Where's the rest of the cost?

[ButchDeal]

I was originally looking at a wind generator as we have a windy conditions here also.

Yes everyone does. We have high winds here. Would be a terrible location for wind though as we normally have very low winds but occasionally have high winds. The normal wind times are outside of the power band for a generator and the high wind times are as well.
Most people also miss understand the height requirements as well as the need to use normal or mean wind speed not average wind speed. They also miss the high cost as well as maintenance requirements for such a highly moving system.

[motorcyclemikie]

You have not mentioned ANY miss information on SolarEdge documentation. So far everything that you have claimed was inaccurate was instead just miss understanding on your part of the terminology.

You should really be educating yourself BEFORE ordering things.
You have 3 major miss conceptions about the equipment you have ordered already:

The SE7600H will not do any backup.
The P800 will not work with the SE7600H
the SE7600H will not work with your generator.

Yeah, I have my 4400w 240v honda generator for that
So if the P405 & P505 will work why not the P800? They all have 85vdc output and simular output specifications, at this point given what I see other than marketing answers -- I believe it works!
I don't care if my SE7600H will work with my generator

I am glad I ordered the SE7600H, that is my major system component, I am satisfied with it, thanks for initially suggesting it for its capabilities

[motorcyclemikie]

Yes everyone does. We have high winds here. Would be a terrible location for wind though as we normally have very low winds but occasionally have high winds. The normal wind times are outside of the power band for a generator and the high wind times are as well.
Most people also miss understand the height requirements as well as the need to use normal or mean wind speed not average wind speed. They also miss the high cost as well as maintenance requirements for such a highly moving system.

Yes Butch, I have the same conditions here along with generator/wind noise and bird strikes make it down the list for me -- and the maintenance Factor, I am lazy!

[foo1bar]

Yes sir Foo, I wasn't being exact on the numbers.

I assumed the per 250w panel 30vdc out as mfg. stated -- 250w / 30v = 8.33A (P/E=I)

2 panels in parallel is 500w / 30v = 16.66A

Ok - so you're expecting 16.6A out of the two in parallel.

with the added 3rd panel in series with the previous 2 panels is 750w / 60v = 12.50A

It doesn't work like that.
If you had 16.6A coming out of the two in parallel, you'd have to have 16.6A going through the single panel. (Kirchoff's law of currents says sum of currents going into a node must equal the sum going out)
16.6A through that module means you've either just fried that module or all your current is going through the bypass diodes - so you're getting ZERO power out of that third module.
Most likely when you put a load/inverter/optimizer on the system you'd actually wind up with about 8A (a little above the Impp for the single module) and about 4A for each of the other 2 panels.
And your power output would be significantly less than what you'd get by wiring them in a normal configuration.
BTW - what are the specs on the panels you are considering?
What is the:
Vmpp
Impp
Voc
Isc
?
Because you're talking about 250W here - but the specs posted earlier in this thread were for 335W modules.

You'll notice that the 2 panels exceed the current limits of the P800 optimizer until you add the third panel, I think that might cause confusion here.

No - the confusion seems to be that you think you can sum the 3 module's power and divide by the voltage to determine current.
It does not work that way.

You'll also notice I am stuck on the P800 until I prove to myself otherwise, Solaredge says it IS compatable with the 3 phase inverters, they didn't say NOT with single phase inverters.

They explicitly say that P800 is only compatible with larger 3-phase inverters. If you can't even use it on a 14.4kW 3-phase inverter, why would you think it'll work with a 7.6kW single-phase inverter which is even farther off from what it's designed for.

With the PV panels being cheaper than optimizers, I can see eliminating excessive unneeded cost at this point,

Sure.
Determine what you have to have for rapid shutdown, and buy a string inverter.
That's really your best/cheapest option since you don't have complexities to your roof (ie. shading, different orientations, etc)

[foo1bar]

They all have 85vdc output and simular output specifications,

It is not a straight 85V DC output.
The optimizers communicate in a proprietary, trade secret way with each other and the inverter.
Sometimes the optimizer will output 80V and 3A, sometimes it will output 60V and 4A, sometimes 40V and 6A. We do not have the details on how those optimizers and the inverter communicate so that each optimizer does an appropriate voltage/current for the power it has available, AND the total voltage/current being supplied to the inverter is at the best operating point for the inverter.


