9.45kW of older SunPower SPR-225's...Are my Inverter options limited?

[oilerlord]

Hello everyone,

I bought 42 used (about 5 years old) SunPower SPR-225's. What's turning out to be an issue is the positive grounding that they require. I'd like to install a Solaredge 7.6kW or 10kW inverter along with
42 P400 optimizers but my installer says the transformerless design isn't compatible with these SPR-225 panels. In addition, I can't use Enphase, SMA, or ABB micro inverters because of high voltage concerns in extreme
cold weather (I need to allow for -50C record temperatures).

Our design lends itself to strings of 6 panels. For that reason, he's recommending three SB-3000-US-12 inverters. He did originally spec larger SMA inverter(s), but he tells me the small number of panels per string
may cause problems with the minimum DC start voltage. The arrays are as follows:

SW Garage - 12 panels
SW House Wall - 12 panels
SW Top of house - 6 panels
SE Front of house - 6 panels
E Top of house - 6 panels.

Total: 42 panels - 9.45kW

I do have some flexibility with the last three arrays of 6 - perhaps removing the E array, and splitting the 6 panels between the SE front and SW top.

I'm going to contact Solaredge in the morning, but if anyone has any ideas; I'd love to hear them. Is there a way to implement the Solaredge solution with these SPR-225's? If not, assuming we don't want to change the design, which inverter(s) would you use, and how would you string the arrays?

Thank you for your time. I appreciate it.

[silversaver]

Hello everyone,

I bought 42 used (about 5 years old) SunPower SPR-225's. What's turning out to be an issue is the positive grounding that they require. I'd like to install a Solaredge 7.6kW or 10kW inverter along with
42 P400 optimizers but my installer says the transformerless design isn't compatible with these SPR-225 panels. In addition, I can't use Enphase, SMA, or ABB micro inverters because of high voltage concerns in extreme
cold weather (I need to allow for -50C record temperatures).

Our design lends itself to strings of 6 panels. For that reason, he's recommending three SB-3000-US-12 inverters. He did originally spec larger SMA inverter(s), but he tells me the small number of panels per string
may cause problems with the minimum DC start voltage. The arrays are as follows:

SW Garage - 12 panels
SW House Wall - 12 panels
SW Top of house - 6 panels
SE Front of house - 6 panels
E Top of house - 6 panels.

Total: 42 panels - 9.45kW

I do have some flexibility with the last three arrays of 6 - perhaps removing the E array, and splitting the 6 panels between the SE front and SW top.

I'm going to contact Solaredge in the morning, but if anyone has any ideas; I'd love to hear them. Is there a way to implement the Solaredge solution with these SPR-225's? If not, assuming we don't want to change the design, which inverter(s) would you use, and how would you string the arrays?

Thank you for your time. I appreciate it.

Double post

[silversaver]

Hello everyone,

I bought 42 used (about 5 years old) SunPower SPR-225's. What's turning out to be an issue is the positive grounding that they require. I'd like to install a Solaredge 7.6kW or 10kW inverter along with
42 P400 optimizers but my installer says the transformerless design isn't compatible with these SPR-225 panels. In addition, I can't use Enphase, SMA, or ABB micro inverters because of high voltage concerns in extreme
cold weather (I need to allow for -50C record temperatures).

Our design lends itself to strings of 6 panels. For that reason, he's recommending three SB-3000-US-12 inverters. He did originally spec larger SMA inverter(s), but he tells me the small number of panels per string
may cause problems with the minimum DC start voltage. The arrays are as follows:

SW Garage - 12 panels
SW House Wall - 12 panels
SW Top of house - 6 panels
SE Front of house - 6 panels
E Top of house - 6 panels.

Total: 42 panels - 9.45kW

I do have some flexibility with the last three arrays of 6 - perhaps removing the E array, and splitting the 6 panels between the SE front and SW top.

I'm going to contact Solaredge in the morning, but if anyone has any ideas; I'd love to hear them. Is there a way to implement the Solaredge solution with these SPR-225's? If not, assuming we don't want to change the design, which inverter(s) would you use, and how would you string the arrays?

Thank you for your time. I appreciate it.

Solaredge power optimizer required Voc <48V on P300 and Voc < 80V on P400, but you cannot use transformerless inverters.

BTW, I don't think you can find anything allow for -50C operating temperatures. Even the solar panels...... DC min V required.... has to be transfermer inverter....min 7 panels each array.

you can choose SMA SB2500HFUS for 6 panels on each array but not on multiple roofs and Voltage drop below min DC 220V might also be a problem.....

There is an optimizer from Tigo Energy might work for you, but again, you cannot find anthing for -50C operating temperature.



I'm sure someone will comment soon. good luck.

[oilerlord]

Solaredge power optimizer required Voc <48V on P300 and Voc < 80V on P400, but you cannot use transformerless inverters.

BTW, I don't think you can find anything allow for -50C operating temperatures. Even the solar panels...... DC min V required.... has to be transfermer inverter....min 7 panels each array.

you can choose SMA SB2500HFUS for 6 panels on each array but not on multiple roofs and Voltage drop below min DC 220V might also be a problem.....

There is an optimizer from Tigo Energy might work for you, but again, you cannot find anthing for -50C operating temperature.



