Deciphering my Electric Bill

[LoeiI]

31 minutes ago, bluejets said:

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.

 

Cheers for the explanation, the 19W figure was on the screenshot of the phone app i didn't realise i had screenshotted it when it was dark so it was hardly generating when i took the figures today at 11.42am the generated power on the app was 1706W with 1702W used and 4W going back to the grid and it now says todays generated power is 7.8Kw but the actual box on the wall is saying Etoday 7.86kWh I tend to agree with you that the Pac and the app figures are probably the power being generated in real time. The booklet supplied with the installation says there are 8 Mono 540W solar panels as i said in the OP i wasn't here for the install so never actually saw the panels but i have attached a pic of the bloke fitting them for some size perspective (I cant get on the roof as my knee is Knacked) is it too simplistic to assume that 8 x 540W panels generating in perfect sunny conditions would produce around 4000W ??    Thanks again

 

[Fruit Trader]

10 hours ago, LoeiI said:

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

 

The display default is Normal Pac (Power AC side)

 

Pressing the button should provide other values like Vac Iac frequency on the AC side and total production.

PSI have gone from selling standard Sofar brand inverters (with their logo) to a custom version along with display message variation and custom app. Not much detailed information available about the firmware.

PSI products are available to anyone online which raises the question: who installed the sytem and how was it setup for export. Maybe best contact the installer and let them explain how the system has been configured for export and express your concerns about production levels at the inverter and mobile app.

 

[LoeiI]

2 minutes ago, Fruit Trader said:

Maybe best contact the installer and let them explain how the system has been configured for export and express your concerns about production levels at the inverter and mobile app.

I've met him once when he came to seal a leak (there was a small damp patch on the ceiling) he didn't (or wouldn't ??) speak any English and the Mrs was struggling to understand anything technical, my initial post was aimed at any solar users with a similar set up and whether my system was producing what would be expected, I'm not in any way an expert but was under the impression from what the Mrs said originally that it would pay for itself in 2 to 5 years ? although he could have meant Jupiter years which now seems closer to the mark  

[LoeiI]

22 minutes ago, Fruit Trader said:

PSI products are available to anyone online which raises the question: who installed the system

As I said in the OP he's a big hitter at the temple she goes to so he'll be getting the benefit of the doubt or he may just be a really good bloke I really don't know, but most of the comments regarding this post are that the system is not functioning as it should

[bluejets]

13 hours ago, LoeiI said:

8 x 540W panels generating in perfect sunny conditions would produce around 4000W ??   

Yes, I would imagine that would be a good estimate, BUT, that is at peak time (instantaneous).

To give you an example, my system is 22 panels @250W per panel. ( installed back in 2016).

Peak (5000W) usually occurs in January around 11am.

Total for the day can be as much as 30 kWh, winter maybe around 22-25.

 

The main difference from you to me would be in consumption.

Where I might use 10kWh a day, yours seems a lot more running you RAC's. 

 

There is another difference that Thai PEA have so far to think about is, we get paid for any feedback to the grid.

When first installed, rate was around 6c/unit....then it crept up slowly each financial year to around 10c/unit before declining again down to the 6c mark.

Lucky for me though it started again to increase (political pressure I imagine) where it now stands at around 13.5c/unit (for Qld).

Poor buggers in Vic get around 3c/unit I believe.

 

Be-all end-all, mine paid for itself in around 4 years. (with gov subsidies of more than 60%)

I also run a storage hot water system(250 litres) which comes off the inverter before feedback.

A timer switches it off the grid between 4pm and 9am next day to ensure that 99% of the time(not raining) it runs off my generated power.

So in all, my HW is essentially free, and average payment for feedback per 3 month period is around $150 to $200.

 

Until Thai PEA do similar, you will never be in that boat though.

I'm waiting to see if they even move a small amount in that direction and I'll be putting solar array on the house in Khon Kaen province.

