diy solar

diy solar

2x Sol-Ark 15K's + HomeGrid Stacks

Unirac ULA, the newer aluminum brackets. I have both kinds.

You haven't included X direction diagonals. No earthquake concerns? At least one should help stiffen against vibration in the wind.
Is that the racking? I need to add 8 more panels this spring. I was trying to decide how I was going to do the racking. This array was installed 9 yrs ago. I restrung it and pulled new wire when I added the Sol Ark in September. I have 2x9 (x2) and an 8 panel string. When I finish I’ll have 2x8 for my 3rd MPPT. Any suggestions would be appreciated. It has taken some pretty good wind loads over the past 9 yrs. I thought it was overkill when they augered down 6 ft in the first place. But probably not. I’m thinking of adding 4 poles for the rack extension and then building off that. I could probably get away with adding 2 poles and build off the end of my present array.
 
Post your PV panel data sheet (or at least label, but they we'll have to guess temperature coefficient), and MPPT specs.
And tell us your location's historical coldest temperature on record.
This will let us evaluate voltage/current for series/parallel recommendations.

Depending on "efficiency", watts/m^2, you might be better off removing all panels and installing new (or used) replacements. That can mean 50% power power from existing rack area. Although, those are pretty large panels, probably recent and around 200W/m^2 already.


I've done a few silly looking things like threading on an extra 5' of horizontal pipe and supporting with diagonal strut.
I plan to disassemble, replace horizontals with 21' pipe, put up new panels. One array I want to reorient, so its strings peak at a different time of the day.

If you do expand rack, in line is easiest but consider additional angles. Bit more difficult to get correct PV string lengths, but can fit more kWh within same kW of SCC and utility export limit. Likely free standing, but I wonder if 45 degree pipe fittings off the end would be any benefit.
 
Post your PV panel data sheet (or at least label, but they we'll have to guess temperature coefficient), and MPPT specs.
And tell us your location's historical coldest temperature on record.
This will let us evaluate voltage/current for series/parallel recommendations.

Depending on "efficiency", watts/m^2, you might be better off removing all panels and installing new (or used) replacements. That can mean 50% power power from existing rack area. Although, those are pretty large panels, probably recent and around 200W/m^2 already.


I've done a few silly looking things like threading on an extra 5' of horizontal pipe and supporting with diagonal strut.
I plan to disassemble, replace horizontals with 21' pipe, put up new panels. One array I want to reorient, so its strings peak at a different time of the day.

If you do expand rack, in line is easiest but consider additional angles. Bit more difficult to get correct PV string lengths, but can fit more kWh within same kW of SCC and utility export limit. Likely free standing, but I wonder if 45 degree pipe fittings off the end would be any benefit.
I have thought about that. I thought if I can source 8 more compatible panels that would be the cheapest way to go. These panels are no longer manufactured.

1677368608988.jpeg
 
I currently have 44 for 13.4 kWh. Some loss over the 9 yrs but we generate about 90% of our needs. Another 8 will put us close to needs. I agree adding higher wattage panels would be perfect. Here is my calculator results for what we have. I have the MPPT room and the wire in place to add the 8 additional panels. Would be a quick and easy addition. I also have the real estate as these are in our field. The Sol Ark will take the additional panels on the 3rd MPPT. Ending up with 2 strings of 9 on both MPPT 1 & 2 and 2 strings of 8 on the 3rd. Could make the 3rd MPPT 2 strings if 9 by adding 10 panels but it wouldn’t look right with the 2 odd panels.

1677368916840.jpeg
 
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Post your PV panel data sheet (or at least label, but they we'll have to guess temperature coefficient), and MPPT specs.
And tell us your location's historical coldest temperature on record.
This will let us evaluate voltage/current for series/parallel recommendations.

Depending on "efficiency", watts/m^2, you might be better off removing all panels and installing new (or used) replacements. That can mean 50% power power from existing rack area. Although, those are pretty large panels, probably recent and around 200W/m^2 already.


I've done a few silly looking things like threading on an extra 5' of horizontal pipe and supporting with diagonal strut.
I plan to disassemble, replace horizontals with 21' pipe, put up new panels. One array I want to reorient, so its strings peak at a different time of the day.

