EMPA Unveils Five-Tier Model to Quantify Energy Supply Security and Guide Future Policy

EMPA Unveils Five-Tier Model to Quantify Energy Supply Security and Guide Future Policy

(IN BRIEF) Empa, in partnership with ETH Zurich and Lawrence Berkeley National Laboratory, has developed a five-tier pyramid model to quantify energy supply security, addressing a longstanding gap in energy-system planning. Each tier—from self-production through complete autarky—provides quantitative indices that collectively capture the dynamic nature of modern grids reliant on renewables. Applied to Switzerland’s present and 2050 scenarios, the model indicates that a diversified renewable mix, higher domestic generation, and strategic storage solutions can bolster security cost-effectively, illustrating how policymakers can balance sustainability, cost, and supply reliability.

(PRESS RELEASE) DÜBENDORF, 14-Jul-2025 — /EuropaWire/ — EMPA researchers have introduced a comprehensive model to quantify energy supply security, filling a critical gap in planning future energy systems. While existing scientific tools reliably assess sustainability and costs, assessing uninterrupted supply has remained elusive. Led by Matthias Sulzer of Empa’s Engineering Sciences department and developed in collaboration with ETH Zurich and the U.S. Lawrence Berkeley National Laboratory, this pioneering framework appears in iScience.

At its heart lies a five-level pyramid of quantitative indices. Self-production, the base tier, compares a country’s annual domestic energy output with its consumption. The second tier, autonomy, measures import reliance and the robustness of supply routes. System adequacy, the third level, assesses—in hourly or finer resolution—whether available sources can meet demand in real time. The fourth tier, self-sufficiency, gauges the ability to function without imports during specific intervals. Finally, complete autarky envisions a scenario where a nation relies solely on its own energy production year-round.

The energy trilemma describes the balance between sustainability, equity, and supply security that must be taken into account in the energy transition. Graphic: Empa

Although these levels build upon one another, the team emphasizes that all five must be considered together to reflect the complexity of modern grids—especially those driven by variable renewables. An average annual balance, they argue, fails to capture the short-term fluctuations inherent to wind and solar power.

The model proposed by the researchers structures energy supply security into five levels, which build on each other but are viewed as a whole. Graphic: Empa

To demonstrate practical applications, the researchers applied their model to Switzerland’s current and projected 2050 energy systems (the latter in collaboration with the Association of Swiss Electricity Companies). Their analysis suggests that a diversified mix of renewables, combined with increased domestic output and additional storage—ranging from hydro reservoirs to thermal waste-heat storage and vehicle batteries—can enhance Switzerland’s supply security without prohibitive cost increases. Achieving full self-sufficiency remains technically possible but economically inefficient; a balanced approach to imports and domestic generation optimizes the energy trilemma of sustainability, affordability, and security.

Media Contacts:

Prof. Matthias Sulzer
Engineering Sciences
Phone +41 58 765 47 29
matthias.sulzer@empa.ch

Dr. Georgios Mavromatidis
Urban Energy System Laboratory
Phone +41 58 765 42 99
georgios.mavromatidis@empa.ch

Anna Ettlin
Communications
Phone +41 58 765 47 33
redaktion@empa.ch

SOURCE: EMPA