Iñigo Capellán Pérez: “Net Energy Analysis: Through a Systems Lens”

July 5, 2023

(Conversation recorded on May 24th, 2023)

Show Summary

On this episode, global systems researcher Iñigo Capellán Pérez joins Nate to discuss net energy analysis, and its use as a tool in analyzing the feasibility of an entire system. While net energy analysis is complex and polarized, some form of it will be necessary to guide society into a resource-constrained future. The energy outlook of a technology changes when scaled up to meet the needs of a larger society. Many models and EROI analyses that fail to take a system-wide view and only look at a single technology use case, only reflect the partial net energy story. When looking at the huge scale-up needed for ‘solutions’ such as Green Growth and Net Zero Transitions, do the hopes for renewable technologies hold up the lifestyles we’ve come to expect over the last century of fossil surplus? Do our policymakers and leaders have the full picture to make competent decisions? How can we best use these tools to make creative responses to guide us through a Great Simplification?

About Iñigo Capellán Pérez

Iñigo is an Industrial Engineer currently doing research with The Group of Energy, Economy and Systems Dynamics (GEEDS) of the University of Valladolid. He holds a Master degree in Electric Energy and Sustainable Development and a PhD in Economics with his dissertation on “Development and Application of Environmental Integrated Assessment Modelling towards Sustainability” at the University of the Basque Country. His research interests focus on the analysis and modeling of the energy-economy-environment systems, the transition to renewable energies in the context of the depletion of fossil fuels and climate mitigation and the technical and social transformations towards sustainability.

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Show Notes & Links to Learn More: 

PDF Transcript

00:00 – Iñigo Capellán Pérez works, info, GEEDS, and the paper referenced in this episode: Dynamic Energy Return on Energy Investment (EROI) and material requirements in scenarios of global transition to renewable energies

00:45 – EROI, Nate’s Frankly

03:34 – Integrated Assessment Models

03:45 – IPCC Models

06:46 – Peak Oil

10:10 – Degrowth

12:40 – Beyond Growth

16:22 – Biofuels EROI

17:10 – Societies need about 5-15:1 EROI to sustain themselves

17:45 – Carlos de Castro Carranza – GEEDS 

25:40 – Green Growth myth of energy substitutability

31:10 – Investment timeline into fossil fuels vs renewables

35:05 – Biophysical Economics

39:35 – Material, land, etc., limitations of renewables

40:20 – Planetary Boundaries

42:39 – Renewables (wind, solar, and geothermal only) are 5% of primary energy production

42:56 – EROI of the system declined and continues to decline

48:25 – Ukraine/Russia impact on energy

49:25 – Dependence on Russian Fertilizer

53:30 – Energy Cooperatives

59:49 – Collapse Jared Diamond

1:02:18 – TGS Episode on Hydrogen


Teaser photo credit: The 40.5 MW Jännersdorf Solar Park in Prignitz, Germany. By Parabel GmbH – Own work, CC BY-SA 3.0,

Nate Hagens

Nate Hagens

Nate Hagens is the Director of The Institute for the Study of Energy & Our Future (ISEOF) an organization focused on educating and preparing society for the coming cultural transition. Allied with leading ecologists, energy experts, politicians and systems thinkers ISEOF assembles road-maps and off-ramps for how human societies can adapt to lower throughput lifestyles. Nate holds a Masters Degree in Finance with Honors from the University of Chicago and a Ph.D. in Natural Resources from the University of Vermont. He teaches an Honors course, Reality 101, at the University of Minnesota.

Tags: energy transition, net energy, net energy analysis, systems thinking