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How much electricity would I use...

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coffee
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How much electricity would I use...

#1 Post by coffee » January 28th, 2011, 9:51 am

Help please.

How much electricity would I use for an hour if I have a 230 watts tv.
It would be great if you can show how you work it out too. Thanks.

Nick
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Re: How much electricity would I use...

#2 Post by Nick » January 28th, 2011, 10:06 am

It depends whether you switch it on.... :D





Sorry, Coffee. Maybe someone will come by why can be more useful...

coffee
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Re: How much electricity would I use...

#3 Post by coffee » January 28th, 2011, 10:13 am

Hello Nick,

Would you by any chance know how much electricity would I use for an hour if I have a 60w light bulb. :smile:

coffee
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Re: How much electricity would I use...

#4 Post by coffee » January 28th, 2011, 10:15 am

I have to cut down the electricity bill if I can.

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Dave B
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Re: How much electricity would I use...

#5 Post by Dave B » January 28th, 2011, 10:25 am

Mornin' coffee.

If you are talking "amount" then the 230 watts is that, the generating company will charge you by the number of Watts you use per unit of time, normally kW/h, thousands of Watts per hour, or, a 1000W electric fire left on for one hour uses 1kW/h!

But that is made up from the mains or line voltage where you live and the current, in amps, that the device uses.

The watts (W) is the "power" rating, (P) is the product of the mains voltage (V) times the current drawn in amps (A). I am not sure where you live but if it is in the UK your mains voltage is 240V.

So that gives us two parts of the formula:

P = VxA

Therefore 230(W) = 240(V) x A (for the UK)

From that (sorry if you remember your maths but I will do every stage here):

Move the voltage to the left of the = sign by dividing both sides by V:

230/240 = 240 x A/240

The 240s on the right cancel out leaving:

230/240= A = 0.956 amps that's close enough to 1 as makes no difference here.

For the US you would use 120 volts as the line voltage.

So, in theory, a 1 amp fuse would be OK for the TV, but it ain't that simple! Some devices "suck in" a higher current for a second or two when they are first switched on, and some TVs do this. Therefore a higher value fuse would be called for, in this case I would use a 3 amp fuse. This will give adequate safety.

So, to cover it again:

If you have the power rating the fuse rating will be at least the value of the power divided by the voltage or P/V=A

If you have the current drawn and the power the voltage will be the power divided by the current or P/A=V

If you have the voltage and the current then multiplying these together will give you the power or V x A=P

(Just to confuse matters electricians will use the letter "I" to mean current rather than "A" as I have used here!)

Come back if you do not understand this :smile:
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Griblet
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Re: How much electricity would I use...

#6 Post by Griblet » January 28th, 2011, 11:12 am

We don't need any complicated sums.
In the UK, at least, a "unit" of electric power is a kilowatt-hour, which is, of course, 1,000 watts used for one hour. Now as near as dammit 230 watts is a quarter of 1,000 watts, so you'll use one "unit" in four hours. We don't need to consider voltage or current for your purpose, only the cost per unit which you'll find on your electricity bill.
However, (a) the telly won't in fact use as much as 230 watts and on standby it'll be much, much less. (b) many electricity companies charge one figure for the first so many units, and then less thereafter. With that complication, figuring your overall cost can be done in a number of different ways.

A 60-watt bulb will use very close to what it says on the box. 1,000 divided by 60 is 16.66. so that's how long it will take to use a unit - 16 hours, 40 minutes.
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Alan H
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Re: How much electricity would I use...

#7 Post by Alan H » January 28th, 2011, 12:27 pm

While Dave B is, of course, quite correct, I agree with Griblet that a simple approach is all that is needed here!

You can get the cost of 1 Unit (aka 1 kWhr) from your last bill, but should be around 12p to 15p (in the UK).

A 60 W lightbulb uses 1 Unit of electricity in just under 17 hours. This will be a tungsten filament lightbulb, and you'll get much the same light from a much lower power CFL bulb- say an 11 W. This will last 90 hours for the same cost, so will save you some money, but you have to balance that with the initial outlay of buying the new bulbs.

Your TV on standby will consume much less than a lightbulb, so may not be worth paying too much attention to (but remember it is on standby for long periods, consuming energy, but otherwise doing nothing).

