Find Out if Your Home Works for Rooftop Solar Panels     – CNET

Find Out if Your Home Works for Rooftop Solar Panels – CNET

It’s been a weird year for the solar industry, with incentives weakening in some places and longtime companies hitting financial trouble, but as long as energy prices continue to climb there may be a case for adding solar to your roof. The federal solar tax credit is pinned at 30% the cost of any solar system installed through 2032 and solar prices have fallen dramatically over the past decade.

Houses differ by the amount of sun they have available, their energy consumption, the local cost of electricity and the utility policies they’re subject to. Necessary repairs — like replacing your roof before attaching solar panels to it for 25 years — add cost and another consideration for the project.

We’ll break down the house-specific considerations and give you a clearer idea of whether your house is a good fit. If you’re looking for more home energy advice, take a look at how to save money and energy in a few smaller ways by adjusting your thermostat, turning off your lights and using your ceiling fan this winter.

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Does your roof work for solar?

If your roof is up to code, it should be able to handle the weight of a solar system with no problem, but your installer should double check before applying for permits. 

The roofing material is going to be more important. If your house is topped with common materials like asphalt shingles, concrete tiles or metal pro panel, you should have no problem. Less common materials like slate or clay might require an installer that specializes in your type of roof. 

According to Wyldon Fishman, founder of the New York Solar Energy Society, also consider the age of your roof. If your shingles were put on more than 15 years ago, they may be coming to the end of their life. You might want to consider replacing it before you cover it with panels meant to stay there for 25 years or longer. 

“Less than 15 or 20 years old and you might be able to slide by,” Fishman said. 

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If you’re not ready to put on a new roof and install solar panels at the same time, you might consider a ground-mounted system instead.

If you need a second opinion, a roofer can assess it as well.

How much sunlight do you get?

Imagine looking down on your roof from a hot air balloon drifting over your neighborhood. As you pass by your house (preferably you’d actually be drifting over your neighbor to the south), take note of how well you can see the entirety of your roof from different angles. Are there trees or other structures in the way? 

If it looks like your roof receives a lot of shade, a ground-mounted system or community solar might be better options for you. 

Fishman says to think twice before you start to fell trees to get maximum solar exposure.

Solar panels surrounded by trees.

Trees can affect how much electricity your solar panels produce.

Thianchai Sitthikongsak/Getty Images

“I would rather your house have a deciduous tree for passive solar cooling and heating in the winter (when it has no leaves), and to not discount ground-mounted,” Fishman said.

Also, don’t forget to consider how much room you actually have on your roof for panels, especially on the valuable south-facing side. (The east and west can be worthwhile too.) 

What is your local climate like?

You might imagine that solar only makes sense for people who live in the sun belt, but the truth is that modern solar systems can still generate energy even on cloudy days in most cases. The potential amount of electricity that you can harvest from your location basically depends on two main factors: your latitude and the climate.

Generally, the closer you are to the equator and the fewer clouds you have, the more you can generate. These are the main factors that go into calculating the expected amount of peak sun hours you should receive at your location. Peak sun hours are essentially the hours when the sunlight is intense enough to generate a kilowatt per square meter of surface area.

Peak sun hours is just one factor to consider in deciding what kind of solar system you might want. Other climate considerations might include the amount of snow you receive in a year and if your panels will be accessible enough to clear.

Tips for assessing your own solar compatibility 

The odds are pretty good that there is some sort of solar solution out there that could be beneficial to you, whether it’s in the form of purchasing a system, leasing one, signing a power purchase agreement or looking into community solar. 

  • Determine the best location or locations for solar on your property based on shading.
  • If your roof is the best option, estimate how much life your current roof has left. If it’s less than 15 years, you may want to consider replacing it before adding solar. 
  • Check with a solar installer to see if they can work with the roofing material on your house.
  • Check in with online solar estimators like Google’s Project Sunroof or the National Renewable Energy Lab’s PVWatts Calculator. With just your address, you can get an estimate of how much solar your roof can accommodate, how much energy a hypothetical solar array could produce and how much you could save in the long term. Some solar companies have their own estimators.
  • Estimate the amount of peak sun hours for your location as part of the larger calculation of how much economic sense a solar system makes for your situation.
  • Get multiple quotes from solar installers and plug those numbers into that calculation before making a final decision.

Which kind of solar makes sense?

According to Gilbert Michaud, assistant professor of environmental policy at Loyola University Chicago, the utility savings from most solar systems pay for the system itself in about 10 years. 

“Then you have decades of free electricity after that,” he said, adding that lots of younger people who move around frequently might be hesitant. He notes that a system is also likely to increase property values. 

“Even if you don’t end up staying there it could still end up being a smart decision,” he said.

If you decide that solar panels make sense for your house, next you’ll need to determine if you want to make the energy you generate available to the grid, store it in batteries for your own use or a hybrid of both.

Fishman said there’s no instance she can think of in which adding batteries to a system — whether it’s tied to the grid or not — is a bad decision, but she acknowledges that they remain one of the more expensive components in any solar system.

Both Michaud and Fishman agree that if panels on your house just don’t make sense, check into community solar programsinstead.

Eric Mack

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