Dishwasher vs washing up. energy costs

Steveotwo

I often wonder as I load the dishwasher up would I be better of energy wise just washing up? 

Dish washer model is fairly old, but so Is my boiler with a water tank and I am on a water meter. Is there nothing in it? 

Not a serious problem that I am desperate for an answer for but if anyone knows the most efficient method of washing pots let me know 😅

dunstonh

A dishwasher on eco mode will be so cheap that its not worth the effort of washing up in most cases.  ("most" because not all eco modes are created equal).

Our dishwasher uses 0.54kW per load.   At 5p kWh that is just under 3p a load.        If you are not on economy 7 or an EV tariff but a single rate, then you are looking at around 10p.    
Water is 9.5 litres per load.

Thats a modern machine that is A rated.

DullGreyGuy

It will depend a lot on your appliances, style of washing up by hand etc.

Our dishwasher use 0.5Kw of electricity and 10L of water on its eco setting when its full so about 12p

For your handwashing is variable as old boilers can be 60% efficient where as new ones can be 90%, incoming water temp impacts, how hot you like the water, are you using bowls or a running tap etc etc. A guesstimate says its 1.5kw of gas which would be around 9p 

There are other considerations of if you are doing a full load for a dishwasher or heating a whole tank of water which is then just left to cool when you've used the bit needed for washing up etc. 

In principle our dishwasher could be hooked up to the hot water supply which would notably reduce its energy use but probably increase water use given how long it takes for hot water to get through to the kitchen 

Steveotwo

@DullGreyGuy
Thanks so its likely the dishwasher is the way to go for water and energy. I don't use a running tap a bowl. 
We have just moved in I had a super efficient dishwasher at our old place but this one seems older and doesn't have eco mode 😶

DullGreyGuy

Dishwasher will probably use less energy but its electricity which is more than twice the price of gas and so cost wise it can go either way but there are so many variables its only a very rough calculation. 

The above also doesn't consider the cost of the soap but again that comes down to if you are buying a budget dishwasher tablet at a few pence each or getting small packs of premium ones delivered from your local convenience store at 35p a tablet.

p00hsticks

DullGreyGuy said:

The above also doesn't consider the cost of the soap but again that comes down to if you are buying a budget dishwasher tablet at a few pence each or getting small packs of premium ones delivered from your local convenience store at 35p a tablet.

If we're really going all in with the calculations, we should perhaps be factoring in the cost of a dishwasher compared withe that of a washing up bowl and set of dishclothes!

calleyw

To make it a cheaper use powder not tabs as they are expensive.  I get mine from sainsburys 

https://www.sainsburys.co.uk/gol-ui/product/sainsburys-dishwasher-powder-12kg

Swipe

I live alone and boil a third of a kettle to do washing up in a bowl (just a few plates and a couple of cups) every other day. I find it easier than loading and unloading the tabletop dishwasher. I use my dishwasher once every couple of weeks just to keep the pump active and to get a good deep clean on everything.

pseudodox

I don't have a dishwasher and just wash up by hand 2 or 3 times a week when I have a sink full.  Also time it for when I have been gardening or DIY jobs as it gets my hands & especially nails clean.  I use the hot soapy water to wipe down worktops & the hob.  If I am not doing greasy pans the water can then be used to spot clean the vinyl flooring or be chucked outside to brush down the paving.  In summer when (if) rainfall is it short supply it can be decanted into a bucket & thrown on garden shrubs.  How does dishwasher water get recycled?  There might be less of it draining away, but what about water use for all the other jobs.  As a solo household I use less than 20 cu m water per year.  The combi boiler is next to the sink so hot water delivery is almost instant.

So it all depends on individual style/preferences/household size etc. There is no definitive right answer.

PRAISETHESUN

I bought a second-hand dishwasher when I moved into my current place, best £50 I ever spent (got an absolute bargain on a relatively new Bosch machine). I value the convenience of not having to wash up, but even then it's cheap as chips to run. Takes me a few days to fill it up and then away I go. There's obviously a few things that need to be hand washed (don't put good knives in the dishwasher, etc) but it's a tiny amount in comparison to washing up everything by hand.

MP1995

Probably the most expensive differences are dishwasher tablet versus a squeeze of washing up liquid, the water use difference and around 10-20p depending what tariff and options you have on your dishwasher.