Tesla, the company that produces electric cars and wall-mounted batteries, announced in October that it would begin manufacturing solar roofing tiles in 2017. Unlike the traditional panels that are designed to be mounted on top of an existing roof, these tiles are made of tempered glass and can completely replace the old roof.

The shingles will be available in several different styles, and all of them will be able to capture sunlight and turn it into electricity with the same efficiency as the traditional roof-mounted panels.

Aesthetics has much to do with the resurgence of solar power’s popularity. No longer is it required to attach panels the size of a pool table to your roof. Instead, in the past few years, solar-powered shingles that blend almost seamlessly with traditional roofing materials have replaced the large racks.

The system sounds exciting, but there are nine things to consider—both pro and con—if you’re thinking about solar installation for your roof:

1. Understand how solar shingles work

These systems are called “building-integrated photovoltaics,” and they combine solar cells with slate, metal, fiber-cement, even ­asphalt roofing. Electricity is generated when the sun strikes a semiconductor layer, typically crystalline silicon laminated to the shingle’s surface.

2. How much electricity can they generate?

While one solar shingle by itself doesn’t produce much power (between 13 and 63 watts), harnessing hundreds of square feet of them together can generate enough electricity to power an entire house. The shingles are installed over new or existing roof sheathing and are then tied in with your home’s electrical system.

3. Tax credits are available

Installing solar energy equipment in your home can qualify you for a credit equal to 30% of your total cost. The credit is available through the end of 2019. After that, the percentage steps down each year and then stops at the end of 2021.

Also, twenty-seven states and several cities offer additional incentives that can reduce pricing on solar equipment and roof installations even more.

4. Lower electric bills can be expected

Savings can be affected by the geographical and physical location of your house. Areas that get fewer days of sunlight or houses that are surrounded by trees won’t get the full benefit of the solar installation.

And while homes in sunnier states can collect more solar power than those in northern climates, the payback from solar is also strongly affected by local electric rates. “If you have a 2-kilowatt PV system in Albuquerque, New Mexico, it produces 25 percent more electricity than the same system in Boston,” says Noah Kaye, of the Solar Energy Industries Association. “But the savings are greater in Boston since electricity there costs so much more.”

5. Higher home value on resale

Another significant factor, often overlooked, is that solar shingles will increase the value of your home. If you decide to sell it, they also help your house sell faster and for more money than a similar property without a solar system.

The United States EPA, reporting in the Appraisal Journal, writes that for every dollar you save in annual utility costs, solar panels increase the value of your home by $20. Simple math calculations show that this can significantly add up. If your system saved you $1,000 a year on energy, the house could sell for $20,000 more on the resale market. In comparison to many other home renovations, solar can often recover more than 100% of the original cost. A 2011 study by the National Bureau of Economic Research similarly calculates that installing residential solar panels boosts home prices by 3-4%.

6. Solar installation: easier but expensive

The good news on solar installation is that it’s easier to install solar shingles than it is to install solar panels. In fact, regular roofing installers can take care of most of the work, but you’ll probably need the help of an electrician to set up the wiring and connect you to the grid.

On the downside, installing solar roof shingles comes with a high price tag. Despite technological innovations, a large installation can still cost anywhere from $10,000 to $20,000. But if the old roof shingles need to be replaced anyway, it could be more cost effective to install solar shingles than to replace the roof with traditional shingles and add roof-mounted solar panels.

Solar shingles can save time and money by using a single installation crew and a single product that provides both roofing and solar energy production.

7. Appearance is a matter of taste

As previously mentioned, one of the primary benefits of a solar shingle system is the visual appeal. Solar panels are bulky and stick out from the roof, while tiles are designed to match the existing roofing. Although solar shingles may not match all roofing correctly, they do blend in, creating a sleek appearance for most people.

On the other hand, while the stylish look of solar shingles is appealing to some, unless you intend to cover your entire roof with solar shingles, the contrast of the solar tiles against the traditional shingles might not suit others. Aesthetic preferences are a strong consideration before investing in solar.

8. Surprising durability

It seems counter intuitive to use glass as roofing material, but manufacturers are guaranteeing the tempered glass tiles for 15 years or longer.

CertainTeed, for example, claims that their Apollo II system has been tested and rated to withstand 250 pounds per square inch and winds of up to 110 miles per hour.

9. Decisions, decisions

If solar shingles are to be a sound investment for you, your house should have a roof with a southern exposure that is not blocked by trees.

The pitch (angle) of the roof also makes a difference. A steep pitch will not work efficiently. Your contractor will need to check the angle to confirm that your roof is suitable.

The condition of your existing roof will also play a part in your decision. Solar shingles can be blended in with your regular shingles, providing that the old ones are still in good shape. Otherwise, you will need to replace the entire roof.

Solar systems have made tremendous strides recently: Better aesthetics, shorter paybacks, and easier installations head the list. But the initial outlay may prohibitive for many. It’s a difficult decision and a very personal one. If you decide to go ahead, make sure that you hire experienced professionals to do the solar roof installation.