Co-digestion in RNG: Challenges, Opportunities, and the HoSt Advantage
8 October 2025
As the U.S. dairy RNG market faces headwinds—driven in part by fluctuating LCFS credit prices—developers are increasingly turning to co-digestion as a viable and scalable alternative. Unlike traditional dairy-only projects, co-digestion projects are not reliant on subsidies. Instead, they often sell gas on the voluntary market, offering more flexibility and resilience in uncertain policy environments.
The benefits of Co-Digestion
Co-digestion involves blending multiple organic waste streams—such as food waste, FOG (fats, oils, and grease), and industrial byproducts—with traditional feedstocks like manure. This approach offers several advantages:
The Challenges
However, co-digestion isn’t without its complexities. Unlike single-feedstock systems, co-digestion requires a menu composition that needs to be monitored much more closely to correct for changing inputs. In addition, pre-treatment is more extensive than for liquid pumpable feedstocks such as cow slurry.
The HoSt Advantage
For many developers in the USA, the concept of co-digestion is relatively new. For HoSt, it’s the norm; as anerobic digester experts, HoSt has a lot of experience with co-digestion. In Europe, where co-digestion is widely adopted, we’ve delivered dozens of successful projects using three or more feedstock streams. Our in-house biological process team provides tailored advice on feedstock blending, ensuring stable operations and maximum gas output.
As the U.S. market evolves, co-digestion represents a significant opportunity to unlock new value from organic waste. With the right technology and expertise, developers can turn complexity into competitive advantage.
Let’s talk about how HoSt can help you navigate the co-digestion opportunity.
The benefits of Co-Digestion
Co-digestion involves blending multiple organic waste streams—such as food waste, FOG (fats, oils, and grease), and industrial byproducts—with traditional feedstocks like manure. This approach offers several advantages:
- Higher Biogas Yields: Many co-digestion feedstocks are more energy-dense than manure, resulting in greater biogas production.
- Diversified Revenue Streams: By tapping into the voluntary RNG market, developers can reduce reliance on regulatory incentives.
- Waste Diversion: With increasing bans on organic waste in landfills, co-digestion provides a sustainable outlet for materials that would otherwise go to waste.
The Challenges
However, co-digestion isn’t without its complexities. Unlike single-feedstock systems, co-digestion requires a menu composition that needs to be monitored much more closely to correct for changing inputs. In addition, pre-treatment is more extensive than for liquid pumpable feedstocks such as cow slurry.
The HoSt Advantage
For many developers in the USA, the concept of co-digestion is relatively new. For HoSt, it’s the norm; as anerobic digester experts, HoSt has a lot of experience with co-digestion. In Europe, where co-digestion is widely adopted, we’ve delivered dozens of successful projects using three or more feedstock streams. Our in-house biological process team provides tailored advice on feedstock blending, ensuring stable operations and maximum gas output.
As the U.S. market evolves, co-digestion represents a significant opportunity to unlock new value from organic waste. With the right technology and expertise, developers can turn complexity into competitive advantage.
Let’s talk about how HoSt can help you navigate the co-digestion opportunity.
