ILIOS consortium secures £200 million construction mandate for UK pioneering STEP fusion energy plant

The UK government has progressed its fusion energy ambitions by appointing the ILIOS consortium to oversee the design and construction of the Spherical Tokamak for Energy Production (STEP) facility. Located in Nottinghamshire, the prototype plant aims to demonstrate commercial fusion viability by 2040, potentially transforming the global low-carbon energy landscape.

UK Fusion Energy has appointed the ILIOS consortium led by a Kier Nuvia joint venture alongside AECOM, AL_A, and Turner & Townsend to deliver the initial £200 million phase of the Spherical Tokamak for Energy Production (STEP) programme. This flagship initiative, overseen by the UK Atomic Energy Authority (UKAEA), aims to establish a world-leading prototype fusion power plant at the West Burton site in Nottinghamshire. The UKAEA is an executive government body responsible for researching and developing fusion energy and related technologies.

This development signals a strategic shift from theoretical research to large-scale infrastructure delivery. By integrating expertise from high-hazard civil engineering and nuclear construction, the project seeks to prove fusion's commercial viability by 2040. For the energy and construction sectors, this represents a multi-decade commitment to specialized supply chains and advanced engineering standards, with the broader programme holding a potential value of up to £10 billion.

The project’s scale is expected to generate significant economic impact, supporting approximately 8,000 jobs during its peak construction phase. Beyond local employment, the successful implementation of the STEP facility offers a strategic roadmap for decarbonizing industrial power grids. For investors and global energy stakeholders, the UK's progress provides a critical benchmark for the technical and financial feasibility of fusion as a sustainable, high-output alternative to traditional fission or fossil-fuel-based energy sources.