Fusion Energy Calculator

Calculate energy released from nuclear fusion reactions

Fusion Parameters

Select fusion reaction and mass to calculate energy release

kg
%
MeV
Total Energy Released
3.4 × 10¹⁴
Joules
Usable Energy
1.1 × 10¹⁴
Joules (after efficiency)
Equivalent TNT
81,300
Tons
Homes Powered
2,859
For 1 year
Understanding Nuclear Fusion

Nuclear fusion is the process where two light atomic nuclei combine to form a heavier nucleus, releasing enormous amounts of energy.

  • Power source of stars like our Sun
  • Requires extremely high temperatures (>100 million °C)
  • Produces no long-lived radioactive waste
  • Potential for virtually limitless clean energy
  • Deuterium can be extracted from seawater
Fusion Energy Formulas
E = Δm × c²
Δm = mass defect
c = speed of light (3 × 10⁸ m/s)
Where:
E = Energy released
Δm = Mass defect (kg)
c = Speed of light (m/s)
Typical mass defect: ~0.7% of original mass
Fusion Reactions
Reaction Equation Energy Released Temperature Required
Deuterium-Tritium D + T → He⁴ + n 17.6 MeV 100 million °C
Deuterium-Deuterium D + D → He³ + n 3.65 MeV 300 million °C
Deuterium-Helium-3 D + He³ → He⁴ + p 18.3 MeV 500 million °C
Proton-Proton p + p → D + e⁺ + ν 1.44 MeV 15 million °C
Carbon-Nitrogen-Oxygen Multiple steps 26.7 MeV 15 million °C
Fusion Facts
  • Fusion powers the Sun and all stars
  • 1 kg of fusion fuel can produce energy equivalent to 10 million kg of coal
  • Deuterium from one liter of seawater could produce as much energy as 300 liters of gasoline
  • ITER is building the world's largest fusion reactor in France
  • Fusion produces no greenhouse gases or long-lived radioactive waste

Stellar Nucleosynthesis: Fusion reactions in stars create heavier elements from lighter ones, starting from hydrogen and helium.

Stars generate energy through nuclear fusion in their cores:

  • Main sequence stars fuse hydrogen into helium via the proton-proton chain
  • Massive stars use the CNO cycle for hydrogen fusion
  • As stars evolve, they fuse heavier elements (helium, carbon, oxygen)
  • Each fusion step releases energy that counteracts gravitational collapse

The Sun fuses about 620 million tons of hydrogen per second, converting 4 million tons to energy via E=mc².

Fusion requires overcoming the Coulomb barrier - the electrostatic repulsion between positively charged nuclei:

  • Nuclei must be heated to extremely high temperatures (millions of degrees)
  • Plasma must be confined at sufficient density
  • Confinement must be maintained long enough for reactions to occur
  • Materials must withstand extreme conditions

Current approaches include magnetic confinement (tokamaks) and inertial confinement (laser fusion).

In fusion research, Q-value represents the ratio of fusion power output to heating power input:

  • Q < 1: Net energy loss
  • Q = 1: Breakeven (energy out = energy in)
  • Q > 1: Net energy gain
  • Q ≈ 10: Required for practical power plants

In December 2022, the National Ignition Facility achieved Q=1.5, the first scientific breakeven in a fusion experiment.

Fusion offers several advantages as an energy source:

  • Abundant fuel: Deuterium from seawater, tritium bred from lithium
  • No greenhouse gases: Only produces helium as byproduct
  • Inherently safe: No risk of runaway reactions
  • Minimal radioactive waste: Short-lived compared to fission
  • No weapons-grade materials: Cannot be used for nuclear weapons

Fusion could provide baseload power with minimal environmental impact.