About to do my first install, best place to catch morning AND mid day sun? (Image heavy)

Getting ready to install 8kw of panels, 20 in total. 16 will fit on my only south (ish) facing roof which is at roughly a 15 degree angle. I'm northern, on the south shore of lake erie.

The garage roof (pictured below) gets nearly 100% sun from about 10am to 8pm in the summer, and from about 11am to 5pm in the winter. That's where most of my panels are going.

Here's where it gets fun


This deck gets sun from about 630- till about 4pm in the summer, and from about 830am till about 2pm in the winter.

I was thinking about mounting some or all of my remaining panels on top of the railings to catch the early morning sun, laying flat, looking at the sky. I want to do vertical but i think it would look trashy. I'm not really convinced horizontal won't look trashy tbh.

Here is the lot I'm working with to give a better reference. Picture is roughly 4pm in late spring. Installing on the main house structure MAY be an option but only if it'll provide SIGNIFICANT benefit over somewhere else, it's a brand new roof and I don't enjoy poking holes.
The garage is unfinished, full tar papered under the mismatched shingles and uninsulated, I could give a crap less about that roof.


The front roof (south) looses sun when it goes behind the neighbor on the left's pine tree at about 5pm. In the winter, the large tree at the corner of my lot is almost a non factor once the leaves are gone.


Ideas, and discussion welcomed and needed. Thanks.

https://www.suncalc.org/ is what I use to work out any panel placement, you could make a canopy for the decking using panels or many other options best to peruse threats in the show and tell to give yourself idea from what others have done

Someone pointed me to opensolar and holy cow I wish I knew about this before. Wicked cool! I think this is how I'm going to go:

Similar to your NW face situation, I will be installing on SE, SW, and NW faces.
For the NW I plan to run rails diagonally and tilt panels so they are parallel to SW face. Multiple rows, spaced apart.
I haven't worked out the exact dimensions yet, but at some low sun angle they will shade each other.
I think the 12s string will be 4 rows of 3 panels, 5' tall in portrait orientation. Maybe about 10' pitch from row to row.
I would like shading of rows to not occur until sun is hitting at 45 degree angle.

areoseek said:

Someone pointed me to opensolar and holy cow I wish I knew about this before. Wicked cool! I think this is how I'm going to go:

View attachment 228464
View attachment 228465

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The cost of the system seems to be a self install for $8k. A similar system would run around $30k to $40k in my area for a contracted install.

I recommend running through a calculator, like in my signature block or PV Watts. for each configuration you want and to double check the calculator you posted. Each has a separate algorithm. If you put panels on the South, East, and West you'll need to do three different entries and add them up.

I'm a bit skeptical of any calculator that will post a dollar savings. In my local area, the utility company I use offers three different rate plans, none favorable to solar, Net Metering is gone. When I installed my system, I went from a fixed rate all day long to peak rates from 4 pm to 7 pm where rates triple for those three hours. This eats up most of my savings. I save around 25% per month based off this.

I don't know what your rate plan is now, or what you'll be forced to go to when you switch to solar. One of the guys who came to my house had his sales pitch based off a very favorable Net Metering rate that had expired 7 years before. He also did not take into account most months bills 50% of the costs are fixed costs.

chrisski said:

The cost of the system seems to be a self install for $8k. A similar system would run around $30k to $40k in my area for a contracted install.

I recommend running through a calculator, like in my signature block or PV Watts. for each configuration you want and to double check the calculator you posted. Each has a separate algorithm. If you put panels on the South, East, and West you'll need to do three different entries and add them up.

I'm a bit skeptical of any calculator that will post a dollar savings. In my local area, the utility company I use offers three different rate plans, none favorable to solar, Net Metering is gone. When I installed my system, I went from a fixed rate all day long to peak rates from 4 pm to 7 pm where rates triple for those three hours. This eats up most of my savings. I save around 25% per month based off this.

