Victron SCC calculator

[Ronwattson]

Quick question for those that would know for sure. I don't like to assume anything.
Is the victron SCC calculator results bases on adjustable PV array or fixed? Thanks in advance and wishing all a blessed and happy Thanksgiving with lots of sunshine!

Edit to say it shows an expectation of performance per month. My actual question is which array is this based on? Maximum fixed or maximum at perfect angle?

 

[green mountain boys]

Quick question for those that would know for sure. I don't like to assume anything.
Is the victron SCC calculator results bases on adjustable PV array or fixed? Thanks in advance and wishing all a blessed and happy Thanksgiving with lots of sunshine!

Fixed or tracking... it does not matter. The calculator is just looking for max output of the array so you do not damage your SCC.

The PVwatts calculator is where your question would be more relevant.

 

[Chispas]

The calculator is based on the panel data & so uses the VOC & IMP , the maximum the panel could produce. The angle or tracking will increase yield over time not max. Volts or amps

 

[Madcodger]

Just a heads up... I've used the Victron SCC calculator in the past, and as I recall it recommended several of their SCCs that should work. I recently used it to design a small system that is separate from our off grid house and the single SCC it recommended was much larger and more expensive than needed. I reran the numbers to make sure I hadn't goofed, and got the same result. Thankfully I've now done this enough to just use the numeric output, which is helpful. Just don't automatically assume that the "recommended" device is THE device you need, as another of their fine products might be all you need. They seem to be rather conservative in their estimates these days, in terms of the SCC one needs.

 

[740GLE]

Did the calculator oversize on current or voltage?

I can see it upsizing current as some people want peak max watt vs some over paneling.

 

[Madcodger]

Did the calculator oversize on current or voltage?

I can see it upsizing current as some people want peak max watt vs some over paneling.

I don't recall now. I ultimately decide to split the string to 2S to cut down on the voltage, which made things even less expensive and is often a good way to save $ with very little effort.

 

[agtcovert]

I use it all the time as I've been shopping. It really gives you two options; you can go for high voltage low amps on the RS 450/x00 line which are more expensive but have galvanic isolation. I assume even with the /100 offering 2 trackers you could parallel 4 total strings into it.

What always impresses me though -- you can get the same production on something like a 250/100 with like 4s4p or thereabouts depending on your panel specs. They may get warm, but they're designed for that. Just need to make sure your wire is good for the amps.

 

[Ronwattson]

Just a heads up... I've used the Victron SCC calculator in the past, and as I recall it recommended several of their SCCs that should work. I recently used it to design a small system that is separate from our off grid house and the single SCC it recommended was much larger and more expensive than needed. I reran the numbers to make sure I hadn't goofed, and got the same result. Thankfully I've now done this enough to just use the numeric output, which is helpful. Just don't automatically assume that the "recommended" device is THE device you need, as another of their fine products might be all you need. They seem to be rather conservative in their estimates these days, in terms of the SCC one needs.

I'm mainly talking their monthly yield expected. Is that what to expect adjustable or fixed is my actual question. Maybe I didn't state the question correctly. If the chart is monthly best case scenario is that based on optimal angle is based in fixed. I would think fixed as many have roof mounted PV that are not adjustable. In what case that is can I expect that to be anywhere near accurate. Hope that explains better. Thank you for weighing in to all.

 

[Ronwattson]

Did the calculator oversize on current or voltage?

I can see it upsizing current as some people want peak max watt vs some over paneling.

The numbers I put in were all over panel but not more than 120% and I was hoping you, Q-dog and Sunshine eggo would comment as well as the others that have. You guys have taught me much. My debt to y'all is great.

 

[Ronwattson]

Fixed or tracking... it does not matter. The calculator is just looking for max output of the array so you do not damage your SCC.

The PVwatts calculator is where your question would be more relevant.

I would think the scale they show per month of expected output would matter. Expected fixed vs adjustable would certainly not be the same.

 

[agtcovert]

Sunshine will be around later or tomorrow I'd guess. They're doing Thanksgiving today, so he said.

I'm hoping he doesn't tell me all the ways in which I'm wrong.

 

[Ronwattson]

Sunshine will be around later or tomorrow I'd guess. They're doing Thanksgiving today, so he said.

I'm hoping he doesn't tell me all the ways in which I'm wrong.

He's told me plenty I was wrong about so don't feel bad. I'm hoping their expected output on the month by month is fixed array. It would sure simplify things for me. Thank you for weighing in!

 

[Chispas]

I don't recall now. I ultimately decide to split the string to 2S to cut down on the voltage, which made things even less expensive and is often a good way to save $ with very little effort.

