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We just received our power bill and it is showing a 30% rise in kWh for the past month. Nothing has changed in our home. We were even gone one full week in the month.

To make it more interesting, this past summer our stove would not ignite because the line voltage was 108 V because it requires a 2.4 amps through the igniter before the gas valve will open (at 120 V). I contacted the electrical supplier and they came out, confirmed the condition and changed the tap because AC units were pulling the line down. All was well. They then came back out weeks later, but I don't know what they did. (Changed it back, perhaps?) Yesterday we tried to use the oven and wala-no ignition. I was in a hurry to go somewhere and could not check the voltage, but when I did last night it was 114 V. Are the higher kWh usage and low line voltage related issues? I don't know. With refrigerators and pumps on the line as inductive loads, will their changes in efficiency at lower voltage cause higher kWh? It would seem so since losses would go up. That's the main question.

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closed as off-topic by Leon Heller, laptop2d, Finbarr, Dwayne Reid, Elliot Alderson Jan 7 at 0:52

  • This question does not appear to be about electronics design within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ My energy bill went up 70% last month. Where on the earth do you live? How is your residence heated...gas? coal? heat pump? resistance heat? \$\endgroup\$ – Elliot Alderson Dec 30 '18 at 13:03
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    \$\begingroup\$ I'm voting to close this question as off-topic because it has nothing to do with electronic design. \$\endgroup\$ – Leon Heller Dec 30 '18 at 16:36
  • \$\begingroup\$ Compare it to the same month last year. \$\endgroup\$ – StainlessSteelRat Dec 30 '18 at 17:14
  • \$\begingroup\$ I apologize. I was not aware this was for electronics only. It is after all an Electrical Engineering site... not electronic engineering. Close it. I'll. Ill go elsewhere. BTW - I have checked all the things noted, we heat with oil - but all that is a moot point now, isn't it? \$\endgroup\$ – Roger A Dec 31 '18 at 1:59
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We just received our power bill and it is showing a 30% rise in KW for the past month.

Check your bill. It will be showing "kWh" which is energy usage, not "KW" (which actual signifies kelvin-watts - you meant "kW") which is power, the instantaneous or average power reading.

Nothing has changed in our home.

This gives us a few options:

  • You are mistaken and your usage has gone up. Take a daily meter reading and see what's going on. Compare this with the daily average calculated from your bill.
  • The meter is faulty.
  • The billing periods or meter readings are inconsistent. e.g., 25 days one month and 35 the next.
  • Some of the bills have been using estimated readings. These should be indicated on the bill. If you have had several low estimated bills then the next meter-based bill is going to come as a surprise!

This past summer our stove would not ignite because the line voltage was 108 V.

In general, reduced voltage will result in reduced current. Since power is volts x amps the reduced voltage will result in reduced power too. Exceptions to this will be for devices such as heaters or air conditioning which will remain running until the setpoint is reached. With reduced power available this will take longer and, if they run inefficiently at reduced power then the total energy used will increase.

... the electrical supplier and they came out, confirmed the condition and changed the tap ... They then came back out weeks later, but I don't know what they did. (Changed it back, perhaps?)

A cheap multimeter will allow you to periodically check the mains voltage and see what effect your load is having on it.


First thing to do is take your daily meter readings to figure out what's going on.

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It seems unlikely that a voltage problem would cause that much change in energy usage. If it did, consider yourself lucky that you haven't had motor failures. However if you start having motor failures soon, you will know why. It seems more likely that one or more of your refrigeration units is failing and running 24-7, but not satisfying the thermostat. You should probably check the refrigerators. Check to see if a sump has a bad switch and runs all of the time with the sump dry. Compare the weather for the high month with the previous month and the subsequent month.

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