I wrote this article. Happy to answer any questions.
Why do such articles not distinguish between the cheapest and that which is the cheapest? Including this one.
One might reasonably make a long-term policy for new power plants such as "40% of new power from the cheapest source, 20% each from x, y and z". If x is cheapest in a particular year then gets 60%, and articles tend to describe it as if the preference were "60% x, 20% each from y and z", see? Why is that?