Where's the rest of the cost?

[ButchDeal]

Thanks, no I am off the grid so to speak, I have no taxable income subsequently on available tax credit. I am also retired with more time than money so I DIY everything!

The reason the multiphase optimizers produce 85v output (as opposed to the 60v single phase) is for the higher power required for the multiphase output. The SE7600H (sorry about the last mistype) needs 6 sets min. of the higher output optimizers or 8 sets min. of the (P800) lower output optimizers. I chose the P800 so I can attach 3 X 250w panels and still be within ALL specs., (less than 80voc and less than 15Amax , the Trina 250w panels satisfy this @ 12Amax,-- 2 panels in parallel in series with the third )

Again, sorry about the BOD/COB mix up I won't make that mistake again, I have that locked in! I used your 10% SWAG estimate for the BOD, but you will notice I am allowing $500 for it, I realize that is low but one needs a target, anything more is overrun.

I have found new, the P800 optimizers for less the $50 figure that I quoted. (that's gravy against the overrun)

Thanks for your time and knowledge.

I love the forums, on the motorcycle forums I am the hammer like you guys, here I am the nail and I recognize that, please tolerate me with my questions. I am a degreed electrical engineer and always look to ensure everything is logical, this is a sickness I suppose.

You know the 3 X 250w Trina panel configuration is a electrically viable arrangement with the P800, I know the SE7600H is an excellent choice (one is being shipped to me as we speak), I am going to assume it is workable until I hear otherwise from someone that knows from actual experience, otherwise i'll let you know

I remember when Steve Jobs would fire up his apple prototype at the homebrew computer club meetings, first thing out of his mouth was "great it's still working" after a couple times he assumed it was really a viable configuration. I'll do the same until I find out otherwise.

WHICH P800 are you looking at? P800p or P800s? The P800s is superseded by the P850.
The P800P has TWO inputs for TWO 96 cell PV modules. not really a good way to connect THREE 60 cell modules to it.
The P800S is more costly and hard to find.

You seem to be under the mistaken impression that the optimizers for solaredge just produce 85V. That is just the MAXimum voltage the P800, P405, and P505 will produce.
There is ZERO documentation from SolarEdge that a string of 6 P800 will work together or that you can attache the P800 to a residential single phase inverter.
The inverter and optimizers communicate, it is a digital system.

No installer is going to have ANY experience doing that you are talking about because it is specifically unsupported by SolarEdge and would void the warranty on all the equipment.

You might equate yourself to Steve Wozniak but he INVENTED the personal computer, built that computer from scratch and knew exactly what every piece did.
What you are talking about is putting together equipment that you are not even familiar with, in ways that the engineers have not designed it for and likely (hopefully) put in safety checks to prevent.

You really need to use the SolarEdge design tool to validate your layout.

Also racking is typically not in the BOD, try going to ironridge or unirac an doing a layout of your equipment, they will give you a parts list for the design.

And the main reason that the commercial optimizers produce higher voltages is because most of the newer 3 phase inverters operate up to 1000V DC (they tend to operate around 840V DC) but also to keep the string lengths within range.
Residential inverters operate at much lower DC voltages 400-480V

[ButchDeal]

B.O.S. = (balance of system. What does BOD stand for?

Balance of Design
Also BOM Balance of Materials
all common BOD, BOS, BOM

BOM is mostly used by shippers and resellers
BOD by engineers, architects, and designers

[ButchDeal]

Yeah, mixing the 85v optimizers with the 60v optimizers would be tricky (note#5) because the available output voltage delta is different between to two but yet they perform the same function

NOTE #5 is not about mixing 60V max and 85V max optimizers. They can NOT be mixed as per Note #5 on the residential sheet.

I shared a link to the commercial spec sheet that includes the P800 which has a different Note #5 about :
(5) P730 / P800p / P850 design with three phase 208V inverters is limited. Use the SolarEdge Site Designer for verification.

I bring this up because the 208V 3 phase inverters are closer to the power specs of the residential units (though still higher). Meaning that it is unlikely to be possible to even build a design that is within the specs for the residential units and likely will be disabled by digital communications with the optimizers.

I would suspect that when you pair the inverter with P800 (or p850 ) optimizers, it will simply not pair with them, and thus not be able to be turned on.

-- designing to match the electrical specs of your target inverter (SE7600H in my case) is the critical end result. Solaredge notes specify that string numbers must be maintained (approx 8 strings X 60voc, yet power is regulated by the strings, this allows mismatched string lengths -- I design for this.

