Smooth out Enphase Power Graph?

Questions
#1

Enphase now stores and reports 15 minute power data, but their API still gives 5 minute results that average out OK, but look terrible plotted on PVOutput, but look fine on the Enphase Enlighten site. They plot at 15-min intervals by averaging three 5-min power values. Example from my system yesterday: the 11:45 Enphase-plotted point is 11.056 kW, which is the average of the 11:50, 11:55, and 12:00 API-reported values. See yesterday’s plots below.

Any way PVOutput could plot this same average instead of the sawtooth?? A new PVOutput “averaged” plotting option?

Enphase “Enlighten” Chart for yesterday…

Screen Shot 2018-04-09 at 10.59.26 AM.png1326×792 45.4 KB

PVOutput Chart for yesterday,

Screen Shot 2018-04-09 at 11.07.17 AM.png1880×782 78 KB

#2

Enphase only displays 15-minute intervals, while PVOutput takes these 15-minute intervals and fills in the missing 10-minutes with an average.

Changed this to an ‘idea’, possible solution is to just show 15-minute intervals.

#3

Thanks for the response to the idea. Unfortunately, if I understand your possible solution, when you plot the 15-minute-apart samples (without averaging the three 5-minute values), you’ll get a graph that is offset from actual (either high or low)… but a lot nicer looking.

I don’t know why they export those silly values without smoothing. The useful data is what they plot on the Enlighten site… but I guess 15 minute data would be incompatible for existing API users.

#4

Now I see it… A 5 minute plot is just fine, but it needs to be a 3-period (i.e. 15 minute) moving average. No need to compute and store 15-minute average values. Maybe simpler??

#5

Just showing 15-minute intervals will simply display the table/graph data in 15-minute increments and hide the calculated 10-minute intervals in between, this will make the graph look smooth.

10:30AM
10:15AM
10:00AM
etc...
#6

To try this out, I plotted my data from 4/4/2018 four different ways. The current PVOutput sawtooth (GREEN) looks the worst, but adds up to the exact same kWh as Enphase reports. Your suggestion of sampling the data on the quarter hour (RED) is much better, but overstates the output by 2% over the day. (Sampling at 10 min after the quarter hour (GREEN) is worst, and understates output by 4%.)

If doable, the dotted line (BLACK) is best… a 5 min plot of a 15 min moving average. It is spot-on for correct energy output. The Enphase Auto Uploader could do this if it could compute and store the moving average data instead of the raw data, and (I think!) nothing else would need to change in PVoutput (or PVOutputPRO)

Here’s a zoom in on my plot, then the whole day of April 4th…

Screen Shot 2018-04-11 at 3.42.36 PM.png2130×1108 141 KB

1 Like
#7

Thanks - we just need to make sure the end result energy is the same.

#8

It makes sense that a plot of the points at the midpoint of the fifteen minute interval is the way to present the data accurately.

#9

Hi Iwsmiser. Enphase (on Enlighten) plots 15 minute data points as the average of the following three 5 minute points. If you just plot the midpoints, you get an incorrect plot, unless you are one of the minority still getting actual 5-minute data. The data being sent now is A, A, B where A seems to be a peak-5-minute power number, and B is a correction to get to the correct 15-minute average. So (A+A+B)/3 is correct. A 15-minute moving average plotted at 5 minute intervals fits PVOutput’s plotting format, and would give a correct 15 minute average power, and thus adds up to the correct energy for the day.

#10

Bankstownbloke… Thanks for your feedback. I’m thinking the math behind a moving average says the energy has to be the same as the raw data, and it comes out that way for samples on my system and another Enphase Team system. The worst error difference I got was under 0.05% in a day (5 Wh in 10000 Wh) for moving average vs current PVOutput or Enphase Enlighten, and that’s probably accumulated rounding errors somewhere.

I count 77% of the 350 Enphase Team sites with the sawtooth problem. But the remaining sites still get true 5 minute data at this point in time. If everyone gets moving-averaged data, they will all get correct energy calcs, but the minority would lose power precision and see true peaks and valleys smoothed out a bit. Maybe a new primary device called Enphase-Avg or whatever would allow the user to make the choice??

FYI… Below is a recent sample of raw data vs 3-period-moving-averaged data (BLUE vs RED) from a PVOutput site still getting true 5-minute data:

Screen Shot 2018-04-12 at 1.53.11 PM.png616×668 54.5 KB

#11

I was just googling this and glad to see its not just my outputs with enpahse that look bad. Hopefully there is a solution.

#12

Looks nice! I downloaded today’s PVOutput live data for my system, moving-averaged the output power data, and uploaded it back. Take a look.

BEFORE…

Screen Shot 2018-04-14 at 9.04.54 PM.png1924×772 100 KB

AFTER…

Screen Shot 2018-04-14 at 9.33.01 PM.png1904×780 95.5 KB

#13

I haven’t had this issue with my Enphase system. I just changed the Status Interval under Live Settings for my system to 15 minutes, and the Poll Interval under Automatic Uploads to 15 minutes.

This is yesterday’s graph. It’s nice and smooth.
https://www.pvoutput.org/intraday.jsp?id=60768&sid=54224&dt=20180414

#14

Congrats! You’re one of the few (about 1 in 5) that is still blessed with true, 5-minute data from Enphase. Look at the POWER data on your “live” page, and you’ll see unique data values for every 5 minutes. Doesn’t matter how often you poll. Enphase changed policy last year… can’t tell you why you are lucky!!

#15

Nope. I got my system installed after that change was made. I’m on 15 minute intervals. The data on my PVOutput is every 15 minutes. I just logged into EnlightenManager to check, and all data there is in 15 minute intervals.

Like I said in my last comment, I changed the time settings to 15 minutes and got a nice smooth graph. The day I setup PVOutput I did have a staircase up/down graph, but after changing the polling intervals, it smoothed it out.

#16

I just had my system installed and is up and running on pvoutput and I seem to be getting 5 minute data from my enphase system

https://pvoutput.org/intraday.jsp?id=36992&sid=58477

#17

I’ve now switched my reporting to what @cjsimmons suggested and thats now cleaned up the output for the PV. That said, it looks like the consumption data from Rainforest Eagle is a bit less granular now, but I can live with that.

How it looks now:
https://pvoutput.org/intraday.jsp?id=15114&sid=12970&dt=20180420
How it looked before:
https://pvoutput.org/intraday.jsp?id=15114&sid=12970&dt=20180418

#18

Perfect! Thanks to cjsimmons and StrangePV! What you found is 15 minute moving average data taken from the 5 minute data that gives us the sawtooth graphs. Not sure if the smooth 15 minute data is coming directly from Enphase or is computed by PVoutput, but the curves look (almost) the same, and the Energy total is identical for the day.

(FYI: Comparing to 5-minute data downloaded from Enphase, the PVoutput power curve is shifted by 10 minutes from the Enlighten curve. For example, the PVoutput data for 6:00pm is the average of 5:55, 6:00, and 6:05 values. The Enphase Enlighten power curve value for 6:00pm is the average of 6:05, 6:10, and 6:15 values. Both are a correct, and both give the same total energy.)

#19

Bankstownbloke: Hope you’re still following this thread. Problem solved by setting STATUS INTERVAL to 15 Minutes, Maybe this is what you were suggesting earlier. I’m intrigued… I can’t find any provision in the Enphase API for 15 minute data, so it appears the existing PVoutput live loader computes a moving average to convert 5 minute data to 15. Yes??

#20

Enphase reports 15-minute intervals, the Auto Uploader to divide the data into 5-minute intervals. By setting a 15-minute interval on PVOutput the additional 10-minute in between will be ignored.