 

[motdaeng]

some more questions:

 

do you have a digital meter? if yes, and your system is sending power back to the grid, 

some member reports suggesting you have to pay PEA for each unit fedding (illegal) back!

 

have you verified that your system is indeed feeding back to the grid? 

a disc meter is running backwards ... test it on sunny afternoons (turn off all appliances in the house) ...

 

what was your consumption in units before installing solar? 

your current electric bill (with solar) indicates 621 units.

 

the screenshot from your app shows 6.9 units generated power, x 30 days resultes about 200 units / months.

that would sounds not too bad, if you may have 8 panels with only 350 max watt (and not 500 watt)  = 2'800 watt max ...

 

do you do not have any bill for the solar installation? with info's panel typ etc

Edited January 8 by motdaeng
spelling

[bluejets]

5 hours ago, motdaeng said:

the screenshot from your app shows 6.9 units generated power, x 30 days resultes about 200 units / months.

We've already been through this so no, what is shown there is kW...units are kWh....... 6.9kW is instantaneous

[Crossy]

Surely the app shows more info than the basic screenshot we are seeing? Even the basic Sofar app has graphing and historical data.

 

Also, @LoeiI can you check the setting of the inverter "no-export" control (Sofar call it anti-reflux), do you have an electronic or spinning disc meter??

 

I also suspect that the display of "Kw" (note the incorrect case) on the app actually means "kWh" there's no way that system can be generating an instantaneous power of 6.9kW!

 

The main page of the basic Sofar app looks like this: -

 

[LoeiI]

6 hours ago, motdaeng said:

what was your consumption in units before installing solar? 

your current electric bill (with solar) indicates 621 units.

 

the screenshot from your app shows 6.9 units generated power, x 30 days resultes about 200 units / months.

that would sounds not too bad, if you may have 8 panels with only 350 max watt (and not 500 watt)  = 2'800 watt max ...

 

do you do not have any bill for the solar installation? with info's panel typ etc

Only got it installed in August 23 and the Mrs used to chuck the bills straight in the bin (I've been saving them since about last June) so no comparisons until later this year, the app states total generated power which is the total for the day and on the inverter panel it gives the same reading as kWh so it looks like an app mistake. The only paperwork she got with the installation was a PSI energy booklet in Thai and a QC sheet regarding power, efficiency etc.

[Crossy]

No inverter manual???

You should be able to download it from the PSI website, with luck.

 

The PEA App, keeps basic historical data for >6 months, but 6 months that data will be on your bill anyway.

[LoeiI]

2 hours ago, Crossy said:

No inverter manual???

You should be able to download it from the PSI website, with luck.

 

The PEA App, keeps basic historical data for >6 months, but 6 months that data will be on your bill anyway.

I'm going to get him back to check the system production levels and ask him (via google translate) about feeding back to the grid etc. 

[LoeiI]

6 hours ago, Crossy said:

Also, @LoeiI can you check the setting of the inverter "no-export" control (Sofar call it anti-reflux), do you have an electronic or spinning disc meter??

Cant see anything on the inverter settings and the meter is a spinning disc type

[Fruit Trader]

1 hour ago, LoeiI said:

Cant see anything on the inverter settings and the meter is a spinning disc type

 

 

 

Note:  Setting Export Power is either 1 or 0

 

 

Edited January 8 by Fruit Trader

[Crossy]

7 hours ago, LoeiI said:

Cant see anything on the inverter settings and the meter is a spinning disc type

 

OK, if you have export enabled your meter should run backwards when exporting. As noted by others, the easy way to check is to turn off all the loads in the house at lunch-time on a sunny day and observe the meter.

 

IMPORTANT NOTE: - Doing this is definitely not permitted so ensure you are not exporting when the meter reader comes and also ensure that you never end up with an overall net-export (meter reading lower than the last one). Many small systems do this, it's absolutely guaranteed that PEA are aware of these systems and tolerate the unofficial net-metering.

