KB's Design

[J.P.M.]

Illustrative rates for the approved GRC. These were updated on 9/13 from what I've posted before.

http://docs.cpuc.ca.gov/PublishedDoc.../195586830.PDF

Those are based on Aug 2016 as a starting point, and don't include some of the "revenue requirement" increases that have occurred since then (if I am understanding correctly).

That's my understanding as well. Couldn't remember/trashed where I stashed that GRC.

Thanx for the reprint.

J.P.M.

Edit: KB: the DR-SES proposed rates are on line 9 of Page 8 of 32 for R1, line 9 on P. 8 of 39 for R2, and line 9 on P. 8 of 39 for the "proposed rates". Use the $/kWh numbers in the rightmost column. All the sets of rates are very similar and will probably change some before finally approved sometime later this year. I used the last of the 3 sets of rates when figuring system revenue under DR- SES.
My spreadsheets list the hourly rates at the top and each hour of the 8,760 hrs. in a year has the appropriate $/kWh rate copied into it. The copy job is ~ 1 week of 168 hourly rates copied for the appropriate number of weeks for summer and a second set similarly copied for winter. There are then mods for 5 holidays and also a 2 - 4 P.M. super off peak adjustment for March and April. As I wrote, sounds like a PITA, and it is, but it's really not more than a big copy job.

More on getting green button data onto the same spreadsheet later.

[kb58]

Thanks guys. Keep in mind that we have an electromechanical meter, so there is no green button data, if you're talking about SDGE usage data.

[J.P.M.]

Thanks guys. Keep in mind that we have an electromechanical meter, so there is no green button data, if you're talking about SDGE usage data.

You're welcome. Yes, I am. You still watching the dial go around huh ? I thought all the meters were changed out by now. Green button data before PV is a good, or at least useful and practical way to estimate hourly use patterns prior to PV. Still possible after PV but takes more monitoring equip.

[AzRoute66]

It sounds like you both know, but it might help somebody to know that pretty accurate numbers can be obtained by taking a stopwatch to the rotating disk. My POCO only gives access to daily meter reads (which are missed and averaged with the following days read as likely as not), and I have been out there timing laps from time to time. Not only did I get overall consumption for typical 'periods' of the day, and an idea of weekday vs weekend, but I was able to measure accurately the 'hardwired' loads such as the cooler motor and hot-tub. Not nearly as useful or comprehensive as an hourly CSV file, but better than throwing darts at a kWh dartboard. Note that my meter is digital, not mechanical, but is either 'not smart' or the utility has not provided any access other than the kWh totalizator reading and the little pseudo-disk LED segments that sequence across the bottom of the display to provide the same function as the rotating disk.

[J.P.M.]

It sounds like you both know, but it might help somebody to know that pretty accurate numbers can be obtained by taking a stopwatch to the rotating disk. My POCO only gives access to daily meter reads (which are missed and averaged with the following days read as likely as not), and I have been out there timing laps from time to time. Not only did I get overall consumption for typical 'periods' of the day, and an idea of weekday vs weekend, but I was able to measure accurately the 'hardwired' loads such as the cooler motor and hot-tub. Not nearly as useful or comprehensive as an hourly CSV file, but better than throwing darts at a kWh dartboard. Note that my meter is digital, not mechanical, but is either 'not smart' or the utility has not provided any access other than the kWh totalizator reading and the little pseudo-disk LED segments that sequence across the bottom of the display to provide the same function as the rotating disk.

I used the same type mechanical meters and got very accurate usage numbers for many years for many devices using the old meters. They are better measurement tools than the their replacements. If I still had the old meter, which got replaced about a month before PTO, it would have been a lot easier to calibrate my PV monitor than what I finally wound up doing. A stopwatch, 100 rotations of the old meters and a little ingenuity yielded a lot of information over the years that was at least as accurate as anything I can do now. I could get the old style back, but SDG & E charges a fee to do it = $75 up front + $10/month to go back to analog. I've got all my stuff pretty well dialed in, and I'm a cheap SOB. So screw them. Nothing personal, just business.

