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    Fusion energy in 2026: a crash course

    Fusion energy aims to generate power by fusing light nuclei, usually deuterium and tritium, which releases nearly four million times more energy than burning fossil fuels and emits no carbon dioxide.[1][2][3] As of October 2026, laser fusion has reached ignition 11 times but its lasers still draw far more electricity than the fusion releases; ITER's deuterium-tritium experiments are scheduled for 2039, and private firms promise power plants from 2028 onward.[4][5][6][7]

    Editor reviewedUpdated Fusion energyEnergy and climatePhysics

    Why fusion matters

    Fusion is the process that powers the Sun: light atomic nuclei join to form a heavier one and release energy.[8] On Earth, the easiest reaction joins two forms of hydrogen, deuterium and tritium, which produces helium and a neutron.[1] Gram for gram, it releases nearly four million times more energy than burning coal, oil or gas, and it emits no carbon dioxide.[2][3] Deuterium can be taken from ordinary water.[9] The catch is that the fuel has to be heated to about 150 million degrees Celsius.[10]

    The field is chasing a heat source with no carbon emissions, a fuel supply measured in millennia, and no high-activity, long-lived waste.[3][11][12] Deuterium-tritium (D-T) is the reference fuel because it is the easiest reaction to drive in the laboratory, but it brings two engineering burdens: tritium has to be bred from lithium, and 14 MeV neutrons damage materials.[1][13][14] Performance is tracked by the Lawson triple product of density, temperature and confinement time, and by the gain Q (fusion power out divided by heating power in).[15][16]

    A map of the field

    Fusion approaches differ in how they hold the hot fuel together. Magnetic confinement holds a plasma in magnetic fields long enough for reactions to happen.[17] Inertial confinement heats and compresses a fuel capsule fast enough to reach fusion conditions.[18] The course pages cover each branch:

    Key ideas in one minute

    Three numbers matter: how hot the fuel is, how dense it is, and how long it holds its heat. Multiplied together they give the “triple product”, which must pass a threshold first worked out by John Lawson in 1955.[27][15] “Ignition” at NIF means the fuel capsule gave off more energy than it absorbed.[28] That is not the same as a power plant producing more electricity than it uses.[5]

    Several gain figures are in circulation, and they are often confused. NIF’s best target gain is 4.13 (8.6 MJ out for 2.08 MJ of laser energy).[29] Measured against the roughly 300 to 400 MJ its lasers draw from the grid per shot, overall gain is far below 1.[5] ITER targets a plasma gain of Q of at least 10, which means 500 MW of fusion power from 50 MW of heating.[16] SPARC aims for Q greater than 1.[20] None of these figures is the same as net electricity.

    Who the main players are

    Public programmes still anchor the science. ITER, built in France by seven members, is the largest machine and is assembling its vacuum vessel.[30][31][32] Lawrence Livermore’s NIF leads laser fusion.[4] Germany’s Max Planck Institute for Plasma Physics runs Wendelstein 7-X.[22] China’s EAST holds a 1,066-second high-confinement record, and China is building BEST, a burning-plasma tokamak aimed at demonstrating electricity around 2030.[33][34]

    Private capital has grown fast. The Fusion Industry Association counted 56 companies employing over 16,000 people, which raised $4.48 billion in the year to July 2026.[35][36] The largest recent rounds went to Commonwealth Fusion Systems, Proxima Fusion, Helion and Inertia Enterprises.[37] Tech companies have become customers: Microsoft has a power purchase agreement with Helion, and Google has one with CFS.[38][39]

    Where the frontier is (October 2026)

    • Ignition is repeatable but not yet efficient. NIF reached its 11th ignition in June 2026, and a 20 percent laser upgrade is starting.[4][40]
    • The net-energy race among magnetic machines. CFS said SPARC was almost 80 percent complete in August 2026 and publicly targets Q>1 in 2027, without naming a first-plasma date.[41][42][43] Helion says its Polaris prototype produced measurable D-T fusion in early 2026, a result not yet independently verified, and that it is building its Orion plant for a 2028 start.[44][7] General Fusion reported a 1 keV electron temperature on LM26 in October 2026, measured with the UK Atomic Energy Authority.[25][45]
    • ITER’s components are all on site. The ninth and final vacuum vessel sector was delivered on 5 October 2026, and sector module 9 is due in the pit in early December.[46][47]
    • Public money and rules are moving. Germany launched a milestone-based fusion programme on 7 October 2026, with 500 million euros by 2029 and up to 2.5 billion euros in total; Japan’s METI runs a comparable scheme; and two bipartisan fusion bills were introduced in the US Congress in late September 2026.[48][49][50][51]
    • Long pulses. In 2025, WEST ran for 1,337 seconds and Wendelstein 7-X held a record triple product for 43 seconds.[52][53]
    • Engineering gaps. The US Department of Energy’s 2025 roadmap lists the remaining gaps: materials, plasma-facing components, the fuel cycle, blankets and plant integration.[54]
    • Regulation. The NRC proposed a fusion rule under its byproduct-material framework in February 2026; no final rule had been dated by October.[55][56]

    The timeline debate has its own analysis page, and dated milestones are in the tracker.

