Electric Costs

[torrenova]

I'm getting some "unusual" spikes in the readings and I want to try and isolate what we are using as residual and appliance related usage. I'd appreciate any help you can give.

I've isolated the aircon so that is not what I am concerned with, which should make things easier. I'm more concerned with the build up of all the things which you have around and use everyday.

Computer (new HP quad core) - used 16 hours a day

Monitor (new HP 19" LCD) - used 16 hours a day

Modem - used 16 hours a day

Television (32" flat screen CRT) - used 12 hours a day

Satellite receiver - used 12 hours a day

Fridge - on 24 hours a day

Oven - used once a week

Washing machine - once every 2 days on a 2 hour wash

Kettle - a few times a day

Hot water - on demand, perhaps 15 minutes a day, running at 6kw at present

Probably some other minor things like the occasional hair drier etc. but I wondered if anyone has gone through this before. Thanks

[runker]

That's a lot computer and TV time. If your goal is to reduce your power usage why not put these things on a power strip and when they are not being used turn off the power going to them.

[longball53098]

What does "unusual" spikes mean? Do you mean one month the units used is much higher than another month? When you have this spike are we talking about 10 units or 1000 units?

What I see from you're list of appliances the biggest user of power is the fridge as it runs 24 hours a day and depends how often the compressor is running on any given day. The next is the oven. You say once a week but how long? One hour? 4 hours? Using an oven is typically a 1 to 3 or 4 hour situation. It takes 10 to 15 minutes to get it heated to a set temp and then over the period of use the coils use power to keep that set temp. Only way to know what the usage is for this appliance is to record the units on the meter before use and then at the end of use. You say the shower heater is used once a day for 15 minutes. At 3.5 baht per unit this equals about 5.25 baht per shower for a 6kw heater.

Here is a simple formula to use to figure the cost of any appliance with a known wattage and known amount of time used.

How to calculate the cost of using a 60 watt light.

1. Start with the number of watts for the light bulb. 60

2. Convert this to kilowatt-hours by dividing the watts by 1000 60/1000 = 0.06 kwh

3. Multiply the kwh by the number of hours(Nh) of usage. Nh =number of hours 0.06 x 10 hours = 0.6 kwh

4. Multiply the usage hours by the average cost per kwh from your electric invoice. In Thailand this is about 3.5 bt/kwh 3.50 baht is the average cost of 1 kilowatt-hour of electricity in Thailand 0.6 x 3.5 = 2.10

5. This is the cost to light a 60 watt light for 5 hours. 2.10 baht for 10 hours use

You can fill in the wattage and hours used for any device you know that has a fixed on time usage. Lights, computer, monitor, fan. Won't work for a fridge or AC or heater/oven as the unit is no on all the time.

I hope I have helped you a bit. I'm sure others will add to this or tell me I'm wrong somewhere.

[BangkokWildcat]

What does "unusual" spikes mean? Do you mean one month the units used is much higher than another month? When you have this spike are we talking about 10 units or 1000 units?

What I see from you're list of appliances the biggest user of power is the fridge as it runs 24 hours a day and depends how often the compressor is running on any given day. The next is the oven. You say once a week but how long? One hour? 4 hours? Using an oven is typically a 1 to 3 or 4 hour situation. It takes 10 to 15 minutes to get it heated to a set temp and then over the period of use the coils use power to keep that set temp. Only way to know what the usage is for this appliance is to record the units on the meter before use and then at the end of use. You say the shower heater is used once a day for 15 minutes. At 3.5 baht per unit this equals about 5.25 baht per shower for a 6kw heater.

Here is a simple formula to use to figure the cost of any appliance with a known wattage and known amount of time used.

How to calculate the cost of using a 60 watt light.

1. Start with the number of watts for the light bulb. 60

2. Convert this to kilowatt-hours by dividing the watts by 1000 60/1000 = 0.06 kwh

3. Multiply the kwh by the number of hours(Nh) of usage. Nh =number of hours 0.06 x 10 hours = 0.6 kwh

4. Multiply the usage hours by the average cost per kwh from your electric invoice. In Thailand this is about 3.5 bt/kwh 3.50 baht is the average cost of 1 kilowatt-hour of electricity in Thailand 0.6 x 3.5 = 2.10

5. This is the cost to light a 60 watt light for 5 hours. 2.10 baht for 10 hours use

You can fill in the wattage and hours used for any device you know that has a fixed on time usage. Lights, computer, monitor, fan. Won't work for a fridge or AC or heater/oven as the unit is no on all the time.

I hope I have helped you a bit. I'm sure others will add to this or tell me I'm wrong somewhere.

Wow, great explanation there longball....interesting breakdown...Thanks!

[katabeachbum]

I'm getting some "unusual" spikes in the readings and I want to try and isolate what we are using as residual and appliance related usage. I'd appreciate any help you can give.

I've isolated the aircon so that is not what I am concerned with, which should make things easier. I'm more concerned with the build up of all the things which you have around and use everyday.

