German grid control cooperation

German grid control cooperation

The German TSOs operate a joint balancing market. They use the concept of the Grid Control Cooperation (GCC), which involves four levels of cooperation:

1. Avoidance of counteracting balancing energy activations

It is inherent to the system that there are times when individual gird areas have a shortage of capacity, while other grid areas simultaneously have a capacity surplus. Without the GCC, balancing capacity would be activated independently within each gird area with opposing signs. The goal of Module 1 is to avoid counteracting activation of balancing capacity through controlled and targeted energy exchange between the grid areas. The potential savings lie in the reduction of counteracting activation of balancing energy (aFRR and mFRR) and the associated costs. This principle of netting balancing energy needs has been extended to our European neighboring countries through the IGCC and PICASSO platforms IGCC and PICASSO platforms.

    [GM(M1]LINK: Europäische Kooperationen -> PICASSO & IGCC

2. Joint balancing capacity dimensioning

The goal of Module 2 is the joint, cross-balancing grid load area dimensioning of the balancing capacity and thus the reduction of the required capacity and the corresponding costs (for aFRR and mFRR). The dimensioning is identical to that of a fictional German grid area. The GCC allows the participating grid areas to access the jointly held reserves, thereby reducing the required reserves.

3. Joint procurement

Module 3 enables German TSOs to obtain balancing capacity across the internal German grid area boundaries. The potential savings lie in cost reductions through direct competition among providers in a nationwide market, as well as a reduction in technical effort for the providers. This module is also transferable to our neighboring countries. However, cross-border procurement of FRR requires a mechanism that ensures the cross-border transmission capacity necessary for the exchange of balancing capacity. The example of joint aFRR procurement with the Austrian TSO APG has shown that this is possible for the German TSOs. More details can be found under ALPACA.

4. Cost-optimal activation of balancing energy

The goal of Module 4 is the cross-balancing grid area economic optimization of balancing capacity activation. The potential savings lie in the reduction of costs for balancing energy. To this end, all bids from all grid areas are listed in a common merit order. The needs of all grid areas are netted, and the remaining balance is called off from the common merit-order list.

Following this principle, the new European platforms MARI and PICASSO also operate.

Due to initially unknown fluctuations in consumption and generation, the power balance of a grid area continuously deviates more or less from the required power equilibrium. This resulting balance error must be compensated by the activation of aFRR (automatic Frequency Restoration Reserve). The aFRR demand of the participating grid areas is reported online to the coordinating optimization module. This module calculates a correction value that, in turn, impacts the power balance error. Accordingly, the input value of the secondary controller changes, resulting in the aFRR optimization system optimally and cost-effectively calling the calculated aFRR amount from the GCC grid areas. The correction activation is calculated online with a resolution of every second.