Just after a majority of Tesla Motors tsla shareholders approved plans for the all-electric automaker to acquire solar energy firm SolarCity scty , Tesla CEO Elon Musk dropped one of his famous bombshells, this time about the company’s new solar roof product.

He told them that the company’s new roof would actually cost less than traditional rooftop shingles to make and install, according to Bloomberg.

“Electricity is just a bonus,” the billionaire told the crowd.

“So the basic proposition will be: Would you like a roof that looks better than a normal roof, lasts twice as long, costs less and—by the way—generates electricity?” Musk asked. “Why would you get anything else?”

While Tesla’s solar shingles are expected to still be considered a premium product at rollout, Bloomberg reports that the company expects they would incur lower production costs than traditional roof tiles. A large part of these savings stem from the carmaker’s anticipation that its roofing, manufactured by Tesla’s new automotive and solar glass division, would be lighter and easier to ship, thus reducing costs on breakage and transportation. (Read Fortune’s exclusive look at Tesla and SolarCity’s battery solar farm here.)

First unveiled at a Tesla event on Oct. 28 to great fanfare, the roofing material jointly developed by the carmaker and SolarCity would look just like any other premium roof tiles, while doubling as solar panels for power generation.

The shingles would reportedly feature tempered glass made by Tesla, a new solar film from 3M mmm specifically designed for this project, as well as solar power technology jointly developed by Tesla, SolarCity and Panasonic. The idea is to make solar-paneled roofs “as appealing as electric cars,” Musk said at the event.

Read More: Here Are Important New Details About Tesla’s Solar Roof

Tesla’s merger with SolarCity was approved “overwhelmingly” by an 85% majority of unaffiliated shareholders, according to the company. Growing concerns over potential safety issues related to its touted Autopilot driver-assistance feature, as well as uncertainty over federal tax breaks for electric cars under the incoming U.S. administration, has left the automaker in a tough spot this year, according to Reuters—sending its stock price tumbling by almost 20% this year.

For more on the Tesla-SolarCity deal, watch Fortune’s video:

After merging with SolarCity, of which Musk is the largest single shareholder, Tesla now has business all the way from solar electricity generation to batteries and electric cars. Elon Musk is also the CEO of the private space exploration company SpaceX.