The build, the journey, and whatnot.

[Pi Curio]

Since I've finished working on the first portion of my system, I wanted to make a thread where I could share all the different bits and pieces of my journey in solar power from the beginning, and going forward.

I think it could make for an interesting thread, where I could go into more detail for folks who are just getting into solar power, are curious about my build, are looking to build something similar, or just love to talk solar.


So without further ado, starting with my first solar power system build.

A small 12V backup system.
Intended to power Lights, TV, laptop, a small electric Kettle, and for charging phones, power tool batteries, etc.

600W Inverter / 600W Solar / 20A SCC / 12V 100Ah LiFePO4 storage


Now that the system is working as intended, I'll be taking the components from the test bed and start rebuilding the system onto lil something I've been working on.

To be continued...
​

Index:

1. In the works...
2. ExoCore - the initial sketch

 

[sunshine_eggo]

Thoughts/comments/questions:

I'm assuming that's a suitable fuse on the battery (+) terminal?

230VAC/50Hz output?

"small kettle" on 600W? I thought you 230VAC folks insisted on uber kettles! Curious - What kettle works @ 600W?

600W solar?

600W / 14.4V = 42A

20A MPPT means you're only able to utilize about 290W (see the datasheet for that MPPT on 12V systems). If that's the intent, that's fine, but most don't plan to over-panel by 100%.

 

[Pi Curio]

Thoughts/comments/questions:

I'm assuming that's a suitable fuse on the battery (+) terminal?

230VAC/50Hz output?

It's a 150A MRBF fuse, a bit excessive but it's only there in case of catastrophic failure as the cable is way bigger(4AWG/25mm2) than required for the 12V Inverter. The rest of the system has its own appropriately rated fuses.

Yes, a 230VAC-50Hz

"small kettle" on 600W? I thought you 230VAC folks insisted on uber kettles! Curious - What kettle works @ 600W?

Yeah, but my 2200W AC one ain't gonna fly on this lil system

But this little guy will do just fine to make me a nice cup of coffee if the lights go out. https://www.amazon.de/-/en/AWK810/dp/B004PEJ076/ref=sr_1_2?crid=Z3527FX1GCH7&keywords=0.9l+kettle+400w&qid=1701634985&sprefix=0.9l+kettle+400w,aps,206&sr=8-2

600W solar?

600W / 14.4V = 42A

20A MPPT means you're only able to utilize about 290W (see the datasheet for that MPPT on 12V systems). If that's the intent, that's fine, but most don't plan to over-panel by 100%.

The more the merrier

Figured, that 20A SCC would suffice for a 12V 100Ah, it's just about right to keep it charging at 0.2C.

Good catch though, not sure if there's an actual term for it but the idea is to extend the duration of the SCC's charging peak throughout the day by having enough solar power "range" to do that.

For example, where a 300W array would be producing say only 140W at 10 am, the 600W array would be already providing enough power to the SCC to hit its charging peak, same for when the sun is past peak height/angle closing sunset.

By the time there's only 50W ish going into the battery, you know the day is almost over

Plus, it does help to have extra on not-so-ideal cloudy days.

 

[sunshine_eggo]

It's a 150A MRBF fuse, a bit excessive but it's only there in case of catastrophic failure as the cable is way bigger(4AWG/25mm2) than required for the 12V Inverter. The rest of the system has its own appropriately rated fuses.

Yes, a 230VAC-50Hz

Yeah, but my 2200W AC one ain't gonna fly on this lil system

But this little guy will do just fine to make me a nice cup of coffee if the lights go out. https://www.amazon.de/-/en/AWK810/dp/B004PEJ076/ref=sr_1_2?crid=Z3527FX1GCH7&keywords=0.9l+kettle+400w&qid=1701634985&sprefix=0.9l+kettle+400w,aps,206&sr=8-2

Truth. Us yanks don't usually appreciate the value of a kettle, and our 120VAC/15A circuits set the upper limit of what our kettles can do, but I can't tell you how much I enjoy quickly boiling 0.5L of water for some such purpose in our 2L kettle.

