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

[ApproximatelySean]

I do PWM water heating directly off array. It is the most efficient method as far as conversion loss from wires, battery, electronics and inverter. The battery full output of the controller can be used to switch the array voltage in a direct connect method. Studies have shown that 2X ideal resistance produces more daily power. The early two module ACTii appears to have a common voltage shunt option. I know of no others. Many have built their own as these are fairly simple circuits I have a very minimal battery and heating water from panel voltage doesn't screw with charging or battery level and saves having to have an extra KW of battery. Here is what I use, the wall picture is my first arduino system under bubble wrap IP67 protection. One of these was made with a $9 inverter board from China. While many of you have tons of excess power, this pictureView attachment 149757 is a southern view of my camp. See any panels? A challenging site, yet I have plenty of hot water due to how efficient the system is.

thats very interesting! how do you determin how much excess power is available? any more information on construction?

 

[SamDeleted]

Installing and configuring a Tristar controller for a wind system | Hugh Piggott's blog

 

[ApproximatelySean]

Installing and configuring a Tristar controller for a wind system | Hugh Piggott's blog

i never thought of using an pwm charger that way, ''Conect all the charging sources direct to the battery''? in my case with the 48v batt and 190v pv would that work? or does my victron mppt count as the charging source?

 

[SamDeleted]

i never thought of using an pwm charger that way, ''Conect all the charging sources direct to the battery''? in my case with the 48v batt and 190v pv would that work? or does my victron mppt count as the charging source?

I haven't done it myself , But obviously you can't hook 190v to a 48v battery,


so I can only imagine you'd use your mppt as normal - hook the Tristar in load division mode to the battery, it must sense the batteries are full by voltage and start diverting power

It's something I've been thinking about for a while , hopefully someone here more knowledgeable can help

 

[SamDeleted]

In the comments below the article:

 

[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