Dr J R Stockton wrote:

In uk.transport.london message
om, Tue, 12 May 2009 20:33:14, Tony Polson
posted:
Dr J R Stockton wrote:

Wiki Electric locomotive indicates that ordinary engine powers are in
the 5 MW range. Therefore, significantly more than a ton of SCs would
be needed to approach ordinary performance levels And a ton of SCs
would give 0.03 MWh, corresponding to less than half a minute of 5MW.


Looking at those data another way, 5.0 tonnes of SCs (say) would provide
two and a half minutes of 5.0 MW. That's about 208 kWh.

All of that 208 kWh could come for free, from regenerative braking - in
other words saving about £20 each and every time it gets used.

But you have to add the cost of transporting that five tons, plus the
weight of the gear required to mount and use it - and you have to
compare it with regenerative braking by (in principle, it will not be
that simple) reversing the motors and putting the energy back into the
wires.


That's all true. But it might still be worth it.

Rather than you throwing up a smokescreen because you don't like the
idea, it would be nice to hear from someone with a little more knowledge
and an understanding of the figures behind the principle.