If you do expand rack, in line is easiest but consider additional angles. Bit more difficult to get correct PV string lengths, but can fit more kWh within same kW of SCC and utility export limit. Likely free standing, but I wonder if 45 degree pipe fittings off the end would be any benefit.
My first thought was to thread the 2 end pipes and couple an additional length with 2 additional posts in the ground.
 
You don't need identical panels, just PV string of similar Vmp. Could be a few percent different, and could be different number of different voltage panel for similar string Vmp.

9s2p x 2 + 8s = 44 panels.

At first I was thinking 11s.
44.8 Voc x 11 = 493V, should be OK if inverter MPPT has 600Voc absolute max.
But there may be wattage limits per MPPT? Usually just voltage and current.

Oh, SolArk spec sheet says 500V max (and less if higher current)

Your 9s would be the max, except in mild climate could be 10s.

Another 10 panels and you could have all strings of 9.
Multiple orientations and you can overpanel without clipping.

Consider, for instance, 10s of these Silfab in parallel with 9s of suniva.
Or even in parallel with 8s Suniva + 1 SilFab.
I haven't checked dimensions.
Others available from Santan as well.

My first thought was to thread the 2 end pipes and couple an additional length with 2 additional posts in the ground.

Yes, that extends horizontally.

I count 11 panels across. I considered extending bottom of array forward, less tilt. Would drive another row of low posts, and tie rails in to bottom end of existing rails. Different tilt, just put one (or two?) full strings there.
OK for parallel string to be different orientation. Do not connect panels of different orientation in series.

Top clamp, not bottom bolt? That tolerates other panel dimensions. Although many are same/similar in one direction.
 
You don't need identical panels, just PV string of similar Vmp. Could be a few percent different, and could be different number of different voltage panel for similar string Vmp.

9s2p x 2 + 8s = 44 panels.

At first I was thinking 11s.
44.8 Voc x 11 = 493V, should be OK if inverter MPPT has 600Voc absolute max.
But there may be wattage limits per MPPT? Usually just voltage and current.

Oh, SolArk spec sheet says 500V max (and less if higher current)

Your 9s would be the max, except in mild climate could be 10s.

Another 10 panels and you could have all strings of 9.
Multiple orientations and you can overpanel without clipping.

Consider, for instance, 10s of these Silfab in parallel with 9s of suniva.
Or even in parallel with 8s Suniva + 1 SilFab.
I haven't checked dimensions.
Others available from Santan as well.



Yes, that extends horizontally.

I count 11 panels across. I considered extending bottom of array forward, less tilt. Would drive another row of low posts, and tie rails in to bottom end of existing rails. Different tilt, just put one (or two?) full strings there.
OK for parallel string to be different orientation. Do not connect panels of different orientation in series.

Top clamp, not bottom bolt? That tolerates other panel dimensions. Although many are same/similar in one direction.
Newer versions of the spec sheet show 500V at 26A as the max. I've only gone up to around 8800W on a single input though so I can't confirm what the actual max is.
 
You don't need identical panels, just PV string of similar Vmp. Could be a few percent different, and could be different number of different voltage panel for similar string Vmp.

9s2p x 2 + 8s = 44 panels.

At first I was thinking 11s.
44.8 Voc x 11 = 493V, should be OK if inverter MPPT has 600Voc absolute max.
But there may be wattage limits per MPPT? Usually just voltage and current.

Oh, SolArk spec sheet says 500V max (and less if higher current)

Your 9s would be the max, except in mild climate could be 10s.

Another 10 panels and you could have all strings of 9.
Multiple orientations and you can overpanel without clipping.

Consider, for instance, 10s of these Silfab in parallel with 9s of suniva.
Or even in parallel with 8s Suniva + 1 SilFab.
I haven't checked dimensions.
Others available from Santan as well.



Yes, that extends horizontally.

I count 11 panels across. I considered extending bottom of array forward, less tilt. Would drive another row of low posts, and tie rails in to bottom end of existing rails. Different tilt, just put one (or two?) full strings there.
OK for parallel string to be different orientation. Do not connect panels of different orientation in series.

