Andy wrote:

Just to be clear, I wasn't arguing for air conditioning to be fitted,
but I still think you are mis-estimating the effect of regeneration on
the total energy consumption and heating for the new trains. The whole
point of regeneration is to reuse the energy which used to be 'wasted'
in resistor banks on the trains (with the original rheostatic train
brakes). My understanding is that little of the recovered energy goes
back to the lineside equipment, if the current rails are not
receptive, then the spare energy goes to resistors, like in older
stock. The extra big lineside equipment is purely because more current
is needed in the first place.

What happened to the test of trackside rotating cylinders designed to store
the energy from regenerative braking?