We got our PG&E bill for last month; since we were gone for almost the full billing period, we used amazingly little gas and electricity. We used so little gas that we were subject to their minimum transportation charge (13 cents per day), and our electricity usage was 200 kilowatt hours less than a typical month. Most of the reduction was due to cooking and lighting, but I had made a point of unplugging things like the subwoofer since it wasn’t going to be used while we were gone.
I was curious how much of a difference that made, so I dug out the Kill-a-Watt and tested; the subwoofer idles at about 15 watts, which adds up to almost 11 kWh during a month. It’s probably worth putting it on a smart outlet and only turning it on when the amplifier is active.
I could also consider putting the amplifier on a smart outlet and only turning it on when I need it, though I haven’t gotten around to finding out how much power it uses in idle mode. And then there’s the TV and the TiVo….