fronius multi flow technology

smart inverters for smart systems

We want to achieve more than simply storing raw solar energy for later use. Fronius Multi Flow Technology is an intelligent energy control system that efficiently combines the power from the PV system, battery and additional power sources for any kind of storage applications, such as backup power, self-consumption, tariff optimization and grid support.

Multi Flow Technology

Multi Flow Technology

Current from the photovoltaic generator to the inverter

Feed-in current from the inverter to the consumer (load) or to the grid

Charging current from the inverter to the consumer (load) or to the grid

Discharge current from the battery to the inverter

AC charging current from additional energy sources and/or from the grid

Advantages of Fronius Multi Flow Technology

Conventional inverters only allow one energy flow in the energy storage system at a time; several simultaneous current flows are not possible. This means the energy produced is not optimally used, and not all applications can be implemented.

With Fronius Multi Flow Technology, the inverter becomes the intelligent control centre of the photovoltaic and energy storage systems. Parallel connections ensure optimum usage and flexible applications. Energy is directed to where it is needed most at any time, making it a flexible, reliable, efficient and powerful system.

Fronius Multi Flow Technology enables both energy storage units and photovoltaics to supply a home with electricity at the same time. If the consumer requires more power than the output of the photovoltaic system is currently capable of meeting, the battery supplies the shortfall in parallel.

Without Multi Flow Technology, batteries and photovoltaics cannot provide power to the consuming loads simultaneously. The user must either draw the energy shortfall from the grid or turn off the PV system (even though it is generating solar energy), in order to use power from the battery.

Multi Flow Technology enables the photovoltaic system to supply the home with solar energy while charging the rechargeable battery. If the output from the PV system exceeds the consumer's requirements, the surplus energy is stored in the battery. If the energy storage unit is fully charged, the extra electricity is fed into the grid.

Without Multi Flow Technology these parallel energy paths are impossible. The excess electricity from the photovoltaic system could only be fed into the grid.

In emergency situations, for instance during a power outage, Multi Flow Technology provides a backup power supply from the photovoltaic system and the battery. The array can continue to supply the house with solar energy in emergency power mode, even when the battery has been discharged.

Without Multi Flow Technology, the energy from the PV system often cannot be used for emergency power and the user is literally left in the dark.

Adrian Noronho - Sales Management NA, MEACA, APA

“To make 24 hours of sun a reality, the energy must be directed to where it is needed. Multi Flow Technology optimises the PV storage solution by allowing energy to be directed to several destinations, forming an important step on the road towards our energy future.”

The AC charging function: additional flexibility for your battery

Inverters with Fronius Multi Flow Technology can draw an AC charging current from additional energy sources or the grid, in parallel to other energy paths. This means the inverters are capable of performing many additional functions in comparison with conventional solutions:

Coupling with other energy sources

Alternative energy sources, such as micro combined heat and power stations or wind turbine, can also be connected to the system via the AC charging function. Surplus energy from these complementary generators can be stored in the battery. This helps to provide a reliable power supply even when the PV system supplies minimal solar energy, such as in the winter. 

Using time-dependent electricity tariffs

More and more utilities are billing customers using a time-dependent rate schedule. Using the AC charging function, the user can charge the battery with electricity from the grid when prices are lower. The household is then supplied with cheaper power from the battery when energy rates are higher during periods of peak demand. 

Minimum charge for emergency power situations

Many photovoltaic storage systems provide an emergency power supply in the event of a power failure. The AC charging function ensures a minimum charge level in the event of a power outage, so an energy reserve will always be available. The battery will never be flat when needed most. The user can fully charge their storage system in good time whenever notice of a grid shutdown is received. 

Conservation charging

If insufficient solar energy is available over longer periods – for example, if the photovoltaic system develops a fault – the AC charging function kicks in to prevent deep discharge of the battery and the ensuing premature degradation. 

Improving grid quality

The rising number of photovoltaic systems on low-voltage grids increases demand for specific grid services. Photovoltaic storage systems with an AC charging function make an active contribution to improving grid quality. Consumers can charge their batteries when too much energy is being fed into the grid, thereby relieving grid strain.