The article is saying that if we built more transmission lines, or increased storage capacity, or had localized pricing, that more of the power generated would get used, and we wouldn't need to turn on the fossil-powered plants as much.
More wind wasted is precisely equal to more fossil fuel burnt right now.
Further, the article described why simply building more production doesn't solve things, because most of it would be built in Scotland, and we wouldn't be able to bring in any more power into the grid where it's needed then we do now.