Computer (new HP quad core) - used 16 hours a day dontknow

Monitor (new HP 19" LCD) - used 16 hours a day dontknow

Modem - used 16 hours a day nothing

Television (32" flat screen CRT) - used 12 hours a day Plasma alot, LCD less but much, just feel the heat from it

Satellite receiver - used 12 hours a day not much

Fridge - on 24 hours a day Depending on fridge, look at the yellow Egat sticker if its energy class 5. Depend how often its opened and if its used to cool down or just keep cool

Oven - used once a week 1-1,5 unit an hour

Washing machine - once every 2 days on a 2 hour wash hotwater machine, 1 unit an hour

Kettle - a few times a day 1 unit an hour

Hot water - on demand, perhaps 15 minutes a day, running at 6kw at present. 1,5 unit a day

hairdyer 1-1,5 unit an hour

Probably some other minor things like the occasional hair drier etc. but I wondered if anyone has gone through this before. Thanks

1 unit is 1 kw/hour

[T_Dog]

Good posts here.... One thing I would add: The size of the fridge can make a large difference, as the larger ones are frost free. Had one in the USA that would dim the lights when the frost-free feature kicked in. Modern ones are probably a lot better, but if you watching your house meter, the fridge might be noticeable.

On a funnier note, the biggest spike we had was when the neighbors tapped into our meter to weld the roof on their new house. 1700 baht extra that month! They unhooked when they saw me photographing the set-up.

[wilsongbrown]

Good posts here.... One thing I would add: The size of the fridge can make a large difference, as the larger ones are frost free. Had one in the USA that would dim the lights when the frost-free feature kicked in. Modern ones are probably a lot better, but if you watching your house meter, the fridge might be noticeable.

On a funnier note, the biggest spike we had was when the neighbors tapped into our meter to weld the roof on their new house. 1700 baht extra that month! They unhooked when they saw me photographing the set-up.

I saw one of those 'green living' type programs from oz where a family's house is monitored for energy consumption and ways to save and was astonished to see the fridge was the major use of energy in the home. So I agree with this post, my newly bought fridge with it's not very large freezer compartment costs as much to run as my pool pump. And I only use it to keep the wholesale dogs' dinner in it

Edited July 16, 2009 by wilsongbrown

[johng]

They unhooked when they saw me photographing the set-up

Cheeky buggers !!! at least they could have tapped into the supply side of the meter and saved you the bill.

[Donnyboy]

Good posts here.... One thing I would add: The size of the fridge can make a large difference, as the larger ones are frost free. Had one in the USA that would dim the lights when the frost-free feature kicked in. Modern ones are probably a lot better, but if you watching your house meter, the fridge might be noticeable.

On a funnier note, the biggest spike we had was when the neighbors tapped into our meter to weld the roof on their new house. 1700 baht extra that month! They unhooked when they saw me photographing the set-up.

I saw one of those 'green living' type programs from oz where a family's house is monitored for energy consumption and ways to save and was astonished to see the fridge was the major use of energy in the home. So I agree with this post, my newly bought fridge with it's not very large freezer compartment costs as much to run as my pool pump. And I only use it to keep the wholesale dogs' dinner in it

Some fridge tips:

make sure your fridge temperature isnt set too low

door seals are making a complete tight seal when closed

load up your freezer compartment with bread or ice

dont leave fridge door open longer than you have to

[Donnyboy]

Good posts here.... One thing I would add: The size of the fridge can make a large difference, as the larger ones are frost free. Had one in the USA that would dim the lights when the frost-free feature kicked in. Modern ones are probably a lot better, but if you watching your house meter, the fridge might be noticeable.

On a funnier note, the biggest spike we had was when the neighbors tapped into our meter to weld the roof on their new house. 1700 baht extra that month! They unhooked when they saw me photographing the set-up.

did you give them the bill?

[neverdie]

Good posts here.... One thing I would add: The size of the fridge can make a large difference, as the larger ones are frost free. Had one in the USA that would dim the lights when the frost-free feature kicked in. Modern ones are probably a lot better, but if you watching your house meter, the fridge might be noticeable.

On a funnier note, the biggest spike we had was when the neighbors tapped into our meter to weld the roof on their new house. 1700 baht extra that month! They unhooked when they saw me photographing the set-up.

I saw one of those 'green living' type programs from oz where a family's house is monitored for energy consumption and ways to save and was astonished to see the fridge was the major use of energy in the home. So I agree with this post, my newly bought fridge with it's not very large freezer compartment costs as much to run as my pool pump. And I only use it to keep the wholesale dogs' dinner in it

Some fridge tips:

make sure your fridge temperature isnt set too low

door seals are making a complete tight seal when closed

load up your freezer compartment with bread or ice

dont leave fridge door open longer than you have to

Donnyboy, Thats the one I have problems with. I live with 2 thais and they are always turning the fridge right down, in their minds to save electric & as a consequence the fridge is always running as the mild difference in temp is constantly dropping away. I tried to educate them but they basically just laughed at me. The thing that really erks me is Im the one that pays the dam_n electricity bill, so go figure

[T_Dog]

"did you give them the bill?"

