That's about seven times larger than any other rooftop installation in the world. (For comparison, the current largest installation on a single roof is a 42-acre, 11.5-MW solar farm on the Dera Baba Jaimal Singh in Beas, India.) Thanks in large part to this solar power system, Tesla says the GF1 won't directly consume any fossil fuels. The factory will be able to store excess energy in Tesla's own Powerpack batteries for use when the sun isn't shining. It's likely that Tesla will also be using its own photovoltaic panels, thanks to its acquisition of SolarCity.
Additionally, the Gigafactory will use a closed-loop system to save water, will heat its factory using waste heat – a byproduct of battery manufacturing – and recycle batteries onsite. A document given to investors also outlines how Tesla is lowering operational costs and the cost of cells and batteries, for which production recently began. Tesla says GF1 will have 35 GWh of annual cell production capacity and 50 GWh of battery production capacity by the end of its current construction phase.