01 / 09

CREST Gold Award 2026

Why don't we use Nuclear Fusion for a large proportion of our energy yet?

Ralph Pahwa
Ore Olushola
Hriday Nijhawan

Tokamak interior

Physics 01

What is Fusion?

  • Combines light elements in the form of plasma
  • Fusion is often done with the nuclei of light atoms like hydrogen isotopes
  • Forms helium and excess neutrons
  • The nuclei need to collide with each other at very high temperatures, over 10 million °C
Deuterium-Tritium fusion diagram

Deuterium-Tritium nuclear fusion mechanism

Physics 02

What is Plasma?

  • Some of the electrons are freed from the atoms or molecules, it changes state and becomes a plasma
  • It consists of a partially ionised gas, containing ions, electrons, and neutral atoms
  • Plasma is often contained by high strength electromagnets
States of matter

States of matter and plasma

Physics 03

Magnetic Confinement

  • The plasma is confined by powerful magnetic fields, holding it away from material surfaces, using the toroidal geometry of tokamak devices
Tokamak schematic

A tokamak reactor

Physics 04

Inertial Confinement

  • Laser beams vaporise a Hohlraum cavity, producing X-rays that compress a D-T fuel pellet to ignition
  • The pellet reaches around 100 million °C, allowing fusion to occur
  • Mass difference between reactants and products is released as energy via E=mc²
🔬

Hohlraum with D-T fuel pellet
Inertial Confinement Fusion

ICF compression and ignition sequence

Overview 05

The benefits and drawbacks
of nuclear fusion

Benefit

Nuclear fusion produces nearly four million times the amount of energy than burning oil or gas, and four times the amount of energy for nuclear fission

Drawback

Temperatures exceeding 10 million °C are required. Maintaining this along with high-pressure requirements may melt the container and let plasma escape

Benefit

The fusion process releases no greenhouse gases nor toxic atmospheric pollutants. Unlike fission, it leaves no radioactive waste that is difficult to dispose of

Drawback

Breaking even on a fusion reactor requires a Q factor of 1. Achieving Q above 1 consistently remains one of the central unsolved challenges in fusion research

Economics and Business 06

Economic and
Business barriers.

  • Fusion target: ~$80-100/MWh to compete with wind and solar by 2040
  • Decades of R&D before a single unit of electricity is produced
  • $10bn raised by fusion start-ups since 2020, but no revenue yet
  • High-risk, time needed, dependent on investors
$10bn
raised by fusion start-ups since 2020 (IEA)
$80-100
per MWh needed to compete by 2040
Helion fusion reactor

Helion Energy fusion reactor system

Politics 07

Political Factors

  • 40 countries now run active fusion programmes (IAEA)
  • Governments building regulation and policy frameworks, but slowly
  • ITER delays caused by international cost disputes
  • Fossil fuel lobbying actively slows development
ITER construction aerial

ITER under construction, Cadarache, France

Conclusion 08

Fusion isn't just
a physics problem.

The science is advancing. The barriers are systemic.

⚛️
Scientific
Plasma containment, the Q-factor barrier, and materials that can withstand neutron bombardment remain unsolved engineering challenges
📈
Economic
Costs are uncompetitive, timelines run decades, and the business model relies on potential rather than revenue
🏛️
Political
International cooperation slows progress; lobbying from incumbent energy interests actively hinders development