Ive been looking at this as well, trying to find different ways to skin the cat, so to speak. my Idea is to have 2 x panels 2s & 2 SCCs , more for redundancy than anything else but saving money is always welcome. I looked at Victron 100/30 SCCs (€120.00) & tried to find the biggest panels in 2S to match. Some JA Solar 505 W have a voc of 45.75 but with the temperature coefficient worked in at -5 c they could be producing 49.49v next up in the Victron range is the Blue solar 150/35 (€145.00) but no bluetooth so on to the Smart solar 150/35 (€180.00) . Im not sure if the Bluetooth is worth it ? Maybe a smart shunt will be enough info? It seems Victron has a range of overlapping monitoring options. All said and done saving money isnt my priority & pushing a charge controller to the ist voltage limit might not be a good long term bet.
Edit: It seems that with 2 or more SCCs the Victron connect app can synchronise the charging so that bulk, absorb & float are the same.

 

[Madcodger]

To me, the bluetooth units are well worth it because they make it very easy to make adjustments and serve as a secondary way to monitor if necessary. For monitoring, I like VE Direct and a Raspberry Pi running Venus OS. Easier than you'd think to set that up.

Re: SCC sizing, if you can keep voltage low (under 250 for sure, and under 150 where possible) you save a lot. Victron's 450V units take a big price jump compared to their lower voltage devices, and may not be necessary much of the year. The other thing to avoid in a small building is fan noise. Victron's SCCs with passive cooling (just a big heat sink and no fans at all) are fantastic, but you need to remain under 250V to use them. If you live somewhere that gets very cold (I'm in Maine) you really need to factor in voltage being very high at sunrise and just after in winter, to avoid the SCC making magic smoke (very bad). Splitting a string of panels is sometimes a great way to keep voltage low, even if the SCC occasionally maxes out on amperage and limits your production. If that happens only at peak production times, the tradeoff is worth it to me if I can eliminate fan noise and avoid paying for a much larger unit, when that larger size is needed only rarely. And as you note, two SCCs can also get the job done.

 

[Q-Dog]

I'm mainly talking their monthly yield expected. Is that what to expect adjustable or fixed is my actual question. Maybe I didn't state the question correctly. If the chart is monthly best case scenario is that based on optimal angle is based in fixed. I would think fixed as many have roof mounted PV that are not adjustable. In what case that is can I expect that to be anywhere near accurate. Hope that explains better. Thank you for weighing in to all.

Are you talking about the daily yield graph? I haven't messed with the calculator since they revised it, mostly since I already have my stuff installed.

 

[Chispas]

Im leaning towards the Bluetooth units. Victron have got this nailed as any other alternative, like a dongle or the MPPT controller, end up costing the same.

you really need to factor in voltage being very high at sunrise and just after in winter, to avoid the SCC making magic smoke

Because of shading, we don't get any direct sun on the panels until 2 hours after sunrise, but yeah, best keep the smoke in.The Raspberry Pi thing sounds interesting, im going to read up on that, any links you might have would be appreciated.

 

[Madcodger]

As you wish, @Chispas ...

Raspberry Pi running Victron's Venus firmware - Victron Energy

Ever wanted to run the Color Control GX/Venus GX firmware on a Raspberry Pi? Now you can thanks to Izak Burger whose guest blog below describes how this came to pass. For the geeks amongst you, please note that the port works on the Raspberry Pi revisions 2 and 3, but not on the original […]

www.victronenergy.com

Victron's Venus OS on a Raspberry Pi, install and configuration

The Victron Remote Management (VRM) portal and their Venus OS monitoring software deliver best-in-class access to information about your boat (, RV, or fixed solar) electrical sytem. But, running one of these systems has typically required Victron hardware which starts around $300. Victron has a...

panbo.com

Victron VRM through Raspberry Pi

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off-grid-garage.com

https://forums.raspberrypi.com/viewtopic.php?t=340667

Personally, I used a 3B+ and it worked great (sold that property earlier this year, and new owner now presumably still using it). Getting ready to install another Victron system in a building on this property and will use a 3B+ again.

I think I MIGHT have even convinced the guru of all things Victron, @sunshine_eggo to try this, but he would need to confirm or deny that. Personally, I find it's not as capable as a CerboGX by any means, but it's a handy way to monitor a Victron system, and is essentially free if you have the spare RPi and a memory card just laying in a junk drawer, as many of us do.

 

[green mountain boys]

I would think the scale they show per month of expected output would matter. Expected fixed vs adjustable would certainly not be the same.

