I’m researching the technical possibilities for power sharing. We have several sites with multiple small grid connections but not enough power. For example 3x35A + 3x80A when at least 3x160 is needed.
Instead of placing two independent BESS systems, I’m exploring the possibility to share 1 BESS, adding a lot of flexibility. Apart from (local) legislation and legal questions, I’m curious if this is possible with Victron hardware.
Not sure if this is possible using single cerbo.
I’m having single battery used by 2 net connections, 1 net connection 3 phase, the other netconnection single phase. In my setup each net connection has it own cerbo.
The Cerbo’s ‘see’ each other as DC load.
And both Cerbo’s can read the BMS maximum discharge current? If the BMS replies the maximum discharge current is 10 A, what keeps the inverters from both drawing 10 A?
In Germany we have the company “pionierkraft” who offer a solution for selling energy from central PV to several flats while each flat’s has it’s own main energy contract.
If you own a house with several flats, you place an inverter and an extra energy meter within each flat’s circuit after the flat’s grid meter.
The inverters are centrally controlled and will push surplus energy into the flat resulting in 0W grid usage.
Depending on your design for energy conversion, e.g. AC-AC (best), AC-DC-AC high voltage or AC-DC-AC low voltage (worst) the conversion losses might be significant.
With this AC-DC-AC low voltage conversion you might loose 20% energy. But it might be worse it.
You could integrate both Venus OS via NodeRed and adjust DVCC limits to “balance” the load on the DC bus.
Maybe search for redundant grid supply to combine both grid connections into one net.
Then add one battery system to the combined net.
You might have to transform the energy to get rid of phase s not in sync.
In my case, the battery can support the full load of all inverters.
But if not, I would assume DVCC can care of it as both side of the system get the load on the battery from the BMS / smartshunt.
Alternatively as @BjoernK this can be managed with node-red.
The pioneerkraft solutions is a step in the right directions. However it is only single phase and limited to 2 kW. Finding a three-phase AC-AC coupler with decent power is still a challenge.
AC-DC-AC looks like the most common way to tackle the problem with widely available parts. I’ll dive into the DVCC possibilities.
Just install an 90 kVA Victron ESS system in combination with a 3x80A grid connection. With peak shaving enabled, the total available capacity is 3x170A. Installing multiple systems could also be a solution, depending on the physical constraints.
peakshaving is our business