Your 230 W (ie properly on) TV will run for 4 hours 20 minutes on one Unit.

However, if you have any electric heating, this will be by far the greatest cost and anything you can do to cut this down will have the greatest effect on overall cost. This includes washing machine, dish washer, tumble drier as well as space heating.

I'd also look at the tariff you're on: it could be switching supplier could save you a significant amount. Also look at the standing charges: these are over and above the cost of the actual you use, but don't just look at the cost per Unit: you need to include the standing charge (and any other as well). There are several price comparison websites that will do all this work for you, but watch out for switching to a company who may not have put their prices up recently - they may be about to do so!
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Dave B
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Re: How much electricity would I use...

#8 Post by Dave B » January 28th, 2011, 3:04 pm

Coffee did ask how to work it out - I took her request as wanting the formulae.

But true, most people want to know how much it will cost them, then the TV's consumption as a fraction of 1kWh the "unit", is all they really need. If they then know the price per unit they can work out how many pennies per hour or day. I saved money on running a TV by getting rid of it altogether! OK, I do use a monitor for the odd DVD.

Or they can join ePower and ask for one of their "smart meters" that just clip on and measure the house's total consumption and, if you feed in the price, the total cost (got one, frightened me so much I disconnected it :supershock: ). There are plug in consumption meters that can be used for individual appliances that start at about a tenner. I have no idea of the accuracy of such.

It does not help is the tariff changes price (down) after a certain number of units though . . .
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Sel
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Re: How much electricity would I use...

#9 Post by Sel » January 28th, 2011, 7:19 pm

The Physics I learned back when the Earth was cooling is long gone from this old brain but I do have some ideas for electrical conservation.

First, turn off all lights and appliances and have a gander at your metre. It is probably still churning away. That is because so many modern appliances are on standby and thus sucking power continually. One, not so bad , but many add up in costs.

You could start by unplugging all appliances not in use: TV, computer, Microwave and anything with a clock, that is easily unplugged. Choose the air-dry option on your dishwasher. Use a small appliance instead of the stove whenever possible. If your heating is controlled bya thermostat buy a programmable thermostat and have the temp go down while you are usually out of your home and during the night. Replace lightbulbs with those new long lasting low wattage ones.

I hope some of these ideads are usable.
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Dave B
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Re: How much electricity would I use...

#10 Post by Dave B » January 28th, 2011, 7:29 pm

Sel wrote:The Physics I learned back when the Earth was cooling is long gone from this old brain but I do have some ideas for electrical conservation.

First, turn off all llights and appliances and have a gander at your metre. It is probably still churnging away. That is because so many modern appliances are on standby and thus sucking power continually. One, not so bad , but many add up in costs.

You could start by unplugging all appliances not in use: TV, computer, Microwave and anything with a clock, that is easily unplugged. Choose the air-dry option on your dishwasher. Use a small appliance instead of the stove whenever possible. If your heating is controlled bya thermostat buy a programmable thermostat and have the temp go down while you are usually out of your home and during the night. Replace lightbulbs with those new long lasting low wattage ones.

I hope some of these ideads are usable.
Good practice, Sel. Nothing stays on standby in this flat, the only two items that never get turned off are two digital alarms clocks (one by the bed and one, digi-clock/radio in the kitchen). When my all singing, all dancing electronic control microwave went kaput I deliberately bought one with a clockwork timer. Mini oven/grill for lonely pizzas & cheese on toast etc., "health grill" for anything that it will do. Small kettle* with flat element that is safe with a single cup of water measured into it. Low energy bulbs everywhere (except in the hall light controlled by an IR sensor - needs 40W min).

*Kettle small but still 2kW, low wattage kettles actually waste electricity; the extra time taken to heat the water also means proportionately more losses due to radiation & convection.
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lewist
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Re: How much electricity would I use...

#11 Post by lewist » January 28th, 2011, 7:45 pm

A certain Swedish shop best known for its throwaway furniture sells very cheap plugin timers that you can programme to turn off all the standby stuff, for example plug your telly/ satellite receiver/ dvd player etc all into one trailer socket, plug that into the suitably programmed timer and it all goes off and on together and is only on when you are likely to use it. The advantage is it is a passive system which works whether you remember or not.
Carpe diem. Savour every moment.