Top clamp, not bottom bolt? That tolerates other panel dimensions. Although many are same/similar in one direction.
Yes originally were connected 4 strings of 11 into an 11kW SMA combined and run in on one set of 4 gauge. Pulled the 4 ga and ran 6-8 ga. Restrung 4 rows of 9 with the last 4 rows of two make up the 8 panel string. We had the room so they are properly oriented and zero shading. If I we’re doing it again I’d make it so I could change my angle twice a year by pivoting the array on a central axis.
 
You don't need identical panels, just PV string of similar Vmp. Could be a few percent different, and could be different number of different voltage panel for similar string Vmp.

9s2p x 2 + 8s = 44 panels.

At first I was thinking 11s.
44.8 Voc x 11 = 493V, should be OK if inverter MPPT has 600Voc absolute max.
But there may be wattage limits per MPPT? Usually just voltage and current.

Oh, SolArk spec sheet says 500V max (and less if higher current)

Your 9s would be the max, except in mild climate could be 10s.

Another 10 panels and you could have all strings of 9.
Multiple orientations and you can overpanel without clipping.

Consider, for instance, 10s of these Silfab in parallel with 9s of suniva.
Or even in parallel with 8s Suniva + 1 SilFab.
I haven't checked dimensions.
Others available from Santan as well.



Yes, that extends horizontally.

I count 11 panels across. I considered extending bottom of array forward, less tilt. Would drive another row of low posts, and tie rails in to bottom end of existing rails. Different tilt, just put one (or two?) full strings there.
OK for parallel string to be different orientation. Do not connect panels of different orientation in series.

Top clamp, not bottom bolt? That tolerates other panel dimensions. Although many are same/similar in one direction.
Now that’s an idea
 
Yes originally were connected 4 strings of 11 into an 11kW SMA combined and run in on one set of 4 gauge. P

Me of course, I would have seen your SMA Sunny Boy and raised you two Sunny Island.

I almost offered to buy a 11000TL-US from someone (you?) but changed my mind when I realized it couldn't do 208V for 3-phase.
I since bought a TriPower, but have had a hard time finding a good/pretty/cheap step-up transformer.
 
Now that’s an idea

That's what we're here for. Sounding board, no guarantees, but ideas might come to fruition. ????
I've learned a lot from the other guys, and if I ever build a DIY battery, at least I'll find new mistakes to make.
 
Me of course, I would have seen your SMA Sunny Boy and raised you two Sunny Island.

I almost offered to buy a 11000TL-US from someone (you?) but changed my mind when I realized it couldn't do 208V for 3-phase.
I since bought a TriPower, but have had a hard time finding a good/pretty/cheap step-up transformer.
Maybe I have one. As I get closer to retirement I want to make some additions to grease the wheels. Ultimately I need another 22 kWh of storage and a few more panels. That gets us practically grid free. Probably better ways to spend that money but energy independence is a goal. Last year our total energy costs were about $600.
 
They didn't have these at Home Depot, only the side-by-side when I got some, and those gave me difficulty in a 125A QO box.

iu
Does anybody have a link to where we can purchase these? These have a benefit from less likelihood of interference? I'm evaluating my options for transfer switch.

Polaris lugs
Distribution block in wire trough
Double lug transfer switch

That seems to be my options. Double lug is the cheapest but I need to make sure I can pass inspection.
 
eBay, my go-to place for everything.







If you want to spend more:

 
ok thanks. hybrid inverter is not an option for me. the ideal would be an off grid inverter that can blend AC and solar. short of that, I can wire a breaker that can turn off ac input to the inverter when I don't want to use grid power

the more i research this the more i get closer to a workable solution. thanks very much for your input.
Have you looked into Sandi inverters? I almost went that path. They need HV batteries, but man are they tanks. And pretty cheap for what you get.
 
Buy an equivalent part (different brand) from Graingers, then?


I was going to say split-bolt was a way to be cheaper (best if away from enclosure, like on a breaker not a single lug), but this is expensive too. I've only used smaller ones, not 600 MCM.


These things are nothing more than a block of aluminum, tapped with set screws, and tin plating.
They cost as much as I'm paying for a 125A breaker panel with copper busbar (the lower priced lugs we saw), even including main breaker, and assortment of branch circuit breakers (the more ridiculous price lugs).


 
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