CNET también está disponible en español.

Ir a español

Don't show this again

HolidayBuyer's Guide
Smart Home

Find out if your house is a good candidate for solar energy

Sun, space and location can determine if your home can be updated with solar panels.

solar panel on home
Screenshot by Martin LaMonica/CNET

Saving money and the planet though solar energy has a lot of appeal. Not every home is the ideal candidate for a solar energy update, though. Here are some tips to help you decide if solar energy is a viable option for your home.

Check with Google's tool

According to the California Energy Commission, a solar system needs unobstructed access to the sun's rays for most or all of the day. The easiest way to check your home for solar viability is by typing your address into Google's Project Sunroof. I typed in one of Google's suggested home addresses and the tool told me the particular home gets 1,830 hours of usable sunlight per year and has 1,425 square feet available for solar panels. Using 3D modeling the home's roof and nearby trees it estimated that this home could save $8,000 when calculated with a 20-year lease.

Do the legwork yourself

Google's Sunroof is only available in limited areas, at the moment. If you live in an area it doesn't cover, you can still determine how much sun your home gets with just a few steps.

Nearby trees or buildings may block the sun. This could mean substantial loss in energy output. To find out if your roof gets full sun, simply go outside and check a few times throughout the day.

Next, find out how many days of sun your area of the country gets per year. An easy way to get a good estimate is by finding your location on solar maps provided by the National Renewable Energy Laboratory. If your home is in an area of the country that receives very little sun, you may not be able to go solar.

The ideal location for a solar unit is on south-facing roof that's flat and doesn't have obstructions such as chimney, vents or antennas. East and west facing roofs are also a good option because they get a lot of sun. If your only available roof area for solar panels are north-facing or you don't have much unobstructed room for panels, then your home may not be a good candidate.

Check to see if you have enough room for the panels you need

Now that you know the best places for panels, you need to see if you have enough space for them. This will give you a rough estimate.

Take look at your electricity bill to see how many kilowatts on average your home uses each month. Then, measure your available roof space. The average solar panel is around 15 square feet and puts out about 190 watts of electricity per day. Figure out how many panels will fit in your available roof space by dividing your square footage by 15. Then multiply the number of panels by 190 watts and then multiply that number by 30.

Does the number match up with amount of electricity you use per month? If not, you can still use solar panels to supplement your energy usage.

Get an expert opinion

If you feel confident that your home is a good candidate, it is time to contact a professional. Though you can find a rough estimate of the size of solar system you need with the equation above, an exact number depends on a lot of different factors that most people won't be able to figure out on their own. A professional solar installer can also determine what kind of system would work best for your needs.

CNET's affiliate listing of solar companies and resources can be found here.