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Upgrading my Offgrid Setup in Noordhoek valley.


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Finally got around to installing more panels in my offgrid setup in Noordhoek.


Originally I had 6 panels -> FM80 ->  Dead Acid ->Victron 24v 3000va
At some point earlier in the year, I finally got around to installing the 10KW LFP I had lying around since 2019.

...and Now, I finally got around to installing another 6 panels to make it 12 panels on the roof as of yesterday.


Setup is fully offgrid.   I've been offgrid here since I built the place on the plot, never ever had Eskom or CoCT

6 panels worked fine for me on my own, even in winter, but now the GF is living in the house, electricity use has gone up, and we needed more generation, mostly for the crappy winter days, as 6 panels was pretty marginal.   I was fine with turning off stuff and waiting for a day or two to do clothes washing.  The woman wasn't.

Doubling generation capacity enables me to not worry about that.

We're already quite low on power usage - we hover around 4KW / day usage, with NAS+POE Camera's + Electric Fence + Fridge + Lighting ++ 

Current setup here is a 48v 3000va Victron Multiplus + 12 x 300w panels + FM80 + 10KW LFP
The FM80 doesn't talk to the Victron so no stats on solar (will be replacing it next week).

Was enough originally to last about 4 days of crap weather, now we shouldn't be too perturbed about things.
You can see where we installed the panels in the middle of the day yesterday, then the sharp increase in generation.



Overall quite happy with the slapdash way I've handled the install.   Panels have been reused as I need them from my other installs.
The backend side will be installed properly in a week or two  once I have the Victron MPPT that my accountant is selling me.  
No photos till then of that, as its a... mess.


Its been a mess for 5+ years though, so...



Panels are installed in 3S 2P x 2

36v x 3 = 108v @ 8a per string of 3 panels in series.  Which is then paralled for 108v @ 16a for the 3strings in parallel x 2.
And I have 2 sets of that running back the MPPT in the house.  

Used a Y adaptor to conjoin the strings on the roof, as I didn't feel like running more cabling.
Once I get the Victron MPPT will be wiring in a DC disconnect on the backend.    It's been wired directly for a few years, as I like to live dangerously (aka it worked, and I left it to do other stuff).





Edited by shanghailoz
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  • 4 weeks later...

Victron 150/70 MPPT installed - mostly, so I can haz logging...  
Although there is the one point - that the FM80 is a bit noisy when the fan kicks in 2-3 times a day; the Victron MPPT is fanless, so should be quieter overall.

Also redoing a bunch of networking, so many network cables hanging about.  Fun. fun.



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Can do firmware updates over the internet now, which is nice, as the firmware was oldish on the unit.






Now I have PV finally.  (Although it won't kick in until tomorrow).




Had to unplug my battery ve.direct and connect to the MPPT, which means I need to order another ve.direct -> usb cable for my PI.





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Received my 2nd ve.direct -> usb cable today (thanks Jaco / Glodina for the fast shipping), and can finally have both sets of stats (mppt, battery on ve.direct, and inverter on ve.bus)


Now, I finally have logging for production, consumption, and battery.
As you can see in the graph, solar production tapers off once battery is full, as the MPPT throttles output to match usage.
I don't have a grid connection (we're completely offgrid), so no to/from grid.





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A shot from this morning at 8:30am or so.

You can see that battery logging (the blue line)  started from 11am yesterday when I plugged in the new cable, and see the discharge overnight for the battery to get down to about 60% capacity.

You can also clearly see that generation is throttled when the battery is full (the orange lines in the graph).

While 40% discharge would be worrying on Lead Acid, for Lithium, thats pretty ok.  I may add more generation though, as having 20KWhr of battery feels like it would be better in the long run, so I don't need to worry too much about a week or two of marginal winter generation.

Worst case scenario for me in winter is turn stuff off, or grab a generator if I really must, but I'd like to avoid that if I rent out the place, and not have to worry about tenants killing expensive batteries.


Edited by shanghailoz
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I see that the vrm shot above glitched for battery level - i'm definitely seeing the stats though typically


I usually keep a window open to http://venus.local on my laptop so I can keep an eye out on values.
Now that the system seems to be more stable in terms of generation/discharge, I can be less cautious.   

In an ideal world, I'd probably double up on storage, and solar generation.  For now, I'm happy though.





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  • 7 months later...
On 2020/10/16 at 6:05 PM, Jatho said:

Nice thread, your usage is very low do you not have things like electric geysers, oven, pool pump etc?

Better late than never to reply :)


No electric geysers - I use a solar hot water heater.  It does have a geyserwise connected to the solar hot water heater and can draw power to heat if it needs to, but I actually leave it switched off 100% of the time.  I don't have issues with cold water unless its miserable for 3-4 days, and thats rare in Cape Town where we are.

Oven is gas - I use LPG.

Pool Pump - the pool isn't built yet.


This setup is in the "granny flat".  Its the smaller of the 2 houses on the plot.  
The main house shell and roof is done now, and before I left back to Asia I managed to install 24 x JA Solar 395W Mono Percium LW 5BB Silver Frame and a Sunsynk 8.8KW in there.


Thats connected to the lower house, in a pseudo grid tie setup.  It's currently powered off, as I didn't have time to setup and debug before I left.

I may have another post for the main house, can't remember if I made one here or not.  If not, I'll document it.



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