Money saving tip

Redwurzel

Redwurzel

Well-known member
I must sound like Ebenezer Scrooge...

We found boiling a kettle of hot water and mixing it with cold water reduced our energy bill for dishwashing. The electric bill only rose a little, but gas consumption dropped 10%. Gas seems a more expensive energy source than electricity. We reduced our direct debit by £10 per month yesterday because we had built up a £400 credit.

We haven't really got room for a dishwasher and it must be a more expensive way to wash taking into account its capital cost and tablets.
 
I don't think there would be much in this, certainly not a 10% gas saving.


I found a comparison online, it's about 10 months old so unit prices have dropped


  • Running a 3kW kettle for 2.5 minutes will use 0.125kWh (1/8 of a kWh). At 34p/kWh that will cost 4.25p (exactly as @BooJewels stated above).
  • Heating a gallon (4.5 litres) of water from 10C to 60C uses 0.26kWh (just over 1/4 of a kWh). At 10.3p/kWh it will cost 2.7p. But you then need to heat the water you're going to use to wash up with, which is another 0.125kWh and 1.3p, so the total cost is 4p. Plus your gas boiler isn't 100% efficient, so you can add another 0.6p to that for a total cost of 4.6p.
 
There's nothing bad about wanting to save money, or do things in a more efficient way (latter being greener also).

A dishwasher can cheap/ efficient to run, we basically have like 2 days of dishes go in there, and cram it in, and we set it to come on when energy is cheap, about 2am on an eco cycle which is about 4.5 hours, so it's ready to empty when we get up, but we have a tarriff to be able to do that.

This intrigued me though, so had a daft attempt at working it out.

I think dishwashers use about 1kW of energy, per cycle, and there's not a great deal in it from the most efficient to the least efficient cycles, ours ranges from 0.8kW to about 1.4kW I think, per full cycle. So for us that's about 15p to run it, and then maybe 10p for the tablet. So, 25p for two days, which would be hard to beat, I expect.

A kettle is ~2.5kW, but only runs for what 5 minutes? So you're only using maybe a 10th of the hourly use, so 250W, but how many times would you be doing that over 2 days, just to wash up? 4-6? Probably works out a bit more than a dishwasher, maybe 50% more, around 1.5kW of electric?

A gas boiler is using ~20-40kW per hour, but that's kW of Gas, which is about 1/4 of the price of electric (tarriff dependant). If it's a combi and you're running the tap for 5 minutes then that's maybe 2-4kW of gas, plus whatever it takes to wind up, which I bet isn't efficient, never mind running the water through the pipes for such a low volume of water actually required. Do that a lot of times for any use, and it won't work out cheap or efficient. Also boilers are not top end efficiency, unless brand new and top of the range etc (which most aren't).

Long winded answer, but I expect there isn't a great deal in it either way, and it's more actually about efficiency from combining tasks, albeit not that simple in some circumstances. Nobody wants a 2 day stack of stinking (and sticking) dishes, where as having them locked away in a dishwasher is fine.

Electric heaters and electric water heaters are extremely efficient though, the trick with them is use short and sharp bursts, as the unit cost of electric is higher (in most cases).
 
Andy_W said:
There's nothing bad about wanting to save money, or do things in a more efficient way (latter being greener also).

A dishwasher can cheap/ efficient to run, we basically have like 2 days of dishes go in there, and cram it in, and we set it to come on when energy is cheap, about 2am on an eco cycle which is about 4.5 hours, so it's ready to empty when we get up, but we have a tarriff to be able to do that.

This intrigued me though, so had a daft attempt at working it out.

I think dishwashers use about 1kW of energy, per cycle, and there's not a great deal in it from the most efficient to the least efficient cycles, ours ranges from 0.8kW to about 1.4kW I think, per full cycle. So for us that's about 15p to run it, and then maybe 10p for the tablet. So, 25p for two days, which would be hard to beat, I expect.

A kettle is ~2.5kW, but only runs for what 5 minutes? So you're only using maybe a 10th of the hourly use, so 250W, but how many times would you be doing that over 2 days, just to wash up? 4-6? Probably works out a bit more than a dishwasher, maybe 50% more, around 1.5kW of electric?

A gas boiler is using ~20-40kW per hour, but that's kW of Gas, which is about 1/4 of the price of electric (tarriff dependant). If it's a combi and you're running the tap for 5 minutes then that's maybe 2-4kW of gas, plus whatever it takes to wind up, which I bet isn't efficient, never mind running the water through the pipes for such a low volume of water actually required. Do that a lot of times for any use, and it won't work out cheap or efficient. Also boilers are not top end efficiency, unless brand new and top of the range etc (which most aren't).

Long winded answer, but I expect there isn't a great deal in it either way, and it's more actually about efficiency from combining tasks, albeit not that simple in some circumstances. Nobody wants a 2 day stack of stinking (and sticking) dishes, where as having them locked away in a dishwasher is fine.

Electric heaters and electric water heaters are extremely efficient though, the trick with them is use short and sharp bursts, as the unit cost of electric is higher (in most cases).
Click to expand...
Andy_W you never short change the board with your analysis (on any topic).😃👍
 
Andy_W said:
There's nothing bad about wanting to save money, or do things in a more efficient way (latter being greener also).

A dishwasher can cheap/ efficient to run, we basically have like 2 days of dishes go in there, and cram it in, and we set it to come on when energy is cheap, about 2am on an eco cycle which is about 4.5 hours, so it's ready to empty when we get up, but we have a tarriff to be able to do that.

This intrigued me though, so had a daft attempt at working it out.

