At 30 % production of its stated capacity worldwide for wind it certainly underperforms and is spasmodic and unpredictable.
Sadly this means for every Gigawatt of intermittent and expensive wind one requires a corresponding amount of baseline gas or coal or hydro.
Offshore wind is increasingly expensive to build (Australia can`t economically produce wind towers because our electricity costs so high) and has a short subsidized life of about 22 years before rebuilding or scrapping.
Hence the correct term is replaceables.
Forrest`s dreams for hydrogen and renewables depend heavily on taxpayer subsidies.