The true cost of running electrical devices - a useful guide?

[cakeorwine]

I did a thread a while ago on electrical devices - even more relevant now with the coming increase in energy costs.

This might be useful for people to get an idea of what it costs to run devices.

These calculations are based on a unit of electricity being 45p / KWH which is what it could be in October (it's currently about 27p / KWH)

A 1 watt device run for 1000 hours uses 1 unit of energy.

There are 8760 hours in a year - so that 8.76 units of energy = £3.90

For context, my Alexa is about 3 watts and it's on all the time - so it would cost 3 * £3.90 = about £12 a year to run.

A TV is between 50 - 100 watts.

So if a 100 watt TV was run for 10 hours, that's 1 unit (100 10) - so about 45p per 10 hours or 4.5p per hour*

A hairdryer is about 1500 watts (on high speed, high heat). So in 1 hour, it's used 1.5 units or 67p. - so about 1p a minute

A PlayStation 5 on active gaming is about 200 watts - so in 5 hours, it's used about 1 unit - so 8p per hour

An electric shower - about 10 kilowatts, so in 1 hour (full speed, full heat) - it's used £4.50 - so about 7p a minute

Just a few examples - but you can see how devices use energy

Standby mode is very good now - about 1 watt - so a device on standby will use about £4 per year. Obviously lots of devices on standby do add up.

I am sure people can post other examples. It's just useful to know where your energy goes.

This is a great thread, @cakeorwine Thank you for starting it.

@BertieBotts

Be aware that some devices like washing machine, tumble dryer, dishwasher and maybe ovens etc don't use a consistent amount per hour so these calculations can be misleading. For example for things that heat water, they use loads of electricity while heating the water but once they have done that, the pump or motor getting the water around onto your clothes or dishes isn't using anywhere near as much. However as someone pointed out above you can usually find the energy use of the main cycle on the EU energy sheet on the website. This is also how the longer cycles can be more eco friendly despite being longer

Absolutely. It's like ovens which warm up and then don't need much energy to stay at that temperature.

Plug in energy monitors are useful, as is a Smart Meter. It's interesting when we use the oven to cook as we can see that on our gas reading as it's been the only use of gas during the day.

Thank you @cakeorwine - Thermos it is! (I really appreciate the breakdown !)

Be interested to know about dishwasher costs. Our dishwasher on the Eco programme takes over 3 hours. The quick wash takes 30 mins and unless there are very dirty pans/dishes in there this programme is more than adequate (maybe doesn't dry as well but I empty things onto a tea towel on the worktop to soak up excess moisture before putting away).
Ditto my washing machine. Try to put most things through on Eco wash - 1 hour - instead of the full programme which is 2 hrs 50

Quick washes usually use the most power whereas eco washes trade convenience (time taken) for power used.

Be aware some models are sneaky and the eco mode has lower capacity - this is likely if it's actually shorter.

Sometimes the manual will list the power used per cycle. I think most likely only on the very modern machines, as I've never seen this even though I've looked for it over several machines I've owned.

On my washing machine I tend to use either the eco 3:45 cycle or the cottons 40 degree + time saver which says 1.10 but it's about 1.30.

On my dishwasher I use the 45-65 degree wash as this apparently selects a temperature based on the dirtiness of the dishes, which I tend to think is a good idea because it will only be using as much as it needs to use.

This is quite good about the power usage of different cycles - the linked dishwasher one is similar about the dishwasher.

Interesting! I have been putting my washing machine on a shorter cycle in the hope that it would save electricity - but clearly not!

My eco wash is 4 hours, btw.

Thank you for this thread. You are my kind of people!

This is maths and physics in action - actually quite a good project for children to learn about energy and to apply maths and physics in real life.

@NewBootsAndRanty

"I was thinking about getting one of those one cup water heater things instead of a thermos - the minimum fill level on my kettle is 2 cups and i live alone."

Or would a smaller kettle work? Those ones you get in hotels- might they have a 1 cup minimum level? I'm not sure....

Oh my link didn't work. This was the video I tried to share.

I fill our kettle to the minimum line to make our tea.

I immediately refill kettle to min line again so that the cold tap water reaches room temp in the kettle ready for next time so a smidge less energy needed to boil.

You will use the same amount of energy and it will cost you EXACTLY the same if you boil 1 litre of water in 1 go or do 250 mls of water 4 times. It's the same mass of water being heated to the same temperature and it requires the same amount of energy.

It will use the same amount of energy to heat the water, but you also have to heat the element and consider heat lost to the surroundings (no kettle is 100% efficient) so it would cost slightly more to do it 4 times.

I boil water in the cup in the microwave for a single cup of tea.
As I’m on Economy 7 I use all power hungry appliances before 7 in the morning (8 in summer).

I boil water in the cup in the microwave for a single cup of tea.
As I’m on Economy 7 I use all power hungry appliances before 7 in the morning (8 in summer).

Last evening we had the tv on, 2 iPads charging. A PC on and 4 lights on. My smart meter said I was using 2p and hour so the TV doesn’t use much at all. Not sure if your calculations match what I use

A nice shower before 7am!

I do think it's useful for people to get an idea - a while ago I didn't think too much about the cost of running some gadgets like a gaming PC - but you can see that it can add up if used regularly over a long time -as the cost of energy increases.

And some relatively low 'lifestyle' costs can reduce your usage quite a bit.

I have a shower timer now - you simply press the time you want and it beeps after that time. I am encouraging DS to use it.

It's the watts you need to look at - as your rate may be different to the standard rate

Depends on the TV you have and the PC - some are better than others.

Apparently - I didn’t actually hear this - Radio 4 said that air fryers are use 75% less energy than an oven (but which oven?). So a cheap air fryer should pay for itself quite quickly.

Depends on how much energy your oven uses.
Pay back time is interesting.

Any idea on cost of gas v electric for boiling a kettle? I use an electric kettle but was thinking of buying one for on the hob but gas is getting expensive as well so not sure if it is worth it.

If you want to know exactly what a device is using, I have used a plug in power monitor - you can see the typical wattage and then if you leave it in, you can get a picture of the KWH used.

TVs seem to be from 50 - 100 watts depending on model.

So 10 hours of TV watching could cost 45p. Which can add up over a month or a year

It's the standing charges that are going up. So even if you use nothing and sit in the dark eating your delivered takeaways, you will still be charged more.

www.moneysavingexpert.com/utilities/what-are-the-price-cap-unit-rates-/

Cost of running a PC depends on the type of PC and what you're using it for. My PC is about 70-110W on normal use, but can go up to about 250W when gaming. My Mac Mini on the other hand sits around 10W.

Not sure if it has been said but buy a gizmo. Costs about £20[or it did about 1 year ago]. We went around the entire house and measured the actual usuage of each electrical appliance. Sometimes measured the appliances over a 24 hour period. Like fridge and freezer etc.
Some of our appliances are old, so could find out the real usuage.

Made several changes based on all the readings.