Tesla seems to have done it pretty quickly for South Australia: https://electrek.co/2018/05/11/tesla-giant-battery-australia-reduced-grid-service-cost/ https:/

Tesla seems to have done it pretty quickly for South Australia: https://electrek.co/2018/05/11/tesla-giant-battery-australia-reduced-grid-service-cost/ https://electrek.co/2018/05/11/tesla-giant-battery-australia... Elon promised "Tesla will get the system installed and working 100 days from contract signature or it is free." And then had the entire thing connected and powering the South Australian power grid in just 63 days: https://www.theguardian.com/technology/2017/mar/10/elon-musk-i-can-fix-south-australia-power-network-in-100-days-or-its-free https://www.theguardian.com/technology/2017/mar/10/elon-musk... I'm fairly confident that 100 days is less than decades.