On 09/02/2021 09:55, John Rumm wrote:
On 08/02/2021 22:35, Paul wrote:
Tim Streater wrote:
On 08 Feb 2021 at 16:32:11 GMT, Andrew
wrote:

They could mount the land-based windmills on giant concrete 'sleds'
running on rails. When it is windy the sled moves itself up the incline
and then has the capability to generate power as it runs back down
again ? :-)

Didn't I see a report about a US scheme that involved storing energy
by having
a railway line going up a long slope (few miles IIRC) and allowing
trucks with
20 ton blocks of concrete on to roll down the hill to generate volts
as they
went?


There's this one

https://www.ien.com/product-developm...y-than-it-uses


Might be the same one.

https://arstechnica.com/cars/2017/09...ctric-vehicle/


It's a transportation job, with net energy output.

The truck never needs to be charged, and in fact
at night, it needs to empty the battery out so
there is room for charging it via regeneration,
the next day. The truck drives uphill empty, and
that takes less energy than is regeneratively
generated by driving downhill with a full load
in the back. All thanks to electric motors that
function as motors or as generators.

I wonder how many quarrys have that kind of setup where the raw material
needs to be transported *down* from the quarry?

I would expect a large proportion to have a more traditional arrangement
where rock needs to be hauled out of a big hole in the ground, rather
than the transportation of a mountain top down hill!

Which still doesn't mean that the bottom of the quarry isn't higher than
the surrounding land that the trucks are taking it to, with loads being
transported up from the quarry to the exit and then back down further
than it came up.