A close up of white BESS.  They are set on concrete and there is a thick layer of gravel below.  They sky above is a grayish white - almost the same color as the BESS units. The Tesla logo is on the first unit you see in the top left.

Firestone (BESS)

Partners:
Tesla
United Power
ENGIE

This Battery Energy Storage System (BESS) is projected to save United Power as much as $1 million annually by storing energy and releasing it during peak demand times.

The batteries supplied by Tesla will have a storage capacity of 16MW hrs — enough to simultaneously power 600 to 700 homes. These batteries are larger versions of the lithium ion batteries found in Tesla's electric vehicles.