I could easily get an old meter and use it as a utility grade meter as a further check against what the PV monitor with my other two calibration methods - which are independent of one another and agree pretty much dead nuts with one another, but that seems a waste of time/resources and little more than another source of uncertainty. I define the POCO meter as accurate by default and have the PV monitor calibrated against that and pretty well dialed in. Another metering device would be like having 2 watches and never knowing the accurate time.

[bcroe]

I used the same type mechanical meters and got very accurate usage numbers for many years for many devices using the old meters. They are better measurement tools than the their replacements. If I still had the old meter, which got replaced about a month before PTO, it would have been a lot easier to calibrate my PV monitor than what I finally wound up doing. A stopwatch, 100 rotations of the old meters and a little ingenuity yielded a lot of information over the years that was at least as accurate as anything I can do now.

In agreement here. When my meter got changed out for net metering, the old one ended up in the basement
for making various measurements. I got a couple more old revenue meters (cheap), which will help keep track
of things if there is ever a wiring upgrade. Bruce Roe

[AzRoute66]

JPM and Bruce,

So, your current utility meters do not have anything analogous to the old spinning disk? As I said, my digital meter has a totalizer readout in kWh, and the little LED 'segment' display where the marker moves left to right across the bottom of the display and represents 7.2 Wh. I just figured all 'modern' non-mechanical meters would have at least that much info at the faceplate...

[J.P.M.]

JPM and Bruce,

So, your current utility meters do not have anything analogous to the old spinning disk? As I said, my digital meter has a totalizer readout in kWh, and the little LED 'segment' display where the marker moves left to right across the bottom of the display and represents 7.2 Wh. I just figured all 'modern' non-mechanical meters would have at least that much info at the faceplate...

Mine does not.

The current meter at my house displays other stuff that has some use for NBC calcs that the old meter wouldn't/couldn't do, and some other stuff (if I get creative) that can/may/may not be useful. I prefer the old meter because I could get a lot of consumption/use rates with the old mechanical type much quicker and more easily, and chasing vampire loads was somewhat easier with an old meter. Perhaps that's an example of how what some call progress can stifle choice or flexibility unless I schtupp the POCO $75 up front and a $10/month spiff for the privilege of keeping the old meter.

Being on NEM 1.0, NBC doesn't concern me personally, and I've had all the 240 V uses like HVAC, elec. H2O heater, oven, etc., dialed in with the old meter long ago. Any use rates for 120 V stuff is easy to get with a Kill-a-Watt meter. Life goes on.

[philips]

JPM and Bruce,

So, your current utility meters do not have anything analogous to the old spinning disk? As I said, my digital meter has a totalizer readout in kWh, and the little LED 'segment' display where the marker moves left to right across the bottom of the display and represents 7.2 Wh. I just figured all 'modern' non-mechanical meters would have at least that much info at the faceplate...

My SDG&E meter has a square - square - triangle thing on the LCD that is sort of like the spinning disk. But it actually gives you the current power reading as well, so it is no big deal.

[philips]

For anyone else following this, attached is the pertinent info from the link above (noting the times will shift). I'm going to assume the following:
Summer peak: 4-9pm M/F
Summer semi-peak: 9-12pm and 6am - 4pm M/F
Summer off-peak: 12-6am

Winter I'll leave as-is

I recall that going forward, May will be a winter month now in SDG&E - so summer rates are June through October.

[cebury]

PG&E territory has been on the shifted time windows for a while AND shortened 4 month Summers. They let folks stay on the old solar friendly TOU for 5 years until 2020 before we have to switch, too.

[J.P.M.]

Yeah I know about peak summer hours shifting to 4-9pm - we recently had an in-company SDG&E presentation where they passed themselves off as our best friends...

For anyone else following this, attached is the pertinent info from the link above (noting the times will shift). I'm going to assume the following:
Summer peak: 4-9pm M/F
Summer semi-peak: 9-12pm and 6am - 4pm M/F
Summer off-peak: 12-6am

Winter I'll leave as-is

Ugh, I don't use Excel a whole lot but this'll be jumping in at the deep end!

