Saved by a Cloud ?

[007 RED]

When I considered installing a small scale grid tied solar system, I was well aware that any excess electricity produced by the system could be fed back into the grid and thus make the old style meter spin backwards, something that is frowned upon by the PEA ,and could result in problems if noticed by the meter reader during his/her monthly visit. 

 

Hence, when I installed my system I incorporated a @Crossy ‘No Export’ device which allows me to automatically prevent the inverter from exporting excess power to the grid on the day that the meter reader is due to visit.  The device is connected to an app on my mobile so I can change the setting or shut the export off if required in an 'emergency'.

 

From my past 2 years billing history I could see that the meter reader normally came on the 15^th of each month, with a few exceptions when he/she came a day earlier or later, possible due to holidays that month.  So, to ‘play safe’ I programmed the automatic system to stop exporting on the 14^th through to the 16^th of each month inclusive.  I also put an alert into my phone calendar on the 13th to remind me each month of the pending meter reader’s visit.

 

So, last Sunday morning (13^th) my phone alerted me to the fact that the meter reader was due in the next few days.  No problem I thought, Sundays is a none working day for the PEA (except for emergencies) and the automatic ‘No Export’ facility will ‘kick in’ on Monday to prevent any excess from being exported and the meter spinning backwards prior to the meter reader’s visit.

 

How wrong could I be?  Totally!

 

FYI.  Sunday 13^th was a ‘reasonable power production day’ with a fair amount of sunshine and intermittent clouds.

 

My better half and I were at home when shortly after lunch I heard a motorbike stop outside the house.  From our living room I was unable to see who it might be, so I switched the TV over to our CCTV and to my horror the meter reader was just getting off his bike and approaching the pole, which has 4 meters on it (one being ours).

There was no time to get to open the app on my phone to turn the No Export device on, so instead I grabbed the air con control unit which was close to hand and turned that on in the hope that the start up power would stop the disc from spinning backwards (if it was in fact spinning backwards) ????????????.

 

From the CCTV, I watched the meter reader print off the bills and post them into ours, and our neighbour’s, letter boxes and then get on his bike and drive off back down our little cul-du-sac.

 

To say my heart stopped, would be an understatement.  I had no was of knowing if the meter disc was spinning backwards, and if it was, did he notice it?  I watched the CCTV playback several times to see if the was any indication that he may have noticed the meter spinning backwards, and if it was did he take a video on his phone, but there was nothing other than him punching the numbers into his handheld device and then printing out the bills.

 

I then looked at my system’s monitoring facility to see if there was any indication of the meter likely to have been spinning forwards or backwards.  The graph below shows the system output on Sunday 13^th.

 

FYI..... The bill showed the meter was read at 13:10 hrs.   The system's monitoring facility makes a record every 15 minutes.

 

Looking at the above graph, at 12.55 hrs the system was producing 1.4kW, which no doubt would have had the disc spinning backwards like a ‘Whirling Dervish’ considering our minimal usage at that time e.g. fridge/freezer + fan + LED TV.  Then just prior to the meter reader arriving, the power output dropped dramatically to a mere 0.35kW at 13:10 hrs, possibly due to a nice big cloud passing overhead at the time. ????????????

 

I’m not counting my ‘chickens’ quite yet, as it’s still possible that the meter reader may have spot something untoward and reported it when he was at the depot on Monday.  I'm also mindful that if someone looks at our meter readings since the system was installed (4 months ago) they may notice the considerable reduction in units used.  So, for the next week or so I’m leaving the system in the ‘No Export’ mode just in case someone from the PEA comes around to inspect.  FYI.  The panels and GTI are not visible from the roadway.

 

Lesson well learnt.  I’ve modified the automatic ‘No Export’ facility to now stop exporting during the week of the meter reader’s visit.

 

On the upside, my small scale grid tied system has been working very well, in fact far better than I had originally planned.  Preinstall, our bills were on average about 1,000 THB/month and I had anticipated a 75% reduction.  The current bill was for the grand sum of just 150 THB, so turning off the export facility for a week when the meter reader visits may be a desirable thing to prevent going into a negative reading at some time in the future when we get some really good sunshine during a month..

[Crossy]

February is an odd month for our man too, he usually rolls up on the 18th or 19th, it's been Feb 16th for 3 years.

 

So I'm expecting him tomorrow, he usually arrives about 6.30 AM anyway so there wouldn't be export at that time, but I disable for 16th to 19th, if he comes early then export gets turned back on as soon as his motorcy disappears.

 

I expect you'll be fine.

