is is possible to connect on Victron a hydrogen tank storage (for example 100 KG) with reversible electrolyzer, (house hybride ongrid installation 3x5000VA multiplus with 15kWp solar panels)
in the way
the not used elektricity produced by PV panels is stored in hydrogen tank (in the period of solar over production)
the missing electricity not produced by PV panels is generated from hydrogen tank
(in the period of solar underproduction)
?
OR at least with standard electolyzer to produce hydrogen by summer solar overproduction that will be used in winter with modified gas boiler?
I would say the victron side of this system is simple. The hydrogen production/storage and usage is in my opinion really advanced.
From victron point of view. You could just use node red to determine if there’s excess solar in summer. If there is node red can send signal to hydrogen electrolyzer to produce hydrogen and use the excess. Assuming the electroclyzer is scalable in terms of power usage you could have several node red if statements to ramp up hydrogen production depending on how much excess PV there is.
In theory from victron system point of view this is as simple as an immersion heater setup. Except rather than a hot water tank you have a tank of highly flammable hydrogen…
Then using the hydrogen if it was being used to produce electricity then you again have lots of options, just wiring it in as a generator or if you want more granular control node red is there again for you.
Node red will allow you to program events based on system criteria. The options are endless.
It will be very system dependent but here’s some very rough pseudo code that might make it a little cleared. So if the battery is at 98%, PV coming in is over 1000w but loads are less that 500w then turn on hydrogen electrolysis to use excess power. And if this criteria isnt met then turn off.
I personally prefer to add a buffer to the turn off. Just in case turning on hydrogen electrolysis has increased start up load and the code turns the machine on and off. Hence the criteria in the else condition
if(SoC > 98 && PV > 1000 && loads < 500w){
//turn on a smart switch that activates hydrogen electrolysis in my example the code will return 1 to pass into a smart switch node
return 1; //on command.
} else if( PV + 200w < loads)
{
return 0; //off command
}
Then near enough the same concept during the winter for turning on the generator that uses the hydrogen.
The if statement criteria can be endless, so you can factor in time of the day/year. Or even add hydrogen tank data to the system so the if statements can factor in volume of hydrogen in storage etc. Node red is a nice system for you to make something completely custom, as complicated or basic as you want.
I’ve seen lots of people use a shelly smart switch to turn on their hot water immersion heats using this logic. the return 1/return 0 are passed into http nodes which send a message to the shelly switch via shelly’s http api that turns on/off the smart switch.
If you need a hand writing the node red code I’m happy to lend a hand if you define the criteria/what you want.
Hi Matt,
thank you for your replay. So the node red is programming interface supported by Victron to program multiple conditions on the system, similarly as it is explained on this video where one instance can be directly setted on Victron software using AC-OUT2 :
The video seems to be suggesting you use VeConfigure assistants to achieve you goals. This is an option and will allow you to use the onboard relays to control certain things. LIke turning on a generator under certain conditions.
I havent used VeConfigure assistants in awhile so they may have improvev but in my past experience the conditions (the if statements in my previous answer) in the VeConfigure assistants are too limiting for my use cases.
I prefer to use node red and have really granular control over the “turn on” and “turn off” criteria. It will also mean you can integrate turning on devices via http/api’s rather than needing onboard relays as node red can just send http or api requests to smart devices to turn them on.
In the case I chose to use node red, where the cable for solar over-production will be connected, still on AC-OUT2? I have 3-phase system with 3x multiplus 5000VA , each-one per 1/2/3L phase, in this case it is programmed for each multiplus separated, or all 3 multiplus are working simultaneously to swith on/off electricity?
I suppose it depends on the hydrogen electrolysis machine. Is that three phase/ will that draw power from each phase.
I’m not as clued up on three phase setups but I believe PV on L2 can power loads on L1 it will just have higher losses via the battery and inverted back out.
Same for the other direction is the generator that’s powered by hydrogen three phase also?
I think Node red defaults to treating the 3 multiplus as one unit if configured in three phase mode i believe (unless you dig deep into node red). At least that’s how it works if units are in parallel so i assume three phase is the same.
