Solar Panel Monitoring and Switching Project

Don’t know if this is a possible project… I should add for someone with little or no experience but quite happy to learn.

I have a solar panel at a remote location. I would like to be able to monitor the following:

Load Current
Battery Voltage
Solar Panel Voltage

I would also like to be able to switch the following:

Feed between the Panel and controller (indicated in green)
Feed between the battery and controller (indicated in green)

Need to be able to monitor across the internet, I’m OK with the port forwarding stuff.

I’d like to be able to output the data on a nice analogue or digital readout and the switches be a red/green On/off style.

Anyone any ideas or suggestions as to the way to go about this? Basic to start with please :slight_smile:

Is there an internet connection at or close by the solar panel location?

Sorry, yes I should have added that. The is a 3g/4g router so internet connection is fine.

I have the option of wired or wireless too

ElProblemo: Don't know if this is a possible project... I should add for someone with little or no experience but quite happy to learn.

I have a solar panel at a remote location. I would like to be able to monitor the following:

Load Current Battery Voltage Solar Panel Voltage

I would also like to be able to switch the following:

Feed between the Panel and controller (indicated in green) Feed between the battery and controller (indicated in green)

Need to be able to monitor across the internet, I'm OK with the port forwarding stuff.

I'd like to be able to output the data on a nice analogue or digital readout and the switches be a red/green On/off style.

Anyone any ideas or suggestions as to the way to go about this? Basic to start with please :)

You going to have to design a Battery charger with control. I built one that uses a LT3652 Buck regulator that converts from '12V' solar cells (0..22V) with maxpower tracking. My circuit also uses a LTC2943 coulomb counter that keeps track of battery capacity, battery voltage.

Your power switches and current sensors are going to have to be descrete components. None of this is suitable for an Arduino. An Arduino could measure/control the results, but the actual work would require dedicated hardware.

You are going to have to design high side current sense amplifiers that you can scale to your ADC range (Arduino is 0..5V) 10bit. The design will have to know your voltage ranges and Current ranges. To measure a current you could use Allegro's ACS712 if their ranges meet your specs. Voltage reading could be just resistor dividers, if absolute accuracy is not required. N-MOSFET and P-MOSFET switches could be used if the Current and Voltage losses are acceptable. Even Relays could be use for the the switches.

How much power can you waste in the control circuit? If the control circuit use 200mA, 24 hours a day, that is 4.8 Amp Hours of power.

A deepcycle 6V battery has 232Ahr weighing 84lbs, so for 168lbs you can have 232Ahr at 12V. Your solar array would need to be at least 450W. I figure the 'control' consumption should be less than 10% of system performance. Most solar systems are designed for 7 days without charging(clouds, winter limited days). So if you have 232Ahr capacity, that equates to 33Ahr a day or 1.3 amps per hour. During high Noon, on bright days your charger would need to handle 32amps from your panel.

I'm just throwing a bunch of mud at the wall. You question was just too vague.

You might want to start with professional equipment. midnite-solar-classic-lite-150-mppt-charge-controller

Chuck.

ElProblemo: I have a solar panel at a remote location. I would like to be able to monitor the following:

Load Current Battery Voltage Solar Panel Voltage

With a suitable current sensor you could measure the current. It would also be easy to measure one voltage.

If the solar panel is connected to the battery there is no simple way to measure the voltage on the battery separately. And it would not really provide any useful data if you briefly disconnect the solar panel and read the battery voltage. The voltage on a lead-acid battery is really only meaningful if the battery is unused (ie. neither charged nor discharged) for several hours.

...R

The controller is off the shelf, my project isn't the controller, it's the monitoring of the three lines from the controller, 2 voltage and one current. The additional controls will be the switching of the solar panel so it's isolated and switching load so the lights go off.

In addition I'm talking about a 100w 12v panel and two 12v 38Ah batteries, no inverter, it's all for 12v equipment.

This will all have to be achieved over the Internet.

Sorry for confusion.

ElProblemo: The controller is off the shelf, my project isn't the controller, it's the monitoring of the three lines from the controller, 2 voltage and one current.

You need to post a link to the datasheet or user manual for the controller.

I can't imagine how there is a separate wire for current - unless the controller has built-in monitoring circuits. Hence the need to see the datasheet.

...R