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5 battery install Lake of the Pines
- Thread starter h2ofun
- Start date
I have no reason to believe PGE likes me. We shall find out soon. Up to 22.02kw. Will I hit the max of 22.8? An hour to go
Your experience, and mine, illustrates why orientation and shading is such a big factor. If there was no issue with orientation or shading, everyone would max out at 1 pm on June 20.
In my case, max production seems like it might have been in late May or maybe late July coming up, as my set up is 35 panels facing mostly south on a 20% roof vs. 13 facing mostly north. on a 20% roof.
The closer the sun gets the more the north 13 come in to play, but there seems to be a slight loss, due to roof angle for the south 35.
In my case, max production seems like it might have been in late May or maybe late July coming up, as my set up is 35 panels facing mostly south on a 20% roof vs. 13 facing mostly north. on a 20% roof.
The closer the sun gets the more the north 13 come in to play, but there seems to be a slight loss, due to roof angle for the south 35.
That's not quite right, assuming by orientation you mean azimuth (so the panels point towards the equator).
At solar noon on the summer solstice, the sun's elevation angle in the sky is your latitude plus 23.5 degrees (the angle of the tilt of Earth's axis relative to the place of its orbit). So that's only optimal if your panels are at that elevation angle. Roof mount panels are usually at the roof elevation angle, so the day of the year when the sun's elevation angle is optimal will vary with roof slope. On a ground mount array, you could set it to the optimal solstice angle, but that would only make sense if you were changing the angle every month or so. If you wanted to choose one elevation angle to maximize production for the full year, you wouldn't pick the extremal elevation angle.
Cheers, Wayne
ICF Submitted: 5/20/2021
Request for 7 day discharge data: 5/24/2021
Homeowner Requested Report from Tesla: 5/24/2021
Tesla Replied with Report: 6/2/2021
Report sent back to SGIP for ICF review 6/2/2021
Revised ICF Received: x/x/2021
ICF Inspection: 6/23/2021 scheduled
ICF Approval: x/x/2021
Just got the email
TRC Energy Services, and we conduct Self-Generation Incentive Program (SGIP) rebate inspections on behalf of PG&E on the 23rd. So, guess moving along, even though have not received anything back on the ICF
Request for 7 day discharge data: 5/24/2021
Homeowner Requested Report from Tesla: 5/24/2021
Tesla Replied with Report: 6/2/2021
Report sent back to SGIP for ICF review 6/2/2021
Revised ICF Received: x/x/2021
ICF Inspection: 6/23/2021 scheduled
ICF Approval: x/x/2021
Just got the email
TRC Energy Services, and we conduct Self-Generation Incentive Program (SGIP) rebate inspections on behalf of PG&E on the 23rd. So, guess moving along, even though have not received anything back on the ICF
YES, shade, I have lots from neighbors trees, and some from my home structure. I have a lot pointing north, which maybe okay now, but nothing in the winter. this is why I am trying to over kill stuff. I have plenty of batteries. Just need enough solar to charge as much as possible, and send as much to PGE NEM2 for winter use when I will have to pull from the grid.
Not to be that guy, but the start of the sentence is "if there was no issue with orientation or shading...." which is exactly what you elaborated on, so the sentence is not only right but exactly right! Ha!
Well, hope that came through with the humor as intended, because if there is anyone on here who adds value its mr. wwhitney.
So, a question, does it follow that there is no "ideal" orientation? Or would it be based on latitude? I guess this only matters if you have the option to install at a selected angle.
Or, here is another question I don't think I have seen, if a person's roof allowed, is it better to install all south facing, or some east, some south and some west?
Assuming, let's say, a 20 degree roof angle in SoCal.
No problem, that's why I prefaced my remarks with "assuming by orientation you mean azimuth". : - )
But as I pointed out, if you pick one optimal orientation for the year, you don't expect the maximum production on the solstice (ignoring temperature effects), since that's an extremum of the solar conditions over which you need to optimize.