Even if a P800 could work with a SE7600 (which is doubtful - it is at the least unsupported so not covered by warranties, and likely a long-shot that it'll work)
But even if it does - you still need the optimizer to be compatible with the modules that you're plugging into it.
And you don't have that.

[motorcyclemikie]

Ok - so you're expecting 16.6A out of the two in parallel.


It doesn't work like that.
If you had 16.6A coming out of the two in parallel, you'd have to have 16.6A going through the single panel. (Kirchoff's law of currents says sum of currents going into a node must equal the sum going out)
16.6A through that module means you've either just fried that module or all your current is going through the bypass diodes - so you're getting ZERO power out of that third module.
Most likely when you put a load/inverter/optimizer on the system you'd actually wind up with about 8A (a little above the Impp for the single module) and about 4A for each of the other 2 panels.
And your power output would be significantly less than what you'd get by wiring them in a normal configuration.
BTW - what are the specs on the panels you are considering?
What is the:
Vmpp
Impp
Voc
Isc
?
Because you're talking about 250W here - but the specs posted earlier in this thread were for 335W modules.




No - the confusion seems to be that you think you can sum the 3 module's power and divide by the voltage to determine current.
It does not work that way.


They explicitly say that P800 is only compatible with larger 3-phase inverters. If you can't even use it on a 14.4kW 3-phase inverter, why would you think it'll work with a 7.6kW single-phase inverter which is even farther off from what it's designed for.

Foo, the only thing we need to know is Ohm's law.. Why wouldn't we get double the current from 2 panels in parallel. We are making these 3 X 250w panels to electrically look like 1 X 750w panel just the way the panels are built with individual cells in certain configurations that dictate what you want for voltage & current output.
The given is the wattage, the voltage and the current is proportional but it always equals the 750w of the 3 X 250w panels.


This is the panel specs I have in mind.
Rated Power: 245W[
]Open circuit voltage (VOC): 37.5 V[*
]Max power voltage (VMP): 30.2 V[*
]Short circuit current (ISC): 8.68 A[*
]Max power current: 8.13 A[*
]Power Tolerance 0/+3%[*
]Maximum system voltage: 600V (UL)[*
]Fuse Rating: 15 A[*
]IP65 Junction Box w/MC4 Compatible Connectors[*]Frame: Anodized aluminum alloy[*]Weight: 41 lbs[*]Dimensions: 1650


Sorry about the differing panel sizes, the smaller 245w/250w fit my roof layout better and 3 won't exceed the 800w limit of the P800 optimizer.

I have noticed how Solaredge generously derates several of the electrical parameters of their equipment, consumer electrical equipment typically is 12 to 20% derated. solaredge allows more wiggle room on these parameters, this may not mean anything however it appears to me that they do not overrate their equipment, that means I can use the equipment to its full parameters and possibly a little further. that's where I had the 3 X 335 watt panels figured in, but yes it does violate the 80v rule.

[John_Dumke]

MotoMike, I think the main reason 3 panels for an P800 optimizer won't work (assuming the inverter sees the P800's) is you are caught between the Minimum of 8 optimizers per string and a Maximum string wattage of 5,250.

Three 250 Watt panels x 8 optimizers is 6,000 watts exceeding allowable Max wattage.

Max wattage may be less if the panels are not all in a perfect orientation and the 6,000 watts is only theoretical and max real wattage is less.

[motorcyclemikie]

MotoMike, I think the main reason 3 panels for an P800 optimizer won't work (assuming the inverter sees the P800's) is you are caught between the Minimum of 8 optimizers per string and a Maximum string wattage of 5,250.

Three 250 Watt panels x 8 optimizers is 6,000 watts exceeding allowable Max wattage.

