But due to the British grid system it can be produced anywhere and, unlike the USA, it will still be useful to the National Grid.
This is one of the biggest fallacies of the "renewable energy" brigade.
The assumption that you can just pump energy into the grid whenever it's available and that it will "make a difference". Shows no understanding of the big picture of power generation and distribution.
As said, frequency regulation on the grid requires that producers and consumers are carefully balanced. Throw that off when the sun comes out or the wind blows and the result is that you have less predictability and therefore need to keep more expensive, inefficient standby capacity available to fill in the gaps.
We're not talking about large scale, efficient, modern coal plants here - they can't respond quickly to changes in demand.
You need gas turbine generation and other much more dirty technologies to cope with this unpredictability.
In addition, changing the load on plant greatly increases the fatiguing due to thermal cycling, etc. So, guess what? Suppliers are not going to splash out on decent, efficient machines for standby generation. They are going to us old, dirty plant that is expendable or nearing the end of its' life anyway.
End result? Adding unpredictable, if "green", sources of energy to the current grid is probably more damaging to the environment.
To make use of renewables, we need a grid where demand can be managed to a much greater degree, using smart appliances or pumped storage, etc. Might as well not build another wind turbine until this is the case IMHO.
Kevin