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FAQ: GridFree and the power output regulations (VDE-AR-N4105 and CEI 0-21)

Question: There exists a regulation VDE-AR-N4105, which says, that output power form the solar power-plan must be limited, with not more than 70% of the current of the installation allowed to be sent back to the grid. How is this applied for GridFree self consumption systems? 

Answer: There are several grid standards that give specifications for grid-tied commercial solar power plants to regulate the output power to the grid. For example: the German VDE-AR-N 4105 and the Italian CEI 0-21 regulations. More of such regulations are expected to come in the future.

By increasing the frequency of the AC voltage in the grid, the Grid operator has ability to control the power of the solar installation that feed (supply) the energy to the grid.

It is important to realize that these standards are designed for solar installations that directly feed energy into the grid. In the past (pre 2012/2013), majority of the solar power plans installations were hard-wired to the grid, with no power control. In such installations when the sunshine is at full, all energy is fully pushed into the Grid with no regulation possible. 

With ever growing number of solar installations it is important to have the technical methods to be able to control the output power to the grid in order to make sure of the stability of the grid.

There is a fundamental operational difference between the commercial solar-power plant and the self-consumption GridFree installation:  the GridFree installation should be designed in a way to feed no energy to the grid.  This means the production of the solar power is fully dependant on the consumption at the very place - with no overflow of the energy to the Grid. 

From this point of view, the GridFree installation (e.g. installation equipped with one or more current relays) is over-reaching the power regulating standards like German VDE-AR-N 4105 and the Italian CEI 0-21. These standards request to regulate the power send back to the grid in some steps. The GridFree installation natively regulates the output to the Grid to full Zero power.

In the future we expect the grid operators to become even stricter in regulating the power generation from the solar power plans, with more and more power limitations. From this point of view the GridFree installation is far advanced and fully beyond any possible future regulations. 

Conclusion: the GridFree installation, with no overflow to the Grid, is technically above the power limiting regulations of the grid regulators both for present time and also for the future.