AIBU to think working out kWh shouldn't be this hard

[NumbSkills]

Divorced, moved into my own home and now counting every penny.

I'm trying to only use my washing machine and the likes when it's best price but I'm struggling to work out how much each applicable uses.
For example, I have a washing machine that says 73kWh/100. This can't mean actually 73 kWh because an hour at 28p/hr would equal £18 for each wash!

So how do I work out the cost of literally running it for each kWh. Same with oven and other white goods.

AIBU to think it should be made simpler for numbskulls like my good self?!

That measure is per 100 washes

Is this what you want? https://powercostcalculator.co.uk/cost-to-run-washing-machine/

Ignore that number, it’s not useful as that’s the 73kWh for 100 “average washes” and no one knows what that means.

Find the manual and it should tell you what the power usage is for each wash program.

It annoys me too! Especially the gas bill which is even more ridiculous to work out. You just have to do the /100 (divide by 100) part to get the actual cost.

It means 100 washes are 73 kWh so 1 wash will be 0.73 kWh.

You can then look at your tariff for a price per kWh.

I'm being so thick here!

Going by my washing machine that says 73kWh/100, and using the website give here, I have to convert 73kWh to watts so that's 7300 watts? Yet the website says most washing machines are between 400-1500 watts. So now the idea my extremely cheap budget end washing machine is 5 times more expensive seems a little odd to me.

Have I done something wrong here? I x1000 and it would have made more sense to only times by 100 to make it 730 which is fairly mid-line, but then that wouldn't be kw as there are 1000 watts in one kw.

@TisButThyName

*It means 100 washes are 73 kWh so 1 wash will be 0.73 kWh.

You can then look at your tariff for a price per kWh.*

So that means 0.73 x .28 (28p/kw) equals 0.2044, which is 20p per wash?

Yup that's right. Or at least for a standard wash. Different temperatures and faster spin cycles will use more kWh.

Energy (Joules) = Power (Watts) x Time (seconds).

A kWh is 1000 Watts used for 1 hour. (Or 3600000 Joules of energy).

So the coolest temp and slow spin will be the 400W power rating (0.4 kW).

Yeah, 20p sounds about right. For comparison our normal 30C wash was 17p last time I worked the figures out, and that was before the price drop. Similar for a dishwasher run - the tablet cost more than the 'leccy.
Basically anything that's sporadic doesn't cost much. It's the things that quietly sit there eating 20W 24/7 that end up costing you £50/year each.

First thing: kW and kWh are not the same thing.
kW is the power being given out at any one time.

kWh is a kilowatt HOUR. That is one kW for one hour.

If I use a machine that uses 1kW for half an hour, then that's half a kilowatt hour only.

If a kWh costs 30p then half a kWh costs you 15p.

If you use a 2kW machine for 3h that is 2x3kWh. At 30p a kWH that will cost 2x3x30p=180p or £1.80.

look at your electricity bill for the price per unit (kWh)

Look at the power of your machine, in kW and times that by the time it is on for in hours. Now you have energy used, in kWh

Then times that by your price per unit

(remember, hours are not decimal)

Just to confuse things further, that 730/100 is an average.
So if you wash everything on 90C, it will be higher.
If you wash everything on a 20C cycle, it will be lower.

Thank you all very much for this.

I think I was exciting it all to cost a lot more to run, and am finding it slightly confusing my bills are as high as they are - I guess having lights on costs more than you realise! I assumed the main cost belonged to white goods and can see that, especially considering I don't use them every day, this is not the case.

Maybe I won't stress so much about a washing load now though!

just fyi

https://energysavingtrust.org.uk/top-five-energy-consuming-home-appliances/

It's typically things that heat or cool - so kettles are a common thing, electric showers too, tumble driers, fridges/freezers if they are not efficient etc.

Washing machines, I think unless you use it a lot (multiple times a day) and on very hot wahes, probably isn't having too significant an effect.

We bought Tapo smart plug which I plugged the washing machine into. It told me on the app exactly how much energy the washing machine used so I could accurately calculate the specific load I used rather than the average.

All our lights and lamps are LEDs so very low wattage. It isn't usually lights though that use the most electric. Tumble dryers are really bad and then there are the things you use daily such as maybe an electric shower, dishwasher, kettle, toaster, fridge freezers are plugged in and on 24/7. It all adds up.

The Tapo can be used for anything that plugs in to check usage. We bought a 3 pack when the energy prices hiked so we could see if there was anything we could cut back on.

Just get a smart meter and you can use the display to see how much you are consuming each day and what it costs.

Some versions will even glow orange at times of high usage which can help you identify the energy monsters.

Thank you all once again for this.

It's brought peace of mind, and yet the surprising fact is my standing charges are now sometimes more each day than the amount I actually use! But it's massively improved now I can literally count every single item I use like this. Really appreciate your patience explaining it and useful websites and ideas like the various gadgets to keep tabs on things further.