Deciphering my Electric Bill

[LoeiI]

Hi all I got some solar panels fitted last year (well the Mrs did when I was in the UK by a bloke who's a big hitter at the temple she goes to) I'm basically trying to figure out if they're saving me much money. My main problem is I cant decipher the electric bill very well I cant see a price per unit (if I divide the nett energy cost by the number of units used its always slightly different but around 4 baht) then there's the monthly service cost (I'm assuming this is like the standing charge in the UK) then there is the FT value which seems to fluctuate from bill to bill I don't know what FT stands for either. I've got an app that tells me what the solar panels are generating but not sure how it correlates with the PEA bill.

Simple replies only please my heads a bit like a 50 bob cabbage these days TIA

[Gweiloman]

https://www.pea.co.th/Portals/1/Knowledge PEA/Electricity Tariffs JAN66 Unofficial Translation.pdf?ver=2023-01-27-133655-423

 

This should help.

[LoeiI]

14 minutes ago, Gweiloman said:

https://www.pea.co.th/Portals/1/Knowledge PEA/Electricity Tariffs JAN66 Unofficial Translation.pdf?ver=2023-01-27-133655-423

 

This should help.

Thanks for that, it seems the service cost is the same as the UK standing charge, I also wasn't aware that there were different rates for kW/h usage, still not sure what the Ft value is tho 

[Gweiloman]

10 minutes ago, LoeiI said:

Thanks for that, it seems the service cost is the same as the UK standing charge, I also wasn't aware that there were different rates for kW/h usage, still not sure what the Ft value is tho 

As far as I know, the Ft is some sort of a surcharge. The government plays around with this to give discounts. A few months ago, it was around 90 satang per unit and currently, it’s only about 20 satang.

 

Out of curiosity, what size is your solar installation?

[Crossy]

"Ft" is the "Fuel Tariff" which is a per-unit charge which is the easy way that the authorities use to change the rate without an act of parliament.

 

The actual per-unit rate varies with usage as you can see from  @Gweiloman link.

 

You can use this calculator to take the mystery out of things https://eservice.pea.co.th/estimatebill/#

 

If you are not on the government "my solar roof" system you will be spinning a conventional disc meter backwards if your generation exceeds local usage, this is not permitted so don't let the meter reader see it.

 

Without knowing exactly what your solar system consists of it's hard to be more help.

 

[Gweiloman]

In your app, there’s probably a menu item whereby you can set the current electricity price. Don’t forget to add the Ft charge but ignore the standing charge as it’s negligible. The app should then show you how much “revenue” you have generated from your solar. This should give you an indication of whether it was a worthwhile investment.

[MJCM]

1 hour ago, LoeiI said:

My main problem is I cant decipher the electric bill very well I cant see a price per unit

 

Can you post it? So that we can post a clarification

 

Before posting Please remove all personal  identifying info, like PEA Nr, QR codes etc etc

 

Edit: Price per unit is on a sliding scale, the more you use the more you pay. (and on top of that is service charge, FT charge, AND VAT 7%)

 

 

[MJCM]

An option for the OP is.

 

Day 1:  (early morning)

Go to the Electricity Meter and NOTE it's reading

Day 2: (early morning)

Go to the Electricity Meter and NOTE it's reading again and subtract Day 1 reading from Day 2 reading

 

Day3:  (early morning)

Go to the Electricity Meter and NOTE it's reading

After that. Turn off SOLAR

Day 4: (early morning)

Go to the Electricity Meter and NOTE it's reading again and subtract Day 3 reading from Day 4 reading

 

This will give you a VERY rough calculation (not incorporating back spinning meters etc)

 

[LoeiI]

19 minutes ago, MJCM said:

 

Can you post it? So that we can post a clarification

 

Before posting Please remove all personal  identifying info, like PEA Nr, QR codes etc etc

[LoeiI]

43 minutes ago, Crossy said:

"Ft" is the "Fuel Tariff" which is a per-unit charge which is the easy way that the authorities use to change the rate without an act of parliament.

 

The actual per-unit rate varies with usage as you can see from  @Gweiloman link.

 

You can use this calculator to take the mystery out of things https://eservice.pea.co.th/estimatebill/#

 

If you are not on the government "my solar roof" system you will be spinning a conventional disc meter backwards if your generation exceeds local usage, this is not permitted so don't let the meter reader see it.

 

Without knowing exactly what your solar system consists of it's hard to be more help.

