New 11kW Ground Mount in N San Diego

[12CV2]

SOLAREDGE INCREASES POWER LEVEL ON ITS FAMILY OF POWER OPTIMIZERS
SolarEdge announces the new P320 Power Optimizer. This Power Optimizer has been designed specifically for the latest high power 60-cell modules being release over the course of 2015. The new P320 supports 60-cell modules up to 320Wp with a short circuit current (lsc) of up to 11amps.

Their website hasn't been updated yet except for posting the updated datasheet. Looks like it could be a while until are widely available although not many panels on the market that would require them. I guess when LG eventually launches their 310/315/320W panels, these will be ready.

http://www.solaredge.us/files/pdfs/products/power-optimizers/se-P5-series-add-on-power-optimizer-datasheet-na.pdf

[sensij]

Two quotes I received noted that the P300 was being discontinued. One of the quotes originally said P300 but was updated to P400 with no cost change due to P300 being discontinued (so I think it is probably really being discontinued)

Turns out that our guesses on SolarEdge's product mix were wrong. They've just launched the P320, with the same MPPT range as the P300 but the ability to handle higher input current. This is clearly the most appropriate optimizer for the higher power 60 cell panels that are starting to show up in the market. What it means for the future of the P300 is unclear, but it suggests that they don't see the P400 as the most optimal product for those panels.

It also looks like the -2 series (NEMA 4 rated) of optimizers is being discontinued in favor of the -5 series with better NEMA 6 rating, which is consistent with what my installer told me about the availability of different optimizer sku's.

[SunEagle]

Especially with a couple years of panel fouling / degradation, a 7.6 kW inverter on a 7.2 kW system is a probably not worth the extra cost. Lots more lessons to learn!

You also have to figure in the circuit breaker size for the pv system will be larger for the 7.6kw inverter and may be too big for the Main Panel buss capacity. Going with that 6kw inverter may clip some of the panel generation but can be used on most house panels without needing to de-rate the main CB.

[halemo1970]

I'm new here

Hi
I'm new here & want to learn about installing my own solar system
thanks for all

[sensij]

Especially with a couple years of panel fouling / degradation, a 7.6 kW inverter on a 7.2 kW system is a probably not worth the extra cost. Lots more lessons to learn!

[Carl_NH]

Sensij

Our array is on 38* angle and azimuth 211* and we are in NH. I understand it's about perfect for production this time of year.

As I mentioned in my edited post, we are planning to build another house with a 6KW system in 2 years and I will swap inverters at that time..

Lesson learned.

Thanks

Carl

[sensij]

So we are loosing 4-5 KW a day or roughly 100KW month due to clipping. Now the interesting thing is every other SE Inverter than the SE6000 has a 10-15% over the rated AC output capability.

Extrapolating performance in March to the rest of the year is faulty. For panels mounted close to latitude tilt, this is the best performing time of year, since the temps are cool and the angle of incidence is best. Summertime will probably produce more on a raw kWh basis since the days are longer, but if you are looking for peak kW, this is the time of year to see it.

[Carl_NH]

I too am working up the design for a 7.2 KW ground-mount array, and am comparing the advantages of a 24 panel LG300 array plus optimizers and a string inverter, with 24 LGA1C-B3 AC panels. My design site is about 140' from my service panel, so I tend to favor the AC panel approach with #6 AWG cables to the panel, to avoid long heavy DC cables. How far from your house is your ground site? Also, what mounting frame is being proposed by your installers? Since I am figuring on doing 80% DIY, I am basing my design on the Ironridge ground-mount system.

Hi Hillsider,

I have read this thread with interest as we just installed 24LG 300 panels, 24 SE 300 Optimizers, and the SE6000 Inverter system - vendor said it would handle the load but didn't say it would not convert it!

My understanding about DC overrating was incorrect, as the SE6000 inverter will accept up to 7500WDC, but MAX AC output for this unit is 6000W AC.

So we are loosing 4-5 KW a day or roughly 100KW month due to clipping. Now the interesting thing is every other SE Inverter than the SE6000 has a 10-15% over the rated AC output capability.

For instance the SE7600 max AC output is 8450 W AC and the SE11400 is max AC output is 12000 W AC - its like Solar Edge and the SE6000 was at the top of the design limit. So with your 7200 W output you will be fine with the SE7600 if you go that route.

By the way, I learned that the SE6000 when over current, it "shuts down" or limits the current input to the inverter keeping it at the max 6000 W AC output so as not to convert the excess to heat at the inverter, it lets the heat out at the panel level. In any case, as I have learned buyer beware!

I intend to build another house with 6KW system in the coming years, so will swap inverters at that time.