    Questions readers ask

    Has anyone produced more energy from fusion than they put in?

    Yes, but only at the level of the fuel target. The National Ignition Facility first got more fusion energy out than laser energy in on 5 December 2022 and had done so 11 times by June 2026. Its lasers still draw roughly 300 to 400 megajoules from the grid per shot, so it is nowhere near overall break-even.[23][4][5]

    When will ITER start fusion experiments?

    Under its 2024 baseline, ITER starts research operation in 2034 and deuterium-tritium operation in 2039.[6]

    How much private money is going into fusion?

    The Fusion Industry Association counted $4.48 billion raised by 56 companies in the 12 months to July 2026, and $14.24 billion in total since 2021.[35]

    Is fusion power safe?

    According to ITER, a fusion plasma cools within seconds if anything goes wrong and the machine holds only a few seconds of fuel, so a runaway reaction is not possible. Fusion also produces no high-activity, long-lived waste.[57][12]

    Sources

    Each numbered claim is a statement we checked against the sources listed with it. Status shows how well established it is.

    1. [1]

      The most efficient fusion reaction in the laboratory is between the hydrogen isotopes deuterium and tritium, which produces helium and one neutron. confirmedas of 2026-10-10

    2. [2]

      Controlled fusion releases nearly four million times more energy than a chemical reaction such as burning coal, oil or gas. confirmedas of 2026-10-10

    3. [3]

      Fusion does not emit carbon dioxide or other greenhouse gases. confirmedas of 2026-10-10

    4. [4]

      On 20 June 2026 NIF achieved ignition for the 11th time, with a yield of 7.9 megajoules and a target gain of about 3.8. confirmedas of 2026-10-10

    5. [5]

      NIF's lasers draw roughly 300 to 400 megajoules of electricity to deliver a 2-megajoule shot, so its ignition shots are far from overall energy break-even. confirmedas of 2026-10-10

    6. [6]

      ITER's 2024 baseline schedules the Start of Research Operation in 2034, deuterium-deuterium operation in 2035, full magnetic energy in 2036 and the start of deuterium-tritium operation in 2039, about four years later than the 2016 plan. confirmedas of 2026-10-10

    7. [7]

      Helion's first commercial plant, Orion, in Chelan County (Malaga), Washington, is designed to deliver at least 50 megawatts and begin initial operations in 2028. confirmedas of 2026-10-10

      • Orion · Helion Energy (retrieved 2026-10-10)
    8. [8]

      Fusion, the process that powers the Sun and the stars, occurs when two light atomic nuclei combine to form a new, heavier nucleus, releasing energy. confirmedas of 2026-10-10

    9. [9]

      Deuterium can be distilled from all forms of water. confirmedas of 2026-10-10

    10. [10]

      Deuterium-tritium fusion in the laboratory requires temperatures of about 150 million degrees Celsius. confirmedas of 2026-10-10

    11. [11]

      ITER estimates that easily extractable land-based lithium could supply fusion plants for more than 1,000 years, and lithium in seawater far longer. confirmedas of 2026-10-10

      • Fuelling · ITER Organization (retrieved 2026-10-10)
    12. [12]

      According to ITER, fusion reactors produce no high-activity, long-lived nuclear waste, and activated materials could be recycled or reused within 100 years. confirmedas of 2026-10-10

    13. [13]

      Tritium for future plants is to be bred when neutrons escaping the plasma react with lithium in a blanket lining the reactor wall. confirmedas of 2026-10-10

      • Fuelling · ITER Organization (retrieved 2026-10-10)
    14. [14]

      A key materials challenge is building components that can withstand the 14 MeV neutrons from deuterium-tritium fusion, energies that fission-reactor experiments cannot easily mimic. confirmedas of 2026-10-10

    15. [15]

      The triple product is the product of plasma density, energy confinement time and temperature, and is the standard figure of merit for fusion performance. confirmedas of 2026-10-10

    16. [16]

      ITER's main performance goal, Q of at least 10, means 500 megawatts of thermal fusion power from 50 megawatts of heating power put into the plasma, in 400-second pulses. confirmedas of 2026-10-10

    17. [17]

      Magnetic confinement fusion holds the plasma with carefully designed magnetic fields long enough for fusion reactions to occur. confirmedas of 2026-10-10

    18. [18]

      Inertial confinement fusion heats and compresses a fuel capsule rapidly enough to reach the temperatures and densities needed for fusion. confirmedas of 2026-10-10

