> crisis in the UK of negative electricity prices

Yes. And this is often touted as "renewable now cheaper than..."

But those decreasing prices are not actually a sign that renewable energy is cheaper to produce, but that it is actually useless and thus worthless at certain times.

Now that may entail some business opportunities, but it's not that simple. For example most industrial applications can't easily be turned on or off as the wind blows and the sun shines.