Well, in the UK calm days ARE an issue. Because they don't have...

Well, in the UK calm days ARE an issue. Because they don't have Diesel back-up generators which would be expensive to run. And ALL the micro-grid solutions listed in your link have Diesel generators, or the solution isn't actually a microgrid anyway. ABB are definitely not providing microgrids in all types of environments and for all types of purposes. Didn't see a single Cornish village listed.

Yes, the SW of England an north of Scotland have exposure to atlantic swells but on calm days those swells are, from memory, less than a metre.