So it has been a full week now and even with mostly cloudy days, I've not needed Eskom or Generator at all. Truly Off-Grid!

I'm thoroughly impressed with the JAR PV's power delivery under cloud, the inverter power management and the battery performance.

The highest loads I've had was 60% of the 12kW max, lowest SoC was 75%  of the 33.2kWh pack and PVpeak was 8.2k W (of 8.8kWp)

I've kept a close eye on everything and did a lot of "energy management" manually. Mostly switching on loads when there was excess energy available after the battery was fully charged.

These loads included filling water tanks, topping up geyser temps, running aircons and, pumping up air compressors.

This will be way too time consuming to sustain indefinitely. Since I do embedded uP hard and software for a living, I'm thinking to design a controller to automate these functions.

I've identified the following requirements/wish-list so far:

1) Monitor & Configure up to 4 inverters via RS232 (inverters need the latest version firmware for ON/Off control)

2) Monitor BMS via RS485

3) On a small GLCD, display the following: Batt SoC, percentage outgoing inverter load, percentage incoming PV power (all averaged from inverters data streams)

4) Allow user options/changes/configurations/setups with a rotary knob and the GLCD

5) Switch on/off specific prioritized loads (geysers, aircons, compressors, water pumps etc) via Power Line Communications(PLC) modules.

6) Monitor possible lightning approaching (AS3935 lightning sensor module I2C) and also PV Tamper wire sense loop.

7) Control a motorized PV DC multi pole switch (with large Off-state switch gap) via RS232TTL

😎 Communicate with a  Generator Controller for start/stop/switch-over etc functions via RS232TTL

9) Add a BTLE module (RS232TTL) for comms to a PC on a network with Internet  (perhaps a WiFi Module?)

10) Add a 433Mhz Transmitter for messaging my alarm system on chosen exceptions such as tamper, failures, low battery etc  (1 TTL pin)

11) Keep the hardware cheap, simple and easy to build on breadboard in case someone else wants it.

12) Write the embedded code in a structured manner to easily add/remove/modify modules.

I'm probably missing a lot here, so any suggestions will be most welcome please.

It's obvious this will take a lot of time but I'm hoping to slot it in-between all the other "salt mine" stuff. Fortunately I've used most of these modules in the past and therefore have the libraries for them.

 

 

 

 

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1 hour ago, Trober said:

6) Monitor possible lightning approaching (AS3935 lightning sensor module I2C)

This is something I have considered, but it would have to control a relay, so I could automate things.

I never got into Arduino's and the like though.