Tesla has officially opened its lithium-ion battery cell "gigafactory," but the company still has substantial work to do.
It must ramp up cell production in order to help meet CEO Elon Musk's goal of producing 500,000 electric cars per year by 2018—and use renewable-energy sources to do it.
The original renderings of the gigafactory included a roof covered with solar panels, and that's apparently something Tesla still intends to pursue.
During a recent talk at the nearby University of Nevada in Reno, Tesla Motors CTO JB Straubel said the gigafactory will rely almost entirely on renewable energy, according to CleanTechnica.
In a Q&A session that was part of the talk, Straubel said Tesla wants to make the factory a "net-zero facility."
"Net zero" refers to buildings that generate as much energy as they use.
Computer-generated image of proposed Tesla Motors Gigafactory
To achieve that, Tesla plans to cover the gigafactory's roof in solar panels, Straubel said, as seen in the renderings.
He said the gigafactory was "designed from the beginning with solar in mind," with a roof free of unnecessary equipment that might hinder the installation of solar panels.
Despite the factory's massive size (debate over how big it will ultimately be continues), Straubel said the roof alone will not provide space for enough panels to meet power needs.
So Tesla plans to place solar panels in the hills surrounding the factory as well, he said.
While none of the solar panels have been installed so far, Tesla has made a design decision that commits it to using renewable energy.
The company elected not to build a natural-gas pipeline to the factory, as a way to "force the issue" of using renewable energy, Straubel said.
Tour of Tesla battery gigafactory for invited owners, Reno, Nevada, July 2016
Tesla now has no options but to develop alternatives to fossil fuels for the gigafactory, he noted.
In addition to use of renewable-energy sources, the gigafactory was built with a focus on energy efficiency.
Energy savings could be as high as 80 to 90 percent compared to previous cell manufacturing, according to retired engineer and Tesla owner Eric Jackson, who visited the factory for the recent grand opening.
Chemicals used to manufacture cells are kept in a closed system, allowing materials to be reused, and minimizing potential air pollution.
Tesla needs to ramp up cell production at the gigafactory quickly in order to support production of its 215-mile, $35,000 Model 3.
That car is supposed to enter production just 12 to 18 months from now, and Musk expects to be selling half a million of them by 2018.