Voltage is regulated by the optimizers
power is determined by how much wattage in PV you attach to the optimizers in the string as well as the optimizers. They can shift of MPPT to reduce power at times if needed.

You are not really designing anything but throwing hopes on the wall and hoping something doesn't go up in a ball of fire.

How are you planning to attach 3 PV modules to a P800p which is designed for two in parallel. If you are hoping to go series then you would need the P850...
You seem to fixate on one aspect at a time ignoring all others that are out of spec

[motorcyclemikie]

Yeah, i'm locked in on BOS now, the BOD was something I picked up a couple post back.

The P850 is like the P800 from the Wattage aspect. They raised the VOC level to 120v on the P850 from the P800 83v and dropped the max current 2A. With NEC2027 69xxxx I can comply at 75VOC (two panels in series) with the P800

I think the P800 with work out just fine with the single input, if that did in fact work as it should, that is all that is needed.. My three panels would electrically look like one 750w 75VOC 12Amax. I am convinced this is the configuration for me. It would reduce the number of P800 to 8 instead of 24, that is only a $800 savings which would be 25% system cost otherwise. Looks right from my position. I see lots of complaints about systems with limited production be cause of optimizer failures, and how long the system were down waiting for service.
This seems right if you eliminate unneeded parts that are prone to failure. I can understand wanting to regulate individual panel performance with a optimizer per. Shading is not a problem for me, also because of existing constraints I can' find a optimizer over 850w

An installer package would be a 3X factor on the money.

[foo1bar]

I think the P800 with work out just fine with the single input, if that did in fact work as it should, that is all that is needed..

Why would you expect a P800 optimizer to work with a normal 240V residential inverter? I do not see anything that indicates that they will.

Do you understand that these are not just voltage converters?
All the optimizers communicate with the inverter. When they don't communicate, they're going to output their basic "safety" voltage of 1V.
When they are communicating and working the voltage they output depends on the entire system. One may have 40V output, it's neighbor may have 50V (or 30V).

Really, if you're concerned about optimizer failure (I'm not) - then go with a straight string inverter.

I haven't seen a lot of complaints abut optimizer failures. I've seen quite a few about microinverter failures, which might be confused with optimizers as they're both on the roof.

As for the tax credit - you may still be able to take advantage of some of it even if you're retired. Often retired people have an IRA or 401k that they are withdrawing from. Doing a conversion of part of those funds to a Roth IRA can generate taxable income - sometimes very significant taxable income. And then the withdrawals from the Roth IRA are tax-free. So you essentially pay for the taxes in future years via the credit from your solar install this year. I am not telling you that you should do this since I do not know the details of your financial situation. But it is something I think would be good for you to talk with your tax person about. (probably talk to them either this week or plan to talk to them in late April, because they're likely to be really busy real soon.)

[motorcyclemikie]

Why would you expect a P800 optimizer to work with a normal 240V residential inverter?

Yeah, that is why I have included the SE7600H inverter in the system. These operate at 400 to 500voc, in the article they mention eight strings minimum that output 60voc , 11800w 23.5Amax. So 8 X 60voc =480vdc input to the SE7600H Perfect for me and the SE7600H this will meet those specs

The optimizers P600 and above are basicly designed for attaching 2 PV panels in series this doesn't work great for shading on individual panels, but anyone would doing a commercial installation would find a clear spot and eliminate additional cost.

I am using the P800 as intended, however using 3 panels instead of 2 is simply adding the power of the third panel, this pushes the current from 8A to 12Amax this is within the P800 spec


Thanks for the tax info, being a disabled Vietnam vet I am tax exempt in my county. They like veterans here.

Thanks

[ButchDeal]

Yeah, that is why I have included the SE7600H inverter in the system. These operate at 400 to 500voc, in the article they mention eight strings minimum that output 60voc , 11800w 23.5Amax. So 8 X 60voc =480vdc input to the SE7600H Perfect for me and the SE7600H this will meet those specs

The optimizers will output 1V each until activated by an APPROPRIATE inverter via digital commands. the SE7600H will NEVER send that command to commercial optimizers.

The optimizers P600 and above are basicly designed for attaching 2 PV panels in series this doesn't work great for shading on individual panels, but anyone would doing a commercial installation would find a clear spot and eliminate additional cost.

As I mentioned MOST of them attache two PV modules in Parallel with TWO sets of connections,...

