South Australia has rolling blackouts in the summers when the coal "peaker plants" come online, and it takes 30-45 minutes in some cases for them to come online during a surge in demand due to blackouts. The government turned to Tesla to install (at the time) the biggest industrial battery in the world at 100MW / 129MWh and it is really working. Here is some info on it with some details (electrek is a Tesla fanboi site, but the reporting is accurate):

https://electrek.co/2018/09/24/tesla-powerpack-battery-austr...