Everything Solar Forum

Has anyone experience with the Sharp ND-N2ECU and ND 72 EL(R)UF panels.
They were panels that were built for a few years, ~2006 and 2007; they were 40 and 20 cell panels as opposed to the standard 60 cell that were being made at the time. It was to allow people without open roof space for the 60 cell panels, to add more solar by using smaller panels and half panels; not sure why production was halted.
Originally I was always told not to ‘mix’ panels with different wattages. Since these were panels combinations that Sharp was offering; I figured original instructions were not accurate. But in many instances, the string wiring went from a 142 to a 72, to another 72 in the next row down, and across through several 142s. We were never instructed by Sharp as to doing wiring differently.
Is there a problem with not wiring all 72s and then going to the 142s?
Sharp Tech Support, told me to remove and check each panel. Customer has two different arrays and if I do so, ANY savings they have had over the last twelve years, will be GONE!
I worked for a company who sold ~ 10 of these systems.
The Systems all worked, per design. Now, it seems that production wattage is less than it was, on this one. Haven’t checked others yet.
When I check open voltage on the strings, they are actually slightly higher than sum of panels (to be expected in Colorado).
Back to my query: does anyone know of any issues with these panels?
If 72 cell half panels are removed from strings, will that help?
Why did Sharp stop production?
Trying to narrow scope of troubleshooting to keep labor costs as low as possible.
Thanks.

Mark Stahl
EnergySaver Consulting
HUD ID # D 1001
Cell: 719.325.6368

My understanding is that if you do not have optimizers, and thus use a simple string inverter, you are limited to the weakest cell.  So if you mix say a 100 watt panel with three 200 watt panels your inverter will only see 400 watts, (100 x 4 panels).  So it is not that you cannot mix but when you do it is the weakest panel that dictates the output per string.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net
------------------------------

Original Message:
Sent: 12-08-2021 08:49 AM
From: Mark Stahl
Subject: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

Has anyone experience with the Sharp ND-N2ECU and ND 72 EL(R)UF panels.
They were panels that were built for a few years, ~2006 and 2007; they were 40 and 20 cell panels as opposed to the standard 60 cell that were being made at the time. It was to allow people without open roof space for the 60 cell panels, to add more solar by using smaller panels and half panels; not sure why production was halted.
Originally I was always told not to 'mix' panels with different wattages. Since these were panels combinations that Sharp was offering; I figured original instructions were not accurate. But in many instances, the string wiring went from a 142 to a 72, to another 72 in the next row down, and across through several 142s. We were never instructed by Sharp as to doing wiring differently.
Is there a problem with not wiring all 72s and then going to the 142s?
Sharp Tech Support, told me to remove and check each panel. Customer has two different arrays and if I do so, ANY savings they have had over the last twelve years, will be GONE!
I worked for a company who sold ~ 10 of these systems.
The Systems all worked, per design. Now, it seems that production wattage is less than it was, on this one. Haven't checked others yet.
When I check open voltage on the strings, they are actually slightly higher than sum of panels (to be expected in Colorado).
Back to my query: does anyone know of any issues with these panels?
If 72 cell half panels are removed from strings, will that help?
Why did Sharp stop production?
Trying to narrow scope of troubleshooting to keep labor costs as low as possible.
Thanks.

Mark Stahl
EnergySaver Consulting
HUD ID # D 1001
Cell: 719.325.6368

These Sharp modules all have the same rated current and were intended to be used in series.  No problem with putting 40 and 20 cell modules in series.  If the system required two strings, the strings needed to have the same total number of cells.

I found these datasheets.  The 20-cell modules were triangular to match available roof lines.  The problem these days is replacing a failed module since direct replacements are no longer available. Sharp modules of that vintage had a major problem with backskin delamination.

------------------------------
William Kaszeta
President
Photovoltaic Resources International
Mesa AZ
bill@kaszeta.org
------------------------------

Original Message:
Sent: 12-09-2021 10:27 AM
From: David Hrivnak
Subject: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

My understanding is that if you do not have optimizers, and thus use a simple string inverter, you are limited to the weakest cell.  So if you mix say a 100 watt panel with three 200 watt panels your inverter will only see 400 watts, (100 x 4 panels).  So it is not that you cannot mix but when you do it is the weakest panel that dictates the output per string.

