The Role of Science in the Energy Debate

If we were guided by science, there would be a lot less hot air and more informed debate around energy.

Nothing in society is possible without the availability of sufficient energy. Nothing. Energy is a fundamental prerequisite of life and represents a particularly important factor of everyday life.

When we speak about energy policy, we are dealing with a subject that has far-reaching consequences. The energy system represents the lifeline of our entire economy and society. Changes in it take decades, not years. For these reasons, we must conduct these debates on the basis of scientific evidence, not wishful thinking or sloganeering.

The purpose of this series is to apply basic science and arithmetic to the question of sustainable energy. It will be shown that by applying straightforward calculations, it is possible to construct a plan for sustainable energy that adds up. We don’t need to pick sides or make leaps of faith. We only need basic arithmetic.

The Global Energy Context

Global primary energy consumption in 2022 was approximately 570 EJ (exajoules), equivalent to about 158,000 TWh. Of this, about 82% came from fossil fuels:

  • Oil: 31%
  • Natural Gas: 24%
  • Coal: 27%
  • Nuclear: 4%
  • Hydro: 7%
  • Renewables: 7%

This reliance on carbon-based fuels results in annual CO₂ emissions of over 36 billion tonnes from energy-related activities alone.

The Physics of Energy Conversion

All energy conversions are governed by the laws of thermodynamics. The First Law states that energy cannot be created or destroyed, only converted from one form to another. The Second Law tells us that in any conversion, some energy is always “lost” to heat—meaning no conversion can be 100% efficient.

These laws are inviolable. They set hard limits on what is physically possible. No amount of innovation or investment can circumvent them.

Hydrogen: A Promising Vector

Hydrogen (H₂) is often proposed as a clean energy carrier. When produced via electrolysis from renewable electricity, it offers a pathway to store and transport energy without direct carbon emissions.

Key figures for hydrogen:

  • Energy content: 120 MJ/kg (lower heating value) or 142 MJ/kg (higher heating value)
  • Electrolysis energy requirement: approximately 39.7 kWh per kg H₂ (practical systems)
  • Theoretical minimum: 39.4 kWh/kg (based on thermodynamics)
  • Current industrial efficiency: 60-80%

Hydrogen fuel cells convert hydrogen back to electricity with efficiencies of 40-60% (PEMFC type), producing only water as a byproduct.

The Approach of This Series

This series will systematically examine:

  1. The current energy demand of a representative industrialized economy
  2. The physics of various energy conversion pathways
  3. The technical potential of renewable energy sources
  4. The role of hydrogen as an energy carrier and storage medium
  5. The economics and practical constraints of a sustainable transition

Each part will rely on publicly available data and basic physics calculations. The goal is not to advocate for any particular technology but to show what is physically and technically achievable.

The numbers are what they are. Our job is to understand them and act accordingly.

In the next installment, we examine the actual energy consumption of an industrialized nation and calculate what substitution of fossil fuels would actually require.

This series is adapted from academic research on sustainable energy systems and hydrogen technology conducted at leading European technical institutions.