On 5 November 2025, the Commission released its Sustainable Transport Investment Plan (STIP), a key component of the Clean Industrial Deal released in February this year. The STIP provides a framework to encourage investments into renewable and low-carbon fuels for the aviation and maritime sectors.

To meet the demand for alternative fuels driven by FuelEU Maritime and ReFuelEU Aviation, the Commission estimates 20 million tonnes of annual production capacity by 2035 with an associated price tag of EUR 100 billion. The STIP proposes that at least EUR 2.9 billion be deployed by industry until the end of 2027.

The Commission acknowledged that the current obligation framework has not been sufficient in stimulating new production, particularly for e-fuels which can incur costs up to ten times that of conventional fuels. As a result, potential investors are looking for additional risk alleviation beyond mandates.

To counter this, the STIP proposes using EU funding instruments such as InvestEU, the Innovation Fund (which has provided funding for the EHB auctions) and Horizon Europe to support sustainable fuel projects targeting maritime and aviation offtakers. The concept of double-sided auctions, an intermediary mechanism allowing suppliers (who prefer long-term agreements) and buyers (short-term preference) to be matched, will also be further explored.

Building on further support, the Commission will also consider increasing the scope of the ETS SAF support scheme (DR 2025/723, where allowances are allocated based on SAF uptake), which could result in a similar mechanism for Sustainable Maritime Fuels (SMF).

Biomethane specific measures

Within the framework, biofuels (particularly biomethane) are expected to provide two-thirds of the 2035 fuel requirement, a recognition of the maturity of the production technology. Further, biomethane can leverage existing natural gas infrastructure, including grids and ports. The STIP puts emphasis on the development of new and underused feedstocks such as manure and agrifood residues, which is targeted at biomethane production.

The STIP appears bullish on natural gas as a transition fuel for maritime, noting “LNG, with effective methane slip mitigation technologies, can reduce also GHG emissions.” This could translate to funding for such technologies, from which bioLNG would also benefit.

Furthermore, biofuels and biomethane have not been explicitly ruled out of participating in Innovation Fund auction processes, a move that European lobby group Transport and Environment has criticised.

Commentary on existing support

The Commission called upon Member States to make use of the flexibility and simplification offered by the Clean Industrial Deal State Aid Framework (CISAF) for more rapid capacity deployment, as well as ensuring national measures for biomethane do not indirectly introduce barriers to single-market trade.

The Commission also recognised that current Member States’ biomethane subsidy schemes have caused eligibility issues for producers and market players in general. The STIP expects that the Union Database (UDB) will alleviate some of these eligibility issues by eliminating double claiming, but the Commission has also pledged to work with Member States to address the inconsistencies.

These measures are particularly relevant to grid blending mandates, where the French and Dutch proposals have sought to prevent biomethane imports from being eligible to receive incentives. Overall, the STIP is a bullish signal for biomethane, as it opens access to funding pools previously reserved for RFNBOs, while retaining support via national schemes. It also provides alignment between the two types of supports, provided a robust system for green claims is fully established.