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.

Turns out my Set Top box - it has a quick standby mode and full on eco standby - but that takes longer to warm up.

On quick standby, it runs at 10 watts - so about £35 a year. I have changed the settings now so it goes to full eco standby.

Useful to know @cakeorwine. Thanks for posting.

Thanks. That makes it really clear.

I was quite surprised by my set top box actually.

It's useful to know which devices can have a reduced use - such as showers, without having a 'lifestyle' impact - where as turning a light off and sitting in the dark is not going to save much money relative to the potential lifestyle impact.

I can see when DS wakes up as my Smart Meter display suddenly kicks in as his gadgets come on

Thanks!
It would be great to have someone do this for fridge freezer, freezer, fridge and electric ovens, washing machines, tumble dryers - or that they were available on manufacturers' websites.

www.centrica.com/media-centre/news/2022/vampire-devices-cost-households-147-per-year/

I think it was AO that had average running costs on their website. I got a heat pump tumble dryer after seeing the figures laid out.
it’s made a massive difference.

Devices are supposed to come with product fiches that say the energy usage per year.

e.g.

www.currys.co.uk/products/grundig-vitaminzone-gkf3581vps-6040-fridge-freezer-stainless-steel-10227700.html

The product fiche is

currysprod.a.bigcontent.io/v1/static/gkf3581vps-38952.pdf

About 280 KWH per year - so about £126 a year or £10 a month

What would a fan be, around 12 inches?

That has been disproved.
It's based on old data, from the USA, with devices that don't have efficient standby

www.theguardian.com/money/2022/apr/29/tech-expert-energy-vampire-devices

A typical device on standby uses about 0.5 - 1 watt. So about £2 - £4 per year.

If you have a lot of devices, then it can add up

My washing machine tells you how many kWh are used per cycle so it's fairly easy to work out how much it costs to use.

The generic energy usage per year isn't very helpful as it depends how often you use it, which cycle etc.

I did this recently -when we brought one

Our fan is about 50 watts. So in 20 hours, it would cost 45p

So about 2p an hour?

No I agree.
It does give you a vague idea though

I've just done an experiment in the house.

My 'background' power usage was about 40 watts - so about £160 a year.

Router - consumes about 8 watts when turned on. That's about £32 a year - or 70 units.

Set top box - 12 watts when in stand by mode - so about £47 a year - 120 units

Boiler - I turned the switch off and it seems to be using about 6 watts - so £24 a year - about 52 units

Alexa - 3 watts - so about £12 - 26 units

I have made a change with the set top box - it's now in eco mode. Alexa may go off during the day as well as no point it being on when I am not in

The router - reluctant to turn that off during the day - but maybe it could make a difference. Nothing important that is wi-fi enabled when I am not in but I know that routers need updates. Maybe there is an eco setting on it.

It will make a difference in the energy that I use. And if a lot of people did similar, then that could add up.

I have a plan with DS to see if we can reduce our energy usage this year.

Does anyone know how energy efficient these are? Or how to work it out please?

www.lakeland.co.uk/21736/dry-soon-3-tier-heated-airer#product-details-accordion

I have one that I leave on overnight. We don’t have a smart meter though, and can’t get one, and I wonder how it actually compares to using the dryer for an hour instead.

What about a 750kw oil filled radiator ?

That's a good point.

It depends on how long it takes to heat it up - I guess you mean a 750 watt radiator?

Obviously once it heats up, it then occasionally tops up the energy.

I have a fan heater - it's 2000 watts. But it reacts to the room temperature so you can see that once it's warmed the room up, it just occasionally comes on again to maintain that temperature.

A 2000 watt heater without thermostat control would cost about 2 units per hour - 90p. But then it would just occasionally need to come on once it's warm enough

Kettles use a lot, I was staying in a house with a smart meter and whenever I put the kettle on it would jump up and say we were using 45p per hour or something like that. One of the changes I made a few months ago after we got a killer electric bill was that I started to boil the kettle with more water then filled up a thermos flask with that water and then whenever I wanted a cup of tea, I'd use water from the thermos rather than boil the kettle. Now our electric company is going under and selling, and we're going to lose our very very good fixed price contract, and we're going to have to get more expensive electricity (granted, not as expensive as you're looking at in the UK but still 3 times more expensive than I'm paying now) I'm going to get an even bigger thermos so I only have to boil the kettle once a day. And turn the heating down even lower in the winter (we reduced our usage by about half just by turning the heating down a few degrees, the kettle thing, and halving our sauna usage).

I've just bought an energy monitoring smart plug for £10 to see how much all my devices are using in the background. Fridge freezer is the highest at 1.2KW per day, Sonos, Alexa and WiFi are the next largest- about 0.2-0.3 KW per day.

I'd really recommend it - very interesting to see the true energy consumption of gadgets, and we've already identified so e to start turning off at night.

Not the thermos and the kettle thing!!

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.

Boiling 1 litre of water - it's 330, 000 joules of energy. That's about 0.09 KWH - so about 4p

It will cost 4p if you boil 1 litre in 1 go and put it in a thermos or 4p if you boil 1 litre in 4 lots of 250mls

It may cost 45p an hour at the moment - but it doesn't take long to boil water

If you want to save money boiling water, then boil less water. Boiling for the day and putting it in a thermos will not save money.

Based on 28p per kw roughly, a 9kg vented tumble dryer uses 5.34 kWh for a full load cycle and approx 636 kWh over a year (if you use your dryer around two times a week). This means that approx, a vented tumble dryer costs £1.50 per cycle and £178.08 per year on average. You can double that after the next price rise though. I am practicing drying clothes on a rack and keep pulling it back inside every time it bleedin rains!

@Natsku thats not going to save you any money and leave you with like warm tea to boot.

why not just boil what you need?

Please don't turn your routers off. They cost about £10 a year to run. Overnight your service provider will push firmware updates and changes to config files.

A lot of service providers also use an automated stabilisation process to keep your broadband healthy. If it detects regular power interruptions, the speed will be slowed down until it becomes stable again and will then ramp up over the next 7 days. If you switch off every night, the line will never be seen as stable and your speed will be throttled. You will reboot your router and the speed will pick up again for 30 mins or so, until the dynamic line management kicks in again and slows you down.

Just don't turn the router off please.

I can't boil just enough for one cup, that goes below the minimum line in my kettle. The thermos keeps it plenty hot enough because I don't take milk in my tea so usually I have to add cold water to cool my tea down enough to drink it.