Max wattage may be less if the panels are not all in a perfect orientation and the 6,000 watts is only theoretical and max real wattage is less.

John, I think that spec reflects the SE7600A, The spec for the SE7600H is 10250w I believe I read somewhere.

Yes, the plan calls for 24 panels, eight strings of 3ea.

[jflorey2]

Yeah, I have my 4400w 240v honda generator for that
So if the P405 & P505 will work why not the P800? They all have 85vdc output and simular output specifications, at this point given what I see other than marketing answers -- I believe it works!

Then go for it! Ignore the advice given here as "marketing answers" and try it out. You'll be supporting the solar industry twice over - first when you set up a system with the P800, and then again when you buy a different system to get it to work. But you'll learn a lot in the process.

[ButchDeal]

Yeah, I have my 4400w 240v honda generator for that

sure you can use the honda to back things up but it will NOT work with your solaredge grid tie inverter or ANY grid tie inverter for that matter.

So if the P405 & P505 will work why not the P800? They all have 85vdc output and simular output specifications, at this point given what I see other than marketing answers -- I believe it works!

a 9mm bullet will work in a 9mm hand gun but a but that 9mm will not work well in a .38 handgun.

And stop saying it has 85VDC output. it has MAX 85V DC output. it is a computer distributed swam technology and designed to output as a swam way above the voltage range of the SE7600. You keep looking at it as an individual piece of equipment but it is PART OF A SWAM tech designed to do something different than you think.

I don't care if my SE7600H will work with my generator

as long as you don't expect it to work with your generator and ISOLATE it from your generator you will be fine but your comments have already indicated that you are not planning to do this.

I am glad I ordered the SE7600H, that is my major system component, I am satisfied with it, thanks for initially suggesting it for its capabilities

Your expectations do not seem to match with the capabilities of the equipment.

[ButchDeal]

John, I think that spec reflects the SE7600A, The spec for the SE7600H is 10250w I believe I read somewhere.

Yes, the plan calls for 24 panels, eight strings of 3ea.

That is not a string. you are talking about 1 string of 8 PV optimizers each with a bastardized string of 2 pv modules in parallel and those two then serial with a third PV module.

Nothing in any of this will work.

[ButchDeal]

John, I think that spec reflects the SE7600A, The spec for the SE7600H is 10250w I believe I read somewhere.

Yes, the plan calls for 24 panels, eight strings of 3ea.

The max string power for the SE7600H is 6kW
The Max DC power input is 11.8kW but would have to be on more than one string.

[motorcyclemikie]

Then go for it! Ignore the advice given here as "marketing answers" and try it out. You'll be supporting the solar industry twice over - first when you set up a system with the P800, and then again when you buy a different system to get it to work. But you'll learn a lot in the process.

Thanks JF, yeah since I stuck my foot out this far about the aspect of cost savings, I guess you are right. I have more or less committed myself. My idea, my task. I already have the P800 on the way, I found a solar wholesaler close by -- might be he can give me a good price on panels, racking ect Their panel prices start at $.50w.

One last thing, are used PV panels a waste of money... Thanks

[motorcyclemikie]

That is not a string. you are talking about 1 string of 8 PV optimizers each with a bastardized string of 2 pv modules in parallel and those two then serial with a third PV module.

Nothing in any of this will work.

You are right not eight strings, but one string of eight optimizers.

You still don't get the picture, just as all PV panels don't have a identical cell count, voltage and current specs. they are usable because they match what is needed for the application. Now break this 750w PV panel into three pieces, and wire back together the 3 X 250w panels you created. As long as it goes back together electrically, it looks the same to the application.

This will work,

[ButchDeal]

You are right not eight strings, but one string of eight optimizers.

You still don't get the picture, just as all PV panels don't have a identical cell count, voltage and current specs. they are usable because they match what is needed for the application. Now break this PV panel into three pieces, and wire back together. As long as it goes back together electrically, it looks the same to the application.

This will work,

I believe that i have exactly the picture if what you are trying to do fine. You can stick that 9mm into the .38 but it isnt such a good idea.