Can be made with excess wind energy.
So if a supplier can use that excess power to generate another product which can be sold, that's a win-win for them: they won't have to pay the penalty for oversupplying the grid, and they can sell the generated hydrogen for additional profit.
[1] https://www.cleanenergywire.org/factsheets/why-power-prices-...
So if you're only going to run it when power costs are negative, you're amortizing the capital costs over running the plant for the equivalent of six days a year in 2017 Germany.
But parent's link didn't really back up their claims, and concerns about capital efficiency for infrequently used plants are valid.
There are some strong assumptions behind this article, it chooses the following scenario: Wind + Solar + H2 for seasonal storage. And then proceeds to dismantle it. But nobody said this has to be the scenario.
I think it's far more likely something like: Wind + Solar + hopefully clean base load (e.g. Nuclear) + Hydro + Hydro storage + Lithium storage + H2 storage for transport (planes, trains, ships) + H2 storage for seasonal purposes
Fact of the matter is, there is no clean alternative to H2 (at the moment) for large transport vehicles (i.e. cargo shipping, planes, trucks) so unless you are willing to keep using carbon based fuels for these purposes you are stuck with H2.