Energy · Updated July 2026Momentum · accelerating ↗

How close are we to fusion power?Can we bottle a star?

or, simply: Can we bottle a star?or, precisely: How close are we to fusion power?

Fusion has crossed scientific breakeven, but an economical power plant still requires a much harder engineering breakeven.We have made a tiny star flash in a laboratory; now we have to turn that flash into a dependable power station.

We are here

NIF achieves ignition — 3.15 MJ out from 2.05 MJ of laser energy — scientific breakeven, a 70-year milestone. Next up — SPARC targets Q > 10 (expected 2027).

01 · Where we stand

Four tests between here and the goal

Each threshold is a falsifiable claim with a named next test. We move the meter only when a result is public.

Scientific ignitionGet more energy out of the fuel than we shine in✓ Achieved · Dec 2022

100%

Proven byNIF, 3.15 / 2.05 MJ

Engineering breakevenMake the whole power station pay back its energyEarly

40%

Next testSPARC targets Q>10, 2027

Grid economicsMake fusion cheap enough for the gridEarly

12%

Next testARC pilot plant, early 2030s

THRESHOLDS — Thresholds for Nuclear Fusion.

Scale

NOTE — Q = energy out ÷ energy in. Below 1: a science project. Above ~30: a power plant.

02 · How we got here

The record behind the verdict

Major events set large; context events set small but never hidden. Everything below the TODAY rule is a schedule, not a result.

1920–19502 events1 shown

The theory takes shape

Fusion moved from a stellar explanation to a laboratory proposition. The basic reaction was understood before anyone had a machine capable of holding it.

1920

Eddington proposes stellar fusion

Suggests the Sun runs on hydrogen fusing into helium — the principle behind all fusion research.

A. Eddington

1934

Fusion achieved in a labTheory

Oliphant and Rutherford fuse deuterium, confirming the reaction is reproducible on Earth.

Oliphant & Rutherford

1950–19903 events1 shown

The machines are built

The first generation of confinement machines turned equations into experiments. Tokamaks, large facilities, and sustained plasma became the field’s shared engineering language.

1958

The tokamak is bornExperiment

Soviet T-1 begins the magnetic-confinement line that still dominates fusion research.

Kurchatov Institute

1968

T-3 stuns the field

Soviet tokamak reaches ~10 million °C; Western labs pivot en masse to the tokamak.

USSR

1983

JET switches on

Europe's Joint European Torus begins operation — long the largest tokamak in the world.

EUROfusion

1990–20224 events2 shown

Chasing breakeven

Decades of larger machines narrowed the gap to useful gain, but each record exposed another layer between hot plasma and a power station.

1991

First controlled fusion power

JET produces ~1.7 MW of fusion power for the first time in a controlled experiment.

JET

1997

JET record: Q = 0.67Experiment

16 MW of fusion power from 24 MW in — the gain record that stood for 25 years.

JET

2006

ITER agreement signedFunding

Seven parties commit to the largest tokamak ever — a $20B+ bet on burning plasma at scale.

ITER (35 nations)

2021

Private fusion wave

Commonwealth Fusion raises $1.8B; the private fusion sector passes $5B cumulative funding.

CFS · Helion · TAE

2022–20352 events2 shown

From physics to power

NIF crossed scientific breakeven, while high-field magnets opened a smaller reactor path. The frontier is now engineering gain, maintainability, and affordable electricity.

2022

NIF achieves ignitionExperimentWe are here

3.15 MJ out from 2.05 MJ of laser energy — scientific breakeven, a 70-year milestone.

LLNL

TODAY · below this line: schedules, not results

2027

SPARC targets Q > 10ExperimentTarget

Commonwealth Fusion's compact high-field tokamak aims to prove net-energy plasma with REBCO magnets.

CFS · scheduled

2035–20351 event0 shown

Events outside the declared eras

Events outside the declared eras begins with arc — first electricity. The result established the next question for the field.

2035

ARC — first electricityExperimentTarget

A proposed pilot plant intended to put fusion-generated power on the grid for the first time.

CFS · proposed

03 · The data behind the verdict

Why the meters read the way they do

The learning curves and comparisons that justify each threshold's percentage. Every series is measured, with the source event linked in the timeline above.

The Q ladder

From plasma experiment to power plant

19.5×goal ÷ best observed

Observed QCommercial goalScientific breakeven

NOTE — Q = energy out ÷ energy in. Below 1: a science project. Above ~30: a power plant.

Private capital entering fusion — momentum and belief, not yet capability.

NOTE — Private capital entering fusion — momentum and belief, not yet capability.

ITER programme (lifetime, public)22 $B
Private fusion raised (total)7.1 $B

COMPARISON — The public megaproject still dwarfs any single private raise — but the private sector now rivals it in total committed capital.

04 · What it unlocks

If the remaining tests pass

Downstream capabilities, drawn dashed because they depend on results not yet in.