Comparing cost of electric shower to oil water heating

Bexm

Hi

We have recently got a smart meter and have realised our electric shower is using so much electricity!

We are intending on doing up our bathroom in the near future and trying to work out if it would be cheaper to switch to a mains shower. 

We have an oil boiler but have no clue how to compare how much electric we'd used against how much oil we'd use for a shower to know if we'd be better off!

Weve got a tank level display thing but there's no smart meter like the electric. 

Any ideas how we'd do this?

Bex

Bexm

@wittynamegoeshere
I have watched our smart meter when someone's showering and its costing around 15-30p (on our old tarrif as not updated) a shower depending how long they are in there for.
You can also see the huge spike in the mornings on the daily graph (our readings go every 30mins)

We've only got a oil tank level monitor, nothing to show actual use. 
Its a Combi oil boiler, so no hot water tank. 

We have an electric shower on our ensuite also, so we'd still have something if we had boiler probs. 

Reed_Richards

Heating oil cost about 55p per litre at the moment and you get about 10.35 kWh per litre so that would be about 5.3 p per kWh if your boiler was 100% efficient, 6.25p per kWh at 85% boiler efficiency.  Whereas electricity currently costs about 20.5 p per kWh. You'll leave a certain amount of unused hot water trapped in the pipes feeding your shower so if that cools down that would be a small extra cost per shower. 

If you have a hot water tank that tank will lose heat but since it will do that anyway it doesn't enter into the equation when working out the cost of a shower.  So a shower with water heated by an oil boiler will cost roughly one third the cost of an electric shower.    

matelodave

As said above, it will cost you three times more to use leccy than it will oil. If you've got a combi boiler the the only heat losses are those in the pipework between the boiler and the shower. Obviously the best way to save energy is to use less hot water especially in the shower.

Don't believe the myth that showers are cheaper than a bath especially if you like long luxurious ones under a deluge of water.

Ten minutes at 15 litre/min = 150 litres which is twice the capacity of a normal bath, so get an eco shower that delivers around 6-8lpm and only shower for five minutes and you'll only use 30-40 litres.

Astria

Bexm said:

@wittynamegoeshere
I have watched our smart meter when someone's showering and its costing around 15-30p (on our old tarrif as not updated) a shower depending how long they are in there for.
You can also see the huge spike in the mornings on the daily graph (our readings go every 30mins)

Most showers have an economy setting where they'll use something like 7kw (or less) instead of 11kw, but you'll obviously have to reduce the amount of water passing through it to gain the same temperature of water, which isn't a bad thing considering a lot of places now have water meters also.

7 kw for 5 minutes (typical showering time) should be about 0.58 kw, so about 10p at current prices. Oil would be cheaper, gas cheaper still, but before you start ripping things out because they cost too much, consider how much it's going to cost to replace. Showering every day is only like £36/year.

Ectophile

If you think our showers are unsafe, you should see the "suicide showers" used in some other countries.

The heating element is a bare coil of resistance wire inside the shower head. The only added protection is a metal electrode between the heater and the shower jets. If you're really lucky, the electrician may even have connected that electrode to earth.

In reality, deaths from electrocution by UK electric showers is very rare. In ours, the heater is inside an earthed metal tube. And clean tap water is a very poor conductor of electricit anyway.

QrizB

wittynamegoeshere said:

On anything outdoors, the path to the terminals is sealed and there's a drain hole elsewhere to get rid of any condensation or water that's found its way in.

Many outside electrical fittings are IP44, not sealed against jets. Example.

We're getting off the point, though.