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Ha. We had a request for that on a homedepot shed of only 8X10 to have 4 foot cantilever overhang on 3 sides. Customer had looked up the specs on ironridge xr1000 rails and was sure it was ok because ironridge said so.
We tried to explain that that makes the shed into a glider and we are not licensed to manufacture air craft...Comment
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On one hand they allow mixing those optimizers with raw panels so you'd need only as many as you have potentially shaded panels. OTOH RSS would still be required resulting in string level shutdown, not module level if I understand this correctly. Looks like SMA is having difficulty to catch up with SE if optimizers / module level RSS are required. The idea of optimizers to be installed on only potentially shaded panels is interesting if they could come up with some data communication over the same DC wires for RSS purposes and very dumb/cheap RSS module for the rest of unshaded panels eliminating need for string level RSS. At least this solution works with their string inverters which would probably mean it would work with any other string inverter: SMA states their optimizers simply lower voltage of the panel boosting its current when it gets shaded. While this approach seems to be simpler than SE it imposes the same limits on max string length from Voc side as for raw strings, about 13-14 panels max.
It seems the company Tigo they subcontracted module level electronics to produces different kind of modules: when shopping I was offered modules just for RSS without optimization. On 24 panel array it resulted in $1,300 IIRC vs $750 for their conventional RSS. Since OC is still on 2014 NEC I went with conventional one for simplicity and lower cost. What bothers me with Tigo offering is their modules consist of 2 parts- some common 'base' and another module type specific extension. All of them share the same base but extensions vary from one type of the module to another. This must require extra connectors inside the modules and depending how that is done can affect reliability.Comment
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Structural loading determination and requirements to deal with such loadings vary by area and jurisdiction. Many use ASCE 7, or various sections of it for such things.Last edited by J.P.M.; 08-18-2017, 11:59 AM.Comment
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It looks like they abandoned microinverters solution, all info on SMA site about that direction is from 2013. They're pushing now their own optimizers: http://www.sma-america.com/powerplus.html
On one hand they allow mixing those optimizers with raw panels so you'd need only as many as you have potentially shaded panels. OTOH RSS would still be required resulting in string level shutdown, not module level if I understand this correctly. Looks like SMA is having difficulty to catch up with SE if optimizers / module level RSS are required. The idea of optimizers to be installed on only potentially shaded panels is interesting if they could come up with some data communication over the same DC wires for RSS purposes and very dumb/cheap RSS module for the rest of unshaded panels eliminating need for string level RSS. At least this solution works with their string inverters which would probably mean it would work with any other string inverter: SMA states their optimizers simply lower voltage of the panel boosting its current when it gets shaded. While this approach seems to be simpler than SE it imposes the same limits on max string length from Voc side as for raw strings, about 13-14 panels max.
It seems the company Tigo they subcontracted module level electronics to produces different kind of modules: when shopping I was offered modules just for RSS without optimization. On 24 panel array it resulted in $1,300 IIRC vs $750 for their conventional RSS. Since OC is still on 2014 NEC I went with conventional one for simplicity and lower cost. What bothers me with Tigo offering is their modules consist of 2 parts- some common 'base' and another module type specific extension. All of them share the same base but extensions vary from one type of the module to another. This must require extra connectors inside the modules and depending how that is done can affect reliability.OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNHComment
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nah, all they need to do is to run their own small residential install company so their engineers would get up the roof once in a while and see how things work / don't work in the field. That would get things moving quickly. ASIC is just one of the possible ways to skin proverbial cat.Comment
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nah, all they need to do is to run their own small residential install company so their engineers would get up the roof once in a while and see how things work / don't work in the field. That would get things moving quickly. ASIC is just one of the possible ways to skin proverbial cat.
They have a lot to do to catch up .
SolarEdge has the most efficient inverters by far as well as very reliable optimizers that fully integrate.
SMA so far has done little technically with the tigo system. The next step would have them communicate and integrate with the inverter, then have dedicated (cheaper / more reliable) inverters without the built in MPPT. This second phase will likely require new optimizers as the tigo does not maintain constant voltage like the SolarEdge optimizers...
Then increase the efficiency based on the constant voltage,
thats just to get where solarEdge is now....
OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNHComment
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I am talking about R&D on the technical side not the installation and documentation stuff which is a lot easier to improve.
They have a lot to do to catch up .
SolarEdge has the most efficient inverters by far as well as very reliable optimizers that fully integrate.
SMA so far has done little technically with the tigo system. The next step would have them communicate and integrate with the inverter, then have dedicated (cheaper / more reliable) inverters without the built in MPPT. This second phase will likely require new optimizers as the tigo does not maintain constant voltage like the SolarEdge optimizers...
Then increase the efficiency based on the constant voltage,
thats just to get where solarEdge is now....
IMO any manufacturer needs to maintain close connection with the field, the rest can be solved one way or the other. SMA has such channel but it doesn't sound it gets high enough priority within the company. The moment they change that and allow field to drive internal product development we might see more relevant offerings.
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OH but thats just a little bit, but thats like loosing an entire modules production on a 10kw array.
Constant voltage is not really required except to enable longer strings. I think SMA/Tigo approach to optimization when they just maintain constant current flowing through optimizer leads to simpler on the roof modules and opening possibility for mixing optimizers with raw panels to reduce the cost. It sounds though Tigo overcomplicated its implementation negating that advantage.
I am not talking about simplisity of installation with tigo, solaredge or string. I am talking about simplicity of the elctronics and reliability of the equipment. SMA has multiple complicated MPPT inputs on their inverters, SolarEdge doesn't have any, simpler and less parts, more reliable.
SolarEdge is very simple to INSTALL you can't get much damn simpler. but that is completely different.
As for the install part, solaredge has things like integrated auto rapid shut down, integrated module level monitoring
SMA could add these two things and integrate the monitoring, and simplify the optimizer communication, but that likely would add complexity to their already complex systems.
I would hope that they are starting over with a simpler system that has the features built in, instead of trying to bubble gum and duct tape more to the existing systems they have.
IMO any manufacturer needs to maintain close connection with the field, the rest can be solved one way or the other. SMA has such channel but it doesn't sound it gets high enough priority within the company. The moment they change that and allow field to drive internal product development we might see more relevant offerings.OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNHComment
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nope, the same- when optimizer needs to only maintain current passing through by lowering its voltage it simplifies design a lot: fully irradiated panel would look like no optimizer is there while fully shaded would look like short. Too bad it seems they lost beauty of this idea in the implementation. I agree, duct taping 2 company offerings was not a smart move unless they saved on the idea above and currently busy developing normally integrated product.
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