The following submission statement was provided by /u/lughnasadh:

Submission Statement

As OP notes, the project is “getting closer and closer to having something with a very stable output profile that we traditionally think of being what’s capable with a fuel-based generation power plant.”

It's an interesting question as to just how much storage a 100% renewables system would need to provide all the backup needed to supply continuous power.

A recent study that did this for Germany points out that the issue here is that most of the time that storage capacity would be small relative to total generating capacity, but that occasionally (concurrent long periods of low wind) there would be a need for very high storage reserves to be called upon.

It suggested batteries for the bulk of the normal storage requirements, and hydrogen stored in salt caverns for the rarer times much more storage needs to be called on.

Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/xtrzq1/the_uss_largest_ever_combined_windsolarbattery/iqrg8z5/