I don't know what your rate plan is now, or what you'll be forced to go to when you switch to solar. One of the guys who came to my house had his sales pitch based off a very favorable Net Metering rate that had expired 7 years before. He also did not take into account most months bills 50% of the costs are fixed costs.

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I've already purchased everything and am self installing. I entered my daily kwh usage (I have an energy monitor) and I pay a fixed 15 cents per kwh. Not a grid tie system, that rate won't change. We don't have peak or off peak rates here. Just regular expensive natural gas power at fixed rates that change every 2 years.

You can't really mount panels to a deck railing.

If you're not considering ground mounts then I would go with this strategy, pick a string length, 6 or 7 panels, and then put as many strings on roofs as you can. Forget about direction and just get everything up that you can. It'll all get sun sometime.

If you're gonna have multiple MPPT's you can mix 6's and 7's too of course.

If you want to start with shed and no house, then fit everything you can on the shed. 4 strings if you can.

hwy17 said:

You can't really mount panels to a deck railing.

If you're not considering ground mounts then I would go with this strategy, pick a string length, 6 or 7 panels, and then put as many strings on roofs as you can. Forget about direction and just get everything up that you can. It'll all get sun sometime.

If you're gonna have multiple MPPT's you can mix 6's and 7's too of course.

If you want to start with shed and no house, then fit everything you can on the shed. 4 strings if you can.

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Ground mounts are definitely an option

The 6000XP has two MPPTs, each requiring at least 100 volts, and no more than 480 volts. With a limitation of 17 amps of current imput per MPPT, this makes it hard to place them in parallel, so you may be limited to 10S2P. So without doing the math, each of the two strings should have 10 panels, not in parallel.

From the pic in post #7, with North to the right and South to the left, placement would be 10 on the South Side of the Barn, and 10 on the East side of the House. These are the panels I thing you're getting:


You could do things with a third MPPT to the battery, but this may not work if the batteries and inverter talk to each other for charging.

Penn can be a cold place, so for the 10P option, would need to run the temp compensation to see if 10 panels busts the 480 volt limit, which I think you may be limited to 9P for that. Math will tell.

I see now the 6000XP is an off grid inverter, so I'm assuming everything you hook to this will be off the utility box and on a separate circuit.

areoseek said:

I've already purchased everything and am self installing. I entered my daily kwh usage (I have an energy monitor) and I pay a fixed 15 cents per kwh. Not a grid tie system, that rate won't change. We don't have peak or off peak rates here. Just regular expensive natural gas power at fixed rates that change every 2 years.

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For me, natural gas is so cheap I would not swap to an electric appliance.

areoseek said:

Ground mounts are definitely an option

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Edit to add, inspiration came from here.

chrisski said:

The 6000XP has two MPPTs, each requiring at least 100 volts, and no more than 480 volts. With a limitation of 17 amps of current imput per MPPT, this makes it hard to place them in parallel, so you may be limited to 10S2P. So without doing the math, each of the two strings should have 10 panels, not in parallel.

From the pic in post #7, with North to the right and South to the left, placement would be 10 on the South Side of the Barn, and 10 on the East side of the House. These are the panels I thing you're getting:

Hyperion 395W 108 Half-Cell Mono PERC BOB Bifacial Solar Panel

DetailsHigh conversion efficiencyModule efficiency 20.2% achieved through advanced cell technology and manufacturing processExcellent weak light performanceMore power output in weak light condition, such as cloudy, morning and sunsetExtended mechanical performanceModule certified to withstand...

www.renvu.com

You could do things with a third MPPT to the battery, but this may not work if the batteries and inverter talk to each other for charging.

Penn can be a cold place, so for the 10P option, would need to run the temp compensation to see if 10 panels busts the 480 volt limit, which I think you may be limited to 9P for that. Math will tell.

I see now the 6000XP is an off grid inverter, so I'm assuming everything you hook to this will be off the utility box and on a separate circuit.



For me, natural gas is so cheap I would not swap to an electric appliance.

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Spot on, thank you! Yep, all gas appliances. My usage is so high because of the pool, ac, and dehumidifiers (yay northeast basement and high water table).

