Would it not be easier and more efficient...
to use that excess energy to turn water into steam and store the steam instead? Certain railroad operations used to use what they called a "fireless locomotive" where a coal-fired steam energy plant would charge a huge thermos bottle (oddball-looking boiler) on a locomotive and get from 8 to 10 hours of functional yard-switching operations out of that locomotive before it needed recharging. It wouldn't be that difficult to use a similar process to store steam created by those wind turbines' excess electricity and use it to drive more highly-efficient steam turbines during the morning surge and maybe even balance some of the summertime air conditioning load.
