Solar dump load to heat water (off grid system) Victron

[Rocksnsalt]

Done in an Overlanding RV…

2nd version:

 

[Michelle Konzack]

So I have a common problem but im hoping things have inproved since none of the solution i've found so far are optimal, I'd like to dump excess solar PV 'Not battery power!' into a water heater, preferably id like the dump whatever is available be it 500w 1kw or 3kw so PWM seems like a good idea for the dump load?
Originally i was looking at power diverters like the Eddi, I cant remember if they pwm but they dont seem to work off gird anyway,
'Or could i fool the eddi into thinking it on grid by attaching a heating element dump somewhere else?'
In any case id appreciate any recommendations, i'm running victron, smart shunt, smart solar, multiplus, Lithium 5kwh server rack, im willing to go the arduino route if necessary, however since the victron smart shunt is 'Smart' surly there is a way to program that after the battery has reached 100% soc that a pwm dump load will start but not draw any current from the battery? seems like a perfect use for the smart shunt..

Do you have the PV AC or DC coupled?

I am Off-the-Grid and have (currently) a VictronMultiPlus-II 24/5000 running and use 3 SmartSolar to charge my Batteries
However, I use also currently for testing a Fronius Primo 4-1 together with a Fronius Ohmpilot and the Fronius SmartMeter connected to the ACout of the MultiPus-II.

The SmartMeter is measuring how much AC power is required (Can be AC loads or even charging via the MultiPlus-II) and then it send all excessive energy to the Ohmpilot which support 0-3kW @230V SingelPhase or 0-9kW @400V ThreePhase.

I am currently developing a similar thing which is DC based and integrated in Victron Systems

 

[kmin]

With AC inverter it's really simple, also direct DC is simple, but component cost is little higher.
May be you want have a look also another thread:

Who here has the best dump load management system going on?

Google seems to have a wide range of answers, how long will a sand battery store useful heat? Several months. It's seasonal storage.

diysolarforum.com