When it’s fully complete, Tesla’s Gigafactory in Sparks, Nevada, will be the largest building in the world, sprawling over 15 million square feet on a plot of land more than three times larger than Central Park. The building, which Elon Musk has called “the machine that builds the machine,” will eventually also be the first large-scale battery factory to run on 100% renewable energy. The roof, which was designed to accommodate solar power, includes a solar installation that will eventually include around 200,000 solar panels that can provide most of the building’s energy when paired with Tesla’s batteries.

When it’s finished, it will be the largest rooftop solar array in the world. Inside the factory, high-energy manufacturing processes that would normally be powered by natural gas have been redesigned to avoid fossil fuels by maximizing energy efficiency. Waste heat from equipment like compressors or high-temperature ovens can be used both to run the equipment efficiently and to help keep the factory warm in the winter. LED lights and a lighting system designed to reduce power use means that lighting the building can save 144 megawatt-hours of energy in a month versus traditional lighting setups (the equivalent, the company says, of the energy needed to drive a Model S 480,000 miles).

Tesla’s new factory has many more high-tech features that will make it the most advanced, energy-efficient factory in the world. To get an insider’s look into this crazy Nevada-based factory, check out this story from Adele Peters.