How much electricity do you use in a day?

SuiDreams

I would like to join your thread after reading this I am even more concerned about our Electric usuage we used 408 units over a 28 day period (14.6 units per day, previous bill was 12 units per day) despite using less electric. Electric oven broke down last month (and not replaced yet). There are 2 of us and one small dog in a small three bedroom semi. CH is Gas, plus Gas hob. No Dishwasher, Tumble Dryer, Electric Shower or emersion heater. Main useage is lighting, Fridge/Freezer, Washer, TV/Video/DVD/Cable Box and PC. Going to read meter daily to see if we use more on certain days. Already have Energy saving light bulbs, wash at 30 etc. Will have a look round tonight to see if there is anything pluged in that shouldn't be. Will probably unplug video as well as hardly ever use it now. Any other idea's

Cardew

rizla01 wrote: »

Actually we too are doing a meter reading table but wanted to know where to start on the cutbacks. Having read through this thread have taken note of all that has been said but no-where mentioned the good ol PC. 100 watts per day is a lightbulb and we are very careful about turning those off.

The difficulty with PCs is they vary so much in power consumption; that is before you start talking about applications they are running.

Older PCs used much less electricity - Not long ago Microsoft estimated an average home PC used 60watts - the more powerful machines in use today produce more heat so need better cooling with fans etc. Old CRT screens used a lot more power than LCDs. Scanners/printers etc have different consumptions etc.

If you use your PC a lot, and don't need the computing power of a powerful machine(gaming etc) a laptop can use a small percentage of the power of a desktop - they all have sophisticated power management facilities.

As said above if you really want to get down to how finding how much your various appliances are using, those cheap power measuring meters(NOT the Electrisave) will tell you. Plug in your PC for 24 hours and it will tell you down to a Watt how much it has used. Same with fridge, freezer, washing machine, dryer, TV etc etc. You can very quickly build up a picture of your consumption

dc

:rolleyes2 Over the last few years our daily consumption has gone up from 8 to 14 units, despite trying to reduce with stuff like low wattage lighting. Trying to stem wallet leakage.;)

I can only deduce that the main reason for the increase is due to a proliferation of digital set top boxes, cable receiver, and Networked/Broadband. ie Devices that are never switched off. I suspect the ageing fridge freezer might be guilty too

The leakge search continues :rolleyes2

kittiwoz

Alikay wrote:

We're all clean-freaks and shower daily - twice if going out at night or have played sport.......but surely that wouldn't make our bils so high?

Yes, I think it could. Heating water is a very energy intensive process.

From what you say it seems conservatively reasonable to assume a total of 35 mins shower time per day. This would equate to seven five minute showers or five seven minute showers. Apparently a typical efficient shower uses 9 litres per minute and a power shower can be double that, 18 litres per minute. (The info on power showers was found on a US website so may not represent what is typical in the UK. Please feel free to correct.) So we are talking about 315 litres of water per day or 630 litres for a power shower. A typical shower temperature is 40 degrees C so if I assume a feed temperature of 15 degrees then that is a rise of 25 degrees. The specific heat capacity of water at constant pressure (measured at atmospheric pressure and 25 degees C) is 4.1813 kJ/kg/K (kilojoules per kilogram per kelvin) so that leads to a daily energy consumption of 32927.737 or 65855.474kJ for a power shower. Dividing by 3600, the number of seconds in an hour, to convert to kWh gives a result of 9.15kWh or 18.29kWh for a power shower.

Note that I have used a number of approximations. If you typically take more or less showers of longer or shorter duration or if the temperature you have your shower or that of the feed to your shower is different it could affect the calculation considerably. For example if you took seven seven minute showers that alone could account for around 25.6kWh with a power shower. Similarly if I presumed you only required the water to be heated by 23 degrees (still using the shower for 35 mins a day) you would use around 16.8kWh with a power shower, rather than the 18.3kWh I suggested previously.

Without knowing the specific values for how much water you shower uses, how much you use it and what the inlet and shower temperatures are it isn't possible to calculate the energy usage with any real precision. However the above hopefully serves to give some sort of idea of the figures involved. The simplest savings you can make are by taking shorter showers at lower temperatures. You can get low-flow shower heads but they shouldn't be fitted to electric showers because it can cause overheating. If your shower is a power-shower then it might be worth thinking about replacing it. I would suggest you run the shower at normal settings into a big measuring jug for 10 secs. See how much water you have. Repeat the experiment a few times and whatever your average result is multiply by six to find out how many litres it uses per minute. Then you can work out how much it is costing over a typical non-power shower and whether it would be worthwhile replacing it.

Alikay

Strewth!! Our 3 teenagers DO take fairly long showers, and probably pretty hot ones too. I'l have to make them aware of the cost - unfortunately its not an area where I have total control due to the need for privacy in the bathroom.The shower is a regular 8.5 kw unit, not a power shower, but its still used quite a lot, so that could be what's causing the high usage.