Thank you for the ideas! I do believe I can do 10s and still be under max voc, but I will verify when it starts to get colder to make sure I don't start to get too high on voltage.

areoseek said:

Ground mounts are definitely an option

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When I look at your trees for a string that needs to be 10S, I don't think ground mounts are practical for shade.

Seems the 6000XP only has 2 MPPTs and a 17 amp current input limit on each MPPT, and with each panel producing 13 amps, paralleling them is outside specs. For my Victron MPPTs, slightly different for each model but I can parallel panels where the VOC of the input equals the amperage rating. This is perfect to put a lot of panels in parallel to a single MPPT. The all in ones tend to have one or two MPPTs that have an amperage rating for each MPPT to not be able to be put in parallel. If shading is not a factor and gabled roofs are not a factor, the single series is awesome, but once you run out of room for 10S facing the same direction or a part of that string is shaded, not being able to be in parallel is not so attractive.

areoseek said:

I will verify when it starts to get colder

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Just go use the record cold for Eerie PA even if this record cold was in 1922.

hwy17 said:

If you're not considering ground mounts then I would go with this strategy, pick a string length, 6 or 7 panels, and then put as many strings on roofs as you can. Forget about direction and just get everything up that you can. It'll all get sun sometime.

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7s, different orientations? Is that ever good?
(Ok if slight differences, but not 45 degree differences.)

Some MPPT might get stuck on lower current of one off-angle panel. Better MPPT would sweep voltage all the way down, find global maxima power.

With one panel off-angle while others are in direct sun, could have Imp pushed through bypass diodes, causing their failure.
I think string inverter should have all panels in a string essentially same angle, and unshaded unless sun is off-angle.
Otherwise, optimizers. Or microinverters.

I have each string a single orientation but parallel identical strings of different orientations.

areoseek said:

Yep, all gas appliances. My usage is so high because of the pool,

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Consider solar-thermal.
I've also seen a design that is heat exchanger in the attic.

Hedges said:

7s, different orientations? Is that ever good?
(Ok if slight differences, but not 45 degree differences.)

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Each set of 7 facing same orientation?

7SE, 7N, 7NE, whatever.

I thought we have a community consensus that paralleling strings is ok in all orientations as long as each string has enough illumination to bring themselves up to the operating voltage, which is any illumination including shaded.

I may be ignorant to the way that affects MPPT's since I'm running fixed solar voltage and never think much into MPPT implications anymore.

hwy17 said:

Each set of 7 facing same orientation?

7SE, 7N, 7NE, whatever.

I thought we have a community consensus that paralleling strings is ok in all orientations as long as each string has enough illumination to bring themselves up to the operating voltage, which is any illumination including shaded.

I may be ignorant to the way that affects MPPT's since I'm running fixed solar voltage and never think much into MPPT implications anymore.

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I'm curious about this if someone will elaborate

hwy17 said:

Each set of 7 facing same orientation?

7SE, 7N, 7NE, whatever.

I thought we have a community consensus that paralleling strings is ok in all orientations as long as each string has enough illumination to bring themselves up to the operating voltage, which is any illumination including shaded.

I may be ignorant to the way that affects MPPT's since I'm running fixed solar voltage and never think much into MPPT implications anymore.

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areoseek said:

I'm curious about this if someone will elaborate

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Since the 6000XP MPPT spec sheet limits you to 17 amp input, and each string 13 amps, paralleling 2P gets you 26 amps, out of tolerance. Also only 2 MPPTs on it.

On my small couple hundred dollar setup with a 15 amp MPPT capable of making a couple hundred watts, I have no issues exceeding the specs since its isolated from the house in case I'm wrong and it catches fire. On the OP's $8k self installed system, I don't like that.

I do consistently have on 3 paralleled strings for that cheap system 3P panels to the Sout, East, and North.

chrisski said:

Since the 6000XP MPPT spec sheet limits you to 17 amp input, and each string 13 amps, paralleling 2P gets you 26 amps, out of tolerance. Also only 2 MPPTs on it.

