1) What is mass balance?

Imagine a world where every product we use can be traced, understood, and trusted. That's where the concept of mass balance comes in. It’s not just a system—it’s a vision for transparent, sustainable supply chains. Mass balance is a chain-of-custody model that meticulously tracks and manages volumes of certified products as they journey through the supply chain, carrying  sustainability information every step of the way.

2) Why do we need mass balance?

Picture a renewable fuel supply chain. Certified and non-certified products often end up mixed together. For instance, different types of raw materials can be processed simultaneously, or renewable fuels might be stored in the same tanks as conventional fuels. Keeping these products physically separated throughout their journey is not just impractical—it’s often near impossible.

That’s where mass balance comes in. It’s a smart, efficient system that allows this physical mixing but still tracks the sustainability information of certified products. By doing so, we preserve the integrity of our environmental claims while using existing infrastructure. It’s about making sustainability work within the realities of the supply chain, rather than fighting against them.

3) How does mass balance work in practice?

Here’s the beauty of mass balance: it embraces the reality of physical mixing. Certified and non-certified products may mingle, but every ounce of certified material still leaves a trace. The magic happens in how information is managed. Quantities and sustainability characteristics, like carbon intensity, are meticulously logged in the certified entity’s records and stay with the product as it moves through storage and processing.

The rule? Certified entities must maintain a “certified in vs. certified out” balance over a specific period, often three months. It’s not about physical traceability—it’s about a mathematical and ethical balance, with strict regulations and regular audits keeping everyone honest.

4) Where is mass balance used in renewable fuels?

Mass balance isn’t just a concept. It’s a cornerstone for major regulatory frameworks across the renewable energy world. From sustainable aviation fuels (SAF) under ICAO CORSIA to renewable fuels certified under the EU Renewable Energy Directive (RED), this model powers real-world sustainability, reaching into systems like ReFuelEU Aviation, FuelEU Maritime, and even the EU Emissions Trading System (EU ETS).

Conclusion: A practical approach to sustainability

Mass balance is a simple, effective solution to a complex problem. It acknowledges the realities of our interconnected supply chains, where separating certified from non-certified products is often impractical. By allowing physical mixing while rigorously tracking sustainability data, it gives us a way to move forward responsibly, using resources efficiently.

This isn’t about overcomplicating things—it’s about using common sense to uphold environmental integrity. Mass balance offers a balance between what’s practical and what’s right, ensuring that we meet today’s energy needs while staying focused on a more sustainable future.