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We had an 100% increase of power consumption last and this year.

It is mostly the night-tariff, which we now consume 27'000 kWh The day-tariff is only around 2'500 kWh.

First we thought this may be due to our new computers, but then the day tariff would need to be high too.

So the only reason could be the electrical heater and water boiler. Both of which are the same for at least the last 10 years, so it kinda doesn't make sense that it went up so much.

So my thought was, could it be that this year for example one rod in the electrical heater corroded which lead to higher resistance => More power draw?

Or do you have any other explanation?

Thanks!

Tim
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  • @ThePhoton To all questions no, expect for the last one, I can't directly say. But I didn't see/hear anything out of the ordinary. –  Jan 14 '19 at 19:02
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    Higher resistance would lead to lower power draw because the supplied voltage is constant and \$P=V^2/R\$. Are you setting your thermostat the same this year as last? Have overnight temperatures where you live been the same this year as last year? – The Photon Jan 14 '19 at 18:46
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    Higher resistance is not exactly a cause of high power drain, if any it could be the opposite. A realy high consumption can more or less have only one real cause: heat production. (For hotter climates: and cold production!) Try to experiment with switching devices on and off, preferrably for a whole night, and note the energy consuption. In other words: go fact finding. –  Jan 14 '19 at 18:49
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    Have you acquired any additional residents, such as teen aged girls? Hot water dripping because of a leaky faucet etc. can cause a lot of consumption. – Spehro Pefhany Jan 14 '19 at 18:51
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    Other things to look for: Do you have a sump pump in your basement? A ventilation fan in the attic? Do you have any old windows or doors whose caulking might have failed? Does your electric heater have a fan, and is it still working smoothly? – The Photon Jan 14 '19 at 18:52
  • Maybe they have just changed the durations of day/night tariffs... – Eugene Sh. Jan 14 '19 at 18:55
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    @ThePhoton The thermostat is still same. Outside temperatures aren't that much diffrent –  Jan 14 '19 at 19:00
  • @WoutervanOoijen I can't measure the power draw of our electrical heater. We have an old electricy counter in our basement, but I don't understand what it shows? Is it kWh consumption maybe? –  Jan 14 '19 at 19:01
  • @SpehroPefhany No, more the opposit, we let go of some servers we have. –  Jan 14 '19 at 19:02
  • Air Cond. & Cooking time on stove and oven can often be the biggest electricity consumers. Electricity theft is another or electric heaters at night. – Tony Stewart EE75 Jan 14 '19 at 19:03
  • @EugeneSh. That wouldn't explain a +100% total power draw and would only change it from day to night –  Jan 14 '19 at 19:03
  • @SunnyskyguyEE75 It won't be any of this, as it is high on the nighttarif. (Starting at 10PM) And we normally don't cook then. How can I identify electricity theft? Our energy line is below ground, so you can't just plug something onto the lines over ground. Or how would that work? –  Jan 14 '19 at 19:07
  • It seems you need to monitor the meter readings by some method. We have digital meters so we can inspect the data online by any hour of any day,. Maybe its time to switch appliances to natural gas which tends to be cheaper – Tony Stewart EE75 Jan 14 '19 at 19:11
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    Does your "old electricity counter" have a glass cover, through which you can see a slowly spinning disk? Disk rotation speed is proportional to electricity use. Easy to judge by eye. –  Jan 14 '19 at 19:31
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    Are you saying that at night last year you used ~13000kWh at night, and nearly or slightly over 2000kWh in the day? You said tarrif, so to be clear, are you commenting on a higher bill where the $$$$ amount per kWh went up, or are you literally saying an appliance is using double the power it did previously? Do you have a sump pump running 24/7? Any other fans or pumps? Did you change any set points on water heater temperature? Regarding power use, turn EVERYTHING off at the main and ensure the meter isnt moving – noybman Jan 15 '19 at 00:58
  • Seen this with time based power uses, if on electric never agree to this, my mom had and it cost her several hundred per month for her kiln and dryer, now she has a gas dryer and an intermatic timer that only let's the kiln turn on at night, when the little triangle thing melts on the outside it shuts down but it cannot run unless the time clock is after 830 or maybe 9 but the time clock saved them tons ,,, not sure if she has used it in the past few years but know it made a big difference in the past – Ed Beal Jan 15 '19 at 01:22
  • @noybman Yes, 27'000kWh in the night and 2'000kWh in the day. No, $$$/kWh stayed the same. But the power consumption went up 103% (Last year about 13'000kWh). We don't have any pumps or Fans running. Only the water boiler and electrical heater which run by night. – Tim Jan 15 '19 at 07:35
  • I am not suprised by a water heater using more power as it ages, but not because of higher resistance, but more due to calcium/mineral buildup and inherit inefficiencies that occur as they age. I've never measured it, but as numerous people have recommended, and I noted - literally unplug EVERYTHINGGGGGGGGGGGGGGG (or kill its breaker) and ensure no power use. then start turning them on one at a time and back off again. You can EASILY see what "thing" from what circuit is the largest power suck in a matter of minutes – noybman Jan 16 '19 at 03:39

