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I just moved into a new house in Northern California. Since we became owners (one month ago), we have been gone abroad and the house has been unoccupied and empty. Before leaving I made sure all appliances were disconnected, heather off, except for the fridge.

Looking at my recent electricity bill, on average the empty house has used 12KWH per day, and now that we are back I see spikes at about 30+kwh or more. That sounds quite unreasonable! my fridge uses no more that 2kwh per day. So where are the other 10kwh/day going? my electricity bill was 80$ for an unoccupied house, I can only imagine what they will be now that we are living in it.. any advice highly appreciated.

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    I assume all of the wall warts were disconnected and lights off. It appears something is leaking to ground. You would have to test this circuit by circuit. You will need a good clamp meter and measure each breaker with everything turned off. If you find nothing turn the refrigerator on and when the compressor stops measure the current.
    – Gil
    Jan 16, 2022 at 5:25
  • If it is the fridge, throwing away the food may be cheaper than running fridge. Jan 16, 2022 at 5:48
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    Start by buying a "Kill-a-Watt" energy monitor ($20-30). A modern refrigerator uses about 1 KWH per day or about 40W average. If yours is significantly more, it's old or weird; contemplate an upgrade. Please list how each of these are powered: Furnace, water heater, range, and dryer. Is this a change from your previous home? Is there any other new appliance like a hot tub? If you don't know that might be your problem right there, not knowing what your loads are. Jan 16, 2022 at 7:15
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    Anything uses electricity will put off heat, 3412 btu's per Kw/h. A infrared laser like a Klein Tools IR1 might be useful finding draw. Also any septic or sump pumps? Jan 16, 2022 at 15:41
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    start by turning off the main breaker and looking at the meter ...it should be showing no power usage
    – jsotola
    Jan 16, 2022 at 20:59

4 Answers 4

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Your first step is to determine where the power is being drawn.

One useful tool for this is a power/current meter that can be clamped inside your panel. If you are uncomfortable working in the panel or you have never done that before, have someone show how. That can be an electrician or an experienced DIYer.

enter image description here

However, if the high power use is intermittent, e.g. on a timer or thermostat, you can't just measure it once. You'd have to hang the clamp off a circuit for perhaps a day, a cold day, while keeping devices off that you know of. You can leave the furnace, kitchen and hot water circuit as last, and perhaps prioritize circuits for basement, garage, yard etc...

Map your circuits

Start with mapping out your circuits. Which breaker serves which outlets? Shut them all off, leave one on, and map out what receptacles, lights, appliances etc.. are working.

There is plenty of info on this site to explain how to map your circuits. An important thing to note is that circuits generally serve delimited areas in your house, but what what's an "area" from your point of view (rooms, spaces) is not necessarily an "area" from a wiring point of view (half of room on one breaker, other half on another breaker shared with room on different floor etc...)

Determine the power/current draw

The second step is to use your meter to determine how much each circuit consumes. After completing the mapping, switch off all circuits, switch off all lights, appliances etc that you know of, leave one circuit on and observe your meter.

Here's a good description of the steps, but the actual power draw or current style of display depends entirely on the type of meter.

enter image description here

Some smart meters can be connected to a more advanced metering/reporting device installed inside. Ask your utility company for more.

enter image description here

If the meter is "running" (showing that power is being drawn) then clearly there's a device running that you have not identified, because you had not switched it off. Go find it.

How to determine whether the meter is "running" depends on the type of meter. If you post a picture of it here, we might be able to help. Otherwise ask your utility company. Some meters have a display with power "bar graph", some report the current, some have a dial that turns etc...

Also review the list above by @xeeka to check off all unusual or obscured power consumers, like heaters, defrosters etc... Some people even have driveway heaters that they don't know of, until they deliberately start hunting for causes of high power consumption.

Images:

https://www.timescolonist.com/opinion/device-links-to-bc-hydro-meter-shows-real-time-electricity-use-4632901

https://app.bchydro.com/content/dam/BCHydro/customer-portal/documents/accounts-billing/customer-care/breaker-test-for-digital-meters.pdf

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12kWh per day is very much energy. It is equivalent to a hair dryer running 24/7 on a medium level of 500W.

Even for the heating of a normally sized aquarium or terrarium that would be far too much.

A defect electric tank heater for domestic warm water could be the cause.

Or sometimes simply the sauna is not switched off.

Sometimes defect sewage pumps run continously - as do defect refrigerators.

Heated outdoor dog or cat shelters could contribute to the high bill.

Some houses or garages have electric anti-frost systems installed.

A defect thermostat of an antifrost gutter heater could be the cause.

Small electric heaters in rooms with water tubes in basements are quite common.

Those anti-frost heaters switch on if the temperature is still far from 0°C, f.e. at 10°C, to have a safety margin if tubes are running in outside walls.

