A 110-recommendation "living document" published in June in EPJ Research Infrastructures puts environmental sustainability at the centre of how researchers plan, build and run particle accelerators. Lead author Hannah Wakeling, an accelerator physicist at the University of Oxford's John Adams Institute, says the guidelines aim to help facilities "make informed decisions that balance scientific progress with environmental responsibility."

How heavy is the energy bill?

The numbers explain the urgency. CERN's full accelerator complex drew 1290 GWh of electricity in 2024, with the Large Hadron Collider alone consuming 695 GWh. In "run" years, electricity costs equate to 5–10% of CERN's annual budget. With the upgraded High Luminosity LHC due online by 2030, a proposed 91 km Future Circular Collider on the drawing board, and China weighing a 100 km machine, energy demand is tracking infrastructure size.

What has RF 2.0 already proven?

The European Union has committed €5.6 m over three years to Research Facility 2.0 (RF 2.0), a consortium that includes CERN, DESY, HZB, ALBA, MAX IV, the Karlsruhe Institute of Technology and four SMEs, with Swiss co-financing from the State Secretariat for Education, Research and Innovation. The goal: facilities running almost independently of the public grid on renewable power.

Hardware numbers are coming in:

• A permanent-magnet redesign at MAX IV cut energy use and heat losses by up to 40% in beam-steering components.
• Solid-state amplifier retrofits with active parameterization controllers at ALBA delivered 18% energy savings over one year versus prior technology.
• 24 phasor measurement units installed at CERN logged 135 voltage sags and rapid voltage-change events in year one; 18 of those adversely affected magnets and RF acceleration schemes.

"RF 2.0 cannot work in one single direction – a multidisciplinary approach is key," says Giovanni De Carne, the project's director and head of KIT's Institute for Technical Physics. He argues that "large-scale research infrastructures are a public good, but they are inflexible and found wanting when it comes to environmental sustainability."

Which R&D lines does the strategy paper prioritise?

The push aligns with top-down signals. The European Strategy Group for Particle Physics, in its 2026 update, called for R&D funding to flow to platform technologies with the highest decarbonisation leverage. Four workstreams dominate:

• Grid-to-RF power conversion, where some studies suggest a four-fold efficiency gain is feasible.
• Thin-film superconducting RF cavities operating at 4.2 K rather than 2 K for bulk niobium.
• Permanent and high-temperature superconducting magnets that minimise heat loss.
• AI and machine-learning tools that trim computing loads and tune reliability parameters.

Wakeling flags trade-offs: "the higher manufacturing impact of a permanent magnet can, in certain cases, be offset by its lower operational impact in as little as one year." The caveat: that analysis is carbon-only.

What comes after the current programme?

Longer-horizon bets aim at step-change size reductions. Plasma-wakefield acceleration uses laser- or particle-driven plasma waves as an accelerating medium and can produce fields up to 1000 times stronger than classical structures. Energy-recovery linacs decelerate a used beam and feed the kinetic energy back into fresh particles, cutting the net power budget of superconducting facilities.

De Carne's team is in late-stage talks to merge RF 2.0 – which wraps at end-2026 – with Innovate for Sustainable Accelerator Systems (iSAS), an 11-lab, six-company initiative focused on superconducting RF cavity efficiency. Wakeling's group wants to learn from space-sector lifecycle tooling such as the Open-source Rocket and Constellation Lifecycle Emissions (ORACLE) repository. "We invite contributions from colleagues within the accelerator community," she says, "to ensure this resource remains relevant, comprehensive and impactful."