I don't understand your statement : "Winter I'll leave as-is". I do however, get the Ugh part.

FWIW, after doing this for several years, I found a method that, while having a lot of redundancy, helps me keep all the necessary balls in the air. I offer it here not in a proscriptive sense but only as one non spreadsheet person's mental spoor.

I started by putting the 6 hourly rates for DR - SES in the upper left corner of a clean spreadsheet and labeling them appropriately.

Then (I prefer to start at row 11, and a few columns from the left side for this one), put the appropriate date in a column (24 rows per single date, and the day of the week (24 rows per single day), Sun. - Sat., in an adjacent column. That will take 8,760 rows, one for each hour of the year.

Then, in another (adjacent ?) column, begin at row 11 and enter the appropriate winter hourly rate for one entire with 1 week ( of 168 hours), starting with Sun. at 0100 hrs., for Mon., by hr., etc. through Sat. nite at 2400 hrs. Easy way here is to do 1 weekday of 24 hours and copy 4 times for the other 4 weekdays, and then Sat. and Sunday, all at winter rates. Do the same for one week (168 hours) in another (adjacent ?) column using the summer rates, beginning also at row 11, and in a 3d (adjacent ?) column, again starting at row 11, with 168 hourly rates using what are moslty the winter prices but with that March & April, 2 P.M. to 4 P.M. super off peak adjustment. You will now have 3 sets of rates, one for winter, one for summer and one for March and April that reflect that 2 P.M. to 4 P.M. super off peak rate "anomaly" for one week, all beginning at row 11.

Then, copy all three columns 51 times (down) and add 1 day of 24 hrs. at the end of each column for a total of (168)*(52) + 24 = 8,760 rows.

You will now have 5 columns,.each with 8,760 rows, one col. for date, one col. for the day of the week, and 3 columns of hourly rates.

Not done yet.

Next, selectively copy the hourly rate information corresponding to the appropriate date, from the winter, summer or March & April column as appropriate into a 6th column. In other words, don't use winter rates for summer dates, etc.

Finally, adjust the 5 holiday date rates in that 6th column as appropriate.

If all that is done correctly, that 6th column will then be an hourly representation of what DR - SES rates are for every hour of the year. Do a file save.

As stated, that seems like a lot of redundancy, but I found it to be a system that works for me to help my luddite brain from getting FUBARed by trying to keep everything straight by only doing one thing at a time.

That 6th column is what I multiply a system's modeled hourly output by to get an estimate of what the value of that system's annual output might be to offset an electric bill using a tariff like DR - SES. Using a 1 STC kW system size is a convenient starting point.

Note too, that as long as the model being used for system performance gives hourly output, that hourly output for any size system, in any orientation, can be inserted onto the just constructed hourly rate sheet and then multiplied by the hourly DR - SES rate in the 6th column to give the value of that system's annual or any period's production.

Note also, that as long as annual system output is < annual use, the estimated revenue produced by any size system working under net metering and a tariff with rates/hr. will be independent of the quantity of electricity used by the household. That is, a, say 5 STC kW system producing 9,000 kWh/yr. will offset just as much ( ~~ $390*5 ~ $1,950 /yr. for you and I and most anyone in N.County San Diego at proposed DR - SES rates) of a 10,000 kWh /yr. DR- SES tariffed bill as it will a 20,000 kWh/yr. DR - SES tariffed bill. The 20,000 kWh bill will of course be more than the 10,000 kWh bill, but the 5 STC kW system will offset an equal $$ amount of either bill, making cost effectiveness considerations a bit easier to calc and maybe a bit more transparent.

That also makes ROI calcs a bit easier. A 5 kW ground mount system at, say, $4.00 * .7 STC/Watt * 5 kW = $14,000/$1,950 = ~ 7+ yrs. using the moron payback method. Numbers approximate.

