Reducing the need for new lines in Germany's energy transition: The hybrid transmission grid architecture

The energy transition will lead to an imbalance in electric power generation and demand along the north-south axis of Germany. To manage this imbalance, the transmission system operators proposed a network development plan that requires several thousand kilometers of new lines, which received extensive opposition. In our recent work, we proposed a landscape-preserving network development approach, i.e., the hybrid architecture, which relies on the conversion of some existing AC lines and transformers to HVDC operation. In this work, we show that this approach can meet the projected capacity and performance requirements with substantially fewer new lines. Due to the high cost of HVDC technology, the investment volume exceeds the current network development plan, but the preservation of landscape and support of public acceptance may justify that cost premium.