Homer Electric Association (HEA) recently launched a large battery energy storage system (BESS) at its Soldotna Generation and Substation Facility in Soldotna, Alaska, using a battery system provided by Tesla.
It consists of 37 Tesla Megapack containers (52,000 pounds / 23,587 kg each), and according to HEA, it has a power output of up to 46.5 MW.
The battery capacity is estimated at 93 MWh, which means that once fully charged, it theoretically would be able to work at full power for two hours (or proportionally longer at lower power). Of course, we know that at a low state of charge, the power output usually happens to be limited.