Understanding a electric meter

sva19

I have a plug in energy monitor and think I have been interperting the results wrong.

I basically plug into a device and use the last button KWH, to see how much KWP it uses. For E.g say I used a table lamp with 100watts bulb, after 1 hour the meter shows a reading of 0.10kwh. Is this 0.10kwh just 1/10 of 1KWP ( 100 watts) on the outside meter reading?

So say my electric costs 0.12pence per KWH. The working out is 0.10 X 0.12p = 0.012 pence (1p) for 1 hour use of the table lamp?

Is this correct or am I doing something wrong?

Robert2009

Yes that is correct.

Rob

sequence

Yes thats right.

Kwatts(instantaneous) * time * cost per unit

sva19

Thanks.

I just tested my modem and router for 1 hr and the reading is 0.01 kwh.

So 0.01kwh X 0.12p = 0.0012p . Not even 1 pence. This seems very cheap to run the broadband??? Is this correct?

I'll do other gadget soon....

sva19

Phone on standby 1 hr = 0.00kwh
TV, Sky, Home Cinema speakers on standy 1 hr = 0.01kwh (0.0012pence)
Laptop on charging and using 1 hr = 0.07kwh (0.0084pence)

Is this normal and expected costs?

Premier_2

sva19 wrote: »

Phone on standby 1 hr = 0.00kwh
TV, Sky, Home Cinema speakers on standy 1 hr = 0.01kwh (0.12pence)
Laptop on charging and using 1 hr = 0.07kwh (0.84pence)

Is this normal and expected costs?

I made some corrections based on 12p per kWh
(If you know where we can buy electricity for just 0.12p/kWh please let us all know )

The phone possibly uses too little to register depending on the accuracy of the device.
If you have the ability to see the cumulative energy, perhaps leave it plugged in for an hour or more and see how many kWh

I suspect you are currently measuring kW (an amount of energy) and extrapolating that over a 1 hour time period not kWh (an amount of energy used over time)

e.g. if you have 100w lamp, it will use 0.1kW
Over 1 hour it will use 0.1kWh, over 2 hours 0.2kWh, etc.
But after 2 hours it will still only be using 0.1kW (100w)

sva19

thanks, will test further.

My 11W energy table lamp used 0.01kwh over 1 hr.

0.12pence. This is the price I use on imeasure for average unit price for electric, and for gas I use 0.04.

Please advise what would be a good normal average to use?

KimYeovil

0.12p is one-hundredth of the actual price - 12p
£0.12 is 12p, not 0.12p; 0.12 pounds is not the same as 0.12 pence

0.12 pounds and 0.04 pounds are reasonable figures to use
0.12 pence and 0.04 pence are not
12p and 4p are fine

http://verizonmath.blogspot.com/2007/08/original-recording-of-verizon-customer.html

Cardew

sva19 wrote: »

thanks, will test further.

My 11W energy table lamp used 0.01kwh over 1 hr.

0.12pence. This is the price I use on imeasure for average unit price for electric, and for gas I use 0.04.

Please advise what would be a good normal average to use?

You missed the point that Premier was making.

You have been using 0.12p it is 12p or £0.12

You arithmetic is correct other than you are out by a factor of 100.

1 Watt costs 0.012p an hour

10 Watts costs 0.12p an hour

100 Watts costs 1.2p an hour

1000Watts(1kW) costs 12p an hour.

sva19

I am using £0.12p (twelve pence in one pound) for the cost of 1 KWP.

I just want to do a straight forward calculation after seeing the reading on the monitor.

When testing the laptop for 1 hour the monitor showed I used 0.07kwh. So 0.07 x £0.12p = £0.0084 cost for 1 hour usage. I this correct?

Mankysteve

Your maths is correct although 7watts for a laptop seams a little low but I could be wrong.