8.7kW system coming Orange County, SoCal

[solarfrank]

All the information are in Power Optimizer Specifications – P300 / P400 and 5250W it is for single phase inverter.

http://www.solaredge.us/files/pdfs/application_note_power-optimizer_P300_400_MAN-01-00173-1.0_Spec_na.pdf

[gvl]

I don't know if odd/even count of panels restriction per the installer is valid, but if not sounds like 1 inverter may work if s_man can fit 8 panels on the west side and have 2 strings with 16/13 panels.

Also I suspect the 5250 w/string limit is due to the input DC voltage restriction which is 500V for SE.

[solarfrank]

Solar Edge support max 5250 W/ string for systems larger than 10.5 KW you need to use 3 strings and combiner box.
SE said you can have minimum 8 modules same orientation on one string. You can have on one string modules in different orientation, in your case you can have 9 orientated E and 8 orientated W on the same string.

Regarding the software please read the disclaimer

You can SE technical support:

USA and Canada: 1 877 360 5292
Email: to support@solaredge.us.

[gvl]

Thanks gvl for your input! I think the agent did not understand what the designer wanted to say. When I tried the Site Designer software from Solar Edge it seems the problem is whenever you try to make a system with different PV arrays that has different orientations then the software force you to choose 1 inverter for each of the PV arrays. So that's why I wondered if Solar Edge users here who has to set up with 2 different orientations has to use 2 inverters or not. The software does allow 3 strings (10,10,9) with same orientation connected to the 10kw inverter.

3 strings sounds familiar. My installer came with plans from the office to arrange the panels as 3 strings, but they quickly realized this was not going to work as the inverter only supports 2, so they wired the panels as 2 strings 15 each. I wonder if there is a bug in the Site Designer software or there is something I don't understand.

As for 2 inverters, if you determine it is a better approach, will this be extra $$$? I'd just go with micros if so. Also keep in mind if you plan to buy extended warranty for SE you will need to pay for each inverter separately, not much extra but still it is your money.

[s_man]

SE 10k supports 2 strings. I suspect the difficulty maybe due to the shading of the panels due to roof pitch. There's a limit on the number of shaded panels in a string, once exceeded there will be no production on that string. If that is the case micros may be a better idea than 2 inverters.

Edit: you can have more than 2 strings per inverter, but they need to be connected in parallel using a combiner box as the inverter only has 2 pairs of DC terminals.

I've just looked through the installation guide, there's nothing about odd/even panel count restriction. All it says that strings can be of different lengths.

Thanks gvl for your input! I think the agent did not understand what the designer wanted to say. When I tried the Site Designer software from Solar Edge it seems the problem is whenever you try to make a system with different PV arrays that has different orientations then the software force you to choose 1 inverter for each of the PV arrays. So that's why I wondered if Solar Edge users here who has to set up with 2 different orientations has to use 2 inverters or not. The software does allow 3 strings (10,10,9) with same orientation connected to the 10kw inverter.

[gvl]

You can't have more than 5250 W per string on Solar Edge Inverters , so if you like to use LG 300W you can have maximum 17 modules/string .

Is this true? According to the specs the recommended max DC power for the 10kWh inverter is 12400W, and it is allowed to be oversized up to 135% depending on the average yearly temperature. Definitely more than 5250W per string.

[gvl]

SE 10k supports 2 strings. I suspect the difficulty maybe due to the shading of the panels due to roof pitch. There's a limit on the number of shaded panels in a string, once exceeded there will be no production on that string. If that is the case micros may be a better idea than 2 inverters.

Edit: you can have more than 2 strings per inverter, but they need to be connected in parallel using a combiner box as the inverter only has 2 pairs of DC terminals.

I've just looked through the installation guide, there's nothing about odd/even panel count restriction. All it says that strings can be of different lengths.

[s_man]

SolarEdge Site Designer

Thanks Frank for your input. I've just tried the software Site Designer from SolarEdge and it seems each roof that has a different orientation (South, West) has to use a different inverter. The SE10000 inverter allows 3 strings connected but all would have the same orientation. I know many of SolarEdge users has 2 different orientations. May I ask if you have the same case, do you have to have 1 inverter for each orientation or you could edit it someway? Thanks for your input!

[solarfrank]

You can't have more than 5250 W per string on Solar Edge Inverters , so if you like to use LG 300W you can have maximum 17 modules/string .

[s_man]

Update

Today the installer's agent called me back and told me they would have to use 2 small inverter SE3000 and SE5000 instead of 1 inverter SE10000. According to him the designer said 2 strings of the inverter has to be the same odd/even number of panels; could not do 1 string odd number (19) and the other string even number (10) of panels. Anyone with SolarEdge inverter had this problem? Thanks for your input!

[NESTCAFE]

Pm sent

Thank you.

[gvl]

Thanks gvl, haven't thought of that simple great tool.
From PVWatts, 2,700kwh/year East facing vs 2,940kwh/year West facing for those panel. So West facing is better a bit, 8.9% difference. Right now at 11am the east facing has shading from a nearby tree too. Probably will go with West facing.

Also have them do analysis with the SunEye shade device, perhaps they already did and that is why they chose the East side. West should also be better for TOU which may be something you want to switch to in the future if you get an EV. With the East-facing panels you won't be making expensive electricity in the late afternoon. For example, I'm with SCE and some of their TOU plans define on-peak as 2-8pm, my SE oriented system, which is yet to be turned on, will not be producing much after 4pm, and probably nothing after 5pm in the summer, and it will be worse in the winter, so I'll be missing out during those hours of production when the price per kWh is the highest.

[s_man]

1. Compare PVWatts estimates for the same array size but East/West orientation for your location to get an idea if one side is better than the other in terms of overall production.
2. Consider specifics of your installation such as shading from trees, hills, chimneys, and surrounding structures.
3. Do you have any vents or the like that get in the way on either side making installation more difficult?
4. If you're considering switching to TOU you need to use the on-peak hours and rates from your utility, your actual hourly usage, and hourly PVWatts estimates to figure out which side will produce more credits.

Thanks gvl, haven't thought of that simple great tool.
From PVWatts, 2,700kwh/year East facing vs 2,940kwh/year West facing for those panel. So West facing is better a bit, 8.9% difference. Right now at 11am the east facing has shading from a nearby tree too. Probably will go with West facing.

[gvl]

But anyway, I thought West facing is better than East facing. Any input? Thanks!
[ATTACH]6754[/ATTACH]

1. Compare PVWatts estimates for the same array size but East/West orientation for your location to get an idea if one side is better than the other in terms of overall production.
2. Consider specifics of your installation such as shading from trees, hills, chimneys, and surrounding structures.
3. Do you have any vents or the like that get in the way on either side making installation more difficult?
4. If you're considering switching to TOU you need to use the on-peak hours and rates from your utility, your actual hourly usage, and hourly PVWatts estimates to figure out which side will produce more credits.

[s_man]

Hi,

Mind sending me a PM on the three companies you got bids for? I am in long beach and have similar requirements.

Thanks so much!

Pm sent.