| Production vs. Grid Voltage,
and OnLine Panels vs. Sun Elevation, for days where the grid voltage was out of spec |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
| This page displays the Production vs. Grid Voltages, along with the corresponding
On-Line Panel vs. Sun Elevation info for days where the grid hit values outside of the normal spec.
We had been seeing some issues with some panels going offline when the grid voltage approached or exceeded the max
acceptable voltage (specified as 240 VAC +/- 5%, which works out to 228 to 252 VAC), so we rigged up a system to be
able to track and log the grid voltage at our house. 1
We have been told that one theory is that all of the solar arrays on the
Vineyard actually are capable of driving up the grid voltage during peak production. It is starting to look to be the
case, as you can see in these graphs (during peak production seasons). Based on what we were seeing, Enphase (manufacturer
of the inverters) tweaked the inverter profiles (to their SAM profile) to allow them to tolerate a wider range of grid
voltages (which is something they regularly do in a few states, including Hawaii and California). So far, this seems
to have helped. Currently, this page looks back a maximum of 365 days, and will display a maximum of the 21 most recent days where the grid went out of spec at our location. |
Wed 03/27/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 53.20 kWh Grid reached above 252 VAC. (260.8 VAC, 8.7% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 51 degrees |
Fri 03/22/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 91.30 kWh Grid reached above 252 VAC. (259.6 VAC, 8.2% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 49 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Thu 03/21/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 95.30 kWh Grid reached above 252 VAC. (259.6 VAC, 8.2% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 49 degrees |
Wed 03/20/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 59.60 kWh Grid reached above 252 VAC. (258.2 VAC, 7.6% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 49 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Tue 03/19/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 88.40 kWh Grid reached above 252 VAC. (259.6 VAC, 8.2% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 48 degrees |
Mon 03/18/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 67.40 kWh Grid reached above 252 VAC. (258.2 VAC, 7.6% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 48 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Sun 03/17/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 64.40 kWh Grid reached above 252 VAC. (261.2 VAC, 8.8% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 47 degrees |
Sat 03/16/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 82.20 kWh Grid reached above 252 VAC. (261.4 VAC, 8.9% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 47 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Fri 03/15/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 49.20 kWh Grid reached above 252 VAC. (259.6 VAC, 8.2% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 47 degrees |
Thu 03/14/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 78.20 kWh Grid reached above 252 VAC. (261.2 VAC, 8.8% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 46 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Wed 03/13/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 84.20 kWh Grid reached above 252 VAC. (261.4 VAC, 8.9% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 46 degrees |
Tue 03/12/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 86.70 kWh Grid reached above 252 VAC. (261.2 VAC, 8.8% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 45 degrees |
Note: Main 2200 VA UPS dumped today at 3:47pm. Wondering if it is related to the grid over-voltage activity... |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Sun 03/10/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 59.40 kWh Grid reached above 252 VAC. (260.2 VAC, 8.4% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 45 degrees |
Note: This one is interesting, as the grid overages seem to follow the production pretty closely. |
Fri 03/08/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 79.20 kWh Grid reached above 252 VAC. (259.8 VAC, 8.3% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 44 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Fri 03/01/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 68.80 kWh Grid reached above 252 VAC. (259.2 VAC, 8% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 41 degrees |
Tue 02/27/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 63.50 kWh Grid reached above 252 VAC. (260.8 VAC, 8.7% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 40 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Mon 02/26/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 49.70 kWh Grid reached above 252 VAC. (253.0 VAC, 5.4% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 39 degrees |
Sun 02/25/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 77.00 kWh Grid reached above 252 VAC. (256.2 VAC, 6.8% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 39 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
Mon 02/12/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 55.70 kWh Grid reached above 252 VAC. (260.8 VAC, 8.7% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 34 degrees |
Thu 02/08/2024 | |
Production vs. Grid Voltage 1 Please see footnote 2 for Production Timeline issues. Total Production on this day: 59.10 kWh Grid reached above 252 VAC. (253.2 VAC, 5.5% above 240V) | Panels Online vs. Sun Elevation Please see footnote 2 for Panels Online Timeline issues. Max sun elevation for this day: 33 degrees |
| Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
| Footnotes | |
| 1
Grid voltage on the 240 volt supply line is being calculated by doubling the measured voltage at a 120 volt
outlet. This is assuming the two 120 volt legs of the 240 supply are close to being balanced,
which should be the case, but, therefore, is not necessarily perfectly accurate.
The Min and Max values are based on the accepted tolerance in the US for the 120 volt legs to be
120 VAC +/- 5%, which works out to 114 to 126 VAC, or 228 to 252 VAC for the grid. | |
| 2
It should be noted that, when comparing the grid voltage with the production curve, that the timing may not
be perfectly synced up between them. The timing of the grid voltage graphing is pretty accurate, as the grid
voltage at an outlet is updated once a minute, so when the database is updated every 15 minutes, the voltage
reading should be withing a minute or so. The production information is collected from the inverters by
the monitor, but is only done so periodically, and not all at the same time (and we do not know exactly how
this timing is handled by the monitor). The inverters save the data they have collected for each panel until
the monitor asks for it, so the production data may actually lag a bit on the time line, compared to the
grid voltage data. As an example, on a sunny day in October 2023, we shut down the entire array using the main cutoff switch. It took about an hour for the monitor to indicate that all of the panels were off line, and not producing (thus, the website graphs for Production and Panels Online were about 1 hour behind real time, even though all of the panels went off line at the same time). After turning the main cutoff switch back on, it was almost 1 hour before the monitor showed all panels back on line and producing (part of this timing is due to the interrogation timing of the monitor, and the time it takes for the inverters to reboot and reset, which means the panels actually don't come back on line at exactly the same time). On the web page graphs, the time between it showing the cutoff, and fully back on line times does corrospond to the one hour that the array was off, however, the events show up about an hour late on the timeline due to the interrogation delays of the monitor. | |
Current Statistics | Historical Statistics | Grid vs. Production Historical Statistics |
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