I found an interesting video from Fully Charged, but one that doesn't fit into the usual forum threads, so I figured to make a new thread to host videos like the one below here. Enjoy!

It's basically a massive battery and a fantastic idea, pump the water up at night using wind power then make renewable energy in the day.

Who said batteries are no good 

Dave this would have fitted nicely in our Rethinking Electricity thread.

You know what? You're right. Oops?

Been there, seen that. 

I've only been to the main visitors centre at this place. Not done the tour through the tunnels. A big electricity capacitor (in essence).

It's near Mt Snowdon if you fancy a challenging walk (why I was in the area).