Advice needed on a Hybrid Inverter for a Solar Trailer

[RememberTheMagic]

Curious why.

Since the VOC on the panels is 85v so to optimize the panels (shading) I will be wiring each string in parallel. This increases the current but keps the voltage the same, likewise the min input on the Growatt is 150v

 

[RememberTheMagic]

ok so it looks like I will just go off grid for now, with this solution, Later I will add an inverter that will just do grid tie.

View attachment 134237

 

[Hedges]

Since the VOC on the panels is 85v so to optimize the panels (shading) I will be wiring each string in parallel. This increases the current but keps the voltage the same, likewise the min input on the Growatt is 150v

Series connections work pretty well to be unaffected by shade (beyond losing the shaded portion.)

With panels in parallel, shade on one section, or just one cell, takes that panel offline.
With panels in series, shade on one section or one cell takes just that section offline.

With panels in series/parallel arrangement, e.g. 4s2p, shade on one section mostly takes just that section offline. Vmp of the two strings isn't that far apart, and they deliver pretty much full power. Shade on two full panels, leaving 4s in parallel with 2s, it doesn't work as well. You would only get about 4 panels worth of power.

 

[Doggydogworld]

Series connections work pretty well to be unaffected by shade (beyond losing the shaded portion.)

What? Shade slashes current coming out of the shaded panel. Since all panels in series have the same current, it pulls the entire string down.

That being said, I'd go with 2S4P on that trailer and use the GroWatt's built-in MPPT.

 

[Hedges]

What? Shade slashes current coming out of the shaded panel. Since all panels in series have the same current, it pulls the entire string down.

Nope. Remaining illuminated panels push current past bypass diode, so you typically lose as little as 1/3 of a panel, if that's all that's shaded.

After someone pitched optimizers to the electronics manufacturer I worked for, I went home and tested my system with 9s2p array by shading one panel. Still got about 17/18ths of the total power.

The diodes are fine for shading when sun is off-angle. If operating near full current and one is shaded, diodes may not be able to handle current and burn up. Some manufacturers mention this.

Solar Bypass Diode Guide: This Is What You Should Know About Solar Bypass Diodes - Power From Sunlight

Solar bypass diodes are built into PV modules (usually into the PV Junction box) for two reasons: they improve overall system performance, and they provide an added level of product safety and are therefore required by regulatory agencies.

www.powerfromsunlight.com

 

[RememberTheMagic]

What? Shade slashes current coming out of the shaded panel. Since all panels in series have the same current, it pulls the entire string down.

That being said, I'd go with 2S4P on that trailer and use the GroWatt's built-in MPPT.

exactly

 

[RememberTheMagic]

Since the VOC on the panels is 85v so to optimize the panels (shading) I will be wiring each string in parallel. This increases the current but keps the voltage the same, likewise the min input on the Growatt is 150v

Sadly the MPPT on the Growatt is bad, I knew this from the start and got a Midnite MPPT

 

[timselectric]

Hopefully you got a great deal, then.
And you seem to know what you need to do to get what you want out of your system.
It's a cool project.

 

[RememberTheMagic]

Hopefully you got a great deal, then.
And you seem to know what you need to do to get what you want out of your system.
It's a cool project.

Ill post the pictures here as I go, I have a bunch of LifePo4 EVE cells I have to make a massive battery pack with (tested that for 1 year with 2 3kw Growatt inverters and 8 panels), so I think the trailer (welding/fabricating) is the biggest challenge.

I am going to make one of the sides on the trailer that holds one array have the ability to tilt and be parallel with the ground to separate it from the other array further; Therefore, reducing any shadowing potentially during the winter months. I will do that with electric cylinders like the old Satellite dishes use to have. I have to make CAD drawings (learning that too) so that the Plasmam cutter can make the part (a friend has one), so all in all a lot of labor, not a ton of cash yet. I picked up parts (steel, Inverters, batteries) over time getting deals along the way knowing I was going to build this as a labor of love. Its gonna be sweet !

 

[RememberTheMagic]

ok finally finished it !

2.4K of Solar, 460Ah LifePo4 Battery Pack (actually 2 of 230ah packs), 6.5K Low Frequency Inverter producing 240VAC Split Phase at 25 amps or 120VAC at 50amps.