True-Up Date

[Just Steve]

So in the NEM contract with my POCO I will have a one time chance to change my true-up date, I live in mid state NY, is there a particular date that would be of benefit to me. Such as after winter before peak generating season or something else, I figure you folks that have had solar for awhile have this strategy figured out.
Thanks
Steve

[Mike 134]

following

[oregon_phil]

I collected two years worth of data before adjusting my annual true up date. My system generates 92% of my annual usage. I adjusted my annual true up month from March (default with POCO) to February. In the willamette valley in Oregon, December, January and February are bad generation months; March is when it starts to get much better. In some years, February is when my net metering balance goes to zero.

[bcroe]

Best time depends entirely on when you generate the most,
and when you use the most. Probably best is shortly after
you start generating more than you use. Here I generate a
surplus of some 14,000 KWhour in summer months, then
gradually use most of it up heating in winter. I start making
more than I am using about beginning of March, true up is
beginning of April. Bruce Roe

[oregon_phil]

Best time depends entirely on when you generate the most,
and when you use the most. Probably best is shortly after
you start generating more than you use.

Well said. That's what I was trying to say, but failed to say it.

If you consistently generate more than 100% of usage, you're not going to care about true up month. If you generate much less than 100% of usage, you have a larger margin for error on picking the "correct" true up month.

My situation, at 92% of generation vs usage and having net positive generation in March allowed me to bank several hundred kwH instead of giving them to POCO. Also, for my POCO, "March" means the end of the March billing cycle, not March 1st. In my previous post, my "February" true up date is actually the end of the February billing cycle which turns out to be February 28th.

[Mike 134]

Bcroe and I both are ComEd customers in northern Illinois. A better term for us is POOF date, either October or April. any excess you have goes poof at the end of the 12-month cycle. You cannot carry it forward into the next 12 month period. But it is a true one for one credit per KWH.

[Just Steve]

Without waiting to see how much I produce as I can get a general idea using PV Watts, would knowing my average consumption help figure this out? 2020 and 2022 were abnormaly high due to extra people living and working from home due to COVID. My annual average is between 12 &13,000 KWH with June, July and August being the highest.

Date	KWH
Dec - Jan 2017	824
Jan - Feb 2017	813
Feb - Mar 2017	687
Mar - April 2017	534
April - May 2017	1012
May - June 2017	917
June - July 2017	1771
July - Aug 2017	1450
Aug - Sept 2017	1683
Sept - Oct 2017	763
Oct - Nov 2017	700
Nov - Dec 2017	875
Dec - Jan 2018	873
Jan - Feb 2018	481
Feb - Mar 2018	569
Mar- April 2018	714
Apr - May 2018	932
May - June 2018	1151
June - July 2018	1556
July - Aug 2018	2624
Aug - Sept 2018	1141
Sept - Oct 2018	1570
Oct- Nov 2018	735
Nov- Dec 2018	886
Dec - Jan 2019	722
Jan - Feb 2019	1129
Feb - Mar 2019	577
Mar - April 2019	895

April - May 2019	1110
May - June 2019	669
June - July 2019	2090
July - Aug 2019	1600
Aug - Sept 2019	1265
Sept - Oct 2019	1017
Oct - Nov 2019	736
Nov - Dec 2019	887
Dec - Jan 2020	987
Jan - Feb 2020	499
Feb - Mar 2020	760
Mar - April 2020	988
April- May 2020	859
May - June 2020	1603
June - July 2020	1783
July - Aug 2020	2978
Aug - Sept 2020	1103
Sept - Oct 2020	1841
Oct - Nov 2020	664
Nov - Dec 2020	786
Dec - Jan 2021	842
Jan - Feb 2021	2907
Feb - Mar 2021	842
Mar - April 2021	1268
April - May 2021	1052
May - June 2021	1519
June - July 2021	2618
July - Aug 2021	2454
Aug - Sept 2021	1350
Sept - Oct 2021	1403
Oct - Nov 2021	689
Nov - Dec 2021	1455
Dec- Jan 2022	743
Jan - Feb 2022	1794
Feb - Mar 2022	959

[Mike 134]

How much does the power company pay you in NY for your excess? Same as you pay to buy? Is it a real true-up (you pay/they pay) or just a starting point for a new 12 month cycle. What happens to any credits you have with the new 12 month calendar?

