Looking very briefly at the referenced report, it is saying what needs to be done for UK to get to net zero carbon emissions by 2050 using existing technology. It seems quite lightweight, all I could see about electricity generational was “Electricity sector and infrastructure: Absolute Zero requires a 3x expansion in non-emitting electricity generation, storage, distribution and load balancing“
Given what it’s terms of reference are, it is probably about right. It is more or less what we would have to do to reach the targets we are aiming for using current technology.
As for the original article, it is just sensationalist nonsense.