Calculating Cost of Running an Electric Shower

Thargor

Hi can someone help me please as Im useless with this kind of stuff, I have a Triton T80si in our bathroom which Google tells me is 9.5 kw, can someone tell me how much that costs to run, as in cost per minute with ESB? Much appreciated, thanks.

Prenderb

I hope I can make this make sense for ya!

a unit of electricity is a Kilowatt-hour, or kWh. This is what ESB/Bord Gais/Airtricity sell you, and they charge something per kWh - the unit cost. You can find the rates in your bill or online, I'm sure...

The way to calculate it is to take the kW rating of your appliance, and multiply it by the number of hours (or no.of minutes/60) you run it for per use, then multiply that by the unit cost and this will give you the cost.

For example, we take the unit cost for a kWh at 10cents, for the purposes of a calculation.

a 1kW appliance running for an hour will cost you 10c - 1x1x10c = 10c
a 2kW appliance running for 30 minutes will cost you 10c - 2x(30/60)x10c=10c
a 10kw appliance running for 10 minutes will cost you 10x(10/60)x10=1.66

for your shower (9.5kW on for 10 mins) you'll do: 9.5 x (10/60) x (unit cost)
Using allthedoyles' rate, but a 10 minute shower: 9.5x(10/60)x19c = 30c


Hope I've not confused you.

allthedoyles

afaik , its 9.5 units of electricity an hour .

A unit of electricity cost around 19 cent inc. vat .

So if you have a 15 minute shower , you will use 2.375 units of electricity , and this will cost you 45 cents including vat .

Of course , I may be corrected on this one .

Prenderb

ESB do an online calculator!

https://www.esb.ie/esbcustomersupply/residential/energy_efficiency/appliance_calc/appliance_calculator.jsp

and apparently

Unit price of electricity based on 2009 (May 1st.) 16.51c per Unit (including VAT).

Thargor

Ye gods what a quick and helpful forum the DIY Board is :P

Wicked, thanks for that, way cheaper than I thought, will have to look elsewhere for the causes of our ridiculous bills, probably all the laptops on all hours of the day, that ESB calculator is a great link, thanks everybody.

allthedoyles

On our June '09 ESB bill , a unit of electricity cost average 22 cent. This is why :

1. 471 units @ € 0.164 = € 77.24
2. Standing Charge = € 17.14
3. PSO Rebate = € -3.82
4. Vat 13.5 % = € 12.23

Total = € 102.79

So € 102.79 divided by 471 units = € 0.218 cent per unit .

This is a domestic household customer .............Dont know where ESB get 16 cent from .?

Prenderb

Obviously they say they charge 16c per unit for the electricity, but as you correctly calculate allthedoyles, the actual cost per unit is higher - though it might vary slightly per month, your method does yield the actual cost per unit as charged on a bill to the consumer. I wonder will their online calculator factor this into consideration? Probably not.

OP, bear in mind that the online calculator and the cost per unit (based on the 16c figure) methods outlined above will only give you the cost of running that appliance for that period of time, and doesn't take into account the fixed costs (standing charge) that the provider also charges you. If you want to portion the fixed costs and VAT to each appliance per 2-monthly charge, you'll have to calculate the actual cost per unit as allthedoyles has 2 posts ago.

For the purposes of quickly costing the shower for 15 minutes though, or any other particular appliance's particular cost-contribution, I'd use the 16c figure just for easiness, because that's what it adds to your bill - the fixed charges will never go away no matter what your usage is.

In fact if you do an allthedoyles' calculation on it, the cost per unit of the electricity will go up as you use less electricity, because the fixed costs are apportioned over fewer kWhs! Now I'm sure we're all confused!

Joey the lips

Thargor wrote: »

Ye gods what a quick and helpful forum the DIY Board is :P

Wicked, thanks for that, way cheaper than I thought, will have to look elsewhere for the causes of our ridiculous bills, probably all the laptops on all hours of the day, that ESB calculator is a great link, thanks everybody.

Doubt its laptops!

Check that the last few bills were not estimated

Check the Immersion is not left on.

Check the dryer is not used a lot

Turn off all the appliences temp in the house. I dont mean the main fuse. Actually go around turning everything off and check and see if the meter is still running. It happens!