I am using the P800 as intended, however using 3 panels instead of 2 is simply adding the power of the third panel, this pushes the current from 8A to 12Amax this is within the P800 spec

Your plan is way out of spec and will void the warranty of both the P800 and the SE7600H
Also the P800s is discontinued and replaced by the P850. the only P800 left is the P800P which has TWO inputs not one.

Thanks for the tax info, being a disabled Vietnam vet I am tax exempt in my county. They like veterans here.

The 30% tax incentive is FEDERAL not state or local

I really don't understand why you are so set on using SolarEdge equipment. You seem to think they are prone to failure and want to completely disregard the installation instructions and void the warranty. Just get a Fronius or SMA inverter and you can avoid the cost of ALL optimizers (unless you need some rapid shutdown at the module level then you are screwed).

[NukeEngineer]

Once upon a time, just out of high school, I worked at a retailer whose name started with an 'R' and ended with an 'ack'. A customer asked me how he could power his 200 watt 12" subwoofer in his house. I suggested a 20+amp power supply ($200+ at the time), but he grabs this 750mA 12v wall wart.

I tried several times to explain, volts ain't everything, but he wasn't having it. The customer purchased that wall wart and I never saw him again.....

This conversation seems very very similar.

[foo1bar]

Yeah, that is why I have included the SE7600H inverter in the system. These operate at 400 to 500voc,

No - they operate at ~240VAC. And operate around 400-500VDC. They do not do anything with Voc. Voc is open circuit voltage, and SE inverters do not have a Voc as they never operate in open-circuit. Voc is a spec for the optimizer's module side of things. It is also a spec for the module itself.

The SE7600H is NOT a 3-phase inverter that is meant to operate with P800 optimizers. At the very least it looks like that combination hasn't been tested and wouldn't be supported.

So 8 X 60voc =480vdc input to the SE7600H Perfect for me and the SE7600H this will meet those specs

A solaredge optimizer is not a simple voltage converter.
A solaredge optimizer is not a simple voltage converter.
A solaredge optimizer is not a simple voltage converter.
A solaredge optimizer is not a simple voltage converter.
(I'd put this in red flashing letters if I could.)

I am using the P800 as intended, however using 3 panels instead of 2 is simply adding the power of the third panel, this pushes the current from 8A to 12Amax this is within the P800 spec

No, you are NOT using it as intended.
They list P800 as being compatible only with >16kW three-phase inverters. (At least this datasheet only shows it for the big power guys - not even the smaller commercial scale 15kW three-phase inverters) https://www.solaredge.com/sites/defa...-datasheet.pdf

Furthermore, how are you going from 8A to 12A?
The P800 is setup to connect in parallel to a pair of 96cell modules.
It does not have 3 sets of leads to connect to modules.
Also - if you did 3 of your modules in parallel you'd have 24A@~42V (mpp - max power point), as I believe your modules are 8A @ 42V (I'm basing that on a previous post in this thread)
If you did 3 in series, you'd have 8A @ ~126V. Both of those approaches are outside specs for the P800 inputs.

I think what you're talking about is like hooking up a yamaha transmission to a harley engine. Might be possible, but it's weird, totally outside warranties, and from a practical standpoint it just isn't workable. (I'm sure there's probably a better metaphor - for all I know yamaha transmissions often are bolted onto harley engines.)

[Bala]

No - they operate at ~240VAC. And operate around 400-500VDC. They do not do anything with Voc. Voc is open circuit voltage, and SE inverters do not have a Voc as they never operate in open-circuit. Voc is a spec for the optimizer's module side of things. It is also a spec for the module itself.

The SE7600H is NOT a 3-phase inverter that is meant to operate with P800 optimizers. At the very least it looks like that combination hasn't been tested and wouldn't be supported.



A solaredge optimizer is not a simple voltage converter.
A solaredge optimizer is not a simple voltage converter.
A solaredge optimizer is not a simple voltage converter.
A solaredge optimizer is not a simple voltage converter.
(I'd put this in red flashing letters if I could.)



No, you are NOT using it as intended.
They list P800 as being compatible only with >16kW three-phase inverters. (At least this datasheet only shows it for the big power guys - not even the smaller commercial scale 15kW three-phase inverters) https://www.solaredge.com/sites/defa...-datasheet.pdf

Furthermore, how are you going from 8A to 12A?
The P800 is setup to connect in parallel to a pair of 96cell modules.
It does not have 3 sets of leads to connect to modules.
Also - if you did 3 of your modules in parallel you'd have 24A@~42V (mpp - max power point), as I believe your modules are 8A @ 42V (I'm basing that on a previous post in this thread)
If you did 3 in series, you'd have 8A @ ~126V. Both of those approaches are outside specs for the P800 inputs.

