The market for energy accumulators has undergone a major transformation in recent years. New and highly powerful systems are appearing on the market almost monthly. DC-based storage solutions with a modern three-phase hybrid inverter are meanwhile a particularly effective alternative.

Hybrid inverters combine the functions of a conventional PV inverter and a battery inverter in one device. In the case of a DC-based system, the direct current generated by the system is first charged into the energy accumulator directly, if it is not consumed, and then fed into the domestic network at a later time via the integrated PV inverter. Hybrid devices not only save space with much easier installation, they also entail less losses, as occur in a AC-end energy accumulator.

Most hybrid inverters fulfil the following functions:

• Feeding the solar current into the building’s own power network and the public grid
• Control and monitoring of the PV system
• MPP tracking
• Communication
• Control of the solar battery charging and discharging
• Pure battery operation for emergency power supply
• Switching centre for a grid-independent, solar stand-alone system in case of Off-grid function

The three-phase hybrid inverters compared here use 2 MPP trackers for the PV system and 1 MPP tracker for the battery.