 

As i said in my OP i wasn't here when it was installed or i would have had a few questions and as the installer is a big hitter at the temple so he couldn't possibly be up to Owt nefarious 

[Crossy]

I hope that's not the shower curtain in your first photo

 

Actually, a Goth shower could be interesting ...

[MJCM]

1 hour ago, LoeiI said:

 

 

 

 

 

Recent Reading: 10535 (reading on the most recent date the meter reader took it)
Previous Reading 9914 (same as above but from the previous month)

Usage 621 Units (Recent - Previous reading)

 

Total Electric Charge 2519,93 (this is the actual price without any extras (so 2519,93 / 621 = 4,057 THB per unit)

 

The Extra's

Service Charge 24,62 (same every month)
FT charge (as said is Fuel Surcharge) (which is 0.2048 per Unit 621 * 0.2048 = 127,18)

 

Vat 187.02 (7% over the total)

Total 2858.75 (you have to pay)

 

So you average price per kW you pay to the PEA is = 4,603 THB

 

[sometimewoodworker]

3 hours ago, MJCM said:

 

Recent Reading: 10535 (reading on the most recent date the meter reader took it)
Previous Reading 9914 (same as above but from the previous month)

Usage 621 Units (Recent - Previous reading)

 

Total Electric Charge 2519,93 (this is the actual price without any extras (so 2519,93 / 621 = 4,057 THB per unit)

 

The Extra's

Service Charge 24,62 (same every month)
FT charge (as said is Fuel Surcharge) (which is 0.2048 per Unit 621 * 0.2048 = 127,18)

 

Vat 187.02 (7% over the total)

Total 2858.75 (you have to pay)

 

So you average price per kW you pay to the PEA is = 4,603 THB

 

The reason why you will always get a different price per unit is because the first 150kWh costs 3.2484 per kWh

the next 250 kWh. ( 151st – 400th) costs 4.2218 per kWh

and everything after costs 4.4217 per kWh

 

then you add on the ft charge for each unit, the standing charge and VAT on everything.

 

And that is only if you are on a 1.1.2 tariff.

The ft charge is valid for 3 months and is currently ฿0.2048 it has varied between about -2 baht and + 1.5 baht. So it makes a huge difference.

[bluejets]

16 hours ago, LoeiI said:

Hi all I got some solar panels fitted last year

Do you have any details on size of the system?

You must really hammer the air conditioner if that is a monthly account WITH a solar install.

 

[Crossy]

6 minutes ago, bluejets said:

Do you have any details on size of the system?

You must really hammer the air conditioner if that is a monthly account WITH a solar install.

 

Looks like about 2.8kWP and a 3kW inverter from the photos, so around 10kWh generation per day.

 

[LoeiI]

4 hours ago, Crossy said:

 

Looks like about 2.8kWP and a 3kW inverter from the photos, so around 10kWh generation per day.

 

According to the app In November it generated 90 kWh and December 107 kWh, there wasn't any rain and not many cloudy days as i remember, I'm trying to find the paperwork see if it has any details on it

[LoeiI]

14 minutes ago, LoeiI said:

According to the app In November it generated 90 kWh and December 107 kWh, there wasn't any rain and not many cloudy days as i remember, I'm trying to find the paperwork see if it has any details on it

Its a PSI P33 it says on the adverts I've just seen the break even point is 5 years (It doesn't say if that's Dog years or Giant Turtle years tho) got a feeling my grandkids will be reaping the benefits 

[UWEB]

In which direction facing your panels? Production is not very high.

[LoeiI]

2 hours ago, UWEB said:

In which direction facing your panels? Production is not very high.

this photo is looking North

[bluejets]

So you are using 20 units a day from PEA and 3 units from your solar...something wrong there.

As Crossy quoted, should be higher than 3.

I get 30 units a day from a 5kw system(summer) and around 20 in winter.

 

Seems your are facing the correct direction and angle should be somewhere between 15 to 20 degrees.

No shading at any time during the day..??

[LoeiI]

6 hours ago, bluejets said:

So you are using 20 units a day from PEA and 3 units from your solar...something wrong there.

As Crossy quoted, should be higher than 3.

I get 30 units a day from a 5kw system(summer) and around 20 in winter.

 

Seems your are facing the correct direction and angle should be somewhere between 15 to 20 degrees.

No shading at any time during the day..??

Angle looks ok and there is no shading until the sun goes behind the trees around 5 pm looking on the app for January the generated power is 3, 7, 2.6 and 4 kWh today could it be down to a bad connection or some other problem you may have heard of before ?