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Alan C.
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Re: How much electricity would I use...

#12 Post by Alan C. » January 28th, 2011, 8:34 pm

I've never understood the need for a "standby" mode on a TV (or anything else for that matter) if you're not using it switch it off! It's not difficult.
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Fia
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Re: How much electricity would I use...

#13 Post by Fia » January 28th, 2011, 9:32 pm

Sel has good advice there, coffee.
I have lived quite a while on fresh air and would add the following:

Golden rule: if not in use, turn it off. I'm in full agreement with Alan C on this.

As has been said: heat uses the most power. Electric heating, cookers, washing machines, tumble driers, dishwashers, electrically heated hot water and irons.

Reduce power consumption for cooking as Dave B said. If you must have the oven on, fill it batch cooking and freeze to micro your home-cooking later.

Washing machines: Only ever wash dirty clothes. Run with a full load. 30o is fine with modern detergents, unless there's an infection issue. Check if you get cheaper overnight electricity, if so run your machine then.

Dishwashers: unless you have more than 4 folk in the house (and even then there's spare cold hands that can be warmed washing up): why?

Tumble driers are wholly unnecessary. If the item isn't dry either outside or over an airer be more organised or less fussy in your clothing that day. I did both babes in real nappies without a tumble drier. It can be done :wink:

Hot water: Don't bath, shower. Much other heating of hot water is luxurious but unecessary. A good wattage kettle will provide enough for washing up. What's left from making a pot of tea is enough to wash your face with. In the summer, wash in cold water. I still do :D

Irons: Ironing is a pointless, boring and tedious time wasting activity. Do something more fun.

Heating is more difficult, but it can be worth heating just one room, and having a pile of thick dressing gowns anyone can use outwith the warm room. It's winter, so wear thermals, invest in sheepskin bootie slippers, and don't be afraid to wear a hat. A tea cosy works too :laughter: but that may just be an odd Brit habit...

Your bedroom doesn't need to be warm as long as your bed is. Put 3 hot water bottles in 30 mins before you retire. Wear your thermals and bedsocks in bed - you'll retain your heat. Of course, if rumpy pumpy is the evening's fun you can dispense with all that for sharing body warmth :wink:

Finally, don't be tempted to go the card meter route. Far more expensive per unit.
Hope that helps, coffee :)

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Alan C.
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Re: How much electricity would I use...

#14 Post by Alan C. » January 28th, 2011, 10:01 pm

Fia
Tumble driers are wholly unnecessary. If the item isn't dry either outside or over an airer be more organised or less fussy in your clothing that day.
I think this is the only thing we disagree about Fia, where we live it rains (almost daily) from November till April, plus we get weeks (months) with no wind at all.
It's either a tumble drier, or constantly buying new clothes and bedding, which is the better option?
I did both babes in real nappies without a tumble drier. It can be done :wink:
my mother did seven of us in terries but she had to have scores of the things, (there was no alternative back in the day)
Irons: Ironing is a pointless, boring and tedious time wasting activity.
I'me with you on that :thumbsup:
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Fia
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Re: How much electricity would I use...

#15 Post by Fia » January 28th, 2011, 10:45 pm

Alan C. wrote: It's either a tumble drier, or constantly buying new clothes and bedding, which is the better option?:
Neither. Get an over the bath airer, and if necessary pop it next to a radiator or move in your warmest room when you leave it if the bathroom isn't heated. Judicious turning dries all the household laundry in the winter. When there's wind, towels and bedding are washed and hung out, even if they don't fully dry they don't take long to finish off...
Alan C. wrote: my mother did seven of us in terries but she had to have scores of the things, (there was no alternative back in the day)
Quite. There is a balance between what is possible and what is convenient. Our Mothers didn't have the latter, and we can learn from the former :D

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Alan C.
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Re: How much electricity would I use...