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So my thought was, could it be that this year for example one rod in the electrical heater corroded which lead to higher restistance => More power draw?

No. Higher resistance will reduce current draw. Thought experiment: disconnect the heater completely to create infinite resistance. Will the power consumed increase or decrease?

It's time for an energy audit. You can start by finding your energy meter and taking hourly readings or time how long it takes for the meter in increment by one or ten units. If these are consistent then you can switch off each circuit in turn and measure the change in timing.

Alternately you can get a power analyser with voltage and current probes and take measurements and log data for each load.

Transistor
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  • Thanks. I've allready tested all devices I can with a wall plug meassurer. They don't seem extra high. Sadly I can't plug my hous eletrical heater into it (Nor plug it out, as it is built into the house. I will try the power reader thing –  Jan 14 '19 at 19:05
  • I just read this but higher resistance will reduce the power used with voltage held constant increasing resistance will reduce current flow its basic ohms law. – Ed Beal Jun 14 '19 at 16:55
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I find it funny that some think an old electric appliance would cost more, especially after no changes , I would bet your service contract changed. My Mom signed up for one of these programs and her heating bill tripled, we changed the house over to gas except for the clothes dryer, and her kiln, now there bills are much smaller but if she forgets and runs her kiln and dryer at the same time her bills are higher than they were many years ago. I installed a time clock on the kiln about 7 years ago because mom would forget, my step dad asked me to do the same on the dryer but then it died and I piped NG and a vent and he said can we change more to gas because the change cut their electric in half.

manassehkatz-Moving 2 Codidact
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Ed Beal
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  • No, contract stayed the same. Even if it changed, it would change how much we pay, not how much energy we actually use. – Tim Jan 15 '19 at 07:37
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It is a very common occurrence that an old water heater will consume higher energy for a number of possible reasons. A heating element's ceramic coating may be bad, resulting in energy going to ground (earth) inside of the water heater instead of producing heat. The Temperature / Pressure (T/P) relief valve may be leaking, so hot water is just going down the drain without you knowing about it. The heater may be full of sediment so the elements may be essentially insulated from the water, making then highly inefficient so that they end up being on LONGER than necessary to make the same amount of hot water. In that case a reading taken at any given moment would not look unusual, because it's about the length of TIME that they are energized that is showing up as an energy increase.

JRaef
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    With the info provided I think you are not correct. Power in the form of heat from an element is the same, if it was leaking to ground a standard 30 amp water heater heater would be done in a very short time. I state this because have you ever watched an arc welder? If there was enough leakage the tank would be done in minutes, maybe hours. – Ed Beal Jan 15 '19 at 01:07
  • @EdBeal Correct. But he might be right about the TP valve leaking. A dripping HW faucet would do the same. – Mike Waters Jun 14 '19 at 16:51