Power Consumption Mystery (residential, resident, difference)

[DetroitN8V]

There's definitely "stuff" plugged in but all major energy hogs are out of use during demand hours and yet my usage is still far higher than it was in the warmer months. I will have to resort to calling APS.

[observer53]

Originally Posted by DetroitN8V

There's definitely "stuff" plugged in but all major energy hogs are out of use during demand hours and yet my usage is still far higher than it was in the warmer months. I will have to resort to calling APS.

Sounds like it... and be sure to let us know what you find out... we all love a mystery, (well, when it's someone else's mystery, at least! ) and whatever's happening could happen to others as well!

[Steve Pickering]

Three KW is major. You have something on like a Pool Pump, Hotwater heater, Electric Range or Air/Heat. If you turn on every light in the house, all the radios and the fish tank, you won't use that much. Big Screen TV's do use a lot. If you feel heat, it is using power.

[Ponderosa]

Originally Posted by DetroitN8V

I shut the heat pumps off around 11:30am at the thermostats. Could they still draw power for an hour and a half after being turned off?

No. Unless you hear it and see it, the compressor is not going. The ac may have a crankcase heater in the compressor but that doesn't pull 3kW kinds of load. The mostly likely "silent" draw like that is an electric water heater where the timer is set wrong. In my house when I had an anomalous bill, I found out the kids were turning it back on so they could take showers in the afternoon and have lots of hot water.

[Ponderosa]

Originally Posted by Steve Pickering

Three KW is major. You have something on like a Pool Pump, Hotwater heater, Electric Range or Air/Heat. If you turn on every light in the house, all the radios and the fish tank, you won't use that much. Big Screen TV's do use a lot. If you feel heat, it is using power.

I have ginormous plasma but it uses "only" about 500 watts (0.5kW). It has to be more than that.

[Ponderosa]

FWIW, my peak kW demand in winter months is around 2.7. I have never hunted down why but presume it comes when we are cooking dinner, running 2-3 TVs, every light in the house is on (women and kids only know how to turn lights on, not off) and all the big stuff off. Summer peak is around 7 kW.

I have a load controller where I can set demand to whatever and it will start swapping out loads to maintain that. It was a requirement years ago from APS. I can't get it under 2.2 without it alarming (too many kWs) so you might not be doing all that bad at 3.

[Steve Pickering]

Half a kilowatt here, half a killowatt there, and before you know it you have three killowatts.


As Ol' Ben said, "A penny saved is a penny earned." You could say "A killowatt saved is a killowatt earned."

[DetroitN8V]

Convinced that something large is still running I went out and had a better look at the water heater. Forgive me for not knowing too much about the system since we're renting this house as we recently moved to AZ. The water heater is solar powered but also has two electric plugs; one for the circulation pump and one for the transfer module. The circulation pump is on a timer, but the transfer module is not. It was definitely running. I just unplugged it so I'll have to see how the numbers look tomorrow with it unplugged during the on-peak hours. I'm not too sure what the transfer module does, but it would make sense that it's working harder now that the garage is much cooler.

[Ponderosa]

Originally Posted by DetroitN8V

Convinced that something large is still running I went out and had a better look at the water heater. Forgive me for not knowing too much about the system since we're renting this house as we recently moved to AZ. The water heater is solar powered but also has two electric plugs; one for the circulation pump and one for the transfer module. The circulation pump is on a timer, but the transfer module is not. It was definitely running. I just unplugged it so I'll have to see how the numbers look tomorrow with it unplugged during the on-peak hours. I'm not too sure what the transfer module does, but it would make sense that it's working harder now that the garage is much cooler.

My old house had solar. The water heater still had a heating element for cloudy days, high demand,cold weather, etc. It ran quite a bit in winter. Another bad thing it did was when rooftop temps got below freezing, it would circulate hot water to the coils up there to prevent freeze-ups. That would cool the stored water and cause the electric element to turn on. All in all though the thing saved a good deal of electricity. But with time and day and demand, it would be hard to justify getting one in this house.

[Ponderosa]

IIRC, the smart meter has instantaneous demand as one of the stats it cycles through. You should be able to go look at the meter after you switch off your heater and see if that makes a difference.