    19. [19]

      The tokamak was first developed by Soviet researchers in the late 1960s and has been adopted worldwide as the most promising magnetic fusion configuration; its name is a Russian acronym for "toroidal chamber with magnetic coils". confirmedas of 2026-10-10

    20. [20]

      Commonwealth Fusion Systems says its SPARC tokamak in Devens, Massachusetts, is intended to be the first commercially relevant machine to demonstrate net fusion energy (Q>1). confirmedas of 2026-08-05

    21. [21]

      Because a stellarator has no plasma current, it can in principle run continuously (steady state) and is less prone to plasma instabilities than a tokamak. confirmedas of 2026-10-10

    22. [22]

      Wendelstein 7-X in Greifswald, Germany, confines its plasma with a system of 50 non-planar superconducting magnet coils and is designed for plasma discharges of up to 30 minutes. confirmedas of 2026-10-10

      • Wendelstein 7-X · Max Planck Institute for Plasma Physics (retrieved 2026-10-10)
    23. [23]

      On 5 December 2022 the National Ignition Facility produced 3.15 megajoules of fusion energy from 2.05 megajoules of laser energy, the first laboratory fusion ignition. confirmedas of 2026-10-10

    24. [24]

      Helion's machines magnetically compress pulsed, high-beta field-reversed configuration (FRC) plasmas and aim to recover energy directly as electricity rather than via heat and a steam turbine. confirmedas of 2026-10-10

    25. [25]

      On 8 October 2026 General Fusion said its LM26 magnetized target fusion machine had reached electron temperatures above 12 million degrees Celsius (more than 1 keV) by compressing plasma with a metal wall over milliseconds. reportedas of 2026-10-08

    26. [26]

      On 5 September 2021 MIT and Commonwealth Fusion Systems ramped a large high-temperature superconducting magnet to 20 tesla, the strongest fusion magnet of its kind. confirmedas of 2026-10-10

    27. [27]

      In 1955 the British physicist John D. Lawson estimated the parameters needed for fusion to give more energy out than is put in, setting a minimum for the product of plasma density, confinement time and temperature. confirmedas of 2026-10-10

    28. [28]

      LLNL defines ignition as a self-sustaining fusion reaction that produces more energy than the energy absorbed by the target capsule. confirmedas of 2026-10-10

    29. [29]

      On 7 April 2025 NIF set records for yield and target gain, producing 8.6 megajoules (plus or minus 0.45) from 2.08 megajoules of laser energy, a target gain of 4.13. confirmedas of 2026-10-10

    30. [30]

      ITER is being built in Saint-Paul-lez-Durance in southern France; Europe, as host, pays almost half of construction costs and China, India, Japan, South Korea, Russia and the United States share the rest equally. confirmedas of 2026-10-10

    31. [31]

      The ITER tokamak's volume and weight are nearly 10 times those of the largest existing tokamaks, and its combined toroidal field coils form a magnet with a cold mass over 6,000 tonnes storing 41 gigajoules. confirmedas of 2026-10-10

    32. [32]

      On 28 July 2026 ITER installed the sixth of nine vacuum-vessel sector modules in the tokamak pit, putting two-thirds of the tokamak core in place almost six months ahead of schedule, and says it is on track to place the last module in 2027. confirmedas of 2026-07-29

    33. [33]

      On 20 January 2025 China's EAST tokamak sustained a high-confinement plasma for 1,066 seconds, the first to pass 1,000 seconds, at nearly 70 million degrees Celsius. confirmedas of 2026-10-10

    34. [34]

      China's Burning Plasma Experimental Superconducting Tokamak (BEST), under construction in Hefei, is designed to burn deuterium-tritium plasma, achieve net fusion power gain and demonstrate fusion electricity generation by around 2030. confirmedas of 2026-01-19· forecast

    35. [35]

      In the 12 months to July 2026, 56 fusion companies raised $4.48 billion, bringing total private fusion funding reported since 2021 to $14.24 billion. confirmedas of 2026-07-13

    36. [36]

      The Fusion Industry Association surveyed 56 fusion companies in 2026, up from 23 in 2021, employing over 16,000 people. confirmedas of 2026-07-13

    37. [37]

      Large recent rounds include CFS's $863 million Series B2 (August 2025), Proxima Fusion's $518 million (July 2026), Helion's $465 million (June 2026) and Inertia Enterprises' $450 million Series A (February 2026). confirmedas of 2026-07-13

    38. [38]

      On 10 May 2023 Helion signed the first fusion power purchase agreement, to supply Microsoft from a plant expected online by 2028 and targeting at least 50 megawatts after a one-year ramp-up, with Constellation as power marketer. confirmedas of 2026-10-10

    39. [39]