There are other advantages to be seen that deal with ave. cost/kWh produced and sizing adjustments possible from time shifting of loads - that being that while ave. $/kWh of generation stays constant, Ave. $/kWh cost goes down with time shifting, allowing system possible system size reductions to be estimated. That is left as an exercise for the reader for now. This post is getting a little long in the tooth.

Another advantage: optimum orientation or tradeoff estimates get a lot easier. I'd guess on an unobstructed ground mount the optimum orientation of a system working to DR - SES in N.County San Diego is ~ 30-32 deg. tilt at an azimuth of ~~ 200 - 210 deg or so. considering max. value of power produced. Simply plug in a model's output for a 1 STC kW system, and choose the orientation that produces the greatest annual $ offset.

That is not to say however, that gaming a T.O.U. tariff by time shifting off peak rate times, or energy conservation measures should not be done to the greatest extent practical before PV considerations or purchase.

To the extent PV is considered among the ways to meet a goal of electric bill reduction, use reduction, time shifting of loads, probably concurrently with conservation measures ought to be done before PV additions, with any PV sizing taking the other measures into account as much as possible.

[J.P.M.]

PG&E territory has been on the shifted time windows for a while AND shortened 4 month Summers. They let folks stay on the old solar friendly TOU for 5 years until 2020 before we have to switch, too.

I believe all the CA I.O.U.'s will be doing something like that in one way or another.

[sensij]

As stated, that seems like a lot of redundancy, but I found it to be a system that works for me to help my luddite brain from getting FUBARed by trying to keep everything straight by only doing one thing at a time.

What... this isn't intuitive enough?

=IF(AND(B16>=DATEVALUE("5/1/2015"), B16<DATEVALUE("11/1/2016")), IF(OR(ISNUMBER(MATCH(B16, 'Tariff Data'!$J$2:$J$9,0)), WEEKDAY(B16,2)>=6), IF(OR(HOUR(C16)>='Tariff Data'!$D$19,HOUR(C16)<'Tariff Data'!$E$19),"S-Off-Peak","S-Semi-Peak"), IF(AND(HOUR(C16)>='Tariff Data'!$D$12,HOUR(C16)<'Tariff Data'!$E$12),"S-On-Peak", IF(OR(HOUR(C16)>='Tariff Data'!$D$14,HOUR(C16)<'Tariff Data'!$E$14),"S-Off-Peak","S-Semi-Peak"))), IF(OR(ISNUMBER(MATCH(B16, 'Tariff Data'!$J$2:$J$9,0)), WEEKDAY(B16,2)>=6), IF(OR(HOUR(C16)>='Tariff Data'!$D$20,HOUR(C16)<'Tariff Data'!$E$20),"W-Off-Peak","W-Semi-Peak"), IF(AND(HOUR(C16)>='Tariff Data'!$D$15,HOUR(C16)<'Tariff Data'!$E$15),"W-On-Peak",IF(OR(HOUR(C16)>='Tariff Data'!$D$17,HOUR(C16)<'Tariff Data'!$E$17),"W-Off-Peak","W-Semi-Peak"))))

[kb58]

...I started by putting the 6 hourly rates for DR - SES in the upper left corner of a clean spreadsheet and....

This is exactly what I was looking for. I know the basic functions of Excel but not well enough to intuitively know what variables should be on rows and what on columns in order for the spreadsheet to successfully scale up to handle all the hours. I won't mention how much of today was spent flailing about on that... I'll try again.

Oh, how did you import hourly generation out of SAM, CSV? I did that and end up with a 2-column x 8000+ row set of numbers. Where I was flailing was figuring out how to effectively do the cut-and-pasting and row/column decisions so that I don't have to manually adjust cell references.

I do know how useful it can be though, ending up with something where I can tweak panel orientation to find the optimum direction to maximize output (and possibly minimize the number of panels needed.

I already have... had... a spreadsheet which showed how important it will be to switch off unnecessary pond equipment during peak hours - it makes a really big difference.

Thanks again.

PS: took me a while to figure out the $X$Y cell reference...