The have a 250kw SolarPV system which generates about 250,000kwh per
annum.


250kW is a miniscule drop in an ocean at 0.00025 GW. But even that drop, when
added with the other dropsn needs some other form of dispatchable generation
capacity to back it up when the sun goes behind a cloud or simply because
it's dark. The costs of this back up capacity is not bourn by the wind mills
or solar PV that makes the grid need it.

Cheers Dave.

Nr Garrigill, Cumbria. 421m ASL.


It is a very small drop, but get a lot of drops and you can start a Boscastle!

I completely take your point about the need for backup. It is however better to have a carbon emitting station working on reduced output for much of the time, only peaking when 'renewable' input is low, than having it working flat out all the time. (at least from an environmental perspective)

The need for backup reduces somewhat if you have a wide range of widely spread renewable options. Wave power hasn't been mentioned yet, but there are a number of projects, including the Wave Hub at Hayle. It currently only has a max capacity of 20mw, but this is easily upgradeable, as the cables come ashore at the old Hayle coal fired station, so much of the infrastructure to transport the power is in place. http://www.wavehub.co.uk/about/ (There are few days a year when there is little swell off west Cornwall, there's been a lovely wave for much of the time recently http://www.cornwallcam.co..uk/

I actually don't think our opinions are massively apart, just looking at things from a rather different angle.

Graham
Penzance (just 19m asl.)