[bluejets]

11 hours ago, LoeiI said:

could it be down to a bad connection or some other problem you may have heard of before ?

Without actually being there and seeing for myself, difficult to say.

However, something is not right, that's for certain.

If the array is around the 3kw mark you should be getting more than 3 units a day...one reading you show goes to 7 which is closer but no prizes...should be more like 10.

It's not rocket science...if you get 3kw generated for 1 hour that's 3 units (3kw x 1 hour = 3kwh or 3 units)...so even at 5 hours a day you could expect to see 15 units total, not 3.

So either the array or the inverter is dodgy, or the app giving incorrect data (unlikely but possible) 

Can you read directly from the inverter unit, does it have a display of total readout per day/week/month?

Might be time to get them back to check the system if it's still warranty.

If not, get another mob to check it.

 

As for the system itself, there should be complete details of the actual array and inverter size written on the install document rather than continually guessing what is what.

 

[motdaeng]

2 hours ago, bluejets said:

....

So either the array or the inverter is dodgy, or the app giving incorrect data (unlikely but possible) 

....

 

a faulty panel could be also one of many reasons, but it is clear that something is not right!

[Crossy]

Just for comparison, our 10.6kWP (so about 3x what we guess our OP has) grid-tie hybrid produced 883kWh in November and 838kWh in December.

 

So, I would expect 294 and 279 kWh respectively from our OP's system.

 

We really need to know what our OP actually has, does he have "no export" enabled, what are his energy usage patterns (if not exporting and not using much during the day then a lot of potential energy is going to waste).

[Fruit Trader]

4 hours ago, Crossy said:

We really need to know what our OP actually has, does he have "no export" enabled, what are his energy usage patterns (if not exporting and not using much during the day then a lot of potential energy is going to waste).

Yes.

 

The PSI P33 inverter (3.3 kW from the Sofar stable) has real time production values available in display along with total production to date. The photo indicates possible CT connected so likely derating and not exporting.

 

It would make sense for the OP to read output from the inverter display at sunny noon; once with all the house appliances turned on and again with them turned off.

[LoeiI]

9 hours ago, Fruit Trader said:

Yes.

 

The PSI P33 inverter (3.3 kW from the Sofar stable) has real time production values available in display along with total production to date. The photo indicates possible CT connected so likely derating and not exporting.

 

It would make sense for the OP to read output from the inverter display at sunny noon; once with all the house appliances turned on and again with them turned off.

I'll check the inverter display in the morning I've attached a screenshot of the app home screen and it appears to be exporting 3 w to the grid and 16 w to the house any further explanation would be greatly appreciated TIA 

[bluejets]

Figures you supplied don't make any sense and conflicting both with info you have already supplied and the readout, such as it is.

 

[LoeiI]

On 1/6/2024 at 12:17 AM, LoeiI said:

It would make sense for the OP to read output from the inverter display at sunny noon; once with all the house appliances turned on and again with them turned off.

The 1st reading with all the electric appliances turned off read, Normal Pac = 1642W

All the appliances (4xAC units, lights TVs fridge freezers etc) were switched on the display read, Normal Pac = 3W 

If i press the button on the RHS it gives a different display like Upv1, Ipv1, Vac,

not sure if these readings are of of any use regarding the fitness of the system but i have pics if required

The reading now is Normal Pac = 350W with 2 x Fridge freezers and 1 AC unit 17000 btu running at 27 degrees which is normal daytime usage hope this makes sense 

, Freq, Etoday and Etotal not sure if these would

[LoeiI]

6 hours ago, bluejets said:

Figures you supplied don't make any sense and conflicting both with info you have already supplied and the readout, such as it is.

 

It doesn't make any sense to me either that's why i consulted the experts

[bluejets]

What I meant was you were showing readings of 19W from the array, 16W used and 3 W as feedback. 

Although these figures add up, it also shows generated power at 6.9kW and that is labelled as "todays generated power" .......generated power over time (today) would be in kWh , not kW.

No idea what this Pac is supposed to represent, can only guess at it being instantaneous power.

 

In all though I can see where you are consuming bucket loads of power when you say only one of your RAC's is 17,000BTU (around 5kW)

 

What is the actual size of your array?

You say the inverter is around 3.3kW but without knowing the panel size, it's really irrelevant as to power being generated.

Asked before but seems to have been lost.

If the Pac is indeed instantaneous power, it does seem a bit low if you had a 3kW array.