You are correct. The chart showing monthly expected output should change if the angle of the panels changes BUT... I think main purpose of the Victron MPPT calculator is to calculate the maximum voltage and amperage with relation to temperature. If you want to look at output of a string, and play with all the variables, then try the PVwatts calculator.

 

[sunshine_eggo]

As you wish, @Chispas ...

Raspberry Pi running Victron's Venus firmware - Victron Energy

Ever wanted to run the Color Control GX/Venus GX firmware on a Raspberry Pi? Now you can thanks to Izak Burger whose guest blog below describes how this came to pass. For the geeks amongst you, please note that the port works on the Raspberry Pi revisions 2 and 3, but not on the original […]

www.victronenergy.com

Victron's Venus OS on a Raspberry Pi, install and configuration

The Victron Remote Management (VRM) portal and their Venus OS monitoring software deliver best-in-class access to information about your boat (, RV, or fixed solar) electrical sytem. But, running one of these systems has typically required Victron hardware which starts around $300. Victron has a...

panbo.com

Victron VRM through Raspberry Pi

Take a live sneak peak at the Off-Grid-Garage in the Victron VRM World The S.P.A.T. Calibration Centre VRM link (new PowerWall 2.1) Here is a step-by-step manual on how to connect your Victron equi…

off-grid-garage.com

https://forums.raspberrypi.com/viewtopic.php?t=340667

Personally, I used a 3B+ and it worked great (sold that property earlier this year, and new owner now presumably still using it). Getting ready to install another Victron system in a building on this property and will use a 3B+ again.

I think I MIGHT have even convinced the guru of all things Victron, @sunshine_eggo to try this, but he would need to confirm or deny that. Personally, I find it's not as capable as a CerboGX by any means, but it's a handy way to monitor a Victron system, and is essentially free if you have the spare RPi and a memory card just laying in a junk drawer, as many of us do.

Somebody did. Maybe it was you.

I'm running Venus OS on a 3B+ (experimenting with dbus-serialbattery driver) and a Zero 2W (propane tank monitor).

 

[Chispas]

@ Madcodger​

Thanks mate I'll give that a look.I know very little about Raspberry Pi but a mate nearby is very up on them. Im not sure how much monitoring I need, Cerbo gx would be overkill for what im planning. For more than 20 years we've relied on the guesswork that is looking at what the SCC display tells you about voltage, either pessimistic or optimistic, I know. It seems the easiest route is the smart solar & a smart shunt.

 

[Madcodger]

@ Madcodger​

Thanks mate I'll give that a look.I know very little about Raspberry Pi but a mate nearby is very up on them. Im not sure how much monitoring I need, Cerbo gx would be overkill for what im planning. For more than 20 years we've relied on the guesswork that is looking at what the SCC display tells you about voltage, either pessimistic or optimistic, I know. It seems the easiest route is the smart solar & a smart shunt.

I also use their Smartshunt to monitor SOC. Very accurate. Feeds into the RPi.

 

[Ronwattson]

Ive been looking at this as well, trying to find different ways to skin the cat, so to speak. my Idea is to have 2 x panels 2s & 2 SCCs , more for redundancy than anything else but saving money is always welcome. I looked at Victron 100/30 SCCs (€120.00) & tried to find the biggest panels in 2S to match. Some JA Solar 505 W have a voc of 45.75 but with the temperature coefficient worked in at -5 c they could be producing 49.49v next up in the Victron range is the Blue solar 150/35 (€145.00) but no bluetooth so on to the Smart solar 150/35 (€180.00) . Im not sure if the Bluetooth is worth it ? Maybe a smart shunt will be enough info? It seems Victron has a range of overlapping monitoring options. All said and done saving money isnt my priority & pushing a charge controller to the ist voltage limit might not be a good long term bet.
Edit: It seems that with 2 or more SCCs the Victron connect app can synchronise the charging so that bulk, absorb & float are the same.

I have been thinking about giving one of these a try.

 

[Ronwattson]

You are correct. The chart showing monthly expected output should change if the angle of the panels changes BUT... I think main purpose of the Victron MPPT calculator is to calculate the maximum voltage and amperage with relation to temperature. If you want to look at output of a string, and play with all the variables, then try the PVwatts calculator.

This is the information the SCC calculator provides so it raised my curiosity. Does this represent fixed or adjustable? It would be nice to know. Guess I will just have to try it both ways and see.

 

[Chispas]

I have used This string calculator but you can safely ignore the minimum amps to a point, overpaneling just means the SCC will clip the current.%25 is an unnecessary margin.

 

[Chispas]

I

I have been thinking about giving one of these a try.

I personaly wouldn't touch anything from Vevor related to electricity.