Section 9 EEG – Controllability of Photovoltaic Systems, Simply Explained

What does §9 EEG regulate?

Section 9 of the Renewable Energy Sources Act (EEG) stipulates that photovoltaic systems must be controllable under certain conditions.

This means that grid operators can reduce the feed-in power of a system if necessary.

This regulation is intended to help keep the power grid stable.

Why photovoltaic systems must be controllable

With the strong expansion of photovoltaic systems, situations are increasingly arising in which a lot of solar power is produced simultaneously. If too much electricity is fed into the grid, this can lead to grid problems.

By making the systems controllable, grid operators can adjust the feed-in at short notice.

Technical implementation of controllability

Photovoltaic systems are usually controlled via digital interfaces.

Typical technologies include:

• Smart meters
• Control boxes
• Energy management systems

These systems make it possible to better control energy flows in the power grid.

Energy management as central control

An energy management system can intelligently integrate photovoltaic systems into the household.

The system automatically decides when solar power:

• is used in the household
• is stored
• is fed into the power grid

This increases self-consumption and uses energy efficiently.