# MPPT String Voltage Calculator
**URL:** https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479
**Category:** Solar Inverters
**Tags:** string-inverters
**Created:** [February 18, 2023, 12:43am UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479 "2023-02-18T00:43:57Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Svarky](https://forum.cleanenergyreviews.info/u/Svarky)
#### Post date: [February 18, 2023, 12:43am UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479/1 "2023-02-18T00:43:57Z")
We have launched a free **Solar string voltage calculator**.
> **[Solar String Voltage Calculator — Voc & Vmp Temperature Correction | Photonik](https://www.photonik.solar/string-voltage-calculator/)**
>
> Free solar string voltage calculator. Calculate maximum Voc and minimum Vmp for your solar panel string at extreme temperatures. Ensure your string voltage stays within inverter MPPT range.
It features a huge database of the latest solar panels from the leading manufacturers. Brought to you by Photonik. Enjoy 👍
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### Author:  [@hybrid](https://forum.cleanenergyreviews.info/u/hybrid)
#### Post date: [February 24, 2023, 4:37pm UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479/2 "2023-02-24T16:37:57Z")
Looks like you have a good start on this. One thing that I think you need to do is make it input your min and max voltages of your inverter, and how many panels you want to use, and then dump out a list of all of the panels that could satisfy those requirements. Also if it’s setup to play with the numbers, then make those numbers appear on only one screen, so you can update one thing and instantly see what changes, rather than having to scroll the screen to do this. Keep working on it to improve it.
Typically the inverter and area for panels is fixed, and then you’re trying to figure out which panels to buy which will meet both the needs of the inverter and the area available.
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### Author:  [@Svarky](https://forum.cleanenergyreviews.info/u/Svarky)
#### Post date: [March 1, 2023, 4:16am UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479/3 "2023-03-01T04:16:46Z")
Thanks for the feedback. I’m assuming you were using the calculator on a mobile phone. It’s much easier to use on a laptop or desktop as you can see all the inputs and results on one screen.
Your other suggestions are mostly available using the Photonik solar design tool. The string voltage calculator was designed to offer solar designers quick access to the latest panels to decide which panels to use. It’s not supposed to replace the full design software.
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### Author:  [@\_Terry](https://forum.cleanenergyreviews.info/u/_Terry)
#### Post date: [March 1, 2023, 11:31am UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479/4 "2023-03-01T11:31:18Z")
Hi Jason,
Since you are talking about the string voltage in Photonik, I found a small error about it. It shows maximum voltage and open circuit voltage when you put panel number, which is good. The default minimal temperature is set at -10 degree, but when you change it to 0 degree, the voltage info won’t show, and you are unable to type “-” to change temperature to -10 degree anymore. Not sure if it is a bug, but it might be worth for you to have a look, thanks.
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### Author:  [@Marty](https://forum.cleanenergyreviews.info/u/Marty)
#### Post date: [March 3, 2023, 8:37am UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479/5 "2023-03-03T08:37:20Z")
@momar, can you please check this.
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### Author:  [@Vulcan\_Suna](https://forum.cleanenergyreviews.info/u/Vulcan_Suna)
#### Post date: [May 17, 2023, 4:24pm UTC](https://forum.cleanenergyreviews.info/t/mppt-string-voltage-calculator/2479/6 "2023-05-17T16:24:17Z")
Hi, do you have a documentation page where the formula is shown and how the input is involved in the calculation