How nLighten Sets New Data Centre Sustainability Benchmarks

Amid rising AI demand and stricter regulations, the data centre industry faces a critical question regarding sustainability.

nLighten, a prominent European data centre operator, is addressing this challenge with the development of a new sustainability benchmark that surpasses conventional industry standards.

nLighten has introduced the first Integrated Carbon-Free Energy (ICFEn) scores for its facilities across the United Kingdom, Germany and Spain.

This development could mark a milestone in how data centre sustainability is measured.

The ICFEn score’s innovative approach moves beyond typical industry metrics by capturing hourly carbon-free energy matching and heat recovery while also factoring in contributions to grid stability.

Where traditional measurement methods often rely on annual averages or a narrow focus on electricity consumption, the ICFEn provides real-time insights into how data centres can contribute to decarbonisation through energy reuse and sector coupling.

The framework was created in partnership with the Fondazione Eni Enrico Mattei (FEEM) and highlights a potential change in environmental impact reporting for the data centre sector.

A new approach to data centre sustainability

The ICFEn framework aims to provide a more holistic view of a data centre's environmental footprint.

By integrating multiple factors beyond simple energy use, it could offer a more transparent and accurate picture of sustainability performance.

This integrated approach accounts for both the energy a data centre consumes and the contributions it makes to the wider community energy system.

Chad McCarthy, Chief Technology Officer at nLighten, says: “Traditional sustainability metrics have focused on the data centres’ electrical energy profile, but ICFEn integrates the data centre into a community energy system, accounting both for consumption and contribution. By accounting for heat recovery and real-time renewable energy matching, we’re providing our customers and stakeholders with a new level of transparency about our actual environmental impact hour by hour, not just year-end averages.”

Understanding the ICFEn framework

The scoring system expands on the 24/7 Carbon-Free Energy concept by incorporating three critical components: the hourly-matched renewable electricity mix, heat recovery systems and contributions to grid stabilisation.

This method is designed to capture the complete environmental picture of data centre operations.

The ICFEn aligns with established sustainability frameworks, including the EU Energy Efficiency Directive, the Greenhouse Gas (GHG) Protocol and the Science Based Targets initiative, providing a credible and robust measurement standard.

This comprehensive approach ensures that the environmental impact of a data centre is evaluated in its entirety, reflecting both its operations and its role in the broader energy ecosystem.

Initial results from nLighten’s data centres in the UK, Germany and Spain have demonstrated strong ICFEn scores. This performance is attributed to progressive clean energy procurement and the implementation of heat recovery solutions.

According to nLighten, from April to June 2025, nLighten’s UK data centres achieved an ICFEn score of 94.61% which is higher than the regional CFE grid average of 56.47%.

nLighten achieves this hourly renewable energy matching by co-locating renewable energy assets within its portfolio and actively assigning their production to data centre operations in real-time. This ensures that its facilities are powered by clean energy as it is being used.

Encouraging sector-wide adoption and transparency

“We’re not just measuring renewable energy consumed; it’s more providing for a quantification of environmental improvement through sustainable projects for which we transparently share the calculation method,” says Francesco Marasco, Vice President of Energy Operations and Sustainability at nLighten.

He adds: “The ICFEn methodology allows us to demonstrate measurable system-wide benefits that lower community emissions. We’re actively encouraging other operators to adopt this framework because raising awareness of data centres benefits everyone.”

To foster industry-wide change, nLighten has published the ICFEn methodology under a Creative Commons licence, allowing other operators to use the framework at no cost.

This move is intended to promote greater transparency and encourage a collective effort towards improving sustainability across the data centre sector.

nLighten plans to roll out ICFEn reporting across all its European sites and will have an independent party review the project’s hourly energy and heat recovery data to ensure third-party validation.