I'm hoping for some different points of view on how to configure my ESS system so as to arrive at the optimal solution. There is a 5KW appliance(hot tub) that I only want to run on solar power(whenever excess solar power is available) or grid power(when someone manually decides to turn on the appliance).
My thoughts are to configure the ESS through assistants to:
"Power the hot tub through ACOut1 when batteries are above 90% SOC and up to 2/3hrs before sunset." The 2 hrs before sunset is to allow the batteries 2hrs to get up to 100%.
In this case, I would need to also connect the hot tub to ACOut2 so that if a person is to turn on the hot tub and the above conditions are not met, the hot tub would be fed from the mains grid not battery power. A backfeed contactor would first/simultaneously disconnect the hottub from ACOut1 consumption using a relay.
Does anybody have any better suggestions?
The system spec:
2units -Multiplus II 48V 5000KVA (running in parallel mono-phase)
2units - SMART Solar MPPT 250/100 VE CAN
36units - solar panels (11.5KW of generation power, 2x panel arrays of 18 modules)
12units - pylontech US2000 2.4KWh 48V Lithium modules
*Self-consumption only, no feeding back to the mains grid
The goals of the system:
To reduce the monthly electrical bill from mains electric, while still achieving a 12-15 year lifespan for these batteries.