I want to build the system below:
- 15.0-3-M Fronius with 20kWp panels, 1 array east of 8kWp and 1 west with 12kWp
- 3 * Multiplus-II 48/5000
- Cerbo GX
- 4 * Pylontech US3000C
- SmartSolar Charger with 2-4 panels (just as backup to be able to start the system if the battery is empty)
- 3-phase switch
My supplier demands, that the PV system feeds directly to the grid through an own grid meter. 100% of the production has to be measured (and sold first). But I have the possibility to use the production immediately myself and it will be discounted from my electricity bill. So if I charge the batteries (from the grid) when there is a lot of production from the PV system, it'll cost nothing.
To me, this can be solved with this setup and ESS (correct me if I'm mistaken, hopefully not... ;-) ). But there are a few questions:
- Is another energy meter needed to measure the production of the Fronius, or will the Cerbo GX communicate with Fronius directly?
- As this setup does not allow the system to produce electricity in case of a longer black out, I wanted to add a 3-phase switch to get the Fronius "behind" the Multis. This might not be legal, but who cares in case of a longer black out?
- So, is this safe (if done properly), or will it lead to problems with the Multis?
- How about ESS? Will it have to be reconfigured to meet this new position of the Fronius?
- How will the Multis then limit the Fronius production? Only via frequency shifting? Are there other options?
I've studied the documentation for two weeks now, but it is simply too much information to get to the bottom of it. Hopefully this community can give me advise and reassurance. Thanks in advance for your help!