On 25/05/17 08:06, Chris Hogg wrote:
On Wed, 24 May 2017 22:44:38 +0100, The Other Mike
wrote:

On Wed, 24 May 2017 13:57:19 +0100, Tim Streater
wrote:

In article , Brian Gaff
wrote:

Maybe its cheaper just to flood old mines and use turbines to generate power
then pump them out when there is little demand. Is it any less efficient
than a bleedin big battery which needs to then be converted to AC in any
case?

Flood them with what?

Something liquid at room temperature and quite dense would be preferable.
Mercury would appear an optimum choice. As for finding an old mine with a
shaft still usable and with roadways still inctact then you are ****ed before
you even start.

The one they're talking about in Germany is still a working coal mine,
but due for closure next year. As to whether an old long-closed mine
can be reinstated would depend very much on the type of mine and the
geology of the site. Coal mines would be near impossible I would
think, but many tin and copper mines in Devon and Cornwall have been
re-opened in the past and even relatively recently after decades of
being closed.

It takes around 4-6 years to pump old mines dry before they can be reopened.



--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher