Can somebody help my with the calculations of my house's kWh per month?

[AeroMagnus]

Simply put, I have to design an off grid solar system for my house and my receipt says I used around 15 kWh/ month according to my meter but once I put all my loads into an excel calculator it throws out around 270 kWh/month, which makes more sense.

 

Can someone knowledgeable help me on this one?

[The1Dickens]

How are you calculating the monthly load? And are you using the same scale of measurements?

[Spotty]

Look at your electricity bills over the past few years. One thing to keep in mind is electricity usage will vary depending on the quarter as your patterns change with things like heating and air conditioning.

[AeroMagnus]

Just now, The1Dickens said:

How are you calculating the monthly load? And are you using the same scale of measurements?

Scales are correct as its pretty easy to use, the monthly calculation is just the rated watts x hours per day on avg (it also accounts for the things that only get used like once a week) then SUM then times 31 

[AeroMagnus]

2 minutes ago, Spotty said:

Look at your electricity bills over the past few years. One thing to keep in mind is electricity usage will vary depending on the quarter as your patterns change with things like heating and air conditioning.

Thats the sketchy thing, apparently my city won't "read" less than 15kWh month and the highest I found was 20 in summer with all the ac on, so IMO I don't think its like the meter isn't reading or something

[The1Dickens]

6 minutes ago, AeroMagnus said:

Scales are correct as its pretty easy to use, the monthly calculation is just the rated watts x hours per day on avg (it also accounts for the things that only get used like once a week) then SUM then times 31 

By receipt you mean monthly statement, correct? What electric company do you use, so I can look up a sample statement?

 

The only thing I could think that might be the case is the 15 reading is the daily average, and it will have the monthly amount noted somewhere else.

[Yoinkerman]

That must be daily use 

[AeroMagnus]

37 minutes ago, The1Dickens said:

By receipt you mean monthly statement, correct? What electric company do you use, so I can look up a sample statement?

 

The only thing I could think that might be the case is the 15 reading is the daily average, and it will have the monthly amount noted somewhere else.

I meant receipt because its literally a receipt as we don't get statements anymore (???), as you can see, the only number in kWh is that 20 and I know its in spanish but it says "consumed in the metered period" 

 

its the only electric company here in mexico, if that helps at all

 

[AeroMagnus]

1 minute ago, Yoinkerman said:

That must be daily use 

in the summer months the math checks out but again, the receipt says right there its billing for one month and more importanly, the amount due is also stupid low

[The1Dickens]

1 minute ago, AeroMagnus said:

I meant receipt because its literally a receipt as we don't get statements anymore (???), as you can see, the only number in kWh is that 20 and I know its in spanish but it says "consumed in the metered period" 

 

its the only electric company here in mexico, if that helps at all

 

Real quick, prolly should not post this if it has any personal information on it.

[Yoinkerman]

Yeah I guess your meter is messed up or something because that looks super low.

 

Essentially 20kwh means you've used 20,000 watts in a month.

 

An AC unit uses about 1000w (1kwh) for every hour it's used.

 

Just that alone should be several thousand watts 

[amdorintel]

8 minutes ago, The1Dickens said:

Real quick, prolly should not post this if it has any personal information on it.

its a different language so most cant read it

 

[AeroMagnus]

10 minutes ago, The1Dickens said:

Real quick, prolly should not post this if it has any personal information on it.

oopsie

[The1Dickens]

10 minutes ago, AeroMagnus said:

in the summer months the math checks out but again, the receipt says right there its billing for one month and more importanly, the amount due is also stupid low

That is super weird. Is the meter difficult to get to? Can you read the meter yourself? How long has it been reading like this? I mean, at some point, someone might come out to repair/replace the meter if it's not reading right, though that largely depends on if any of the techs, or anyone in the office even notices it.

 

 

[amdorintel]

2 minutes ago, The1Dickens said:

That is super weird. Is the meter difficult to get to? Can you read the meter yourself? How long has it been reading like this? I mean, at some point, someone might come out to repair/replace the meter if it's not reading right, though that largely depends on if any of the techs, or anyone in the office even notices it.

 

 

probably not but you never know

[AeroMagnus]

3 minutes ago, Yoinkerman said:

Yeah I guess your meter is messed up or something because that looks super low.

 

Essentially 20kwh means you've used 20,000 watts in a month.

 

An AC unit uses about 1000w (1kwh) for every hour it's used.

 

Just that alone should be several thousand watts 

yeah I understand that concept, we had a couple of units of around 750W run for most of the afternoon and most of the night on that receipt exactly, that alone should've been around 15kWh a day.

 

The only explanation I can think of is that we're stealing my neighbors electricity without knowing (maybe the wires got mixed up when the houses were built? we do share the same wall on one side, and they get waaay more than us in their bills)

[The1Dickens]

6 minutes ago, amdorintel said:

its a different language so most cant read it

 

It was Spanish, so it's not really a stretch to think it's not legible to anyone else. Also, I was able to read it just fine with technology.

[The1Dickens]

1 minute ago, AeroMagnus said:

yeah I understand that concept, we had a couple of units of around 750W run for most of the afternoon and most of the night on that receipt exactly, that alone should've been around 15kWh a day.

 

The only explanation I can think of is that we're stealing my neighbors electricity without knowing (maybe the wires got mixed up when the houses were built? we do share the same wall on one side, and they get waaay more than us in their bills)

Yeah, one way you can check (if you care to) is to flip the main power off for your place and see how many outlets still have power. And what you do with that information is up to you.

 

You could just be neighborly and split the bill with your neighbor, or just let it go quietly, enjoy the near-nothing bill, and when you move out, move on (as it sounds like you don't own the place you are in now) and leave it up to the landlord.

[AeroMagnus]

4 minutes ago, The1Dickens said:

Is the meter difficult to get to?

from outside, yeah kind of, but I wouldn't say impossible to read,also when the technicians come we let them in

3 minutes ago, amdorintel said:

Can you read the meter yourself?

It's electronic and has a display, although I can't read it right now cause I'm 3000km away, I can send my parents tomorrow if you think that any info there could be useful 

7 minutes ago, The1Dickens said:

How long has it been reading like this?

since an electrician came to our house to change the fuses because we were consuming way too much (in hindsight this doesn't really add up, maybe he did something with the wires?) I'd say around 2 or 3 years now

9 minutes ago, The1Dickens said:

I mean, at some point, someone might come out to repair/replace the meter if it's not reading right, though that largely depends on if any of the techs, or anyone in the office even notices it.

You'd think so too when my neighbors are paying orders of magnitude more

[AeroMagnus]

3 minutes ago, The1Dickens said:

Yeah, one way you can check (if you care to) is to flip the main power off for your place and see how many outlets still have power. And what you do with that information is up to you.

 

holy. thats genius, now that I actually have a multimeter I'll definetely do that, thanks!

[amdorintel]

2 minutes ago, AeroMagnus said:

,

the was dickens not me

re "can you read the meter yourself"

 

 

also you can buy a power meter for the outlet and plug your appliance into that to measure watt-hour and various other measurements

[The1Dickens]

1 minute ago, AeroMagnus said:

It's electronic and has a display, although I can't read it right now cause I'm 3000km away, I can send my parents tomorrow if you think that any info there could be useful 

Just to be able to see if the meter is reading that low, really. But it sounds like you'd need one of those fancy readers, anyways, so prolly not much to see on it.

 

3 minutes ago, AeroMagnus said:

since an electrician came to our house to change the fuses because we were consuming way too much (in hindsight this doesn't really add up, maybe he did something with the wires?) I'd say around 2 or 3 years now

Were your neighbors consuming very little before that?

 

This is quite the mystery, now.

[The1Dickens]

6 minutes ago, AeroMagnus said:

holy. thats genius, now that I actually have a multimeter I'll definetely do that, thanks!

Oh, yeh. A multimeter would work. I'd have run around the house with a small lamp...    ._.

[AeroMagnus]

6 minutes ago, The1Dickens said:

This is quite the mystery, now.

I'll keep you updated!

6 minutes ago, The1Dickens said:

Were your neighbors consuming very little before that?

AFAIK they have always paid "more" but not necessarily excessive amounts

[greenhorn]

I am pretty sure something at the fuse/meter level got mixed up, because 15 kWh per month is ridiculously low. For comparison, I live alone in a small apartment and consume about 1500 kWh per year (I use electricity for heating, cooking and warm water). I am guessing your electrity bills will amount to about 3-5 $ per month.

The idea to check whether some of your sockets are still powered even after switching off the mains/removing the fuses is good, this tells you if anything gets its power without it being registered by your meter. If this does happen, then there are two main possibilities: The power is either registered by your neighbor's meter or by neither (if some wires bypass the meter, e.g. in a multi-phase electrical supply where some phases are not connected to the meter by mistake.)