My journey to renewable energy - Solar

itareanlnotani

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Sep 14, 2008
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That shadeline ^^ is looking ominous. That and bird poop, yet more reasons to optimise each panel rather than string them.

I agree about the shading (and made this point a while ago in thread).
Smaller strings if the inverter can support higher amp input.

I don't agree about the micro inverters though.
They aren't reliable, and the cost is prohibitive.
Cheaper just to add more panels..
 

thehuman

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Nov 2, 2004
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I agree about the shading (and made this point a while ago in thread).
Smaller strings if the inverter can support higher amp input.

I don't agree about the micro inverters though.
They aren't reliable, and the cost is prohibitive.
Cheaper just to add more panels..
Maybe the cheap grid ties from ebay .
Some micro grid inverters have a warranty of 12 years.
 

richjdavies

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Sep 9, 2013
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What do you mean by "optimize each panel rather than string them"?
Not what others have said...

You DONT need to have an inverter for each panel (i.e. like a microinverter) - but you DO need an optimiser on each panel - i.e. a module level MPPT

From: https://en.wikipedia.org/wiki/Power_optimizer
" Because of their sequential wiring, power mismatch between PV modules within a string can lead to a drastic and disproportionate loss of power from the entire solar array, in some cases leading to complete system failure.[7] Shading of as little as 9% of the entire surface array of a PV system can, in some circumstances, lead to a system-wide power loss of as much as 54%.[8] Although this problem is most notable with "large" events like a passing shadow, even the tiniest differences in panel performance, due to dirt, differential aging or tiny differences during manufacturing, can make the array as a whole operate away from its best MPPT point. "Panel matching" is an important part of solar array design. "
 

RonSwanson

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May 21, 2018
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Not what others have said...

You DONT need to have an inverter for each panel (i.e. like a microinverter) - but you DO need an optimiser on each panel - i.e. a module level MPPT

From: https://en.wikipedia.org/wiki/Power_optimizer
" Because of their sequential wiring, power mismatch between PV modules within a string can lead to a drastic and disproportionate loss of power from the entire solar array, in some cases leading to complete system failure.[7] Shading of as little as 9% of the entire surface array of a PV system can, in some circumstances, lead to a system-wide power loss of as much as 54%.[8] Although this problem is most notable with "large" events like a passing shadow, even the tiniest differences in panel performance, due to dirt, differential aging or tiny differences during manufacturing, can make the array as a whole operate away from its best MPPT point. "Panel matching" is an important part of solar array design. "
AFAIK the optimisers are around 50% of the cost of a panel i.e. R900-00
 

richjdavies

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AFAIK the optimisers are around 50% of the cost of a panel i.e. R900-00
Yup of course there's a balance to be had here - between balanced, well maintained, smallish strings vs. optimisers for every 1-2 modules; and of course the size and quality of the panel (e.g. moving to 500W panels ... 800W I saw the other day just released).

Mainly though need to be careful of installers designing huge strings some pointed in the wrong direction and with shade on them, meaning the whole string is giving nowhere near its optimum output.
 

Priapus

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Jun 8, 2008
Messages
7,717
Its been a long 48hrs or so.... :D

@Tander

Waiting for the update on yesterday's solar go live.
Me too. Hoping he didn't fall off the roof while cleaning the bird poo

Didn't fall off the roof, fell down some stairs though. :laugh:



That shadeline ^^ is looking ominous. That and bird poop, yet more reasons to optimise each panel rather than string them.

Shading isn't an issue. The panels are not shaded in the slightest from sun rise to sun set. That bet you are referring to us after the panels from the corner of the flat roof. So shading starts from below the bottom row panels.

That shade line is early morning though, won't be much of an issue in my opinion.

Correct. :sneaky:

So, we spent all of Sunday wiring and cabling and testing. It was a long day...
@Gielie01 was onsite to assist with the wiring and was a huge help as always. He did less shouting this time round, which was nice... :p

Some photos

Wiring done for combiner box, DC quick disconnect and AC side of things.
IMG_4983.jpeg

New DB in place and wired up:
PHOTO-2020-08-16-21-58-18.jpg IMG_4993.jpeg

First half of the DB is non-essential loads. Stove and Geyser. ThenWe put in a change over switch to switch between inverter power and Eskom - by passing the inverter if need be. After the change over switch, the rest is all on the inverter.

There were some teething issues that are related to dodgy wiring previous owners did and somehow got a COC for. Like the Geyser being on the same circuit as some plugs. So that had to be rewired today.

Today I have been playing with settings and figuring out the who thing. Still go to figure out where to see max PV generation - but at 11am this morning I was pulling 3kw from the Panels no problem. Pretty chuffed with that!

Will try get some nice graphs going and post the results of tomorrows test up.

Also did a test on the battery to see what it would do when grid dies. We see a brief flicker of the downlight and that's it. The whole house stayed powered.

Will have more updates over the course of the week as I fine tune the system and get it integrated into Home Assistant and Grafana.

