Two Non-Green Energy Systems Repeatability Across Generations – A Physically Grounded Framework for Long-Term Viability

This discussion paper examines the emerging energy landscape from a physically grounded perspective. Rather than framing the future as a simple replacement of a fossil system by a “green” one, it argues that two non-green energy systems now operate in parallel: a long-established, low-material-intensity system based on fossil fuels, hydropower and nuclear energy, and a rapidly expanding, high-material-intensity mineral-based system built on solar, wind, batteries and mineral-intensive grids. The paper proposes Sufficiency as the goal, and repeatability across generations as the means, introducing Time Step 3 – Repeatability Across Generations as a governance and robustness test. The framework asks whether energy systems, infrastructures and industrial pathways can realistically be maintained, rebuilt and lived with again and again over multiple lifecycles — 100–500 years — within ecological limits. Framed this way, sustainability shifts from a question of distant targets, public willingness to pay or political bargaining to one of governance and system integrity: a compliance-based admissibility test that determines, up front, what kinds of systems and projects may be built, extracted and operated in a finite world.