The current energy deregulation in the EU involves forcing utilities to trade electricity in a spot market, that treats the on-demand production of conventional power plants and the random and unpredictable production of solar and wind, as if it's completely equivalent. Of course, that's a fairly effective way to promote solar, as it's far more intrusive than conventional renewable mandates.
As far as I can see, "deregulation" means, "we regulate far more aggressively than before, but there's now a market in there where Wall Street types can make money".
The California case also forced utilities to trade electricity in a spot market. These markets always seem oriented towards purchasing power rather than capacity, which strikes me as odd. Power companies need committed capacity, because they need to have reserves of power. Sure, buying electricity that no one else is using makes sense, but because demand is comparatively inelastic, it's just crazy to have that be how companies ensure they have sufficient capacity.
https://en.m.wikipedia.org/wiki/Enron
https://en.m.wikipedia.org/wiki/2000%E2%80%932001_California...
Deregulating an industry to achieve a specific goal is certainly one approach.
Don't really trust something advocating for deregulated energy markets to not mention the elephant in the room.