Zero Grid Export and Reading energy meter with ESP

[johu]

While that worked for a while it I got CAN busoffs again soon.
So I took the BeagleBone upstairs and connected it to a CanDue. Perfect comms, not a single bus-off event. Took it back down to see bus-offs again.

I took the entire ESS on my desk to go fault finding. In the end I plugged in the USB cable (that supplies BeagleBone, BMS and relay) into my USB hub (5.3V unloaded voltage) instead of the wall wart (5V unloaded voltage). Now it is working although not perfect. I still see occasional bus-offs but they don't disturb operation. I think going over my 5V distribution should solve it for good.

Either the wall wart has faded (was never made for continuous operation) or the extra loads caused too much sag.

Apart from that it was a cool and sunny day today - Saw 1100W on the charger! Something the Manson couldn't have done.

[johu]

Now that I can take advantage of spot market electricity prices (see here viewtopic.php?t=3654) I want to add some extra conditions.

First thoughts:
- When electricity costs > 20 ct/kWh do the normal operation
- Costs < 20 ct: Do not use energy from the battery storage anymore
- Costs < 15 ct: Charge the battery storage from the grid

Would also like to integrate the car charging but I don't want the car connected all the time because that will always run the water pump. Maybe should make that switchable by the VCU or something.

Since you get a 24h forecast of prices you can optimize the timeslot where charging would take place. In summer I'm ok with doing it manually because electricity is usually cheapest around noon. Especially on the weekend. Because solar PV.

In winter it is cheap over night because most of winter we have wind energy and it isn't needed at night. Could half-automate that. Plug in in the evening and then autostart whenever it becomes cheap.