DC coupling
DC coupling in the Speichercampus context: interesting for new PV systems and integrated MPPT systems. Technically, the term is usually described as connection on the direct-current side.
What does DC coupling mean?
With DC coupling, PV modules connect to the storage system on the direct-current side — via its MPPT input, without their own PV inverter. PV energy flows directly into the battery; only what is consumed or exported passes through the PCS.
The efficiency advantage is real, but the true trump card lies elsewhere: under feed-in limitation, DC-coupled PV can rescue energy into the battery that would be curtailed on the AC side, and new PV areas need no additional inverter.
What matters in practice
- string design must match the storage system’s MPPT voltage window
- most economical for new strings and expansions
- combining with AC-coupled existing PV is straightforward
- include lightning and surge protection for the DC lines
Practical example
A farm with feed-in limited to 60 % of PV power routes its new 35 kWp expansion DC-side onto the storage system. The midday energy that used to be curtailed now charges the battery — a yield that would be lost with AC coupling.
The Speichercampus perspective
For Speichercampus, DC coupling is not an end in itself but the tool for new builds, expansions and curtailment cases — the OmniCube A215 offers up to 50 kW of MPPT input for exactly that.