------------------------------
David Hrivnak
Sales/Engineering
EcoLogical (part time)
dhrivnak@chartertn.net

Original Message:
Sent: 12-08-2021 08:49 AM
From: Mark Stahl
Subject: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

Has anyone experience with the Sharp ND-N2ECU and ND 72 EL(R)UF panels.
They were panels that were built for a few years, ~2006 and 2007; they were 40 and 20 cell panels as opposed to the standard 60 cell that were being made at the time. It was to allow people without open roof space for the 60 cell panels, to add more solar by using smaller panels and half panels; not sure why production was halted.
Originally I was always told not to 'mix' panels with different wattages. Since these were panels combinations that Sharp was offering; I figured original instructions were not accurate. But in many instances, the string wiring went from a 142 to a 72, to another 72 in the next row down, and across through several 142s. We were never instructed by Sharp as to doing wiring differently.
Is there a problem with not wiring all 72s and then going to the 142s?
Sharp Tech Support, told me to remove and check each panel. Customer has two different arrays and if I do so, ANY savings they have had over the last twelve years, will be GONE!
I worked for a company who sold ~ 10 of these systems.
The Systems all worked, per design. Now, it seems that production wattage is less than it was, on this one. Haven't checked others yet.
When I check open voltage on the strings, they are actually slightly higher than sum of panels (to be expected in Colorado).
Back to my query: does anyone know of any issues with these panels?
If 72 cell half panels are removed from strings, will that help?
Why did Sharp stop production?
Trying to narrow scope of troubleshooting to keep labor costs as low as possible.
Thanks.

Mark Stahl
EnergySaver Consulting
HUD ID # D 1001
Cell: 719.325.6368

I don't agree that your lowest wattage panel will limit the higher ones to the lower output.  Rather, the problem with mixing different panels has more to do with their different V-I curves.  The string inverter's MPPT function can't work properly and output will be less when panels are a mixture of specs.  And the panel with the lowest current output does limit throughput of the entire string, but not to the extent that all panels are reduced to the lowest panel's power output (since each panel can still have different voltages).  The previous poster is correct though - if different panels each have optimizers or microinverters on them, they operate independently of one another and you will get max power from each, regardless of how different they are.

------------------------------
Mike Curran
Retired from (dare I say it?) Fossil Plant Mgt.
joacchim57@gmail.com
------------------------------

Original Message:
Sent: 12-08-2021 08:49 AM
From: Mark Stahl
Subject: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

Has anyone experience with the Sharp ND-N2ECU and ND 72 EL(R)UF panels.
They were panels that were built for a few years, ~2006 and 2007; they were 40 and 20 cell panels as opposed to the standard 60 cell that were being made at the time. It was to allow people without open roof space for the 60 cell panels, to add more solar by using smaller panels and half panels; not sure why production was halted.
Originally I was always told not to 'mix' panels with different wattages. Since these were panels combinations that Sharp was offering; I figured original instructions were not accurate. But in many instances, the string wiring went from a 142 to a 72, to another 72 in the next row down, and across through several 142s. We were never instructed by Sharp as to doing wiring differently.
Is there a problem with not wiring all 72s and then going to the 142s?
Sharp Tech Support, told me to remove and check each panel. Customer has two different arrays and if I do so, ANY savings they have had over the last twelve years, will be GONE!
I worked for a company who sold ~ 10 of these systems.
The Systems all worked, per design. Now, it seems that production wattage is less than it was, on this one. Haven't checked others yet.
When I check open voltage on the strings, they are actually slightly higher than sum of panels (to be expected in Colorado).
Back to my query: does anyone know of any issues with these panels?
If 72 cell half panels are removed from strings, will that help?
Why did Sharp stop production?
Trying to narrow scope of troubleshooting to keep labor costs as low as possible.
Thanks.

Mark Stahl
EnergySaver Consulting
HUD ID # D 1001
Cell: 719.325.6368

Hi Mark,

How did you resolve this issue? I recently came across some of these 72 and 142 watt Sharp modules in a donation to our nonprofit. My guess is that Sharp designed these to be wired in series and so long as the watts per string were less than 600V and each string was the same total watts, your could mix and match the squares and triangles.

Sharp likely stopped because there wasn't enough demand, especially as all modules becamse more efficient for a given surface area so packing as many modules onto all available roof space wasn't as critical.

