Tesla begins installation of world’s largest rooftop PV system

Tesla appears to have begun installing the world’s largest rooftop PV system. Images shown on BuildingTesla.com (found via Electrek) show what looks like a solar panel installation just beginning.

pv magazine has sent an email to Tesla asking for comment and will update once we have new information.

At first glance, the “70MW” value on a 43 acre rooftop seems like a strong number. The structure is projected to have a 1.9 million square foot footprint. Roughly, 100,000 PV modules – if lain flat, and fairly tight – would fill that space up. A high-efficiency product from solar panel partner, Panasonic at 325W would allow for a 32.5MW installation, under half of the projected 70 MW project.

Per Tesla’s description of the project:

GF1 is an all-electric factory with no fossil fuels (natural gas or petroleum) directly consumed. We will be using 100% sustainable energy through a combination of a 70 MW solar rooftop array and solar ground installations. The solar rooftop array is ~7x larger than the largest rooftop solar system installed today.

Reading into that quote, we see an out for the rooftop being less than 70 MW – in combination with a ground installation. A rule of thumb for ground based projects I’ve been involved in is about 1 MW per 4-5 acres – putting the project potential at a much smaller 8-11 MW potential.

The current world’s largest PV rooftop installation on a single roof is an 11.5 MW plant in India on a 42 acre rooftop. That rooftop is part of a larger 19.5 MW, 82-acre project spread across eight rooftops.