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Writer's pictureMartins Mikelsteins

FCR, aFRR, mFRR explained

What do these abbreviations mean? Here's a short explanation:



FCR (Frequency Containment Reserve)

FCR is the first response to sudden imbalances between electricity supply and demand, acting within seconds to maintain the grid's frequency close to its set point (usually 50 or 60 Hz, depending on the region). It's crucial for immediate stabilization, preventing further frequency deviations. Power plants or battery storage systems typically provide FCR by either increasing or decreasing their output in real time.


aFRR (Automatic Frequency Restoration Reserve)

After FCR has been deployed, aFRR takes over to bring the frequency back to its nominal value. aFRR operates automatically, utilizing control systems that adjust power output based on frequency deviations. This helps restore the balance between supply and demand over a few minutes.


mFRR (Manual Frequency Restoration Reserve)

mFRR is similar to aFRR in its goal to restore balance, but it is manually activated by grid operators. This reserve is used when automatic systems are insufficient or specific grid conditions require a more tailored approach. mFRR activation can take longer, from several minutes up to an hour, and is often used for longer-lasting imbalances.



Each of these reserves plays a vital role in grid stability, especially with the increasing integration of variable renewable energy sources like wind and solar power, which can cause more frequent and unpredictable imbalances.






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