Oct 18, 2015 By The Editors Of consumer Reports® 3 min read

Solar panels — also called photovoltaic (PV) cells — can reduce your monthly electric bill by 50 percent, says Consumer Reports.

No wonder rooftop solar capacity almost doubled from the beginning of 2013 to the end of 2014, according to the Energy Information Administration. Despite that growth, solar provides only a little more than 1 percent of total electric-generating capacity in the U.S. Going solar isn’t a slam dunk for everyone.

Consumer Reports answers these critical questions about solar power:

n Does my house have to be situated in a very sunny spot? The more sunshine you have, the more power your system can produce. But the amount you can save on your bills also depends on the price you pay for electricity and the available credits and other incentives from federal, state and local governments. Most panels are placed facing south, where they get the most exposure. Ideally, your solar panels shouldn’t be shaded by chimneys, trees or anything else on the rooftop.

n About how much power can I expect to get? Most systems can provide 25 to 100 percent of a homeowner’s electricity needs. Solar installers will be able to collect information about the amount of electricity you use, how much you pay for it and what you’ll save if you opt for different-sized systems.

n Is it possible to save up power to use at night or during a power outage? Disconnecting from the grid isn’t really practical yet. Though they are fairly pricey right now, you can have batteries installed along with the solar panels that allow you to store power generated during the day for use at night or at a later date.

n My area is prone to storms. Can hail and lightning damage solar panels? Better-quality solar panels have impact-resistant, tempered glass that can take a beating without damage. But that doesn’t mean you’ll have warranty coverage if a hailstone ruins a panel. Amend your homeowners insurance so that the cost to repair or replace solar equipment is covered for fire, impact and other damage.

n Will panels damage my roof? Properly installed panels should not cause any damage to your roof. In fact, the panels tend to protect the roofing materials they cover by shielding them from precipitation, light and heat. That said, a roof’s working life can range anywhere from 15 to 30 years, and a PV system’s service life can be upward of 25 years. So install the PV system on a roof with at least as long an expected life as that of the solar components. Consumer Reports notes that if you have sufficient land, you can have a ground-mount system installed out of view of the house.

n Aren’t these systems crazy expensive? Buying a system outright will probably save you the most money over time, but it requires a large up-front investment. The typical installation costs about $15,000 to $21,000 in the U.S., according to the Solar Energy Industries Association.

If you install a system before Dec. 31, 2016, you’re eligible for a federal tax credit equal to 30 percent of the amount you spend. So if you spend $18,000, you can slice $5,400 off of the federal taxes you owe. Some states and local governments provide additional incentives. State-by-state information on discounts is available at dsireusa.org. Be sure to ask your municipal office whether there are any local perks.

Solar panels are usually warrantied to last 20 to 25 years, and the systems often pay for themselves after five to 10 years, so you have the potential for free electricity for the rest of their lifetime.