How much it costs to run X watt device for Y minutes?

[AndyAndyAndy]

If I buy for example 1200 Watt device and run it for example 20 minutes, how much will it cost me? Considering some average price for electricity in Thailand.

[robblok]

(1.2 x 4.7 x 20) / 60 = 1.88 bt

 

That is assuming im correct that a KWH is 4.7 bt. I thought it roughly was.

 

[sezze]

The above calculation is correct , but 1 remark .

If it is a engine , like for example a pressure washer , pump , vacuumcleaner , ...  Every time it starts , power consumption is way higher , 2-3 times the value . It might be only a brief second , but it is the biggest difference why inverter things ( airco .. ) use less electricity then the standard ones .

[Why Me]

How much it costs to run X watt device for Y minutes?

 X x Y x unit rate / 60,000 b., where unit rate is baht cost per KWH.

 

robblok is correct. I just give the general formula.

 

sezze I dont think is correct. The cost of a 1000 watt device running for 1 sec. at a 5b. unit rate is 0.14 satang. So even a 3-times increase in starting load is is less than half satang. So you would have to have to start/stop 200 times a day for it to cost 1b.

[Maestro]

The formulas for the cost calculation are correct, but if we wanted to be scientifically absolutely correct we would have to use the correct symbol kWh (kilowatt hour), not KWH (kelvin watt henry), and for the Thai currency we would use THB (Thai Baht), not b (barn) or bt (barn tonne)

 

However, as we are not dealing with rocket science here, it doesn't really matter but I thought I'd mention it for the benefit of the rocket scientists, of which we have at least one I know among the ThaiVisa membership.

 

 

[sezze]

6 hours ago, Why Me said:

How much it costs to run X watt device for Y minutes?

 X x Y x unit rate / 60,000 b., where unit rate is baht cost per KWH.

 

robblok is correct. I just give the general formula.

 

sezze I dont think is correct. The cost of a 1000 watt device running for 1 sec. at a 5b. unit rate is 0.14 satang. So even a 3-times increase in starting load is is less than half satang. So you would have to have to start/stop 200 times a day for it to cost 1b.

It depends on the load and how many times it starts and stops . This comes above the normal running costs , and yes it might not be a lot for a single this , like a 1000watt thing doesn't matter running 20 mins , but doing it 24/7 , 4 times per hour , is 2880 times , during 3 seconds equals 2h20 mins at double power ( 2000watt extra ) or in consumption

about 5kwh extra . It really is the difference between inverters and non inverters . The amount of power running something stays the same , for example the aircon needs x amount of cooling to keep that temperature . The inverter chooses it's power needed and keeps the compressor running , but maybe at 1/4th of total power while the other 1 starts and stops , making bigger consumption in total needed .

[Why Me]

5 hours ago, Maestro said:

The formulas for the cost calculation are correct, but if we wanted to be scientifically absolutely correct we would have to use the correct symbol kWh (kilowatt hour), not KWH (kelvin watt henry), and for the Thai currency we would use THB (Thai Baht), not b (barn) or bt (barn tonne)

 

However, as we are not dealing with rocket science here, it doesn't really matter but I thought I'd mention it for the benefit of the rocket scientists, of which we have at least one I know among the ThaiVisa membership.

 

 

I can't imagine a competent rocket scientist thinking KWH in the formula stands for kelvin watt henry or the b for barn:-) Would be seriously weird.

[BritManToo]

Buy a power meter, plug it in, that's the only way to see the real costs.

You can even enter the unit price and have it tell you the total cost.

https://www.lazada.co.th/products/ts-836a-plug-power-meter-energy-watt-voltage-amps-meter-with-electricity-usage-i274616679-s436448624.html

 

250bht.

[Dazinoz]

12 hours ago, sezze said:

The above calculation is correct , but 1 remark .

If it is a engine , like for example a pressure washer , pump , vacuumcleaner , ...  Every time it starts , power consumption is way higher , 2-3 times the value . It might be only a brief second , but it is the biggest difference why inverter things ( airco .. ) use less electricity then the standard ones .

The standard induction motor, which are the majority of motors takes 6 times full load current at the instant of starting. This is just the nature of the beast. However this is for a very short time. Most devices around the house are not stopped started that many times in an hour, even water pump.

 

My first house I rented in Thailand the water pump was obviously too big for the size of the piping. When the kitchen tap was used the pump would stop/start every couple of seconds. Very annoying as it also sent a "bang" through the stainless tank. I played around with throttling the water inlet and problem fixed.

