out cooler spaces. So when the sun hits a roof, the materials absorb some of the heat and it’s transferred into the attic. A combination of highly reflective shingles, or tile, along with reflective underlayment and attic insulation greatly reduces absorption.

Proper ventilation allows air to circulate to reduce heat buildup.

Reflective Underlayment

Therma Sheet is a reflective barrier offering a “thermal break” between the sun and a home’s attic. A company in Pennsylvania providing insulation solutions,, describes using therma sheet as the difference between pouring coffee in a paper cup and pouring into a foam cup.

Why does the foam cup act protect your hand from the hot coffee more than the paper cup? It acts as a thermal break. Older paper or felt roofing didn’t have the reflective abilities and did little to protect a home from either heat gain or heat loss.

“Therma Sheet can be installed with metal roofing,” says Garvey, “and reflects up to 97% of radiant energy. When used with shingles or tile, the roof’s temperature can be 30 degrees cooler than when using regular felt.”

UV Protection in Shingles and Tile

Most roofs that you’ll see around the San Gabriel Valley are covered with multi-dimensional asphalt shingles. They’re manufactured to comply with the Title 24 demands of the California Energy Commission.

The shingles have granules as a coating that eventually degrade and wear off after many years. You’ll notice them in the gutter. UV protection is layered throughout multi-dimensional shingles so they’re the first line of defense against the sun heating up the home.

Tile manufacturers also ensure their tile products comply with Title 24. Some manufacturers, like Eagle Roofing, also note the weight of tile has thermal properties that are better than asphalt.

Technology keeps improving so the roofs stay cool.

There’s a collective benefit to homes in neighborhoods like Temple City or San Gabriel with cool roofs. It reduces the urban heat island effect. The Cool Roof Rating Council notes that’s “a concentration of buildings and roofs…in urban environments that absorb heat during the day and can’t cool back down to a baseline temperature overnight.”

What About Solar?

In California, reaching the goal of having one million solar roofs took 13 years. To celebrate the milestone in December 2019, Arnold Schwarzenegger, tweeted that politicians should make bold policies that outlast their time in office.

Solar Incentive Programs

Homeowners no longer need “direct incentives” for solar since equipment has dropped in price, notes the California Public Utilities Commission. The original California Solar Initiative program ended in December 2016.

Prices for solar fell 45% from 2015 to 2020, according to the Solar Energy Industries Association (SEIA).

Other incentive programs include $54 million to provide solar incentives to low income single family housing (SASH) program and another $54 million for multifamily low income housing.

California leads the U.S. in solar distribution with 1.1 million projects. A complete look at the results of programs is available through California Distributed Generation Statistics.

Solar Roofing Options

Tesla made a breakthrough in solar roofing with glass tiles that look like traditional roofing tiles. The cutting-edge company is now competing with traditional shingle manufacturers GAF and CertainTeed.

The Bigger Solar Picture in California

The Golden State needs the golden rays from the sun more than ever.

California’s last nuclear energy plant, Diablo Canyon, is scheduled to shut down by 2025. And though natural gas is currently in use, the state is aiming to eliminate carbon emissions by 2045.

Solar accounts for 20% of the state’s electric power, but is this form of renewable energy ready to power the state’s needs?

During August 2020 there was a series of regional rolling blackouts as temperatures hit triple digits. With solar power, when the sun goes down at night, so does the energy supply.

So batteries are needed to keep the lights on, but they’re in short supply as covered in an article on Green Tech, “Western Heatwave Tests California’s Clean Grid Transition.”

Georgia-based Southern Power will be retrofitting two of its solar farms in Kern County and Fresno County and has two 20-year purchase agreements with Southern California Edison.

Yet, California remains the nation’s number one solar market with more than 2,000 companies including manufacturers and installers that employ 74,255 people.

The SEIA claims there’s enough solar power to light up 7.8 million homes.

At-Home Solar

Homeowners who want to power cell phones and laptops can purchase solar panels through the big box retailers or specialty stores that soak the sun during the day so they can charge at night. Solar lamps for camping can also be used as substitutes for night lamps in hallways and bedrooms.

Solar nights are widely used instead of battery-operated lights to enhance walkways and patios at night.

So circling back to the top of the house, what’s a homeowner to do?

Solar roofs may work well and save money in the long-term, but an independent roofing company says save the expense, go with a traditional roof, and still save money and energy.

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I interview entrepreneurs, and dig into the news around Southern California, giving a voice to business owners, artists and more. I also co-write the thriller novel series Tom Stone Detective Stories.

Pasadena, CA

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