[Tropicalevo]

My electricity is from a private supplier and I pay 9 baht per unit.

Bill was about 7,000 to 8,000 baht per month.

13 solar panels and it is down to 2,000 baht per month.

I do not have batteries etc.

The supplier knows that the meter goes backwards during the daytime, but as long as there is a bill every month, they are not too fussed.

My neighbour has the same system and his meter would go backwards and a negative bill at the end of the month. I have a swimming pool. He does not!

The supplier installed a digital meter on his supply. They do not go backwards.

[Crossy]

There's always a risk in spinning the meter backwards, but to go negative really is just taking the michael.

 

When we first pondered solar we visited the local PEA office. When we decided not to go with the official system the supervisor told us in no uncertain terms "you can not spin the meter backwards!!!".

 

On our leaving the office he quietly said "don't let the meter reader see it going backwards"

[Bandersnatch]

My system is off-grid and does not feed-back and so cannot spin the meter backwards. So you would think my relationship with PEA would be stress free, unfortunately that is not the case.

 

PEA thought my meter was broken again. This is my fifth meter - just because it’s not spinning doesn’t mean it’s broken!

 

 

 

 

 

[Crossy]

As predicted Mr PEA rolled up this morning, a little later than usual at 8.40AM.

 

183kWh from PEA, 790kWh from Mr Blue Sky ????  

 

Of course the solar is now on full-bore export, unfortunately it's cloudy and we are just covering local consumption of 1,400W with only about 150W charging the batteries ???? 

[007 RED]

After the scare last month with the meter reader arriving much earlier than expected, I decided to keep my 'No Export' facility engaged for a few days extra after his visit just in case he reported seeing the disc spinning backwards and someone came around to check.  Thankfully, there does not appear to have been any follow-up.  As described in my original post, his visit timing seems to have coincided with a big cloud shading the panels just as he arrived.  But the experience has served as a good lesson for me not to take for granted that the meter reader will always come on a particular day, so in future I will arrange for the 'No Export' facility to kick in earlier than originally programed.

 

Despite the slight hiatus, my small scale system (4 x 415W panels) still managed to generate 173 units during February.  We also used 42 units from our local PEA, just to keep them happy.

 

 

It will be seen from the system monitoring graph above that on a several occasions the system was generating 8 plus units a day which, if this was a regular occurrence, could potentially put me into a negative meter reading situation.  Another lesson learnt.  I'll have to monitor the system more closely and possibly throttle back (activate the 'No Export' facility) to ensure that this does not happen.

[Crossy]

Yeah, the earliest our meter chap ever comes is the 16th (always February), the latest the 19th. So we are set to not export on those days every month.

 

If he comes before the 19th I can manually let the brake off.

 

We are lucky that he usually rolls up about 7AM before any significant generation has started, but ...

 

[007 RED]

1 hour ago, Crossy said:

Yeah, the earliest our meter chap ever comes is the 16th (always February), the latest the 19th. So we are set to not export on those days every month.

 

If he comes before the 19th I can manually let the brake off.

 

We are lucky that he usually rolls up about 7AM before any significant generation has started, but ...

 

As I explained in my original post, from my past 2 years billing history I could see that the meter reader normally came on the 15^th of each month, with a few exceptions when he/she came a day earlier or later, possible due to holidays that month.  The billing data also showed that he/she tended to visit between 10:00 and 10:30.  So, to ‘play safe’ I programmed the automatic system 'No Export' to stop exporting on the 14^th through to the 16^th of each month inclusive. 

 

But, for some unknown reason last month he came at 13:10 on a Sunday (13th) which I would have thought was a non-working day for the PEA (except emergencies), and when the system was in 'Export' mode.  That was a real heart stopper.

 

As my small scale system seems to be doing better than I originally anticipated .e.g. producing more than 7 units a day, I've decided to re-programme the automatic 'No Export' facility to activate a day earlier than previously set, so now it should activate for 4 days, from the 13th to the 16th each month inclusive.  If he visits during the 'No Export' period I can use your little app to switch back to normal export mode if required.

 

[BritManToo]

Much of my house is off grid now.

No more worries about people seeing my meter spin, it's at a dead stop most of the time.

[Crossy]

9 hours ago, BritManToo said:

Much of my house is off grid now.

No more worries about people seeing my meter spin, it's at a dead stop most of the time.

 

Which of course comes with its own set of "problems"  

 

On 2/15/2022 at 6:33 PM, Bandersnatch said:

PEA thought my meter was broken again. This is my fifth meter - just because it’s not spinning doesn’t mean it’s broken!