In article , Johnny B Good
wrote:
On Tue, 17 May 2016 08:12:18 +0100, Brian Gaff wrote:

Can there be anyone who did not already know about this?I remember when
it was being built and all the hype surrounding it. Is it still the
only one?

No, Brian. As I've already mentioned, there's a smaller version just up
the road at Ffestiniog. Apart from the smaller scale (just four 180MW
turbine motor/generators), Ffestiniog isn't buried inside a mountain.

BTW, according to wikipedia, Dinorwig's 6 turbine motor/generators are
300MW, not the 360MW I claimed (possibly a conflation of twice 180MW of a
Ffestiniog turbine and the actual 300MW of the Dinorwig units).

Both facilities are well worth the guided tours (assuming they're still
being run at Ffestiniog - I visited the place about a decade back).

Dinorwig is very impressive for its sheer scale and the fact that it's
completely self contained within the man made caverns of a mountain but
is very light on technical detail (full time tour guides).

Ffestiniog doesn't have the grand scale of Dinorwig but you get to see a
lot more of the machinery close up under the guidance of part time tour
guides whose day job is maintaining and operating the station which means
you get much higher quality information on the technicalities of
operating a pumped storage hydro station, especially if you care to ask
the "Tour Guide" supplemental questions (which, when tried on the
Dinorwig tour guides, often got a blank stare or, at best, an
oversimplified explanation that begged more questions than answers -
luckily today, there's always wikipedia to help fill in the missing
blanks although it falls short of 'hearing it from the horse's mouth'
experience at Ffestiniog).

There is also a similar scheme at Ben Cruachan in Scotland. It's knowna s
the Hollow Mountain.

--
from KT24 in Surrey, England