Electricity Usage Calculator

stinky

Hi

Just trying out my Lidl Energy Meter thing. No instructions came with it, but seems pretty simple to work out. (btw - if anyone has instructions for the PM333-GB please could you send me a copy).

For most appliances I can't be bothered to sit and wait while it calculates how much energy it uses over time. So I was trying to do a bit of maths and work it out quickly. The unit shows how many Watts are being used per appliance. i.e. TV on standby is using 16watts. Meter is working fine as the Kettle uses approx 2000Watts, which would be about right.

Anyway - the maths. Can someone please check my maths and tell me that I'm doing the right thing on my spreadsheet.

16Watts usage/1000 x how many hours its on for.

electric cost approx £0.088 /Kwh

Therefore, cost per day is cost per hour x 24
and cost per year is that figure x365

So 16watts on Standby is costing me approx 3p/day and £12.33/year

Does that all sound about right? This is of course allowing for the fact that the TV is not on standby 24/7 it is sometimes on. But I wanted to get an idea of what things cost just sitting there.

100 watt light bulb left on all year would cost me £77.09 - interesting!

beaker141

Looks about right to me - I had similar figures, although I have got elec down as 11.2p per kw/h (EON online 12 tariff with standing charge)- just check your 8.8p isnt for the first x kwh per period and then its more after that ?

Greenbeast

8.8p sounds about right as we are with npower online with standing charge and the cost is 8.9p

stinky

Thanks guys

Yes, its 8.8p but then there is a standing charge of 17.57p per day on top of that with Scottish Powers fixed till 2010 rate.

Have also just realised (yep I'm slow) that I can work out how many Kwh's I use per day, simply from the bill. So over the last period I used 26.8Kwh's/day. Which is interesting and seems about right when comparing quickly to some american forum postings. 2169 Kwh's for 81 days.

However, that equates to using 26,760 Watts of power constantly over a 24 hour period. That's scary. Its 1,115 Watts every hour. Blimey, what's eating up all that power. Time to investigate further.

No doubt its things like the Combi Boiler, the huge american fridge (yeah I know, its not economical to run, but it looks fantastic - and sometimes style has to come 1st), the electric oven etc. Still seems like a huge amount, considering all the light bulbs are low energy etc.

Paul

Snakeeyes21

thats a hell of alot of electric.
what you doing? growing some plants.
my gas / electric bill is only 350 a year

Cardew

stinky wrote: »

For most appliances I can't be bothered to sit and wait while it calculates how much energy it uses over time. So I was trying to do a bit of maths and work it out quickly. The unit shows how many Watts are being used per appliance. i.e. TV on standby is using 16watts. Meter is working fine as the Kettle uses approx 2000Watts, which would be about right.

Your maths is correct, however I would be very surprised if your TV used 16 watts on Standby.

I have several TVs and all of them have a Standby wattage of less than 1 watt. That includes 2 eight year old CRT TVs a 32" Sony at 0.6w and a 27" Panasonic at 0.9w.

What model TV do you have? and could you be measuring other appliances e.g. freeview box.

However I do understand some sets with built in freeview can have high standby.

The most useful feature of the monitor is to leave it connected for a long time to items with a thermostat e.g. fridge so you can work out consumption.

stinky

Hi

Thankyou for confirming my maths. That's what I needed.

High energy usage may well be down to a faulty oven door. It appears that it isn't fitting correctly - and I've had someone round this morning to fix it, though he couldn't as he needs to order some internal hinge parts. So will be fixed next week.

TV on standby I will check again. Did seem high to me as well. It was definitely only the TV though, nothing else plugged into the unit.

I've been running my Maytag (definitely not one for the money savers - but a beautiful fridge nevertheless) and that has given me figures of 7.68Kwh's over a period of 137.16 hours. Which works out at about 56 watts per hour. £43 per year to run the fridge. Probably expensive in fridge running terms - but perfectly acceptable for such a lovely beast.

Paul

stinky

Rechecked the TV on Standby. Its a new Sony 32v4000 LCD. So yes it was bit shocking that it appeared to be using 16 watts in Standby. Initially, it showed the same reading. So I checked the manual.

Manual states:

"Specified standby power is reached after TV finishes necessary internal processes'

That'll be why then. Left it on for a bit longer, and it goes right down to 1-2 watts. Manual states 0.7watts, so allowing for the meter's inaccuracy, it appears correct.

0.7watts over a year = 54p.

Excellent, all that rubbish about leaving your TV on standby is killing the planet etc. So much mis-information out there.

Cardew

stinky wrote: »

Rechecked the TV on Standby. Its a new Sony 32v4000 LCD. So yes it was bit shocking that it appeared to be using 16 watts in Standby. Initially, it showed the same reading. So I checked the manual.

Manual states:

"Specified standby power is reached after TV finishes necessary internal processes'

That'll be why then. Left it on for a bit longer, and it goes right down to 1-2 watts. Manual states 0.7watts, so allowing for the meter's inaccuracy, it appears correct.

0.7watts over a year = 54p.

Excellent, all that rubbish about leaving your TV on standby is killing the planet etc. So much mis-information out there.

Several of us have been preaching this for the past few years - and got some flack.

It's not that you shouldn't switch off at the mains if you wish, however such is the(false) emphasis of the evils of standby, that lots of people seem to think the most important energy saving measure they can make is to switch the TV off standby - and it aint!

Look at the number of posts on MSE complaining about their high electricty bills - which they can't understand cos "we never leave the TV on standby".