Power showers can be expensive; depending on how the water is heated for the shower. What you may not appreciate is the amount different types of shower will cost you to run. The table below shows seven types.
| Type of shower | Cost of 10 minute shower | Cost of a shower a day for a year | Flow |
| Electric shower 8.5 kW | 21 pence | £ 75 | Low |
| Electric shower 10.5 kW | 25 pence | £ 93 | Low |
| Low flow shower gas heated water in cylinder | 12 pence | £ 44 | Low |
| Low flow shower electric heated (immersion) water in cylinder | 39 pence | £ 141 | Low |
| Power shower using gas heated stored water | 29 pence | £ 104 | High |
| Power shower using electric immersion heater | 116 pence | £ 424 | High |
| Combi boiler power shower 30kW | 25 pence | £ 91 | High |
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Five types of shower and their running costs |
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What may surprise you is that power showers which use gas to heat the water cost about the same as a high powered electric shower to operate, the high power electric shower however will be less forceful. The “same cost, more force” aspect is simply due the lower cost of Gas per kWh.
As an observation, it may in spite of this, be sensible to have an electric shower in case the gas boiler fails. It will also use less water, if that is a concern wher you live.
The very chepest option is just to use a mixer valve off the gravity fed water from a hot water cylinder, where a gas boiler has been used to heat the water, and this is only completely true if you use the full cylinder of hot water over a day or so, otherwise the heat is simply lost to the house.
The key tip here is do not use an electric immersion heater to heat water it costs a fortune!
The tips here are based only on running cost, and it is worth noting that if you are deciding whether to install, for example an electric shower, it will cost at least £ 400 and if you are using and water from an immersion heated cylinder with a low flow shower currently it will take you 15 years to pay back the investment, if money is your only concern.
It is very difficult to recover low levels of heat. Transferring the heat should be possible with losses.
I worked a bit with this company 10 years ago, their heat transfer pipes certainly work, but are probably expensive. http://www.thermacore.co.uk.
The ideal I guess is to transfer low level heat to electricity, I found this which may offer a route in the future http://www.rsc.org/chemistryworld/News/2011/May/03051103.asp
Tell me if you find anything, I'd be interested.
Cheers
Richard
Are you aware of any technology that can reclaim back that energy which is stored as excess heat in the cylinder but not needed for bathing or laundrey? I'm looking at ways of making householders aware of this form of wasted energy. Any ideas?
Keep up the good work.
Les C
Experimenting by plugging the shower tray drain. the factor difference of water consumption is about 8 to 1per minute...quite a saving. The only down side is needle jets calcify quickly, so a caustic head clean is required more often.
Have a play!!!