I think what you're talking about is like hooking up a yamaha transmission to a harley engine. Might be possible, but it's weird, totally outside warranties, and from a practical standpoint it just isn't workable. (I'm sure there's probably a better metaphor - for all I know yamaha transmissions often are bolted onto harley engines.)

Motorcycle engines and transmissions are in one assembly. So while not impossible to use a Yamaha transmission with a Harley engine it is not even close to being practical or cost effective. There would be better ways to achieve the desired results, which is what I think you are trying to say about this electrical project

[jflorey2]

Motorcycle engines and transmissions are in one assembly. So while not impossible to use a Yamaha transmission with a Harley engine it is not even close to being practical or cost effective.

Now you've got it!

As BD said above, if cost is your big issue, get a big SMA inverter and forget about optimizers. Given your statements along the lines of "I have to be effective with my approach" "use my common sense to hang onto as much [money] as possible" it's probably a better approach overall. And unless you have odd array orientations or partial shading, you won't see much benefit from an optimizer or microinverter based system.

[motorcyclemikie]

Many good points taken here,and I did see where the P800 was compatable with the multiphase inverters so that kills this plan, they didn;t really say it couldn't be used with the lower voltage (40vdc) optimisers. I don't have evidence that it won't communicate in a single wave enviromment and nobody has had anything first hand that blew up, anyway i'll modify this and rethink my plan

I thank you guys for your knowledge

[motorcyclemikie]

Now you've got it!

As BD said above, if cost is your big issue, get a big SMA inverter and forget about optimizers. Given your statements along the lines of "I have to be effective with my approach" "use my common sense to hang onto as much [money] as possible" it's probably a better approach overall. And unless you have odd array orientations or partial shading, you won't see much benefit from an optimizer or microinverter based system.

Yeah you guys are right, more than right in fact, I just got hung up on the sunEdge Equipment and I did jump up an order the SE7600h it was a good price at the time so I have that coming to me that'll be here in a few daysI am so curious about weather this inverter can find and talk to a P800 Optimizer which everybody says it is not able to do but nobody has done it I will do it myself and find out I'll let you know if it works out, in the mean time i'll look for a SMA system design and others. I don't know where to look but I'll figure it out -- I can't quit, i've got !k$ invested in this system already.

Thanks for all the advice gentlemen

[littleharbor]

You really need to hit the brakes. If you connect the p800 optimizers they will be considered used and will become worthless to you as you won't be able to return them. Why are you insisting on trying to force a square peg into a round hole? Do you really think your wild ideas are going to work even after you have been told over and over by all these very knowledgable people that they won't? What you are doing is wasting everybody's time here by just figuring that if is has the same brand name that it must be interchangeable.

This will be my last comment here so I'll say good luck with your experiment. I sure hope nobody gets hurt. if you are going to keep plugging stuff into other stuff to see what happens keep in mind, High voltage electricity can be deadly.

[jflorey2]

Yeah you guys are right, more than right in fact, I just got hung up on the sunEdge Equipment and I did jump up an order the SE7600h it was a good price at the time so I have that coming to me that'll be here in a few daysI am so curious about weather this inverter can find and talk to a P800 Optimizer which everybody says it is not able to do but nobody has done it I will do it myself and find out I'll let you know if it works out, in the mean time i'll look for a SMA system design and others. I don't know where to look but I'll figure it out -- I can't quit, i've got !k$ invested in this system already.

We get a lot of people who come on here and take that approach. The posts usually go like this:

"I saw a GREAT deal on panels and I spent all my money on them - 20KW! I have about $100 left, what else do I need?" They are then disheartened to hear that the panels won't even be the biggest cost for the project. They often go away very unhappy.

Stop buying stuff RIGHT NOW. Don't get a P800. Return the SE7600 even if it means paying restocking fees. Stop trying to "see if things will work." Get a copy of Solar for Dummies and read it. If you really want to buy stuff, buy a very small independent system (a panel, charge controller, small battery, small inverter) and experiment with that. You'll destroy the battery quickly - but learn a lot in the process.

You will likely end up with a smaller system than you are thinking about, using a string inverter.