Rich

------------------------------
Rich Stromberg
ESS Prog Dir / PhD Student
Equitable Solar Solutions / Univ of Alaska Fairbanks
Colorado
------------------------------

Original Message:
Sent: 12-08-2021 08:49 AM
From: Mark Stahl
Subject: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

Has anyone experience with the Sharp ND-N2ECU and ND 72 EL(R)UF panels.
They were panels that were built for a few years, ~2006 and 2007; they were 40 and 20 cell panels as opposed to the standard 60 cell that were being made at the time. It was to allow people without open roof space for the 60 cell panels, to add more solar by using smaller panels and half panels; not sure why production was halted.
Originally I was always told not to 'mix' panels with different wattages. Since these were panels combinations that Sharp was offering; I figured original instructions were not accurate. But in many instances, the string wiring went from a 142 to a 72, to another 72 in the next row down, and across through several 142s. We were never instructed by Sharp as to doing wiring differently.
Is there a problem with not wiring all 72s and then going to the 142s?
Sharp Tech Support, told me to remove and check each panel. Customer has two different arrays and if I do so, ANY savings they have had over the last twelve years, will be GONE!
I worked for a company who sold ~ 10 of these systems.
The Systems all worked, per design. Now, it seems that production wattage is less than it was, on this one. Haven't checked others yet.
When I check open voltage on the strings, they are actually slightly higher than sum of panels (to be expected in Colorado).
Back to my query: does anyone know of any issues with these panels?
If 72 cell half panels are removed from strings, will that help?
Why did Sharp stop production?
Trying to narrow scope of troubleshooting to keep labor costs as low as possible.
Thanks.

Mark Stahl
EnergySaver Consulting
HUD ID # D 1001
Cell: 719.325.6368

When I first read this, I was not going to comment, because it gave me a headache. However upon further reflection I thought I would just a say a SHORT couple of things.

It really has nothing to do with models or model numbers, IE, the problem. It really goes to the basic of series, parallel or series-parallel interconnections, be they PV or battery's. Very similar rules because both are power PRODUCING entities, with relevant voltages, currents and resistances.

Panels have quasi-fuses (Diodes) which tend to limit voltage and current "irregularities", though not a "pure' fuse as such. Given the one example I read regarding 3 - 200W panels and a single 100W panel, I might tend to hook the single 100W panel in parallel with one of the 200W panels, sacrificing some OCV but taking an easier road on current, if they were voltage matched. It really would depend on the exact situation, panel per panel. 

Other than a straight straight series connection with little variance between panel voltages and currents, if paralleling strings going into a single string inverter, one tries to match as good as possible the voltages and currents between strings, so as to optimize the possible output of EACH string.

And that's really all I had to say... for me that is short...

------------------------------
william fitch
Owner
www.WeAreSolar.com
------------------------------

Original Message:
Sent: 12-08-2021 08:49 AM
From: Mark Stahl
Subject: Sharp ND-N2ECU and ND 72 EL(R)UDF Panels

Has anyone experience with the Sharp ND-N2ECU and ND 72 EL(R)UF panels.
They were panels that were built for a few years, ~2006 and 2007; they were 40 and 20 cell panels as opposed to the standard 60 cell that were being made at the time. It was to allow people without open roof space for the 60 cell panels, to add more solar by using smaller panels and half panels; not sure why production was halted.
Originally I was always told not to 'mix' panels with different wattages. Since these were panels combinations that Sharp was offering; I figured original instructions were not accurate. But in many instances, the string wiring went from a 142 to a 72, to another 72 in the next row down, and across through several 142s. We were never instructed by Sharp as to doing wiring differently.
Is there a problem with not wiring all 72s and then going to the 142s?
Sharp Tech Support, told me to remove and check each panel. Customer has two different arrays and if I do so, ANY savings they have had over the last twelve years, will be GONE!
I worked for a company who sold ~ 10 of these systems.
The Systems all worked, per design. Now, it seems that production wattage is less than it was, on this one. Haven't checked others yet.
When I check open voltage on the strings, they are actually slightly higher than sum of panels (to be expected in Colorado).
Back to my query: does anyone know of any issues with these panels?
If 72 cell half panels are removed from strings, will that help?
Why did Sharp stop production?
Trying to narrow scope of troubleshooting to keep labor costs as low as possible.
Thanks.

Mark Stahl
EnergySaver Consulting
HUD ID # D 1001
Cell: 719.325.6368