"Bill Wright" wrote in message
...
Dave Plowman (News) wrote:

"excess energy generated from renewables. "


It's a method of storing energy created at a time when it isn't needed
until it is in the short term. And the efficiency is said to possibly be
able to approach that of a rechargeable battery. But I dunno how
practical
it is - pumping water up to the top of a hill and using that to run a
hydro electric system has its problems too.

But renewables don't generate excess energy. Even with all renewables
going full tilt (which is unusual) the total output is nowhere near the
UK's lowest demand figure. So if the energy from renewables was used at
any time to power this storage scheme all it means is that gas-fired
stations would have to work a bit harder.

Renewables are erratic, if you can use the energy storage system to absorb
the peaks and troughs it will probably make renewables useful.

What's the energy density of liquid air? Does it make a useful fuel for
cars/lorries?