Question concerning electricity rate

[JohnnyBKK]

Hello,

 

If I use 36 000 kwh in a month (50 000 watts 24h/24h) on a 3 phase electricity installation where I would be on this price rate list : http://www.boi.go.th/index.php?page=utility_costs

 

I'm not sure how to calculate the price, for example they have "demand charge per kW" and "energy charge per kwh".

 

Best regards,

[skatewash]

I'm far from an electrical expert.  For example, I don't really know what "50 000 watts 24h/24h" means.  Maybe some measure of demand usage?  I don't know.  I didn't know the difference between demand and energy charges.  This helped a little bit:

http://www.learnmetering.com/pages/demand-meters/

and this:

http://www.think-energy.net/KWvsKWH.htm

It would seem to me that you're talking about commercial levels of electricity usage.  The first link above states that some utilities place any customer using a 3 phase installation on a demand meter automatically.  I don't know what the situation in Thailand is.

It does seem likely to me that the level of usage you describe would not qualify for the residential schedule.  That is, you would be metered for both energy consumption and energy demand, rather than just energy consumption as a residential customer would be.  If the schedule you linked to is applicable to 3 phase installations (it doesn't say so) then I would guess you might be in category 3 or 4 (Medium or Large General Service, respectively).  In addition to knowing your energy consumption (36,000 kWh/month) you would need a measure of your demand usage (expressed in kWs for a maximum 15 minute integrated demand period).
 

[how241]

When I first came to Thailand, 8 years ago,  I tried to compare the electric cost in the USA  to Thailand... IF  my math was correct, Thailand electric is almost 10X more than the USA....Has anyone else done a cost comparison ??  Thanks

[steve73]

I was looking at this just recently and found this on wiki... although it's a bit dated for many countries...

 

https://en.wikipedia.org/wiki/Electricity_pricing

 

I pay about 3.5bt/kWhr all in, so around $0.10..  According to the wiki article mainland US was between $0.08-0.17 in 2012 (and probably not much different nowadays , based on oil/gas/coal prices). 

[how241]

So it looks like the electric prices are similar... I guess my math is not so good...ha ha ....Thanks

[KhunBENQ]

Moved to the Electrical forum where similar questions are discussed.

(although this is a bit special)

 

I am only familiar with the household tariffs but this is about commercial high volume. Very different.

[dennism53]

Just ran some quick numbers.

 

I had a two wire system for a year before I had it switched over about a year ago.

 

On the two wire I was paying about 7 baht per kWh all-in ($0.20 US)

On the current three wire system I'm now at 4.2 Baht per kWh all-in

($0.124 US)

 

In the states I was paying less than $0.10

Edited July 19, 2017 by dennism53

[KittenKong]

On 18/07/2017 at 7:21 PM, JohnnyBKK said:

If I use 36 000 kwh in a month (50 000 watts 24h/24h) on a 3 phase electricity installation where I would be on this price rate list

 

LOL. Bitcoin-mining.

 

On 18/07/2017 at 7:21 PM, JohnnyBKK said:

I'm not sure how to calculate the price, for example they have "demand charge per kW" and "energy charge per kwh".

 

My 3-phase electricity bill back in Europe had exactly the same three elements in the calculation, so I imagine it works the same way here.

 

The demand charge is payable according to the size of your "pipe". That's to say that it's a monthly charge per kilowatt (not per kilowatt hour) based on the maximum number of kilowatts available to you, even if you dont use them all. Example: a demand charge of 10B per kw for a supply of a maximum of 100kw would be 1000B per month, even if you dont use it all or even any of it. Look at it as the rental price of the "pipe".

Then you pay the energy charge per kwh. Obviously you only pay for what you actually use, as shown by the meter, though the rate per unit will vary according to how much you use.

 

And there's a single service charge (meter-reading charge) as well. You pay this also regardless of how much electricity you use.

 

 

Edited July 19, 2017 by KittenKong

[KhunBENQ]

On 18.7.2017 at 7:21 PM, JohnnyBKK said:

I'm not sure how to calculate the price, for example they have "demand charge per kW" and "energy charge per kwh".

As no experts on the thread, here is my guess:

 

Demand charge per kWh: a fixed monthy amount based on the required power (kW).

There seems to be a ruleset how to evaluate the power range.

But you see to know that it is 50 kW. So multiply this charge by 50.

 

Energy charge per kWh should be obvious.

 

In the end there will be tax (7%) and likely the fuel surcharge (currently a deduction).

[JohnnyBKK]

Thanks for the answers, please can anyone double check my below calculations ?

 

100 000 WATTS (100 computers using 1000 WATTS each) = 100 kW of demand charge (is this right ?)

100 000 WATTS divided by 1000 = 100 kwh multiplied by 24 hours = 2400 kwh per day multiplied per 30 = approx 72 000 kwh per month.  (is this right ?)

Each computer needs 220 volts, 100*220 = 22 kV  (is this right ?)

 

Is this calculation right ?

 

1. Our demand charge is 100 kW (safe side let's install 120 kW). (120*220 baht (approx)) = 26 400 baht per month of demand charge

2. Our kwh is 72 000 units per month. 72 000 * 3.9 baht (approx) = 280 800 baht per month of electricity usage

3. Our kV is 22 kV

 

We need 200 AMP * 220 VOLTS * 3 PHASE = 132 000 WATTS of capacity.

 

Thanks.

[Crossy]

Pretty close, ignore the 22kV stuff, that's all about if you need your own transformer.

 

You will be pulling 150A per-phase of a 3-phase supply. So a 200A supply is what you want to ask for.

 

BUT

 

That 120kW is going to all be converted into HEAT which you need to remove. Imagine being in that space with 120 single-bar electric heaters!

 

Shifting 120kW of heat is going to need 410,000 BTU which will consume around 40kW of power on top of your computer load.

 

Forget just using fans, the airflow required will be hurricane force.

 

Can you really mine enough to support the costs? Are you sure? Really sure?

 

[JohnnyBKK]

Yes i'm really sure. Thanks.

[blackcab]

Don't forget to include the VAT on the full amount of the electricity invoice.