Lets see how well that theory goes up against recent history.
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Tesla to build world's biggest battery
https://www.telegraph.co.uk/technology/2017/07/07/tesla-buil...
Tesla mega-battery in Australia activated
https://www.bbc.co.uk/news/world-australia-42190358
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Hyundai Plans World’s Largest Grid Storage Battery In Korea
https://cleantechnica.com/2017/12/05/hyundai-plans-worlds-la...
Hyundai Electric completes world's largest ESS
http://komec.kr/eng/Board.asp?menucode=0503010000&mode=2&no=...
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I don't think Korea Zinc or the people of Adelaide are storing their power using public relations. I think, in reality, they had a battery delivered.