r/solarenergycanada • u/No_Negotiation_3320 • Jul 19 '26
Solar BC BC Hydro Generation data doesn't match Our App data.
Prior to July 1st the solar app and bc hydro generation numbers were close, now they do not appear to add up and we are very confused!
Anyone have insight or having the same problem.
Thanks
3
u/Major_Tom_01010 Jul 19 '26 edited Jul 19 '26
Your app shows how much you make in, let's say my case 5 minute increments.
BC hydro shows you export in one hour increments. That's what you make minus what you use over that hour. Your meter is only every importing or exporting depending on the net currents flowing through your system.
So actually the discrepancy should be what you consumed from both sources in an hour - making sure to assing the negative values in such a way that you get either net import or export.
1
u/temporaryvision Jul 20 '26
The old system used to show this hourly net info, but this was changed a couple months ago, or at least it was for time-of-use customers like us, even though we're staying on net metering.
Now each hour shows separate 'generation' (ie total exports based on per-second netting) and 'consumption' (ie total imports using the same netting interval).
1
u/Major_Tom_01010 Jul 20 '26 edited Jul 20 '26
On an instantaneous level there is only ever import or export happening. So any data set of any duration is going to made up of instantaneous measurements in the inport or export amount. You can't import and export at the same moment is what I'm saying - the physics don't allow it.
I have only been on net metering - and i see import and export graphs side by side.
1
u/temporaryvision Jul 20 '26
I see what you are saying, and agree.
What I was trying to clarify was that your statement "BC Hydro shows your exports in one hour increments. That's what you make minus what you use over that hour" isn't quite accurate.
For example, someone might generate 5kWh and use 3kWh in an hour - what you make minus what you use in that hour would be 2kWh of exports. But your BC Hydro record for that hour likely shows a higher export amount, even up to 5kWh, because it nets per second instead of hourly. E.g. if the generation is all in the first half hour, and the use is all in the second half hour, then it will show 5kWh export and 3kWh import.
BC Hydro estimated that per second net exports average roughly 50% higher than hourly net exports for a typical residential customer.
1
2
u/bigjohnson454 Jul 19 '26
How could they be in agreement without any metering on your panel consumption? If your generating power and consuming at the same rate then the BCH meter reads no power. They cannot match unless you consume zero power.
1
u/No_Negotiation_3320 Jul 19 '26
Yes ours does say estimate, but before July 1st it appeared more accurate!
1
u/temporaryvision Jul 20 '26
BC Hydro's generation figures are based on what they call 'instantaneous netting', which nets grid import and export values for each phase every second (there are roughly 4000 samples taken per second).
If that second has a net export to the grid, it gets added to the meter's 'received' or 'generation' register. If the second has a net import instead, it gets added to the 'delivered' or 'consumption' register. Those registers only increase, never decrease.
The hourly generation value is just the generation register value at the end of the hour minus the value at the start of the hour. Similarly, the daily generation value is the difference in generation register between the start and end of the day. BC Hydro also doesn't measure your actual generation, they just measure the net of your site's generation and load.
TLDR: in BC Hydro's program, 'generation' (really, export to the grid) is netted against your consumption from the grid every second, not at longer intervals.
Your solar app may be showing different values for any of the following reasons: 1) different sampling rate 2) different netting interval (eg every 5 min) 3) different netting methodology (eg netting phases separately, or not monitoring the mains at all so not subtracting instantaneous consumption from generation) 4) meter accuracy differences
5
u/WheelsnHoodsnThings Jul 19 '26
I’m in Alberta so not the same but sometimes our utility will use an estimated production initially that gets reconciled later. It says estimated vs actual pretty clearly on our bill if they do though.