[Just Steve]

How much does the power company pay you in NY for your excess? Same as you pay to buy? Is it a real true-up (you pay/they pay) or just a starting point for a new 12 month cycle. What happens to any credits you have with the new 12 month calendar?

It's a use it or lose it plan, carry over month to month then poof after 12 months.

[Mike 134]

Since I had an either of April or October I went with April. Though behind that Jan-Feb-Mar has the least amount of sun, the sun's lower angle, some days covered in snow. Those conditions would likely use up any excess credits I had from the cooler fall months.

[oregon_phil]

Without waiting to see how much I produce as I can get a general idea using PV Watts, would knowing my average consumption help figure this out? 2020 and 2022 were abnormaly high due to extra people living and working from home due to COVID. My annual average is between 12 &13,000 KWH with June, July and August being the highest.

Your annual average is closer to 14,000 to 15,000 kW excluding 2020 and partial year data provided. I took Jan-Feb to mean usage during January.

kwH Usage
	2017	2018	2019	2020	2021
January	813	481	1129	499	2907
February	687	569	577	760	842
March	534	714	895	988	1268
April	1012	932	1110	859	1052
May	917	1151	669	1603	1519
June	1771	1556	2090	1783	2618
July	1450	2624	1600	2978	2454
August	1683	1141	1265	1103	1350
September	763	1570	1017	1841	1403
October	700	735	736	664	689
November	875	886	887	786	1455
December	873	722	987	842	743
Usage Annual Total	14095	15099	14981	16726	20321

In your other post, you gave a range of PV Watts generation estimates. Depending on your actual PV generation and actual usage, you might be well over 100% (don't care which month) PV generation/Usage or in the 80 to 90% range (starting to care which month).

PV Watts Estimate
Low PV Estimate	17089	17089	17089	17089	17089
Middle PV Estimate	17803	17803	17803	17803	17803
High PV Estimate	18400	18400	18400	18400	18400
PV Generation/Usage %
Low PV Estimate	121%	113%	114%	102%	84%
Middle PV Estimate	126%	118%	119%	106%	88%
High PV Estimate	131%	122%	123%	110%	91%

I think you need to take actual data for a couple of PV generation cycles given you have one chance to change true up month.

[Just Steve]

Your annual average is closer to 14,000 to 15,000 kW excluding 2020 and partial year data provided. I took Jan-Feb to mean usage during January.

kwH Usage
	2017	2018	2019	2020	2021
January	813	481	1129	499	2907
February	687	569	577	760	842
March	534	714	895	988	1268
April	1012	932	1110	859	1052
May	917	1151	669	1603	1519
June	1771	1556	2090	1783	2618
July	1450	2624	1600	2978	2454
August	1683	1141	1265	1103	1350
September	763	1570	1017	1841	1403
October	700	735	736	664	689
November	875	886	887	786	1455
December	873	722	987	842	743
Usage Annual Total	14095	15099	14981	16726	20321

In your other post, you gave a range of PV Watts generation estimates. Depending on your actual PV generation and actual usage, you might be well over 100% (don't care which month) PV generation/Usage or in the 80 to 90% range (starting to care which month).

PV Watts Estimate
Low PV Estimate	17089	17089	17089	17089	17089
Middle PV Estimate	17803	17803	17803	17803	17803
High PV Estimate	18400	18400	18400	18400	18400
PV Generation/Usage %
Low PV Estimate	121%	113%	114%	102%	84%
Middle PV Estimate	126%	118%	119%	106%	88%
High PV Estimate	131%	122%	123%	110%	91%

I think you need to take actual data for a couple of PV generation cycles given you have one chance to change true up month.

Thanks for breaking out the info like that, gives me a great visual. When you say "couple of PV generation cycles" what do you mean by that? A couple of months? or something else?
Thanks again.

[oregon_phil]

I gave myself two years to figure it out, but that's just me. Variables: New solar panels are super clean (maybe higher than average output), year to year PV generation and usage variation, other unknowns.

Attachments:

1) Estimated average PV generation using PV watts for your Zip code. This is only an estimate because I didn't know your actual panel count and how many 60deg and 240deg.

2) Your usage history

If you only have one chance to make the true up month change, the more data you can take, the better. Actual PV generation data is better than PV Watts estimate. I have some years better than PV Watts estimate and some years worse than PV Watts estimate. Overall, PV Watts is pretty close for me. On the other hand, my usage requirements have changed due to wildfires, ice storms, and other unknowns.

Good luck!