Q-STEP (Quantum Security-constrained Transmission Expansion Planning) will test whether quantum-informed optimisation can improve National Grid Electricity Transmission's Neptune reinforcement-planning workflow. The project will reformulate the Security Constrained Transmission Expansion Planning (SCTEP) problem as a mixed-integer linear problem and benchmark a quantum-informed solver against the Neptune heuristic and a classical MIP/MILP baseline. Over eight months, it will deliver a Proof of Feasibility and a Proof of Concept using IBM quantum hardware. The project will assess whether quantum-informed optimisation can improve runtime, solution quality and scenario throughput for reinforcement planning. If successful, it could enable planners to assess more network scenarios, improve reinforcement decision-making, support efficient network investment for the energy transition, and provide evidence on the applicability of quantum computing to future network-planning workflows.

Benefits

The project is expected to deliver benefits by assessing whether quantum-informed optimisation can improve the efficiency and quality of transmission reinforcement planning. If successful, faster optimisation could enable more demand, generation and contingency scenarios to be assessed within practical planning timescales, while improved solution quality could identify lower-cost reinforcement options that maintain network feasibility.

The main expected benefits are:

·        Increased scenario coverage: Faster optimisation could allow more future demand, generation and contingency scenarios to be assessed within existing planning timescales.

·        Improved reinforcement decisions: Joint optimisation could identify better combinations of reinforcement options than the current sequential approach, potentially avoiding unnecessary investment.

·        Faster decision-making: Shorter study times could provide planning outputs sooner and support more timely network and connection decisions.

·        Potential future consumer benefit: Any improvement in reinforcement planning efficiency or optimisation quality could reduce future network costs and support more efficient delivery of network investment required for the energy transition.

The benefits will be tested during Proof of Feasibility and Proof of Concept. Financial benefits have been assessed through the project cost-benefit case, with detailed assumptions retained in the supporting internal CBA material.