In message , at 01:09:37 on Thu, 28 May
2009, David A Stocks remarked:
A similar mechanism already exists for off-peak domestic customers
using night storage heaters, who get a contract stating something like
"you get 7 hours of cheap rate elctricity between the hours of 2300 and
0800 the following morning", together with a radio controlled switch
for that part of the supply. The switches are used by the local
suppliers to manipulate their overall load in order to buy bulk
electricity at the best market prices from the generators.

What they forget to mention quite as loudly is that you get charged
*more* for the daytime electricity, not just *less* for the night-time.
Unless at least a third of your consumption is overnight, you will end
up paying more overall.
--
Roland Perry