Brief
TenneT TSO GmbH is seeking support and maintenance services, as well as licenses for Gurobi, a mathematical solver software used in network planning. Gurobi is utilized by all Transmission System Operators (TSOs) in Germany for network planning calculations, including the Federal Network Agency (BNetzA). The use of a standardized solver allows for comparability of calculation results among the TSOs and the responsible authority, which would not be possible with different solvers. Key application areas include: • IAEW Redispatch Tool (Gurobi is the only manufacturer with a long-standing collaboration with IAEW, which is part of RWTH Aachen University). • Interfaces to Powerfactory (by DigSILENT GmbH) • APIs for Matlab and Python distributions. Gurobi licenses are installed on terminal server environments, local computers, and specialized high-performance clusters (SPC). Additional applications include: • IAEW Tune • IAEW Heuristic Tool • Plexos. The close collaboration between TenneT and IAEW leads to complex and costly long-term developments, where the implementation of Gurobi plays a significant role. Reasons for the necessity of operating Gurobi include: • Gurobi is the only solver with migration capabilities and close collaboration with the manufacturers of network planning tools used by TenneT: - Tools from IAEW - INTEGRAL (FGH) - Powerfactory (DigSILENT) - Plexos (Energy Exemplar). • These tools have been extensively customized and developed over eight years to meet TenneT's needs, requiring significant financial and intellectual resources. • Migrating to different solvers is extremely time- and resource-intensive, as APIs may vary: - The application provider must support the migration - Adapting mathematical models requires a high level of expertise, which is available from Gurobi in the TSO environment. • Switching to an alternative solver would necessitate extensive redevelopment, testing, and certification, and the comparability of results with other TSOs would need to be verified and approved. These measures could jeopardize existing integrations and lead to operational disruptions in network planning, preventing the availability of the network development plan. Without this plan, network expansion cannot proceed as planned, leading to high follow-up costs (including parts of the redispatch costs) and potential penalties from BNetzA. • Transition costs would include additional license fees due to the required parallel operation of both solvers for a certain period, as well as significant development, training, and integration efforts not only within TenneT but also with relevant partners (IAEW, FGH, Digsilent, etc.). • Gurobi offers two unique features in the context of transmission system operators: Gurobi Optimizer: globally recognized as the most robust commercial mathematical optimization solver for linear programming (LP), mixed-integer programming (MIP), quadratic programming (QP), and other optimization problems highly relevant to TSOs. Gurobi Compute Server: provides scalability for large-scale optimizations, enabling high-performance distributed computing necessary for addressing extensive optimization problems (e.g., optimizing network flow, planning capacity expansions, ensuring redundancy and failover functions to maintain uninterrupted service to meet the 24/7 operational requirements of a TSO). • Gurobi is a market leader in the energy sector, ensuring compliance with EU energy regulations and cybersecurity requirements for TSOs. The source code is not available to us, and we do not have exclusive usage or modification rights to the software; changes can only be made by Gurobi (the existing contractor).
