Yep agree with the Geothermal to an extent. However I managed to get hold of a professor who lectured in the subject when I worked at UOL. He mentioned quite a few things which reduce the benefit, although nothing which could not be worked around over time.
Water is the big one we are not doing and they simply won't do it. Perhaps that will change over time when they realise that they have painted themselves into a corner.
As for Nuclear, we're not doing what we could. 4x Hinckley Point C and we could well exceed our current Nuclear output. The design is far larger in terms of power output.
My take is they won't get their act together until their nose is hard on the grindstone. We are a long way from that yet.