Electric base board heaters or electric floor heaters could also switch on to maintain anti-frost conditions.

Also many heat pumps use direct electric heaters if running on stand-by or if some components are not working (de-icing of the vaporizer, lost of cooling substance, defect expansion valve etc.) or the temperature of the domestic warm water is set to a high temperature.

Much less probable but not impossible is a defect electric meter - especially if it is an old mechanical Ferraris-type with a spinning disc. The drums for the digits sometimes stick together when they should not.

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  • Perhaps add "driveway heaters", a special category of defrosters that draw a lot of power and might be left unattended.
    – P2000
    Jan 16, 2022 at 19:09
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    Power companies typically estimate that homes take an average of 1 to 1.5 KW on average, as in "this gigawatt nuclear plant will power 1 million homes" or "this 150MW wind farm will power 100,000 homes". Based on that data, the average home takes 24-36 KWH/day. Jan 17, 2022 at 2:02
  • @Harper: 1. "Homes" = average mix of (multi family) houses, each building equaling 1 home? 2. Homes including typical energy needs for car parks, gardening, lifts etc. for a city/quarter with that number of homes? 3. Downtimes for maintenance included? - Windparks are rated for the maximal peak power <> average power. 4. Homes with typical direct electric heating systems like in France? 5. Homes in continental climate areas with high A/C and high winter consume? 6. Losses for transportation/power factor correction etc. included? Here, we have 12kWh per day for an empty house.
    – xeeka
    Jan 17, 2022 at 5:44
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Check your power usage history

Many utilities let customers check their own power usage in detail. The industry standard is 15-minute reports of both usage (kWh) and demand (kW). But one or the other is sufficient (usage = time * average demand) for rough calculations and hourly reports may be enough to determine the problem.

the empty house has used 12KWH per day,

If that is a fairly consistent amount - e.g., 500 Wh/hour, 125 Wh/15 minutes or peak demand consistently around 2 Amp (2 Amp x 240 V x 1 hour = 480 Wh) then your problem is probably some combination of vampire loads:

  • Appliances you can't easily turn off - e.g., built-in appliances such as oven, dishwasher, etc. - though most of these should use very little power when in standby mode
  • Lighting that is always on
  • Consumer electronics that you forgot to unplug - TV, DVD, computers (e.g., a laptop computer when turned off will still trickle charge the battery; monitors and printers will go to a nearly-off standby mode, etc.), etc.
  • Tank electric water heater - will run periodically (but should be "minimal") to replace heat lost to the environment - if you have a dripping hot water faucet then it will run more often.

On the other hand, if you see changes, particularly a pattern that repeats day after day, then that indicates something environmental:

  • Lights that automatically turn on at night will increase usage at night. (Replace with LEDs if they are older types)
  • Heat that runs automatically will generally run more at night because nights are usually colder than days. If the heat uses natural gas then there is still some electricity used for fan and controls.
  • Sump pumps will run when it rains.
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California electric rates are very high. Regarding usage...if the house is heated with electrical resistance heater (like baseboards), it's going to be really expensive during the cold months. If interior conditioned space is supplied by a heat pump that can provide both heating and cooling that will also be expensive, but not as bad as baseboard or other resistance electric heating.

If you are OK with working inside a live electrical panel, you can get an "amp clamp" type multi-meter and check various circuits to see which are drawing power. It's a Sherlock Holmes trek.

George.

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    "OK" regarding the main panel needs to be emphasized here... If you don't know how the main panel can kill you, even when everything is "OFF", do not touch it.
    – Nelson
    Jan 16, 2022 at 5:30
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    I tire of people here saying if you touch a live circuit you're going to die. It starts to sound like a Dave Barry satirical rant about CV19: "OMG, we're all gonna die, we're out of toilet paper we're all gonna die, we're out of bottled water, we're all gonna die...etc. etc. " I've been shocked many times by circuits I though were turned off or had induced voltages. A couple of rules: if you are inexperienced working in a live panel but need to, wear rubber gloves and follow the "one hand rule" never put both hands in the panel at the same time. Rubber boots also help insure safety. Jan 16, 2022 at 9:37
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    @GeorgeAnderson only need one hand in the wrong place and bye-bye.
    – Solar Mike
    Jan 16, 2022 at 11:11
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    @GeorgeAnderson Are you kidding me? A shock on the main panel when everything is "OFF" is about as serious as you can get in a residential setting. If you can't tell the difference between that and a shock from induced current, maybe you shouldn't work on it either.
    – Nelson
    Jan 16, 2022 at 11:29
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    Given the supposed aims of StackExchange, instead of arguing over how many hands it takes to kill someone in an electric panel, you could spend the same amount of typing explaining to the OP, thus fulfilling the reason for the site to exist in helping and teaching people to do it themselves. Jan 16, 2022 at 18:10

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