https://www.reuters.com/article/us-australia-power-tesla/tesla-switches-on-giant-battery-to-shore-up-australias-grid-idUSKBN1DV3VR

Tesla Inc switched on the world's biggest lithium ion battery on Friday in time to feed Australia's shaky power grid for the first day of summer, meeting a promise by Elon Musk to build it in 100 days or give it free.