They are excessively profiting for the current very high electricity prices. This is undeserved and should be used to support the price at other times.
Oil generally isn’t used to generate electricity because it’s not cost effective.
The European winter started early in some parts, and electricity hasn't been as available as expected. Lots of people have turned off their electric heaters and heat with fuel oil in order to reduce costs. Several older plants have also been firee up to cover for off-line nuclear reactors and gas turbines.