      On 30 June 2025 Google agreed to buy 200 megawatts from CFS's ARC plant, which CFS called the largest fusion power purchase agreement to date, and made a new investment in the company. confirmedas of 2026-10-10

    40. [40]

      NIF's Enhanced Yield Capability project, beginning in 2026, will raise its laser energy by 20 percent, with the aim of fusion yields of 30 megajoules and beyond. confirmedas of 2026-03-12

    41. [41]

      As of 5 August 2026 CFS said SPARC was almost 80 percent complete. reportedas of 2026-08-05

    42. [42]

      As of October 2026 Commonwealth Fusion Systems publicly targets 2027 for SPARC to produce more energy from fusion than is needed to power the process, the Q>1 threshold. reportedas of 2026-10-10· forecast

    43. [43]

      In a company blog post current as of October 2026, CFS said it would start operating SPARC "in coming months" and that SPARC is designed to reach Q>10, so Q>1 is not an extremely difficult milestone; CFS has not published a dated first-plasma target. reportedas of 2026-10-10

    44. [44]

      On 13 February 2026 Helion said its Polaris prototype was the first privately developed fusion machine to demonstrate measurable deuterium-tritium fusion and had reached plasma temperatures of 150 million degrees Celsius; Helion also said it was the first company approved to possess and use tritium to demonstrate fusion energy production. reportedas of 2026-02-13

    45. [45]

      General Fusion's October 2026 Thomson scattering measurement on LM26 was made in collaboration with the UK Atomic Energy Authority, and is described in a joint statement and a paper co-authored with UKAEA that was submitted for peer review. reportedas of 2026-10-08

    46. [46]

      On 5 October 2026 ITER took delivery of vacuum vessel sector confirmedas of 2026-10-05

    47. [47]

      As of September 2026 ITER was completing sub-assembly of sector module confirmedas of 2026-09-07

    48. [48]

      On 7 October 2026 Germany's Federal Agency for Breakthrough Innovation (SPRIND) launched a milestone-based fusion programme for the research ministry, providing 500 million euros by 2029 with total public funding intended to rise to as much as 2.5 billion euros. confirmedas of 2026-10-07

    49. [49]

      Japan's Ministry of Economy, Trade and Industry runs a milestone-based programme supporting private fusion demonstration across tokamak, stellarator and laser approaches, with about 60 billion yen of government support anticipated over the three years to 2028; Helical Fusion was named a final candidate on 31 August 2026. reportedas of 2026-08-31

    50. [50]

      On 24 September 2026 a bipartisan group of US representatives introduced the American Leadership in Fusion Act, which would create a Senate-confirmed Assistant Secretary of Fusion Energy, codify the Department of Energy's Office of Fusion and add $10 billion in direct appropriations. reportedas of 2026-09-24

    51. [51]

      A bipartisan permitting bill introduced in the US Senate on 30 September 2026, the American Affordability and Jobs Act of 2026, includes fusion machines that produce electricity among the projects it would treat on the same footing as other energy projects; a procedural vote was scheduled for 9 November 2026. reportedas of 2026-10-05

    52. [52]

      On 12 February 2025 France's WEST tokamak set a plasma-duration record of 1,337 seconds (about 22 minutes). confirmedas of 2026-10-10

    53. [53]

      On 22 May 2025 Wendelstein 7-X sustained a record triple product for long plasma discharges for 43 seconds, surpassing tokamak results for comparable durations. confirmedas of 2026-10-10

    54. [54]

      The DOE roadmap identifies research, materials and technology gaps to close for a fusion pilot plant across structural materials, plasma-facing components, confinement systems, fuel cycle, blankets, and plant engineering and integration. confirmedas of 2026-10-10

    55. [55]

      On 26 February 2026 the US Nuclear Regulatory Commission proposed amending its byproduct-material framework (10 CFR Part 30) to cover fusion machines, with technology-inclusive requirements, and took comments until 27 May 2026. confirmedas of 2026-10-10

    56. [56]

      The NRC's rulemaking status page lists the February 2026 proposed rule as its latest milestone and gives no final-rule date; no final rule had been published by October 2026. confirmedas of 2026-10-10

    57. [57]

      According to ITER, a fusion plasma cools within seconds if disturbed and the vessel holds only a few seconds' worth of fuel, so a runaway reaction is not possible. confirmedas of 2026-10-10

    Revision history (2)
    1. Page created.
    2. Refresh: updated the frontier section with CFS's 2027 Q>1 target, ITER's completed component deliveries, General Fusion's UKAEA-measured result and the new German, Japanese and US funding and legislation.

    Created Oct 10, 2026. Last reviewed by an editor on Oct 10, 2026. Next scheduled review: Jan 10, 2027.

    Cite this page

    "Fusion energy in 2026: a crash course." ContentLora, updated Oct 10, 2026. https://contentlora.com/explain/fusion-energy

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