I'm sure someone will comment soon. good luck.

Thanks for your thoughts. At this point, I just have the panels and they aren't on the roof yet. We like the 12-panel arrays (with 2 strings of 6 each) because it's a clean design but may have to sacrifice aesthetics somewhat to allow strings of 8 or 10.

[sensij]

Yeah, SolarEdge won't work with those panels.

The start voltage for that inverter is 228 V, and it will operate down to 200 V. The next size up has a start of 285 V and operates down to 250 V, but also accepts up to 600 V (instead of 500 V).

If temps get as cold as you suggest, strings of 10 will be too big for the smaller inverter. The Voc will increase in cold temps, and exceed the 500 V max for the inverter. Strings of 6 should be OK as long as you don't have any shade problems. If shade takes out one of the panels, the voltage remaining from the other 5 might not be enough to stay in the inverter's range.

Going to the bigger inverter doesn't really get you anything, because the minimum voltage is also higher, even with the longer string you still may have voltage problems if you have shade. I think your installer's recommendations sound good so far.

[silversaver]

He wants 6 panels on each roof which make it nearly impossible. The cost of inverters are another problem. If the panels are dirt cheap, then dump them and get other panels might save you headache.

[oilerlord]

He wants 6 panels on each roof which make it nearly impossible. The cost of inverters are another problem. If the panels are dirt cheap, then dump them and get other panels might save you headache.

Pretty sure we have this figured out:

1 x SB3000US-12: SW Garage – 2 strings of 6
1 x SB3000US-12: SW Wall – 2 strings of 6
1 x SB3800US-12: SW Top - 1 string of 9 + SE Front – 1 string of 9

The layout of panels is largely unaffected, save for the SW top of house and SE front that are now 9-panel landscape pyramids that still look attractive. Those used SunPower panels were only $0.45/watt, but the biggest bonus is passing the wife acceptance requirement. I would have rather used optimizers for panel-level monitoring but I'm ok without it.

[silversaver]

Pretty sure we have this figured out:

1 x SB3000US-12: SW Garage – 2 strings of 6
1 x SB3000US-12: SW Wall – 2 strings of 6
1 x SB3800US-12: SW Top - 1 string of 9 + SE Front – 1 string of 9

The layout of panels is largely unaffected, save for the SW top of house and SE front that are now 9-panel landscape pyramids that still look attractive. Those used SunPower panels were only $0.45/watt, but the biggest bonus is passing the wife acceptance requirement. I would have rather used optimizers for panel-level monitoring but I'm ok without it.

I understand, but the money you save are going into the inverters.... I don't see much saving there..... Used panels are not qualifly for Fed tax credit.....

Where is your lcoation?

[100Million]

spr-225

I just want to know if you don't use all of your panels I would like to talk to you about buying some

I have a system of 42 panels and I posted my pictures I used spr-5200 with 2 strings of 9 and 3 strings of 8

thanks

Chris

Btw I think you could use http://www.aeesolar.com/catalog/sunny-boy and only have one invertor but you will need extra mc cable and I think you can run 6


SB8000TL-US

8000W

208

300-600

300-480

98.0%

40

030-03175


SB9000TL-US

9000W

98.0%

44

030-03176


SB10000TL-US

10000W

97.5%

49

030-03177

[oilerlord]

I just want to know if you don't use all of your panels I would like to talk to you about buying some

I have a system of 42 panels and I posted my pictures I used spr-5200 with 2 strings of 9 and 3 strings of 8

thanks

Chris

Btw I think you could use http://www.aeesolar.com/catalog/sunny-boy and only have one invertor but you will need extra mc cable and I think you can run 6

Thanks for your reply. I decided to go with ABB Micro 0.25I inverters and CDD monitoring units. The ABB solution satisfied all my requirements:

- Able to withstand low temperatures / high voltages (it turns out that they "only" need to withstand -40C)
- These micros are positively grounded by design (which my SPR-225's require)
- Shading & MPPT obstacles
- Module level reporting (more of a fun option than a requirement)

The installation just started today as it took a long time to finally get the permits approved. I'm installing 41 out of the 42 panels that I bought back in April. The first array going up are 9 panels getting mounted on the west side of my house. It's a PITA putting them up but it's going to look like 9 large tinted windows when it's done. The other arrays are:

- 7 SouthWest front / top of house roof
- 10 West top of house roof
- 15 West garage roof

I also ended up having to change the older MC3 connectors on the panels to MC4 to meet code. Then MC4 connectors and crimper were cheap but the job was tedious. I'll upload some photos as the job progresses.

[100Million]

if you haven't changed out the mc3 connector DONT

I had same and I meet code with these clam shells

they are like 40 cents each

shoalsdotcom/products/mc3-locking-clamshells/[/url]

[oilerlord]

[QUOTE=100Million;169739]if you haven't changed out the mc3 connector DONT

I had same and I meet code with these clam shells

they are like 40 cents each

shoalsdotcom/products/mc3-locking-clamshells

Too late. It cost me about $100 for the MC4 ends (for more than I needed) & crimper. No biggie...got to spend some quality time with my panels.

EDIT: Actually, I still needed MC4 connectors to hook up to the microinverters. Good find though...may help someone else.