Tesla is going to focus its efforts on the Solar Roof for the coming year, CEO Elon Musk told an audience Thursday. The company’s energy-collecting tiles, which look like a standard roof to the untrained eye, have wowed onlookers with their sleek design but have so far only made their way to a handful of houses. Based on Musk’s comments, that’s all about to change.

“This is definitely going to be the year of the Solar Roof and Powerwall,” Musk said during the company’s unveiling of the Tesla Model Y entry-level compact SUV at the Tesla Design Studio in Hawthorne, California. “Because of the extreme challenges with the Model 3 production, we had to basically allocate all resources to Model 3 production because otherwise, we were going to die.”

Musk explained that these efforts will “ultimately be really critical for transitioning the world to sustainable energy.” Solar panels harness sunlight for clean energy, while batteries store the power for use at all times.

“Solar plus battery plus electric vehicles, we have a fully sustainable future,” Musk said. “That’s a future you can feel really excited and optimistic about. I think that really matters.”

The Tesla Solar Roof Tesla

The issues from last year that Musk is referring to revolve around the Tesla Model 3, the entry-level sedan that entered production in July 2017. Tesla struggled to produce enough cars to work through a backlog of nearly 500,000 orders, as the company only produced around 2,000 premium Model S and X vehicles per week before its introduction. Tesla eventually reached a weekly Model 3 production rate of 5,000 in July 2018, resulting in 7,000 cars total, but the chaotic stretch to reach that figures led to Tesla facing a “severe threat of death.” Musk said on Thursday that 2018 “felt like probably aging five years in one.”

That left the solar roof on the back burner. Musk demonstrated the roof in November 2016 as part of an integrated home of the future, with a battery storing energy and a Model 3 charging in the garage. Tesla installed a smattering of roofs for California residents like Amanda Tobler and Tri Huynh in early 2018, but the Model 3 left other projects without enough power cells to fulfill orders.

Musk said on Thursday that the team can “finally allocate engineering attention” to solar projects. This echoes his statements in the third-quarter earnings call, where he said “we also start getting into volume production of the Solar Roof next year.”

Early impressions paint a warm picture of the roof. Tobler’s 2,000-square-foot roof cost around $50,000 once the federal solar investment tax credit is factored in, at a rate of $42 per square foot of solar tiles, $11 per square foot of dummy tiles, and a mix of 40 percent solar to non-solar tiles. This produces 9.85 kilowatts of power. Tobler told Inverse that “I wouldn’t hesitate to do it again.”

Musk also stated that the company will continue its efforts with the business-focused Powerpack. The company has delivered over 1.5 gigawatt-hours of energy in over 30 countries. It completed the world’s largest lithium-ion battery in South Australia in 2017 at 100 megawatts, and now plans to build a gigawatt-hour system in Southern California.

While last year may have looked dark for Tesla, the sun may be about to start shining on more solar roofs than ever.