Norsk e-Fuel is developing plants to produce sustainable aviation fuels (e-SAF) based on renewable power, water and CO₂. As the Energy Transition accelerates, one of the most important questions for the company is: How do we build an e-SAF plant that works with the future energy system, rather than against it?

e-SAF production requires large amounts of electricity. At the same time, Europe’s energy system is rapidly shifting towards renewable power. While renewable electricity has the potential to provide abundant, low-cost energy, its availability is inherently variable. Future industrial plants will therefore need to adapt when and how they use electricity.

Unlike many other electricity-intensive industries, e-SAF production can operate with a high degree of flexibility, increasing output when renewable electricity is abundant and scaling back during grid congestion.

For Norsk e-Fuel, flexibility is a core design principle: future e-SAF plants should become active participants in the energy system while remaining efficient, reliable, and fully compliant with the evolving EU regulatory framework. The challenge lies in identifying where flexibility creates the greatest value without compromising plant performance or fuel production.

To answer this question, Norsk e-Fuel partnered with Energynautics to develop a time-resolved techno-economic optimisation model covering the entire production process.

Energynautics developed a model that maps the complete e-SAF production pipeline, tracing the flow of electricity, water, carbon dioxide, hydrogen, and intermediate storage to the final fuel product. Rather than assuming fixed plant operation, the model simulates how the plant can dynamically respond to electricity prices, renewable generation, weather conditions, and carbon intensity.

A key feature is the optimisation of individual process units and intermediate storage. For example, the model determines when hydrogen storage should be filled or emptied and identifies the optimal times to ramp production up or down. By actively scheduling plant operation, it minimises production costs while maximising the output of EU-compliant e-SAF.

Underneath this operational scheduling, the model captures physical and regulatory realities. Tracking emissions is inherently quadratic, because carbon intensity directly couples process states to volume flows, requiring a true quadratic formulation rather than a linear approximation. Regulatory compliance is then evaluated through a mixed-integer pass, ensuring the model remains robust across all operating conditions. The resulting quadratic mixed-integer model is solved entirely with open-source solvers, combining Ipopt and HiGHS, which guarantee portability of the product.

Beyond operational optimisation, the model also supports strategic decision-making during plant design. Different process capacities, storage sizes, renewable generation profiles, electricity market scenarios, and Power Purchase Agreement options can be evaluated before construction.

The result is a plant design that is optimised not only for today’s conditions, but for tomorrow’s energy markets, enabling reliable, cost effective, and compliant e-SAF production.