Today, if you add a rooftop solar system to your house, the installers will bolt a metal rack through your existing roof and into the rafters of your house. Then the solar panels are attached to the frame. But there are other options available that simply replace your roof entirely with shingles that make electrical power from sunlight. Elon Musk has stated he expects such systems to be available from SolarCity shortly. There are companies that are already in the game, as he noted, but he says Tesla’s/SolarCity’s system will be much better. Here’s a look at what’s out there now.

Dow Chemical Powerhouse Solar Shingles

On the market since 2010, the sleek plastic-coated Dow Powerhouse shingles demonstrate just how far the industry has come in 6 short years. The shingles are only 13% efficient — new solar panels are almost twice as efficient. They are also expensive at $10,000 for 1,000 square feet of coverage. The cost of solar panels has dropped by two thirds since 2010. A stunning technological breakthrough at the time, they are hopelessly outdated today.

SRS Energy’s Solé Power Tiles

In 2009, SRS Energy launched a product that promised to make installation a breeze. Its curved Solé Power Tiles were designed to mimic the shape of interlocking mission-style clay or cement shingles. That allowed them to be easily integrated with the tile roofs so popular in California and other sunny climes.

SolTech Energy’s Icy Glass Solar Heat Shingles

Sweden-based SolTech Energy created an example of the best of both worlds with its translucent glass tiles. Instead of the traditional red clay color of tile roofs, these shingles looked like a roof encased in a thick coating of ice. They captured solar heat and used it to warm air beneath the tiles. That heat is then used to heat water and warm the home during the winter. The company claims the roof tiles can produce about 350 kWh of heat per 10 square feet, depending on weather conditions and the angle of the roof.

SunTegra’s Solar Roof Systems

Elon Musk promises that SolarCity will create a roof that has solar cells built in. New York–based SunTegra Solar Roof Systems is into that game. The company’s integrated solar systems have been installed on homes in the northeastern United States and in California, two prime spots for making the most of the sun’s energy. SunTegra’s solar roof is available in tiles or shingles and costs about 15% more than traditional solar panels. But the manufacturer claims its product is just as durable and weather resistant as conventional shingles. A 15% premium for a product that lasts twice as long might make for a wise investment.

SolarPod Grid Tied Requires No Holes

For ease of installation, the SolarPod might be the best product on the market. It can be mounted to any type of roof and requires no drilling of holes. SolarPod’s Grid Tied solar array is an integrated and modular plug-and-play solar power system that includes a prefabricated frame made from corrosion resistant steel. Because the frame floats above the existing roof, it’s also easy to adjust the angle of the solar array to capture the maximum amount of sunlight for that particular location, thereby increasing solar energy production.

SoloPower on a Roll

SoloPower has developed a flexible solar panel that can be unfurled as easily as a carpet. The thin-film solar panels, linked together in long strips, boast an 11% energy conversion rate and a smooth installation process, thanks to their lightweight and flexible composition. In theory, the flexible solar panels could be unrolled right over the top of an existing roof, in any quantity desired, without the sort of expensive glass and aluminum frames required by most rooftop solar arrays. Although the desire for integrated solar roofs may drive innovation faster, it would be nice to see more flexible — and potentially portable — options hit the market as well.

Most people familiar with Elon Musk expect any system from SolarCity to be state of the art with cutting-edge technology. Expect whatever SolarCity comes up with to revolutionize the industry in much the same way that Tesla Motors has revolutionized the automobile business.

Remember, this was the original quote from Elon about the competition: “It’s a solar roof as opposed to a module on a roof. I think, this is really a fundamental part of achieving a differentiated product strategy – it’s not a beautiful roof that it is a solar roof, it’s not a thing on a roof, it is the roof. That’s … quite a difficult engineering challenge, and not something that is available really anywhere else that is at all good. I think this will be something that’s quite a standout. So one of the things I’m really very excited about the future.”

Also remember that Silevo produces high-efficiency solar PV. The examples above are relatively low-efficiency options.