What is control capacity and why is it necessary?
The amount of electricity generated must be equal to the consumption at any time. If this balance is disturbed, the grid frequency may deviate from the standard 50 Hz, which poses risks to the stability of the grid.
To prevent this, grid operator TenneT uses control capacity: flexible deployable capacity that can be quickly scaled up or down to correct differences between supply and demand.
The different forms of control capacity
- FCR (Frequency Containment Reserve)
- Responds within seconds to small deviations in the mains frequency.
- aFRR (automatic Frequency Restoration Reserve)
- Automatically adjusts to restore balance after the first correction.
- mFRR (manual Frequency Restoration Reserve)
- Used manually in case of larger or prolonged imbalance. Read more about emergency power (mFRR).
What is aFRR (automatic Frequency Restoration Reserve)?
aFRR is a form of control power that is automatically used to bring the electricity grid back into balance after an abnormality has occurred. It is the second step in the balancing process, after the first quick correction by FCR.
If an imbalance arises, TenneT sends a signal to market parties to scale up or down power. This control is done automatically, so that energy assets respond within minutes without manual intervention.
In this way, aFRR ensures that the grid returns to the correct frequency of 50 Hz and continues to function stably, even with larger fluctuations in supply and demand.
How is aFRR activated?
The activation of aFRR is fully automatic and in a fixed sequence, so that the electricity grid quickly regains balance.
Imbalance on the grid
Supply and demand differ.
TenneT detects the deviation
The frequency deviation is detected.
Control signal sent
TenneT sends a signal to market parties.
Aggregator translates the signal
Commands are sent to the connected assets.
Assets respond automatically
The net has been restored.
Who can participate in aFRR?
The aFRR market is accessible to parties that can supply flexible power and respond quickly to control signals from TenneT. These are usually larger energy assets or bundled installations.
Direct participation usually requires a minimum capacity of approximately 1 MW. Typical participants are:
- energy companies and suppliers;
- aggregators;
- asset owners (such as industry and real estate);
- battery storage and charging infrastructure.
In practice, companies therefore usually participate indirectly via an aggregator. This combines multiple assets to meet the minimum asset threshold and regulates market access.
Earning from aFRR: this is how it works
The aFRR market offers companies the opportunity to monetize the flexibility of their energy assets. Instead of just consuming or generating energy, installations can actively contribute to balancing the grid.
There are two main revenue streams:
- Availability payment (capacity payment)
- You will receive compensation for making flexible power available to TenneT, regardless of whether this power is actually deployed. So you get paid for keeping capacity 'standby' that can be immediately deployed in the event of an imbalance on the grid.
- Activation fee (energy payment)
- If TenneT actually gives a control signal and your assets are deployed, you will receive compensation for the energy supplied or purchased. This compensation depends on the moment and the market situation, and may vary per activation.
Assets that can respond quickly, such as batteries, charging infrastructure or flexible industrial processes, are particularly suitable for generating income in this market.
Smartbox
Meet Smartbox: the Dutch EMS
The Smartbox is an energy management system (EMS) developed in the Netherlands that automatically controls energy assets based on real-time control signals from the energy market.
The system is the technical link between aggregator and installation, and ensures that assets respond directly and correctly to activations from, for example, the aFRR market. What does the system do?
- Receives real-time signals from the aggregator and translates them directly into concrete control of energy assets.
- Ensures that installations respond to activations from balancing markets within 20 milliseconds.
- Controls assets to increase or decrease power when the electricity grid requires it.
- Takes care of the automatic execution on location, without manual intervention.
- Makes it possible to use energy assets safely and efficiently within flexibility markets such as aFRR.
- Provides insight into all live energy data and asset performance in the Smartbox Portal.
Who is the Smartbox interesting for?
The Smartbox has been developed for energy companies and energy installers who want to offer their customers more than just hardware.
Installers then not only supply solar panels, batteries or charging infrastructure, but add a complete revenue model to their proposition. With Smartbox, energy companies can actively manage their customer portfolio and realize new revenue streams through flexibility markets such as aFRR.
Want to become a partner? Sign up
We work through a partnership structure where both the partner and the end customer benefit. Customers achieve a higher return on their energy assets, while our partners expand their services and earn money from the use of flexibility.
Curious about the possibilities? Call or email us, or fill in our contact form.