I'l have to start nagging and hammering on the bathroom door whilst they perform their ablutions!

rizla01

Alikay wrote: »

Strewth!! Our 3 teenagers DO take fairly long showers, and probably pretty hot ones too. I'l have to make them aware of the cost - unfortunately its not an area where I have total control due to the need for privacy in the bathroom.The shower is a regular 8.5 kw unit, not a power shower, but its still used quite a lot, so that could be what's causing the high usage.

I'l have to start nagging and hammering on the bathroom door whilst they perform their ablutions!

Or fit a timer.:)

For safety regs there should be an isolator switch outside the bathroom, perhaps in the airing copboard.

You could warn them then 1 minute later, hit the switch.




They will SOON get the message!

dc

:rotfl: :rotfl: :rotfl: :rotfl:

moonrakerz

Cardew wrote: »

To be serious, it is not someone's fault if they don't understand the basics of electricity. So if anyone pastes on here in good faith, I believe any reply(initially) should be polite. Bluntness comes later!

I agree it's not "someone's fault", but so many people are taken in by the drivel that appears, such as the Eco kettle - sheer unadulterated garbage ! and not to put too fine a point on it - lies !

Cardew

kittiwoz wrote: »

Yes, I think it could. Heating water is a very energy intensive process.

From what you say it seems conservatively reasonable to assume a total of 35 mins shower time per day. This would equate to seven five minute showers or five seven minute showers. Apparently a typical efficient shower uses 9 litres per minute and a power shower can be double that, 18 litres per minute. (The info on power showers was found on a US website so may not represent what is typical in the UK. Please feel free to correct.) So we are talking about 315 litres of water per day or 630 litres for a power shower. A typical shower temperature is 40 degrees C so if I assume a feed temperature of 15 degrees then that is a rise of 25 degrees. The specific heat capacity of water at constant pressure (measured at atmospheric pressure and 25 degees C) is 4.1813 kJ/kg/K (kilojoules per kilogram per kelvin) so that leads to a daily energy consumption of 32927.737 or 65855.474kJ for a power shower. Dividing by 3600, the number of seconds in an hour, to convert to kWh gives a result of 9.15kWh or 18.29kWh for a power shower.

Note that I have used a number of approximations. If you typically take more or less showers of longer or shorter duration or if the temperature you have your shower or that of the feed to your shower is different it could affect the calculation considerably. For example if you took seven seven minute showers that alone could account for around 25.6kWh with a power shower. Similarly if I presumed you only required the water to be heated by 23 degrees (still using the shower for 35 mins a day) you would use around 16.8kWh with a power shower, rather than the 18.3kWh I suggested previously.

Without knowing the specific values for how much water you shower uses, how much you use it and what the inlet and shower temperatures are it isn't possible to calculate the energy usage with any real precision. However the above hopefully serves to give some sort of idea of the figures involved. The simplest savings you can make are by taking shorter showers at lower temperatures. You can get low-flow shower heads but they shouldn't be fitted to electric showers because it can cause overheating. If your shower is a power-shower then it might be worth thinking about replacing it. I would suggest you run the shower at normal settings into a big measuring jug for 10 secs. See how much water you have. Repeat the experiment a few times and whatever your average result is multiply by six to find out how many litres it uses per minute. Then you can work out how much it is costing over a typical non-power shower and whether it would be worthwhile replacing it.

Kittiwoz,

Your physics might be impressive, but your assumptions are so far out to make your kWh figures meaningless.

Nearly all electrical showers in UK now sold have 8.5kW, 9.5kW, or 10.5kW heaters(older showers even lower powered) Even 10.5kW showers are rare because of limitations on house wiring and RCDs.

So for 60 minutes showering they will use a Maximum of 8.5kWh/9.5kWh/10.5kWh if the heater is on all the time.

However as they are all thermostatically controlled, the heaters cycle on and off depending on dependant on the temperature of the inlet water and the required temperature and flow rate of the output water..

So as alikays shower is 8.5kWh, for 35 minutes showering per day her consumption would be in the region of 3-4kWh - probably nearer 3kWh

Lastly your references to Power Showers. In UK as far as I am aware there is no such thing as an electrical heated power shower. They have an electrical pump(normally about 0.2kW) to pump water from the mains fed Hot Water Tank.

Smiley_Mum

I took a reading at 8.30pm tonight.

A reading - 13873 kwh

B reading - 33672 kwh

One reading is for sockets and lights and the other is for heaters and immersion.

BTW, just checked energy consumption for my mobile whilst charging and it's 05 watts.

Charger for electric toothbrush is 02 watts and charger for Waterpik 02 watts as well. Buttons.

Also, don't allow the kettle to boil for drinks. You can't drink boiling coffee/tea etc so switch it off just before it begins to boil.

Just boiled 8 fl ozs of water for a coffee, took a little over 20 seconds to heat, not boiling though and used 0.02 kwh of power using a 3kw kettle.