"The film presents the story of the "war of the currents" between electricity titans Thomas Edison, and partners George Westinghouse and Nikola Tesla, which determined whose electrical system would power the modern world. "
It was delayed because of various issues with the production/distribution company; will be interesting to see what it's like. I fear a massive degree of 'artistic licence' and "dramatisation" will be involved.
See
https://en.wikipedia.org/wiki/The_Current_War for more info