On Tue, 08 Dec 2015 06:35:42 -0800, dr.s.lartius wrote:

A neighbour has a new-this-year UK-assembled generic Windows 7 PC, and a
decade-old flat-screen non-CRT Philips monitor from Denmark.

Nocturnally, these are turned off by closing Windows and by pressing the
little button on the lower front of the monitor.

What power, in watts, is each of these two devices each likely to be
drawing during the night?

I've seen PCs vary from a low of half a watt to a high of 5 or 6 watts
(any higher is likely to be a failing Bestec PSU or a shedload of USB
gadgets drawing power via the main board's usb sockets when programmed to
stay live in the cmos setup).

Computer monitors typically draw from half to 2 watts in standby (when
not explicitly switched off) and may draw from zero to half a watt when
switched off by its own power button.

As you can see, there's quite a range of uncertainty in the answer to
your question. The user guides may offer some data regarding their power
consumption (typically true for monitors - far less so, ime, with desktop
PCs) or else you beg, borrow or steal a £9.99 plug in 'energy
monitor' (aka, 'digital watt meter') and take your own measurements.
Maplin's N67FU will give reasonably accurate readings for just this sort
of test.

HTH & HAND.

--
Johnny B Good