Thanks for reading.
 
Last edited:

cfvh600

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Jul 11, 2008
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1,405
Its been a long 48hrs or so.... :D




Didn't fall off the roof, fell down some stairs though.





Shading isn't an issue. The panels are not shaded in the slightest from sun rise to sun set. That bet you are referring to us after the panels from the corner of the flat roof. So shading starts from below the bottom row panels.



Correct. :sneaky:

So, we spent all of Sunday wiring and cabling and testing. It was a long day...
@Gielie01 was onsite to assist with the wiring and was a huge help as always. He did less shouting this time round, which was nice...

Some photos

Wiring done for combiner box, DC quick disconnect and AC side of things.
View attachment 894836

New DB in place and wired up:
View attachment 894838 View attachment 894840

First half of the DB is non-essential loads. Stove and Geyser. ThenWe put in a change over switch to switch between inverter power and Eskom - by passing the inverter if need be. After the change over switch, the rest is all on the inverter.

There were some teething issues that are related to dodgy wiring previous owners did and somehow got a COC for. Like the Geyser being on the same circuit as some plugs. So that had to be rewired today.

Today I have been playing with settings and figuring out the who thing. Still go to figure out where to see max PV generation - but at 11am this morning I was pulling 3kw from the Panels no problem. Pretty chuffed with that!

Will try get some nice graphs going and post the results of tomorrows test up.

Also did a test on the battery to see what it would do when grid dies. We see a brief flicker of the downlight and that's it. The whole house stayed powered.

Will have more updates over the course of the week as I fine tune the system and get it integrated into Home Assistant and Grafana.

Thanks for reading.
Looking great! Thanks for sharing.
 

RonSwanson

Executive Member
Joined
May 21, 2018
Messages
7,170
Its been a long 48hrs or so.... :D




Didn't fall off the roof, fell down some stairs though. :laugh:





Shading isn't an issue. The panels are not shaded in the slightest from sun rise to sun set. That bet you are referring to us after the panels from the corner of the flat roof. So shading starts from below the bottom row panels.



Correct. :sneaky:

So, we spent all of Sunday wiring and cabling and testing. It was a long day...
@Gielie01 was onsite to assist with the wiring and was a huge help as always. He did less shouting this time round, which was nice... :p

Some photos

Wiring done for combiner box, DC quick disconnect and AC side of things.
View attachment 894836

New DB in place and wired up:
View attachment 894838 View attachment 894840

First half of the DB is non-essential loads. Stove and Geyser. ThenWe put in a change over switch to switch between inverter power and Eskom - by passing the inverter if need be. After the change over switch, the rest is all on the inverter.

There were some teething issues that are related to dodgy wiring previous owners did and somehow got a COC for. Like the Geyser being on the same circuit as some plugs. So that had to be rewired today.

Today I have been playing with settings and figuring out the who thing. Still go to figure out where to see max PV generation - but at 11am this morning I was pulling 3kw from the Panels no problem. Pretty chuffed with that!

Will try get some nice graphs going and post the results of tomorrows test up.

Also did a test on the battery to see what it would do when grid dies. We see a brief flicker of the downlight and that's it. The whole house stayed powered.

Will have more updates over the course of the week as I fine tune the system and get it integrated into Home Assistant and Grafana.

Thanks for reading.
Some nice neat wiring, especially on the DB. :love:
 

Priapus

Executive Member
Joined
Jun 8, 2008
Messages
7,717
Time for another update.

I have been struggling to get the house to run on solar. The system kept dropping to the batteries during the day. But it would charge the batteries later with solar. So, lots of trouble shooting and thinking we had faulty equipment.

Eventually, the problem was identified. We had configured the panels in 3 strings, of 4. So this meant we had 160v - which is in the range stated int he manual for the Inverter. 120 ~ 450V

We decided to try changing that configuration to 2 Strings of 6 Panels. This gave us around 260v to the MPPT controller. This resolved all issues, instantly. It seems the MPPT is much happier at 260v than it is under 200v:unsure:

We changed this configuration late yesterday, and then load shedding started at 8pm. The Pylontech kept the whole house running and @Gielie01 was able to enjoy his pizza and watch Street outlaws on the TV. :p

Today is the first day the Solar is working 100% - generation surpasses my 65% expectation:

Screenshot 2020-08-20 at 09.56.49.png

4Kw and it isn't even noon yet. Battery just about fully charged too. The inverter blends battery power with PV power if there is not enough generation lef in the panels.

We have load shedding at 12pm today. Bring it on. :laugh:

Now to get the system setup properly with my HA and automations.


Thanks for reading!
 

Priapus

Executive Member
Joined
Jun 8, 2008
Messages
7,717
Today was a great day for PV generation. Peak was 4199 so just above 80% efficiency on those panels. Turns out the angel made no difference at 48 degrees. Produced 22Kw/h - and didn't even notice when the grid died due to load shedding.

Screenshot 2020-08-20 at 17.36.13.png
 
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