Tesla recently announced that its Gigafactory, which will produce electric car batteries, will be located near Reno Nevada. More interesting to me, being an engineer and renewable energy advocate, is Tesla’s commitment to renewable energy. In his press conference, Elon Musk stated that the factory will produce all of its own energy using a combination of solar, wind, and geothermal. That’s a tall order, so let’s look at the numbers to see how feasible that is.
The factory is expected to be 10 million square feet (about 929,000 square meters), sitting on nearly a thousand acres of land. Tesla’s drawings show the plant covered in solar panels with a field of wind turbines in the distance. Musk said that the factory would be aligned with true north so equipment could be located with GPS and so the solar panels would be aligned with true south for maximum production. Although the picture shows panels on the roof, there’s a lot of land available for a ground mounted array and/or more turbines. The numbers don’t lie. The site could realistically produce more than 2900 MWh of renewable electricity each day … 20% more than it needs. These are conservative estimates on production and worst-case estimates on consumption, and it’s clear that there’s enough renewable energy to run the plant with some to spare.
In other words, you might produce 2400 MWh per day, but that doesn’t mean you’ll always have 100 MW available at any given instant. Sometimes you’ll generate more, other times less. Obviously there will be no solar production at night and less wind production on calm days. To be fully off-grid, Tesla will need some form of storage. Tesla is probably shooting for more than the EV market; it seems logical for them to be looking into grid-level storage as well. What better way to showcase that than to include Li-ion batteries for on-site storage?
But that’s a lot of batteries, the plant isn’t built yet, and the factory needs to produce enough batteries in time for Tesla’s planned rollout of their newest car. My guess is that they won’t be off-grid for a while. Instead, they’ll be grid-tied and take advantage of net-metering, with storage as a future possibility. Either way, the Gigafactory will be a net-zero energy facility that should offer plenty of lessons on energy-efficient building construction and management.