As anticipated in the post about the completion of storage modeling, the past weeks have been dedicated to the development of a new modeling scheme for the electricity grid in WITCH.

Grid is already explicitly modeled in WITCH, but the formulation is quite simplified. It is substantially based on two equations: one aggregated equation linking the grid stock to the power capacity and VRE penetration, and one capital equation which allows calculating depreciation and investments.

First of all, the new formulation has added technical detail, as it now differentiates between transmission and distribution. Additionally, the pooling effects – the load balancing over large areas – have also been introduced, thus allowing the integration of grid into the flexibility constraint. The latter point is fundamental in the perspective of obtaining an integrated and fully coherent modeling comprising system integration of Variable Renewable Energies, storage, and grid.

This step concludes the modeling work in WITCH.

Indeed, as reported in the project outline, the work plan would theoretically consider one additional modeling activity, regarding electricity trade.

However, a more in-depth analysis of the issue has questioned the actual necessity and value added of implementing this aspect in the WITCH model. After all, electricity trade is not considered among the priorities in the IAM research community as far as the power sector modeling is concerned. On the other hand, over this year some time has been dedicated to the collaboration activities with SWITCH, which had not originally been envisioned in the MERCURY proposal. In this light, Task 1.5 has been diverted accordingly.

The next weeks will thus be mostly dedicated to the SWITCH side. As you might recall, the dynamics of decarbonization activity is still pending and will now finally be resumed.

Before that, however, some days will be dedicated to a sort of bridging activity between the WITCH modeling and the dynamics of decarbonization. The results obtained with the new WITCH modeling will be compared to the SWITCH scenarios for China (the latter being, I remind, the main core of the dynamics of decarbonization activity). The idea is to “validate” the new modeling in WITCH showing that the deployment of grid (and possibly storage) as a function of renewable penetration is in line with the outcome of a more detailed energy model (I remind that SWITCH is mostly specialized in the grid modeling).