On Tue, 1 Jul 2008, John B wrote:

> On 1 Jul, 22:01, rosenst...@cix.co.uk (Colin Rosenstiel) wrote:
>
>>> Regen braking has a place here, too, if you can shove the heat from 
>>> the necessary resistors outside.
>>
>> If it's regen braking, rather than rheostatic, the heat goes as energy to
>> other trains and not into resistors.
>
> Ish. On AC, absolutely right; on DC, you need banks of resistors as well 
> because putting it back to the grid if there isn't a conveniently placed 
> train to take it is Too Bloody Hard.

But there are places to send it other than the grid, surely? Supercaps? 
Pumped storage? Flywheels? A giant laser firing into space?

tom

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