I think dishwashers use about 1kW of energy, per cycle, and there's not a great deal in it from the most efficient to the least efficient cycles, ours ranges from 0.8kW to about 1.4kW I think, per full cycle. So for us that's about 15p to run it, and then maybe 10p for the tablet. So, 25p for two days, which would be hard to beat, I expect.

A kettle is ~2.5kW, but only runs for what 5 minutes? So you're only using maybe a 10th of the hourly use, so 250W, but how many times would you be doing that over 2 days, just to wash up? 4-6? Probably works out a bit more than a dishwasher, maybe 50% more, around 1.5kW of electric?

A gas boiler is using ~20-40kW per hour, but that's kW of Gas, which is about 1/4 of the price of electric (tarriff dependant). If it's a combi and you're running the tap for 5 minutes then that's maybe 2-4kW of gas, plus whatever it takes to wind up, which I bet isn't efficient, never mind running the water through the pipes for such a low volume of water actually required. Do that a lot of times for any use, and it won't work out cheap or efficient. Also boilers are not top end efficiency, unless brand new and top of the range etc (which most aren't).

Long winded answer, but I expect there isn't a great deal in it either way, and it's more actually about efficiency from combining tasks, albeit not that simple in some circumstances. Nobody wants a 2 day stack of stinking (and sticking) dishes, where as having them locked away in a dishwasher is fine.

Electric heaters and electric water heaters are extremely efficient though, the trick with them is use short and sharp bursts, as the unit cost of electric is higher (in most cases).
Click to expand...
We try and only wash up once a day and only eat one cooked meal a day.

Remember a dishwasher will cost money to purchase, £400 delivered if its used 1200 times in its life that's 33p/use. I haven't included interest costs neither.

I was surprised gas usage dropped by 10% but it has, which to us is roughly £75 saving a year on gas costs. It could be the reduced gas is from other heating but not 10%. We only use gas to heat water, no gas cooker or fires. Its a 4 year old combi boiler and the water has to move from the upper floor to the lower floor. The kettle is 2.5kw, usually heat 1.5 litre of water. The gas and electric tariffs are fairly standard B/G ones.
 
We have a dishwasher. I prefer to do the pots in the sink. Instant gratification instead of waiting a full day for me favourite glass to be processed 🤣.

Once worked with a lad who swore by having two dishwashers, basically once one had finished he took stuff from it, used it, then filled the other and changed direction. He said it saved putting owt in the cupboards.
 
we have a 21 yaris i used to put £40-£50 in on a regular basis with any of my previous cars suzuki vitara ,ford fiesta now £20 -£25 gives 350 miles aprox downside they are more expensivethan other cars.
 
Redwurzel said:
We try and only wash up once a day and only eat one cooked meal a day.

Remember a dishwasher will cost money to purchase, £400 delivered if its used 1200 times in its life that's 33p/use. I haven't included interest costs neither.

I was surprised gas usage dropped by 10% but it has, which to us is roughly £75 saving a year on gas costs. It could be the reduced gas is from other heating but not 10%. We only use gas to heat water, no gas cooker or fires. Its a 4 year old combi boiler and the water has to move from the upper floor to the lower floor. The kettle is 2.5kw, usually heat 1.5 litre of water. The gas and electric tariffs are fairly standard B/G ones.
Click to expand...
As said above your gas wont have dropped 10% off the back of that change, there is very little difference between the two costs.

Gas usage would fluctuate because your bath might be a minute longer here, a minute longer there or you might have been away for a day or two. 10% would be a significant saving and MSE would be all over it.

There's also the amount of time you spend washing manually and drying vs dishwasher, even if you drip dry.

But the deciding factor for me is videos where people have swabbed dishes after a dishwasher cycle and then swabbed hand washed dishes and grown cultures from it.


https://www.tiktok.com/video/7275413391911701806


For the time saved and not having bacteria all over my dishes, 33p a wash sounds excellent value
 
The biggest money saving tip I can offer is leave the pub at 5pm on a Saturday and go home rather than staying out til last orders and then heading down the village to the bars that stay open later. I haven’t experienced it yet but I am sure I’d save money if I did it. I also would also experience a 7 day week instead of losing Sunday.
 
Yeah I did this same calc 12 months ago but using actual data. My boiler fires up as you turn the hot tap on in kitchen sink but still takes 50s to flush out the cold in the pipes then takes about another 45s to fill a washing up bowl at 45 degrees , as I don't need it any hotter than that. Looking at my notes it took 0.057 metres cubed of gas for the 95s burn which at todays prices is about 4.7p. I don't think 10% swing is realistic.
 
It's a funny one, as a dishwasher will actually use dirty water to wash your dishes. But it's the heat of the water that is significant. But still, I'm not that keen on water mixed with food residue cleaning the dishes - even though the heat of the water effectively cleans them.

On the flip side, it is said that dishes that are hand washed have more bacteria on them. But on the flip side again, children are said to have a much increased rate of allergies if a dishwasher is used. This is because we need to be exposed to bacteria for our immune systems to develop properly.
 
Instead of a tumble dryer, get a 'Dry:Soon' drying pod. I swear by mine. It dries everything in about 40 minutes and doesn't shrink it. I don't actually know how much cheaper it is, but I bet it is cheaper.
 
Norman_Conquest said:
  1. Two ply toilet tissue lasts twice as long if you separate the sheets in half.
;)
Click to expand...
There's no such thing as cheap toilet paper.
First rule of toilet paper....... Thy finger shall not go through!
How many times have you stayed somewhere where the toilet paper is so thin you end up using several sheets to obey rule one.
Consequently the roll disappears very quickly.
Saving Zero money
 
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