Carl

[bcroe]

One last thing to consider though is if you bring back DC then you will have to use metal conduit approx $1/ft and mark it every 10 feet i think. And this approach is not compatible with Micro inverters ... but does work with optimizers. Good luck

Here in the Wild West DC underground conduit isn't metal; 260' of it. Bringing back wires
from each string may allow using the inverter internal combiner function, instead of a
separate combiner box. Bruce Roe

[Poway]

I too am working up the design for a 7.2 KW ground-mount array, and am comparing the advantages of a 24 panel LG300 array plus optimizers and a string inverter, with 24 LGA1C-B3 AC panels. My design site is about 140' from my service panel, so I tend to favor the AC panel approach with #6 AWG cables to the panel, to avoid long heavy DC cables. How far from your house is your ground site? Also, what mounting frame is being proposed by your installers? Since I am figuring on doing 80% DIY, I am basing my design on the Ironridge ground-mount system.

The calculator I like the best

http://www.calculator.net/voltage-drop-calculator.html

computes a 1.4% loss for #6 wire at 140ft
this drops to 0.9% loss for #4 wire (which is cheaper by the foot than #6 at both home depot and lowes now [$0.79/ft * 140 ft * 4 wires = $442 for AC from panel to main]

But what DanS26 said is correct. If you do this with DC (and have the inverter at the house) the voltage would be approx twice as high and with 4 wires could bring back two strings so (so 1/4th the curr in each of the 4 wires) bottom line is small #10 wire could be used

One last thing to consider though is if you bring back DC then you will have to use metal conduit approx $1/ft and mark it every 10 feet i think. And this approach is not compatible with Micro inverters ... but does work with optimizers

Good luck

[DanS26]

I too am working up the design for a 7.2 KW ground-mount array, and am comparing the advantages of a 24 panel LG300 array plus optimizers and a string inverter, with 24 LGA1C-B3 AC panels. My design site is about 140' from my service panel, so I tend to favor the AC panel approach with #6 AWG cables to the panel, to avoid long heavy DC cables. How far from your house is your ground site? Also, what mounting frame is being proposed by your installers? Since I am figuring on doing 80% DIY, I am basing my design on the Ironridge ground-mount system.

Whoooooo.....high voltage DC does not require "long heavy DC cables". Your confusing low voltage battery cables with high voltage home run cabling from combiners at the array.

Do a little more homework on the design.

[Hillsider]

How far is your array from your house?

Looking comments on the following configurations... And PM of recommended installers (thejq any recommendations?)

Ground Mount. Perfect conditions (point south or slightly west... any elevation... no obstructions)

11.95 kW DC
28x SunPower 427W Panels
Solar Edge P400 Optimizers
SE11400 inverter (is this to small for the 11.95 DC if so could drop to 26 panels 11.1KW?)

10.8 KW DC
36x LG 300W Panels
Solar Edge P300 Optimizers (or should I still use P400 optimizers?)
SE11400 inverter

10.8 KW DC
36x LG 300W Panels
Enphase M250 (will these clip ... do I need to use lower wattage panels given ideal pointing of array?)


Thanks

I too am working up the design for a 7.2 KW ground-mount array, and am comparing the advantages of a 24 panel LG300 array plus optimizers and a string inverter, with 24 LGA1C-B3 AC panels. My design site is about 140' from my service panel, so I tend to favor the AC panel approach with #6 AWG cables to the panel, to avoid long heavy DC cables. How far from your house is your ground site? Also, what mounting frame is being proposed by your installers? Since I am figuring on doing 80% DIY, I am basing my design on the Ironridge ground-mount system.

[DanS26]

This is a good read on oversizing.......may help your decision process:

http://www.civicsolar.com/resource/solectria-array-oversizing

[thejq]

Most accurate because it is the highest? Um, ok. This is among the reasons why PVOutput.org data isn't totally reliable. Shutting off the SolarEdge public site is classy, too.

Edit:
You might want to check this thread to see that the SolarEdge end of day energy number could be inflated by several percent relative to more trustworthy data sources.

No, because that's where current is inverted, and the place from where all the data is originated. I trust the source than any sub-sampled, over-sampled, interpolated or extrapolated data from pvoutput, TED or POCO's readings (esp. the last two where transmission lost, heat and usage fluctuation come in play).

But I think we are digressing a little bit, I think we're in agreement that purely basing ones' choice on clipping alone without weighting cost is not smart. When costs are comparable, the effect of clipping (or running at full capacity) is very much dependent on individual situation and personal preference.

Edit: just checked, my SolarEdge public site is still working, did they shut down yours?

[sensij]

The 3% is the scaling factor I put in to match pvoutput against solaredge's end of day output and inverter LCD display which I think is the most accurate.

Most accurate because it is the highest? Um, ok. This is among the reasons why PVOutput.org data isn't totally reliable.

Edit:
You might want to check this thread to see that the SolarEdge end of day energy number could be inflated by several percent relative to more trustworthy data sources.