- all electronics (except the video center) now completely switched off when not in use
...
- video center still left on standby (will put on on/off outlet strip this week)
When you say all electronics are "completely switched off"...does that mean a power strip is turned off, or just that you turn them off? A receiver set-up can draw quite a bit of power when in 'standby' mode (i.e. 'turned off'). To completely kill the power draw, you have to put the receiver (and tvs, etc.) on a power strip and turn off the power strip. Not a huge amount of draw...but things add up quick!
- a second refrigerator and a stand-alone freezer deactivated (just recently, so won't be reflected in kwh use until next month)
Were these energy-star appliances? You'd be surprised how much power older/non-energy star appliances can consume. And on top of it, refrigerators/freezers are a relatively large amount of household energy consumption, even with energy star ratings.
- basement dehumidifier (runs on on/off sensor at around 60% humidity)
- one electric space heater run at low in bedroom from 11pm to 7am (again, thermostat controlled)
The dehumidifier can be a HUGE draw. It's basically an air conditioner that cools down the air to extract the water vapor. Do you discharge your dryer vent into the basement, or is it vented outside? If your dryer vent dumps the wet hot air into your basement, you're making that dehumidifier run all the longer to get rid of all of that moisture from the dryer.
Also, do you have draintile around your basement to drain any groundwater that accumulates? If the draintile sump pump that pumps out the ground water isn't working, it might be leaving more groundwater around your foundation and basement slab....which might be allowing more moisture into your basement, and make your dehumidifier run more. Perhaps try asking your neighbors if they have dehumidifiers, and what their settings are on, and how long theirs run. I don't know what the humidity levels are in VA, but typically the winter months are drier, so your dehumidifier shouldn't really need to run (unless you have groundwater issues). Out here in Missouri, we get 90%-95% humidity in the summers, and my dehumidifier runs a hell of a lot to keep the level at about 60%...but it never runs in the winter (natural humidity levels are down around 45%-50% in the winter).
Also, is the dehumidifier blowing the dry air on any water sources (like a floor drain or other amount of water?) You don't want to cool down the moisture out of the air, only to blow the dry air across some water and rehumidify the air again.
The space heater you should be able to calculate the power draw on. Just multiply about how long it runs for, by how high of an element it has, and that's a fairly close guess.
I'd guess that between your dehumidifier, space heater, and 2nd refrigerator/freezer, that'll account for a bit of load.