If it is that easy, show me one example where any of those technologies have been deployed at a scale required for even a day usage of an entire nation?
Truth is, its hard to do. We will get there, but not sufficiently fast for where we need, hence the continuing need for nuclear.
Not a single one is an example of what I asked.
Maybe the solution for the UK is to create mountainous rivers or move the country to techtonically active parts of the planet.