 

I used to work in a power station with 500 megawatt units. Each unit had 3 boiler feed water pumps with a rating of 9000 hp at 11,000 volts. Full load current was 6.7 megawatts so you can imaging at the instant of starting the amount of power used. As we were the source of power no starting devices were employed it was just DOL (direct on line). Lights dimmed at the power station.

 

Really it doesn't make much difference in home use as the relatively cheap metering will not measure the full staring current as it happens too fast for the instrument to measure accurately. Power Factor also is a component but will not attempt to explain pf. Inverter ACs have a lot of capacitors improving the pf.

[Percy P]

13 hours ago, robblok said:

(1.2 x 4.7 x 20) / 60 = 1.88 bt

 

That is assuming im correct that a KWH is 4.7 bt. I thought it ro

13 hours ago, sezze said:

The above calculation is correct , but 1 remark .

If it is a engine , like for example a pressure washer , pump , vacuumcleaner , ...  Every time it starts , power consumption is way higher , 2-3 times the value . It might be only a brief second , but it is the biggest difference why inverter things ( airco .. ) use less electricity then the standard ones .

This brief second is referred to as the "surge" in electricity

[Max69xl]

14 hours ago, robblok said:

(1.2 x 4.7 x 20) / 60 = 1.88 bt

 

That is assuming im correct that a KWH is 4.7 bt. I thought it roughly was.

 

The government price per kwh is just 4 baht + 7% tax = 4,28 baht.  That's what I'm paying to PEA. A lot of people pay 8 baht or even more which is a rip off. 

[scoupeo]

can someone help to calculate 24h aircon sot for 18000 btu ?

thank you.

 

[stevenl]

12 minutes ago, scoupeo said:

can someone help to calculate 24h aircon sot for 18000 btu ?

thank you.

 

Count on 2300 Watt, https://learnmetrics.com/how-many-watts-do-air-conditioners-use/.

 

For calculation see above in this thread.

[Crossy]

1 hour ago, scoupeo said:

can someone help to calculate 24h aircon sot for 18000 btu ?

thank you.

 

 

A reasonably modern conventional A/C of 18k BTU will swallow about 1.8kW when the compressor is running.

 

If it's correctly sized count on a duty-cycle of about 30%.

 

So each hour of operation would be 1.8 * .3  = 0.54 kWh.

[brianthainess]

16 hours ago, robblok said:

(1.2 x 4.7 x 20) / 60 = 1.88 bt

 

That is assuming im correct that a KWH is 4.7 bt. I thought it roughly was.

 

or 1.2 x4.7 / 3 = 1,88 baht

[scoupeo]

On 10/17/2020 at 2:15 PM, Crossy said:

 

A reasonably modern conventional A/C of 18k BTU will swallow about 1.8kW when the compressor is running.

 

If it's correctly sized count on a duty-cycle of about 30%.

 

So each hour of operation would be 1.8 * .3  = 0.54 kWh.

 

 

so how much would you tell for 1 hour air conditioning in baht please ?

 

thank you.

 

 

[Dazinoz]

51 minutes ago, scoupeo said:

 

 

so how much would you tell for 1 hour air conditioning in baht please ?

 

thank you.

 

 

How long is a piece of string?

 

The answer to your question depends on so many variable. What is the outside temp, what is room temp, what temp do you want room, how big is the room, what aspects is room (which way facing), how many windows and aspects, how many people in room, what is room used for and more?

 

However going by Crossy's rough estimate its 0.54kwh x 4.7 baht unit which equals roughly 2.5 baht an hour.

[scoupeo]

On 10/22/2020 at 1:42 PM, Dazinoz said:

How long is a piece of string?

 

The answer to your question depends on so many variable. What is the outside temp, what is room temp, what temp do you want room, how big is the room, what aspects is room (which way facing), how many windows and aspects, how many people in room, what is room used for and more?

 

However going by Crossy's rough estimate its 0.54kwh x 4.7 baht unit which equals roughly 2.5 baht an hour.

 

 

So even in the worst case it would be 100 thb / day for aircon ?

 

 

[Crossy]

4 hours ago, scoupeo said:

So even in the worst case it would be 100 thb / day for aircon ?

 

2.5 Baht * 24 hours = 60 Baht 

 

But that guesstimate is based on a correctly sized A/C and a user who is not a penguin or polar-bear. If the compressor is running 100% then it's nearer 7.5 Baht an hour or 180 Baht per day.

 

Note:- I am aware that penguins are found in the tropics too, but let's not let facts get in the way of a little humour. If it pains you, insert your arctic/antarctic species of choice ????