We had a couple of friends visit recently and whilst chatting got onto the subject of reducing electricity consumption, at which point I showed them what we have done on the house we are currently building, which we also did on our previous build. They reckoned it was an excellent idea so I thought I would share it!

Like many other folk we try to be conscientious about fully turning off appliances that have a standby function when turning in for the night, but the nature of these sort of devices means you're usually crawling under desks, fighting through a tangle of cables, and wondering if you're going to accidentally unplug the alarm clock and have to spend ten minutes resetting it. Our solution was to duplicate the socket circuits, one is generally used for devices with a standby mode and its twin for "normal" devices and those which we don't wish to turn off; the standby circuit has a master switch installed in our bedroom so last thing at night simply flick the switch and 4 TV's, 4 Freeview boxes, 5 PC's, 3 printers, 1 server, 3 DVD's, 2 VCR's, 1 microwave, 3 Hifi systems and numerous other devices are completely shut down. I should mention that we never use the VCR for recording so not a problem that they lose their clock settings overnight, and the DVD recorders are a bit more clever and don't lose their settings, so I'm not a masochist!

It might seem overkill to install extra circuits but the cost was just under £140, yes we have a lot of sockets, and we have little red dots stuck on those on the "standby circuit" to indentify them; but a quick check with a meter showed that we were drawing over 400 watts prior to switching off at night. Even if the circuit is only off for 6 hours each night it equates to about £85 per year, add in a couple of weeks holiday and you're knocking on the door of £100, so the pay back is very short.

How much is your electric bill? I think that you figures for the savings are too high and above the cost of electricity for leaving things on as opposed to on standby. None the less it is a great idea.

Tony. The circuit was drawing 1.86amps on average ( I checked it 4 times but the readings were very close) before switching off:

1.86a X 230v = 428w

0.428KW x 6 (hours) x 365 (days) = 937KWH

937 x 0.0944 £/kwh= £88.45

This is exact, I'd estimated the previous figure.

We use CF lightbulbs throughout and absolutely no electric heating. The chest freezer was in the garage and had PU insualtion offcuts glued to the outside!. The total electricity bill was around £390.

The most scary items are the Freeview boxes, all four combined drew 130watts!

Tony wrote "1) All this " wasted " electricity finishes up inside your home as heat."

Yeah, heat from electricity! Far better to have to fill the gap with more sustainable fuels, even gas....

A similar idea I have implemented: a duplicate circuit for off-peak electricity. This is energised by a 100 amp capacity contactor into a second consumer unit, with the contactor controlled by a timer. Cost of second-hand kit less than £50.

Advantages (1) very cheap electricity to operate items like tumble driers, immersion heaters, washing machines at night. (2) Green gains because this helps re-balance the grid generators. Generators running at low capacity overnight have poor efficiency, so raising capacity utilisation will improve overall carbon footprint efficiency (3) ultimately, we help cut the total power station build, by using existing capacity more efficiently.

NB you need a high capacity contactor - at least 60A -because motorised items create large inductive loads when they kick-in simultaneously. On no account should you plug a large item, easpecially a motorised one, direct into a plug-in timer, even one with a 13amp rating.

Arthur: my scheme is not aimed at the standby problem, but the much larger problem of using generating capacity more efficiently - and saving a lot of money into the bargain. Just about all 'green energy' - including nuclear- is generated 24/7, so we need to adapt to maximise its use. Otherwise we are wasting it at night and generating extra from fossil fuels instead in the day! The more off-peak is used by consumers, the greater the matching of demand and green supply, and the greater the incentive for suppliers to install green generators.

Regarding contactors: cheap plug in timers do not have suitable contact switching for either high current loads or inductive surges. Even for small loads their operational life is limited. An industrial contactor is essential for any substantial scheme - see Ebay to purchase.