On Sep 15, 10:09*am, "Zimmy" wrote:
"Norman Wells" wrote in message

...
Vortex4 wrote:
"alexander.keys1" wrote in message
....


There have been a lot of comments recently about the waste of energy
due to appliances being left on standby, and various gizmo's that are
on offer to turn them off automatically, or otherwise purporting to
save energy. What everybody seems to be forgetting is that an energy-
saving device comes with most UK socket outlets, it's called a
'switch', and when put into the 'off' position, power cosumption is
zero! None of my appliances, including computers, digital TV
receivers, etc. have come to harm through this practice, I always
switch off at the wall, back in the day when there were fewer
appliances this was standard procedure to avoid fire risk.

David Mackays book is a good read on this subject:
http://www.inference.phy.cam.ac.uk/w...page_155.shtml

So he says he can save all of 45 watts if he turns everything off instead
of leaving it on standby when he's not using it. *The equivalent of a very
dim lightbulb therefore. *Great!

However, he ignores the fact that he's also losing 45 watts of heat. *To
keep his house at exactly the same temperature, an extra 45 watts of heat
need to be pumped out by whatever heating system he has, for as much of
the year as he needs any heating at all. *Admittedly, that may be a bit
cheaper if it's gas-fired, but it's still the same amount of energy, so
it's unlikely to have a huge impact on climate change.

You are assuming that those 45W of electricity are converted to 45W of heat
with 100% efficiency which is clearly not true.

Z

It is. But gas/coal etc to electric conversion isnt 100% efficient, so
although the end user uses the same amount of energy, with leccy much
more is also wasted at the power station. Then there's nuclear...


NT