On my small couple hundred dollar setup with a 15 amp MPPT capable of making a couple hundred watts, I have no issues exceeding the specs since its isolated from the house in case I'm wrong and it catches fire. On the OP's $8k self installed system, I don't like that.

I do consistently have on 3 paralleled strings for that cheap system 3P panels to the Sout, East, and North.

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I'll be doing 10s on each mppt. Should bring me to 400v on each string. I'm fine if it clips on sunny days since most of my year is snow and rain

areoseek said:

I'll be doing 10s on each mppt. Should bring me to 400v on each string. I'm fine if it clips on sunny days since most of my year is snow and rain

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Seems as if whoever sold you that gear did a great job of selling a set of panels that will work anywhere.

The panels output around 37 volts VOC. THe Temp coefficient of these panels are -.304% for each degree centigrade they go over 25 C or 77 F, so more volts as it warms up. A high voltage can ruin the AIO. A high amperage will likely just clip at max input and be fine.

Is this a grid tie, or a completely off grid installation ?

If grid tie, you probably want to go for maximum hours of sun, rather than having a massive unusable mid day peak (in mid summer) that may be limited by the equipment, or how much power may be permitted to be fed back into the grid.

With a VERY large battery that has several days of storage, go for maximum overall power, which will be all panels facing due south.

A small battery might benefit from more early morning power, where the batteries are strongly bulk charging.
A lot of excess late afternoon power might be less useful where the battery by that time is in absorb or already fully charged.

So there can be rather a lot to think about, but in the end it really depends on getting max performance with whatever you have available.

M

Warpspeed said:

Is this a grid tie, or a completely off grid installation ?

If grid tie, you probably want to go for maximum hours of sun, rather than having a massive unusable mid day peak (in mid summer) that may be limited by the equipment, or how much power may be permitted to be fed back into the grid.

With a VERY large battery that has several days of storage, go for maximum overall power, which will be all panels facing due south.

A small battery might benefit from more early morning power, where the batteries are strongly bulk charging.
A lot of excess late afternoon power might be less useful where the battery by that time is in absorb or already fully charged.

So there can be rather a lot to think about, but in the end it really depends on getting max performance with whatever you have available.

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Off grid critical loads

chrisski said:

Seems as if whoever sold you that gear did a great job of selling a set of panels that will work anywhere.

The panels output around 37 volts VOC. THe Temp coefficient of these panels are -.304% for each degree centigrade they go over 25 C or 77 F, so more volts as it warms up. A high voltage can ruin the AIO. A high amperage will likely just clip at max input and be fine.

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I'd like to say I researched them for hours or talked to someone but they were just the cheapest price per watt panels i could find

hwy17 said:

Each set of 7 facing same orientation?

7SE, 7N, 7NE, whatever.

I thought we have a community consensus that paralleling strings is ok in all orientations as long as each string has enough illumination to bring themselves up to the operating voltage, which is any illumination including shaded.

I may be ignorant to the way that affects MPPT's since I'm running fixed solar voltage and never think much into MPPT implications anymore.

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Correct, I misread your post as, "6 or 7 panels, ... Forget about direction and just get everything up that you can"

I agree forget about string directions. Just make panel orientations within a given string same/similar.
Fine, great, to have strings of very different directions.

My measurement"s" of one sample indicated Voc in the shade is similar to Vmp in direct sun.

Hedges said:

Correct, I misread your post as, "6 or 7 panels, ... Forget about direction and just get everything up that you can"

I agree forget about string directions. Just make panel orientations within a given string same/similar.
Fine, great, to have strings of very different directions.

My measurement"s" of one sample indicated Voc in the shade is similar to Vmp in direct sun.

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My own current expansion plan is to maybe get all the way up to 15kW on my 5.5kW charge controller. I've got 8x480's facing West and I'm looking towards adding 1-3 more series facing SW, all paralleled. See if I get there though.