If you have an electric shower you will be well aware that it’s no power shower, but you may not have realised that electric showers cost over three times more to run, and waste water (when compared to traditional showers). Manufacturers of electric showers claim environmental advantages if you buy an electric shower, but only if compared with water wasteful Power Showers.
It is not difficult to prove that electric showers are expensive to run. Electricity costs four times more than gas. If you heat the same volume of water by electricity when you have a gas boiler, it will cost three to fours times more. From the 1st of April 2022, electricity cost was 29p per KWHr and gas costs 7p per KWHr
It is still is the policy of many councils to fit electric showers in favour of traditional showers with no regard for cost or alternatives. This not in the interests of tenants or Council budgets. Many councils and private individuals are not aware of the savings that can be made if they avoid electric showers.
Saving Water – Electric Showers vs Traditional Showers
Having surveyed 2,000 people across the UK, Triton found 86% of respondents claim reducing water waste is important to them. Electric showers can only heat a small volume of water on demand but they do not save water.
The optimal output of a shower to wash away suds quickly and efficiently is 6 litres a minute for 5 minutes, this delivers 30 litres in total. Water needs to be delivered to a shower head with enough pressure to achieve a good spray and dispersal pattern.
In trials by the consumer magazine Which in 2021, they reported on a popular 8.5KW electric shower .On the high setting it gave water flow at a rate of 3.6 litre per minute. Delivering water at 3.6 litres a minute will require close attention to directing what little water you are getting to specific areas of your body. To deliver 30 litres of water to a low flow electric shower will take between 8-9 minutes. If you are not careful in applying the electric shower head to every bit of your body you will miss bits and spend more time in the shower wasting water.
When comparing traditional showers to electric showers , if you shower for 5 minutes at 6 litres a minute under an effective shower head, or 9 minutes at 3.6 litres a minute under an inefficient shower head, this gives no saving of water. In the same survey, 55% thought eco-friendly models cost more, and on the basis of water consumption there is no saving of water.
Saving Water – Electric Showers vs Power Showers vs Traditional Shower
In doing the comparison between electric showers and power showers , manufacturers of electric showers assume that flow rates for power showers is 12 to 15 litres a minute. It is not surprising that a Power Shower uses three to four times more water for a 5 minute shower.
Are electric showers efficient?
Electric showers work by only heating what is needed, hence why they could be much more efficient in comparison to mixers. I agree with this 100%. However, if there is a choice of heating water with gas costing 7p a KW, or electricity at 29p a KW, then any efficiency savings are irrelevant. For efficient showering you need a quantity of water to wash away suds. My personal thought is that you need 30 litres per shower to remove suds, but Which suggests 35 litres. Running an 8.5KW shower for 8 minutes will use over 1KW/Hr, which at the current capped April 2022 price of 29p per KW/Hr means each shower will cost you 29p (plus 9p for the water). If you have a gas boiler 1 KW/Hr would cost you 7p for each shower (8p as a boiler is only 85%) efficient. A family of 4 over a year taking one shower a day for 365 days would save over £300 a year by switching to a traditional shower.
Certainty of Solution & Security of Solution
Councils fit Electric Showers and Combi Boilers as a simple one-solution policy to standardise their housing stock. They will not add a shower to existing vented or unvented systems. This results in the provision of a shower, which could be provided for £250, costing £5,000. Savings on energy bills is not of interest to them because that cost falls on a tenant, but the cost of supplying the electric showers does fall on a Council. I am aware of two reasons for this, which are Certainty of Solution & Security of Solution
Certainty of Solution
If you need to consider the complexity of some existing systems, each system would need a unique survey and, a unique solution. Combi Boilers and Electric Showers run from mains water and all houses have a mains supply, so in all instances it is very likely a Combi Boiler is ‘certain to work’.
The ShowerPowerBoooster is a unique patented solution, a micro pump or series of micro pumps, which can be fitted to any and all systems to achieve a good traditional shower. In most cases a SPB will not be needed, however it is a retrofit solution which will make any system work (vented, unvented, Combi Boiler systems, and electric showers which suffer from pressure variations)
Security of Solution
One reason in support of standardisation of fitting Combi Boilers with Electric Showers was given by my local Council as ‘Fitting electric showers gives the tenant a hot shower even if the Combi Boiler fails’.
However, when the power supply or the water supply to a Combi Boiler fails you lose everything, including showers – no hot water for washing up or for hand washing. Taking out unvented hot water cylinders loses stored hot and cold water.
Vented and unvented cylinders have immersion heaters, which allow unlimited hot water if the boiler fails.
In Conclusion
The future of energy supplies is uncertain, but in the short term you will benefit by applying the best solution to save costs now. In many situations the cost of changing to a traditional shower will pay for itself in the first year, and if you do not have a pressure problem you will not need a ShowerPowerBooster. SPB has hundreds of 5 star reviews and works to boost any and all systems to give you a great shower if you do have a pressure problem. It can be fitted into whatever system of pipework you have. The energy price cap is raised again up in October 2022, so the sooner you make a change the better.
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Alan Wright
BSc(Hons) C.Eng. M.I.C.E
25 years working for Water Companies, Petro Chem Industry, House Building & Renovation
Inventor of the ShowerPowerBooster (and much more)
28/4/2022
55% of respondents think eco-friendly models cost more, but they don’t