 

If your inverter is a clone/badge-engineered Sofar then enabling/disabling export may be as easy as simply disconnecting the current transformer (CT) with export disabled, the inverter will then export any available energy.

[LoeiI]

6 hours ago, Crossy said:

 

OK, if you have export enabled your meter should run backwards when exporting. As noted by others, the easy way to check is to turn off all the loads in the house at lunch-time on a sunny day and observe the meter.

 

IMPORTANT NOTE: - Doing this is definitely not permitted so ensure you are not exporting when the meter reader comes and also ensure that you never end up with an overall net-export (meter reading lower than the last one). Many small systems do this, it's absolutely guaranteed that PEA are aware of these systems and tolerate the unofficial net-metering.

 

If your inverter is a clone/badge-engineered Sofar then enabling/disabling export may be as easy as simply disconnecting the current transformer (CT) with export disabled, the inverter will then export any available energy.

The Mrs has messaged him this morning so am hoping he comes to see me, quick question is it worth exporting ? on the app i have only ever seen it sending 3W to 4W back to the meter. I'm not sure when the meter reader comes as the meter is on a concrete post about half a kilometre away as when i bought the land she got a shed built for the grass cutter etc and somebody ran a cable to it and they never moved it when i got the main house built.

The system only generated 1kWh yesterday but she had the well pump running most of the day watering all the trees plants and topping the fish ponds up so would the inverter generated power on the app be less if the consumption was higher than usual ? I would have thought the generated power would be the same as other sunny days regardless of the consumption, every day in January so far has been sunny but the generation data on the app ranges from 1kWh yesterday to 7.8kwh the day before. TIA 

[Crossy]

Our Sofar inverters when export is disabled usually read a small power in either direction, it's just the nature of the beast.

 

Until we actually know whether it's supposed to be exporting we can't really answer whether it's worth it or not. Have you been able to check the inverter settings?

 

If you are definitely using all the power you are making during the day then obviously it matters not, but you should be making rather more then you are saying, even in the "winter".

 

Yesterday, our 10.6kWP system generated 30kWh, I would imagine your system that's about 1/3 the size would be in the order of 10kWh.

 

 

[JBChiangRai]

25 minutes ago, LoeiI said:

 I'm not sure when the meter reader comes as the meter is on a concrete post about half a kilometre

 

Meter reading in this province is always X days counting back from the end of the month.

[sjk65]

I have a 5kwh 16panels, 340wp.

Last year PEA took away my analogue meter and placed a digital one.

 

On yearly base, I produced around 18kwh a day.

 

Now I thinking of selling back to PEA, but I have to invest 15-25K to get this done.

 

From the 18, probably I use 4 or 5 on the day, that means, selling back around 13.

13 x 365 x 2.2 = 10.400 baht a year

So mony back in 2 years.

 

BUT.... like one person wrote,  other costs of PEA may increase.

 

So what is wise:  keep system like it is, put export meter on zero and use as much on the day from the solar.

Or selling back to PEA 🤔

Edited January 12 by sjk65

[Crossy]

2 hours ago, sjk65 said:

Now I thinking of selling back to PEA, but I have to invest 15-25K to get this done.

 

If you used a registered contractor (and they still exist) and have approved kit then you may be able to get on the export system.

 

It may actually be better to replace your inverter with a hybrid and a suitably sized battery pack to store your daytime production and use it at night.

[sometimewoodworker]

4 hours ago, sjk65 said:

Now I thinking of selling back to PEA, but I have to invest 15-25K to get this done.

That is rather optimistic and actually managing to get the paperwork done an approved is likely to be rather more and then many PEA offices are likely to say no.

Edited January 12 by sometimewoodworker

[sjk65]

4 hours ago, Crossy said:

 

If you used a registered contractor (and they still exist) and have approved kit then you may be able to get on the export system.

 

It may actually be better to replace your inverter with a hybrid and a suitably sized battery pack to store your daytime production and use it at night.

But that means an extra investment.  So ROI will not be reached by me, as I'm on my way to the stars 😉👍