Hi,
Im new to victron products, but I'm seriously considering to get a complete offgrid system from them for my tiny house. In principle, it is a typical PV offgrid system with solar modules, charge controller, inverter etc. Now one of the ideas was to use the excess energy to heat the water in the DC water tank (Fothermo PVB-80) in times when the batteries are full (or above a certain setpoint value). Another was to automate the startup and shutdown of a backup generator. Basically my requirements to the control system can be summarized in the table below as follows:
event |
action |
battery SOC is below certain setpoint minimum (e.g. 10%) |
signal to startup the backup generator |
battery SOC is above certain setpoint value (e.g. 80%) |
shut off the backup generator (if it was on) |
battery SOC is above certain setpoint value (e.g. 90%) |
power the water boiler |
battery SOC is below certain setpoint value (e.g. 50% or the same 90%) |
cut off the power to the water boiler |
battery SOC is below certain setpoint value (e.g. 10%) |
power only a specific selected circuit (with critical components like heating contour pumps etc.) |
The last item in the table is basically emergency standby: when battery SOC is very low and all power supply modes (PV, backup generator) have failed due to one reason or another, it is necessary to power only the selected circuit with critical components, such as heating contour pump group that will circulate water through a propane tankless heater.
Now as I'm new to the victron products, I'm curious if the aforementioned functionality is possible to achieve with standard victron components and what exact components are required for that (probably Cerbo GX is the right tool, but I only took a quick glimpse at it so far). Would be also nice to know if some specific backup generator is required to match the mentioned control logic or any typical backup generator with electric starter would suffice.
P.S. Attached you will see my principal design draft. I'm sorry if I trigger any electrical engineers by not following the correct convention with black/red wires etc., as it's not my core expertise. When it will come to the detailed design stage, I will definitely consult with professionals on the exact layout, required charger control capacities and so on. Any critique and feedback on the system design and the control logic is also welcomed and appreciated.