Figured, that 20A SCC would suffice for a 12V 100Ah, it's just about right to keep it charging at 0.2C.

Good catch though, not sure if there's an actual term for it but the idea is to extend the duration of the SCC's charging peak throughout the day by having enough solar power "range" to do that.

Yep, I mentioned it above, "over-panel"

As long as you don't exceed the 100Voc and 20A PV INPUT current limit:

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-75-10,-75-15,-100-15,-100-20_48V-EN.pdf

You're fine. 3S2P should stay under both if using typical 100W panels. You can technically exceed 20A, BUT the controller can't protect itself in the event you accidentally connect the PV in reverse polarity.

For example, where a 300W array would be producing say only 140W at 10 am, the 600W array would be already providing enough power to the SCC to hit its charging peak, same for when the sun is past peak height/angle closing sunset.

By the time there's only 50W ish going into the battery, you know the day is almost over

Plus, it does help to have extra on not-so-ideal cloudy days.

The typical reasons to over-panel. Victron MPPT calculator will often recommend up to 30% over-paneling because that last 30% is rarely lost as its rarely seen.

 

[Pi Curio]

Truth. Us yanks don't usually appreciate the value of a kettle, and our 120VAC/15A circuits set the upper limit of what our kettles can do, but I can't tell you how much I enjoy quickly boiling 0.5L of water for some such purpose in our 2L kettle.

Ain't that the truth

Yep, I mentioned it above, "over-panel"

I feel silly now, you are correct.

Guess I'm used to hearing the term being used mostly in the context of going with the recommended 30% ish over-paneling to reach the SCC power rating @specific voltage during the peak, and got stuck at viewing the term that way.

A matter of context between the two but as you said, it's still over-paneling either way

As long as you don't exceed the 100Voc and 20A PV INPUT current limit:

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-75-10,-75-15,-100-15,-100-20_48V-EN.pdf

You're fine. 3S2P should stay under both if using typical 100W panels. You can technically exceed 20A, BUT the controller can't protect itself in the event you accidentally connect the PV in reverse polarity.

You're gonna like this bit. I could quite literally over-panel the SCC by 400%@12V comfortably Obviously, at some point, it just becomes a waste of solar but I like there's enough room to tweak things if it becomes necessary.

After what seemed to be a never-ending quest to find just the right panel for my SCC, I came across the Ecoflow 100W rigid panel. The specs said it all, this is the panel!

It may not be as elegant as the 3X 400W SunPower Maxeon3 panels which are not available here, but in the partial shading where these wouldn't perform as well, the array of EcoFlow 100W panels shine. So everything turned out for the better.

One happy camper here

The typical reasons to over-panel. Victron MPPT calculator will often recommend up to 30% over-paneling because that last 30% is rarely lost as its rarely seen.

 

[sunshine_eggo]

You're gonna like this bit. I could quite literally over-panel the SCC by 400%@12V comfortably Obviously, at some point, it just becomes a waste of solar but I like there's enough room to tweak things if it becomes necessary.

Oh, I've done those exercises... heh... imagine this...

MPPT 250/100 on a 12V... (I have same on 48V)

1450W max output
Vmp of about 160V.
Imp of about 65A

160V * 65A = 10,400W array... that's 700% ?

 

[Pi Curio]

An absolute madness, but I love it!

 

[Pi Curio]

In the works...

After much thought, finally got all sorts of bits and pieces I'll need for the build later, on order. I couldn't wait any longer to get started with the making of the prototype build, been nearly a year since I had the idea and it's finally time to have some fun.

Currently, figuring out just the right distances between the components for access, cable routing, and maintenance.

For now, just a small tease, more to come

 

[Pi Curio]

Update:

Little by little, taking shape...


Until all the bits and pieces required to go further arrive, this is where it's at. In the meantime, going over the prototype and taking notes on things that will need to be added and improved on the design of the chassis.


For size reference, the prototype build within the old test bed tower.



Merry Christmas everyone


LE Update:
The work on the system mount rack design is completed.

 

[Pi Curio]

Update:
Development of the Nano - a small-scale DIY 48V Solar Power System
Affordable - Powerful - Practical​

For more, go here.