Offshore wind developers bring harmony to carbon footprinting in update of groundbreaking methodology

Leading offshore wind developers and the Carbon Trust have today updated a groundbreaking common methodology for calculating the carbon footprint of offshore wind farms, bringing harmony and transparency to carbon emissions measurement in the sector.

18 March 2026
Offshore wind

The Sustainability Joint Industry Programme (SUSJIP) is a collaborative programme to accelerate decarbonisation action across future fixed and floating projects for a Net Zero offshore wind industry, with partners including EnBW, JERA Nex bp, Ørsted, RWE, ScottishPower Renewables (SPR), Statkraft, SSE Renewables and TotalEnergies. ​

The programme aims to drive decarbonisation in the rest of the offshore wind supply chain through harmonising carbon reporting in offshore wind. In September 2024, it published its ‘Offshore Wind Industry Product Carbon Footprinting Guidance’, addressing the lack of industry guidance to provide a clear, accessible and freely available reporting standard.

The updated carbon footprinting Guidance follows an in-depth review by an expert working group, giving greater clarity and alignment with current industry best practices. Updates include updated templates for reporting and disclosure; improved guidance for assessing data quality, sensitivity and uncertainty; and the addition of use cases on how to apply the product carbon footprint methodology.

SPR, RWE and Ørsted have given real‑world examples of how the SUSJIP methodology is being applied.  

  • SPR has used the SUSJIP methodology to calculate portfolio‑level baselines and identify emissions hotspots, strengthening supplier engagement and supporting scenario modelling for lower‑carbon design and procurement.  
  • RWE conducted a Life Cycle Assessment on Thor, its flagship offshore wind project in Denmark, using its in‑house tool before benchmarking it against the SUSJIP methodology. This enabled RWE to calculate the project’s carbon footprint, test scenarios such as using greener steel towers, validate assumptions and improve data quality.
  • Ørsted used its LCA model, which is closely aligned with the SUSJIP methodology, to identify major emissions sources, such as steel production and marine fuels. It plans further alignment with the methodology to improve comparability and support supply‑chain decarbonisation.

Recent research from the United Nations Economic Commission for Europe (UNECE) has found Offshore wind to have almost 99% less impact than coal-fired power plants when generating electricity. Although offshore is a lower emission generation source, there are opportunities to further understand the exact impact of the lifecycle of these developments, from material extraction through to decommissioning.

Carbon footprint calculations can be used across the offshore wind industry to provide insights into baseline data, emission hotspots and decarbonisation opportunities. However, to ensure standardisation and comparability, the SUSJIP argues that industry-wide alignment on carbon footprint calculations is vital.

In a position paper also published today, SUSJIP partners make the case for the widespread adoption of its guidance, with harmonisation of carbon reporting in offshore wind leading to better alignment, enhanced transparency and comparability. This is increasingly relevant for developers, as discussions continue incorporating carbon footprint criteria into renewable energy auctions. Indeed, the EU’s Net Zero Industry Act (NZIA) adds important context on the need for harmonisation.

The paper outlines additional benefits of harmonisation for developers and stakeholders, including:  

  • Enhanced transparency of carbon footprint calculations produced by developers
  • Presenting a standard approach for any future greenhouse gas (GHG) emissions monitoring that successful projects may have to undertake as part of potential regulatory obligations
  • Sector-specific rules for the application of the relevant standards for Product Carbon Footprints (PCFs) to an Offshore Wind development (ISO 14067, GHG Protocol Product Standard).  

Mary Harvey, Programme Manager for SUSJIP from the Carbon Trust, said:

“The launch of the SUSJIP Phase 2 methodology reflects our partners’ continued commitment to a harmonised approach to product carbon footprinting of offshore wind farms. Combined with case studies demonstrating real-world adoption over the past year and a position paper setting out a unified developer voice, the revised methodology signals that the industry is ready to adopt consistent, robust PCF calculations and accelerate the reduction of emissions across the sector.

Jean Gavalda, Director of Construction Asset Management, Offshore Wind Business Unit at TotalEnergies, said:

"Through our participation in Phase II of the JIP Sustainability programme, TotalEnergies reinforces its commitment to reducing emissions across our operations and value chain, while advancing a lower carbon energy mix built on renewables such as offshore wind. A shared, harmonised methodology is essential to improve transparency and comparability, enabling the industry to accelerate decarbonisation"  

Louis Alen, Sustainability Officer at JERA Nex bp, said:

“We want to apply the SUSJIP carbon footprint analysis to our Arcadis Ost I wind farm as a test case. Using the methodology, developed within the Sustainability Joint Industry Programme, we will carry out a standardised life cycle assessment (LCA) to map the project’s CO₂ emissions from construction to decommissioning. This provides transparency and comparability within the industry, helps identify emission hotspots, and supports both internal decision-making and external reporting, for example under the Net Zero Industry Act. It is a valuable step to substantiate our sustainability objectives and prepare for future tendering and reporting requirements.”

SUSJIP is the fifth addition to the Carbon Trust’s renewable energy innovation platform, which consists of a portfolio of R&D activities including the Offshore Wind Accelerator (OWA), the Floating Wind Joint Industry Programme (FLWJIP), the Integrator and the Offshore Renewables Joint Industry Programme (ORJIP).

The updated methodology, the SUSJIP partner’s position paper and case studies of the methodology in action are now available on the Carbon Trust’s website.