No, I didn't. In Thailand, you just have to roll with some of the punches.... I figured this was one of them. At the end of a few days, all the other neighbors were telling us how terrible it was for them to do that as nothing goes un-noticed here. If I would have made a scene, I figure it would have gone the other way.

[sendbaht]

Very peaceful of you T_DOG. I know where you live now to find my extension cord.

[yabaaaa]

Good posts here.... One thing I would add: The size of the fridge can make a large difference, as the larger ones are frost free. Had one in the USA that would dim the lights when the frost-free feature kicked in. Modern ones are probably a lot better, but if you watching your house meter, the fridge might be noticeable.

On a funnier note, the biggest spike we had was when the neighbors tapped into our meter to weld the roof on their new house. 1700 baht extra that month! They unhooked when they saw me photographing the set-up.

Fridges dont use much electric its washing machines, electric cookers, aircon , electric showers,etc heres a website with it all on 24 hours for a fridge freezer about 12 baht http://www.newcastle.gov.uk/core.nsf/a/energyrunningcosts

[torrenova]

I know that if something is rated at 3kw then it costs 3*unit rate per hour to run. That is simple. What is not so simple is to know what the TV uses or the computer or other stuff which is not usually categorised but which may be on for a long time., such as a computer.

If the computer and screen use 100w then the daily cost is 100*16/1000*unit price per day. This is about Bt6 or so. However, if the unit was running at 400w then it would be 4 times as expensive. It is stuff like this where my "guestimate" may be well off.

[yabaaaa]

I know that if something is rated at 3kw then it costs 3*unit rate per hour to run. That is simple. What is not so simple is to know what the TV uses or the computer or other stuff which is not usually categorised but which may be on for a long time., such as a computer.

If the computer and screen use 100w then the daily cost is 100*16/1000*unit price per day. This is about Bt6 or so. However, if the unit was running at 400w then it would be 4 times as expensive. It is stuff like this where my "guestimate" may be well off.

Also be aware with things like electric cooker rings on hobs they dont stay on flat out they cycle on and off so full power for a few minutes then turn off then turn back on again . Ceramic halogen hobs do this. It will still be rated at 5-6 kw but its not using it all the time its switched on.

[Donnyboy]

I know that if something is rated at 3kw then it costs 3*unit rate per hour to run. That is simple. What is not so simple is to know what the TV uses or the computer or other stuff which is not usually categorised but which may be on for a long time., such as a computer.

If the computer and screen use 100w then the daily cost is 100*16/1000*unit price per day. This is about Bt6 or so. However, if the unit was running at 400w then it would be 4 times as expensive. It is stuff like this where my "guestimate" may be well off.

theres another thread on electricity costs on running computers here

[Donnyboy]

I know that if something is rated at 3kw then it costs 3*unit rate per hour to run. That is simple. What is not so simple is to know what the TV uses or the computer or other stuff which is not usually categorised but which may be on for a long time., such as a computer.

If the computer and screen use 100w then the daily cost is 100*16/1000*unit price per day. This is about Bt6 or so. However, if the unit was running at 400w then it would be 4 times as expensive. It is stuff like this where my "guestimate" may be well off.

Also be aware with things like electric cooker rings on hobs they dont stay on flat out they cycle on and off so full power for a few minutes then turn off then turn back on again . Ceramic halogen hobs do this. It will still be rated at 5-6 kw but its not using it all the time its switched on.

same could be have said of water heaters, could be rated at 3kw but if set to warm, it could use 2kw or whatever

[Donnyboy]

They unhooked when they saw me photographing the set-up

Cheeky buggers !!! at least they could have tapped into the supply side of the meter and saved you the bill.

agreed, would have been easier to wire it in their own meter on the supply side and not upset anyone (apart for the power company)

[longball53098]

I know that if something is rated at 3kw then it costs 3*unit rate per hour to run. That is simple. What is not so simple is to know what the TV uses or the computer or other stuff which is not usually categorised but which may be on for a long time., such as a computer.

If the computer and screen use 100w then the daily cost is 100*16/1000*unit price per day. This is about Bt6 or so. However, if the unit was running at 400w then it would be 4 times as expensive. It is stuff like this where my "guestimate" may be well off.

Almost every electric device if not all electric devices manufactured in the last several years has a decal or other identifiable plate somewhere on the unit as to the ratings of that unit. What voltages it requires and typically what watts it uses. Most user manuals also give these specs. A calculator can be used to determine the usage it should have. There is no guesstimate here as the decal states how much "juice" it uses. I feel pretty confident that a spec shows the maximum usage not the minimum. If the unit states the use in volts and amps then the calculation to figure watts is used first. Volts times amps equals watts. example an appliance is rated at 240 volts and 16 amps then the watts used is 3840 watts or 3.8kw. In my formula from earlier then 3.8kw used for an hour equals 13.44 baht if 3.5 baht is the unit rate. So if this electrical device is a small aircon or a water heater using power at the above rate you can easily figure the cost per hour. Of course you can try reading you're meter at the beginning and end of using a device but this does not take in to account other devices on the meter that switch on and off during the time of the test reading. Its much easier to calculate the load and watts used if the interest is in a particular device

As someone already said it's not so easy with a unit that cycles on and off frequently.