Controlling a small off-grid PV system model

Hello !!, I just started my first project on Arduino, It is about offering a simple load management system to automatically cut-off loads (previously prioritized) in case of shortage in energy supplying from the PV panel or the battery.

I figured out that i will need to sense the instantaneous output power of my panel + the battery’s S.O.C (State of charge), of which i shall compare with the previously set data to cut-off certain loads.

IF PV Power within range X0 → X1 and S.O.C within range Y0 → Y1, then Lines 1, 2, and 3 will operate seamlessly (suppose we have 3 lines).

As the PV power output and the battery S.O.C decreases, a least important line will be disconnected.

Please help me with different ways to approach this project, what kind of sensors that i need ?

I’m open for any further details and clarifications

Please note that i don’t have much experience with Arduino, Thanks in advance
Pardon my bad English Language

How do you propose to measure instantaneous output power and the battery's S.O.C?

PeterH, Thank you for your consideration and reply.

I believe there is such a technique where i can sense both current and voltage, then multiply it within the arduino's code.

Do you think this is possible ? and what is the main obstacle in this project that i need to overcome in your opinion ?

From long experience, measuring the State Of Charge is pretty well impossible unless you leave the battery disconnected from everything for 12 hours or more - which is not really practical.

You could measure the amp-hrs produced by the solar panel and (separately) the amp-hrs consumed by your appliances and make a rough estimate of how much energy has been drained from or added to the battery. Reckon on adding 20% more than you take out if you want to maintain the State of Charge.

Measuring amp-hrs effectively is not a trivial exercise. Measuring voltage is much more straightforward, but is not much use on it's own.

It sounds like you may benefit from studying several of the example sketches that come with the Arduino IDE to give you a good understanding of what the programming can do.


Shero_93: what is the main obstacle in this project that i need to overcome in your opinion ?

You need to define what you're going to measure, and how. I doubt you're the first person to face this problem and maybe the off-the-grid community know what techniques are useful to solve it, but I don't. If you don't know the answer, perhaps you could find other online communities that focus on this sort of power system who can advise. If you can describe in electrical/electronic terms what you want the Arduino to do, no doubt somebody will suggest ways for you to do it.