@Ian - Your argument works, but is based on the fact that someone else at the end of the pipe, wire or cable is ready to consume that energy. And that that pipe, wire or cable is inside a reasonable range to be able to use it - there is a limit to how far you can "transport" electricity. Otherwise it is wasted.
Unfortunately also at the times when Solar (and indeed Wind) are being productive the demand isn't there.
We could store it of course - the Spanish company I mentioned in a previous post (I think Neil Blanchard mentioned it too but maybe in a different thread) worked out a method of using salt piles to store energy as heat.
Other people have experimented with giant batteries and we have schemes (dating from the 1950s) such as Hydro produced by dams with two reservoirs - the upper one being filled by pumping using excess energy at low peak times. But these have limits in terms of the energy stored vs costs, and potential energy release vs the energy originally produced.
A conventional power station can be stoked up and added to the grid as and when the demand is needed. Even if you take into account the polution of this solution and the resources required, having something you can just pop-on when needed seems far more efficient that making too much of something and storing it and watch it decline until you decide you need it.
Argument - An idling power station does consume energy, but nuclear (at least) makes its own.
The argument the other way is of course that you produced that energy for 'free' via renewables.
But when I check my power bill and find a 5-10% levy added to fund this so called "competitive" energy source, and when I read things like
wind farms being paid not to produce anything then I wonder if that energy is really all that "free" in the first place.
The debate of course is where the 'free' part comes from and what we include in the costs of conventional (including nuclear) energy. Thats tetchy and starts arguments about politics, so I'm not going there.
I remain optimistic about renewables and would agree with an investment in fundamental research into how this can be achieved but again I object to people in the UK being forced to decide between food and heat/light just so someone can make a lot of money from an artificial levy and subsidy. But this takes time. In Scotland we have research into wave energy, it has been going for 30-40 years now and is just about making something useful. Thats the kind of long-term boring but basic research that gets some results.