Depends on what you are optimizing for. The simplest case would be flat horizons all around, no atmospheric effects (on the Moon), no shading, just optimize for total kWhs per year. Then there's a well-defined optimum, the azimuth is always towards the equator, and the elevation angle depends on latitude only.
If you want to optimize kWhs per year, and you don't have time of day weather effects or E/W horizon effects, then all south. Given any of those effects, or a TOU rate schedule and optimizing for $s, there will be a single optimal azimuth which may differ from due south.
Cheers, Wayne
I think I have a slight horizon effect where east has some hills not in the west, but mostly it is that (1) what seems to happen with the south array is that their production does not increase as the sun moves towards the summer solstice, and (2) the house is not directly N/S, its more NW/SE. As a result of that, as we move towards the summer solstice the north array indeed comes more "into play" but its basically balanced out by the 35 panels in the south array becoming a bit less "in play." Its really obvious these days right before sunset. As the roof ridge which acts as the dividing line between then north array and the souht array does not face pure E/W, the south 35 panels are completely shaded that last half hour of sun, not that there are a lot of kwh available in the last half hour, but still.
I just put them all where they fit on the roof. Some that are not "perfect" is better than nothing.
I just put them all where they fit on the roof. Some that are not "perfect" is better than nothing.
Imagine if you put panels on a flotilla in the lake... ground-mount is for sissies... you want water-mount.
I think you also need to take into account what part of the day you already consume the most power, and how easily you can change your usage.
The battery is fine for storing the excess power, but it's always going to be most efficient to use the power as it is generated.
So (taking southern California), you can change where your peak is between around 12pm and 2pm depending on how much east vs west facing panels you have.
These batteries also seem to top out at max 3.5kWh charging steady state, so at some point in the day you're always going to be generating more than you can consume, so it's a balancing act to move any additional usage to that time (pool pump max speed for me).
Given that SCE loves its 4pm-9pm peak, the best ROI is going to be as much west facing as possible though. If you have southwest facing, that would pretty much be the best case scenario.
Here, if there are clouds, they are only part of the morning, but subtract from east facing production. So again, West or SouthWest wins over anything else..
Just got notice from SGIP my ICF has been approved. This email said next is inspection. Well, the inspection person just
left after taking pictures of the batteries, and the 2 gateway serial numbers. He said he goes back and looks at the discharge data,
to make sure there are discharging. This was only his second 5 battery install he has seen. The other also have a generator.
Said he might graph stuff out since when I showed him the app data, and that I was off grid 99% of the time, he was impressed.
Said monday evenings they send all the data back to SGIP/PGE, so things might be moving along again.
ICF Submitted: 5/20/2021
Request for 7 day discharge data: 5/24/2021
Homeowner Requested Report from Tesla: 5/24/2021
Tesla Replied with Report: 6/2/2021
Report sent back to SGIP for ICF review 6/2/2021
Revised approved ICF Received:6/23/2021
ICF Inspection: 6/23/2021
ICF Approval: x/x/2021
left after taking pictures of the batteries, and the 2 gateway serial numbers. He said he goes back and looks at the discharge data,
to make sure there are discharging. This was only his second 5 battery install he has seen. The other also have a generator.
Said he might graph stuff out since when I showed him the app data, and that I was off grid 99% of the time, he was impressed.
Said monday evenings they send all the data back to SGIP/PGE, so things might be moving along again.
ICF Submitted: 5/20/2021
Request for 7 day discharge data: 5/24/2021
Homeowner Requested Report from Tesla: 5/24/2021
Tesla Replied with Report: 6/2/2021
Report sent back to SGIP for ICF review 6/2/2021
Revised approved ICF Received:6/23/2021
ICF Inspection: 6/23/2021
ICF Approval: x/x/2021
Just passed my final on the new solar with the county. Now its off to get PTO from PGE.
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