Energy bill increases

[Deleted member 26715]

Done a bit more Googling and found a site which says the plate rating represents the amount of energy to run an appliance for one hour. So 135W = 0.135kWh @ 28p per kWh for ten hours is 0.135 x 10 x 28 = 37.8p

That's my understanding as well, a 60W bulb will be on for 16.6 hours to use 1 unit of electricity that we get charged for.

 

[Alex321]

I did. The plate says 135W. I know this means 135 Watts but nothing else. Is it usage per hour, day, year? Truly means absolutely nothing to me and I guess 99% of the population.

135W is the instantaneous level of use. And is 0.135kW.

Energy from the grid is sold in units of kWh (Kilowatt-hours), so if you have the device running at full power for an hour, it will have used 0.135 units.

And BTW, anybody who did O level physics (or GCSE later) should know the watts are the unit of energy, and are derived from volts * amps when talking about electrical energy.

 

[jowwy]

Done a bit more Googling and found a site which says the plate rating represents the amount of energy to run an appliance for one hour. So 135W = 0.135kWh @ 28p per kWh for ten hours is 0.135 x 10 x 28 = 37.8p

but what of you could do all that in a 1kw oven in an hour…….on current prices it would save you 7.8p

 

[Deleted member 26715]

but what of you could do all that in a 1kw oven in an hour…….on current prices it would save you 7.8p

I thought ovens were usually 3kw or KW or kW or Kw whichever it is

 

[Low Gear Guy]

The rating plate will indicate the maximum normal power consumption. Once the oven is up to temperature the thermostat will turn the heating element on and off. Thus, running a 2kW oven for 2 hours will use less than 4kWh. The actual energy consumption depends upon the effectiveness of the insulation.

 

[Alex321]

I thought ovens were usually 3kw or KW or kW or Kw whichever it is

That is the maximum power, not the amount they will consume continuously at a given temperature setting. They will usually use that maximum power for a few minutes until the cavity is at the set temperature, then will only be using sufficient power to maintain that temperature for the rest of the time.

And it is kW

Generally, the main units if they are derived from a name are capitalised when abbreviated (but not when written in full - so W or watts), and the multipliers aren't in either case (so k or kilo). Seems an odd convention to me, and I don't always remember, but that is the rule.

 

[presta]

And BTW, anybody who did O level physics (or GCSE later) should know the watts are the unit of energy, and are derived from volts * amps when talking about electrical energy.

No it isn't, the watt is a unit of power.

Power is rate of change of energy, IE energy divided by time, in the same way that speed is rate of change of distance. The SI units of energy and time are the joule, and the second, and the watt is one joule/second. Since power is energy divided by time, if you multiply power by time you have energy: 1kW = 1000W, and 1hour is 3600 seconds, so 1kWh is 1000J/s*3600s = 3.6MJ

 

[presta]

That is the maximum power, not the amount they will consume continuously at a given temperature setting. They will usually use that maximum power for a few minutes until the cavity is at the set temperature, then will only be using sufficient power to maintain that temperature for the rest of the time.

If your oven thermostat has a pilot light like mine you can measure the duty cycle from the light. My oven element is 4482W, so for example, if the pilot light were lit for 20s in every minute the mean power would be 4482W*20/60 = 1494W

 

[vickster]

Apparently turning the oven off say 10 minutes before done can save energy and just using the residual heat to finish the cooking/resting

 

[Deleted member 26715]

Apparently turning the oven off say 10 minutes before done can save energy and just using the residual heat to finish the cooking/resting

I was only thinking about this last night when I turned the oven of after doing some baked potatoes & thought I should have done that 10 minutes ago.

 

[cougie uk]

I was only thinking about this last night when I turned the oven of after doing some baked potatoes & thought I should have done that 10 minutes ago.

Or cook them in the microwave and just finish off in the oven ?

 

[vickster]

This ^^, I always think baking potatoes in an oven (if not being done with something that takes as ridiculously long) is a very high electricity usage pursuit!
(I can't think of anything I would cook in an oven that takes as long as baking decent sized spuds from scratch)

 

[Deleted member 26715]

Or cook them in the microwave and just finish off in the oven ?

This ^^, I always think baking potatoes in an oven (if not being done with something that takes as ridiculously long) is a very high electricity usage pursuit!
(I can't think of anything I would cook in an oven that takes as long as baking decent sized spuds from scratch)

But the skin is the best bit, it's not the same after 10 minutes in the microwave, there are some lines that need to be drawn

 

[vickster]

But the skin is the best bit, it's not the same after 10 minutes in the microwave, there are some lines that need to be drawn

that's why you finish them off in the oven

 

[cyberknight]

Why stop the club ride as well as the cake?

I could just sit there whilst everyone else has coffee and cake i suppose ?