I'm not sure I'm quite following your train of thought, is the implication that offshore wind farms are going to have a greater negative effect on the planet than our current energy mix? I don't think anyone who works in this field from a technical level has an opinion that you can plonk down a solar panel farm and have a net zero effect on the local environment, but there's a bunch of examples of where there's been an accidental positive feedback loop that's occurred with solar panels in certain regions. This is specifically not cited by the article.

Apologies for the lack of clarity in that sentence, there is a recognition that intermittence is one of the biggest challenges that is currently faced by the power grid in it's current form. But we actually have ways to get around this currently, it's just very rare for them to be put in place (there's also some large omissions from the current state of the South Australian power grid that is mentioned).

We still have to explore for coal as an industry, too. So should we presume that the moment our current coal reserves run out that this is the end of all coal power?

No.

Anyways, no-one has really made a case for renewables being a silver-bullet who works in energy policy, I would not be inclined to use this article as a touchstone for the problems the industry faces.