The specialist solar trade fair, Intersolar, which closed its doors last week, saw Solutronic AG launch its latest innovation, the SOLPLUS FEED-IN Solution (FIS). FIS controls the inverters' power output depending on the level of local (in-house) consumption and the grid load. It is installed in-between the SOLPLUS inverter(s) and the grid connection and regulates the amount of energy that is fed into the grid in line with the specifications.
FIS is capable of feeding in a predefined maximum quantity of electricity while taking into account appliances in use in the building.
This means, for instance, if 70% of the maximum DC output of the PV system is allowed to be fed into the grid and a refrigerator, lights and the cooker in the house are all on, the amount of electricity required by these appliances is drawn from the electricity generated the rest is fed into the grid. If no appliances are running, the 70% maximum permitted is fed in.
If no power is allowed to be fed into the grid, FIS can limit the amount of energy generated to the maximum level of electricity consumed in-house. By doing so, FIS guarantees compliance with the legally limited infeed level at all times, but dependent on the local appliances. FIS measures and controls in 3-phase mode if PV inverters are connected to all 3 phases. In this case, each of the phases is controlled and limited individually.
FIS also allows the utility company to reduce the power infeed level remotely by means of ripple-control signals.
The thinking behind the development of FIS takes account of the growing number ofphotovoltaic installations being built and the strain this is putting on the existing power grids. This is leading governments to introduce legislation prescribing the integration of an infeed management functionality in new PV systems and promoting the retrofitting of such a functionality in existing systems. In some countries even, the power supply system is so overloaded that the operators of new installations are no longer allowed to feed the electricity they generate into the national grid.
With SOLPLUS FIS, it's now possible to use photovoltaics solely to cover one's own Basic power requirements without having to obtain the permission of the local utility company. This also means the PV installation doesn't have to be approved or licensed for grid connection.
The advantage here is that the cheap and easily calculable solar power can be used to cover one's basic power requirements. Above all, this system is particularly interesting for larger buildings with medium-range power requirements, such as hotels. And as the price of modules falls even further, it will also become more and more interesting for family homes and for customers who want to reduce their dependency on the power utilities.