#16 Post by Alan C. » January 28th, 2011, 11:10 pm

Fia
Neither. Get an over the bath airer, and if necessary pop it next to a radiator or move in your warmest room when you leave it if the bathroom isn't heated. Judicious turning dries all the household laundry in the winter. When there's wind, towels and bedding are washed and hung out, even if they don't fully dry they don't take long to finish off...
We have an over the bath airer (you didn't notice?)
I could drape all the washing over the radiators, but that just serves to constrict the heat, thereby making the boiler work harder and use more kerosene,

May as well put the stuff in the tumble drier,

At least the electricity running the tumble drier is being produced (in large part) by the burning of Shetlands rubbish rather than the use of fossil fuels . (Though they do have diesel for back up)
Abstinence Makes the Church Grow Fondlers.

Nick
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Re: How much electricity would I use...

#17 Post by Nick » January 29th, 2011, 12:23 am

Fia wrote: Of course, if rumpy pumpy is the evening's fun you can dispense with all that for sharing body warmth :wink:
In my experience, the attempt to generate rumpy pumpy is extremely expensive, with uncertain prospects. But maybe that says more about me than about energy economics... :sad:

Alternatively, try a Selkie :D

coffee
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Re: How much electricity would I use...

#18 Post by coffee » January 29th, 2011, 9:21 am

Hello everyone,

I haven't got time to read all the responds yet so the following is what I think I understood please check to see if it is right.



"If you are talking "amount" then the 230 watts is that, the generating company will charge you by the number of Watts you use per unit of time, normally kW/h, thousands of Watts per hour, or, a 1000W electric fire left on for one hour uses 1kW/h!"

So if the tv power consumption is said to be 230w mean that the tv uses 230w per hour if left on? Which - Would it be written as 0.230kw/h?


***********************************


Actually I have checked again and my tv power consumption is actually 130 for a 32inches tv, which - Would it be written as 0.130kw/h?


I live in the Uk so UK mains voltage is 240V

P=VxA

A=P/V

A=130/240

0.542 Amp =130/240

Is the above working out correct? If so, What fuse would I use here Dave? A 3 amps fuse?

I have to go now, but I will come back later

lewist
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Re: How much electricity would I use...

#19 Post by lewist » January 29th, 2011, 9:22 am

There's lots of good advice here.
Fia wrote:Golden rule: if not in use, turn it off. I'm in full agreement with Alan C on this.
I agree. The automatic timer is good, however, for systems with several components. It turns them all off at once.
Fia wrote:As has been said: heat uses the most power. Electric heating, cookers, washing machines, tumble driers, dishwashers, electrically heated hot water and irons.
I was persuaded to buy a new tumble dryer when I moved back into my house. I never use it. American visitors stuff it full, and seem to have no understanding of the pulley in the ceiling opposite. I might move it into the garage when I clean it in the spring.
Fia wrote:Washing machines: Only ever wash dirty clothes. Run with a full load. 30o is fine with modern detergents, unless there's an infection issue. Check if you get cheaper overnight electricity, if so run your machine then.
Spot on... or off, as the case may be.
Fia wrote:Dishwashers: unless you have more than 4 folk in the house (and even then there's spare cold hands that can be warmed washing up): why?
I fill it and run it every couple of days. I get much cleaner dishes than I would otherwise and it saves hot water.
Fia wrote:Tumble driers are wholly unnecessary.
Absolutely. I have a pulley in the utility room ceiling. There's a radiator under it and everything dries on it fairly quickly.
Fia wrote:A good wattage kettle will provide enough for washing up. What's left from making a pot of tea is enough to wash your face with.
My new kettle is a power saving device. The interesting thing is that there is no technology for saving power. It is made of transparent polycarbonate and you save power by only boiling enough water for what you need. One cup of coffee only needs one cup of water.
Fia wrote:Irons: Ironing is a pointless, boring and tedious time wasting activity. Do something more fun.
I like to have my shirts ironed but nothing else. I create a bit of employment by paying someone to do these tedious tasks for me.
Fia wrote:Heating is more difficult, but it can be worth heating just one room,
I agree, but I do have heating throughout. I have the radiators set to give background heat only in rooms I don't use. I don't want pipes freezing, after all. :smile:
Carpe diem. Savour every moment.

coffee
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Re: How much electricity would I use...

#20 Post by coffee » January 29th, 2011, 10:05 am

My 32 inches tv when standby would use <1w

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