Harry Bloomfield explained on 30/07/2009 :
T i m presented the following explanation :
Indeed and your para above confirms my (and the TV presenters) point
about using appliances at their design voltage.

Agreed, but other than incandescent lamps, there are not many (if any) other
items which have an absolute design voltage or not able to work as
efficiently at a range of voltages.


Of course 'multi voltage' devices will cope so they don't really count
in any case, it's the stuff being designed to run on a fixed 230 being
run on 240 (as it is here right now) where I think they think there
could be a saving.

There is no stuff designed to be run on a fixed voltage any more, just
check the specification pages of equipment. My electric razor will
happily charge itself up on anything between 12v and 240v. My desktop
PC will run on anything between 105v and 245v. The exceptions are old
style lamp bulbs and heating elements, though the later usually have a
little wider tolerance than lamps.

Older PC power supplies had a switch on the back to select 220/110 volt
input. The fuse to protect the PSU at 110v was double the amperage
rating of the 240v one, because as the voltage was reduced by 2 the
current had to double to produce the same output to the PC.

The video mentioned many of these gadgets being installed in lots of
commercial premises to good effect. I get around lots of these places
and I have never seen one.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk