Green Assist: Turning local biomass into sustainable bio-fertilisers

In Castilla y León (Spain), the Fundación Patrimonio Natural de Castilla y León is taking a bold step towards a more circular and sustainable agricultural future: the foundation is developing a new composting plant. This facility will transform local biomass residues into high-quality bio-fertilisers. To bring this idea closer to market, the foundation sought technical and business advice from Green Assist that helped strengthen their model and advance towards implementation.

The plant will use locally sourced biomass boiler ashes, digestate from biogas plants and pruning remains as raw materials, minimising transport emissions and costs. Unlike other composting projects, this plant will not use urban biowaste. Instead, it focuses exclusively on agricultural and food-processing waste, contributing to a cleaner, more resilient agriculture value chain.

Their objective goes beyond producing compost. By optimising the mix of raw materials, the foundation aims to create stable, high-quality compost that can be further processed into bio-fertilisers ready for commercial use. This will help to ensure a safe and effective use in agriculture, close the nutrient loop, reduce dependence on chemical fertilisers, and improve soil health and productivity in the region.

A key innovation aspect of the project is its decentralised approach: instead of investing in one single large plant, the foundation plans to create a replicable model that can be implemented in different areas across the territory. This will help to optimise local biomass management and reduce long-distance transport.

Despite a strong concept and a clear environmental mission, the foundation faced challenges in moving towards implementation and turned to Green Assist for tailored support.

From June to November 2024, the project received advice from a Green Assist expert who helped to refine its business model, analyse market potential, and develop a commercial strategy. The expert also validated the technical approach and checked that the composting process and the bio-fertilisers actually meet EU and national regulatory requirements.

In addition, Green Assist supported the design of a monitoring and reporting system to track the environmental and social impact of the project. This included defining key performance indicators and setting up protocols for environmental externalities, non-financial reporting, and sustainable finance alignment. This bolstered the project's appeal to potential partners and investors, paving the way for future fundraising and implementation milestones.

With Green Assist support, the project has reached a significantly higher maturity level and is now ready to move towards the demonstration and implementation phase. Over the next two years, the foundation plans to finalise technical studies, validate commercial terms, and build new partnerships. It is also considering applying for EU funding to scale and replicate the model across the region.

"Thanks to Green Assist, we were able to strengthen our technical foundation, develop a clear business model, and align our project with both national and EU-level sustainability standards. This support was invaluable in transforming our vision into a tangible, impactful initiative for our region's future," said Jesus Diez, Programmes Director at Fundación Patrimonio Natural de Castilla y León.

Green Assist aims to build a pipeline for high-impact green investment projects in sectors related to biodiversity, natural capital and circular economy, as well as in non-environmental sectors.

Learn more about how Green Assist can help you get free tailored support for your green project or contact us at cinea-green-assist ec[dot] europa[dot] eu (cinea-green-assist[at]ec[dot]europa[dot]eu) . To request advisory services from Green Assist, simply fill out this short form.