Helion is a fusion developer founded in 2013 and based in Everett, Washington. It develops pulsed FRC compression and direct electromagnetic energy recovery, targeting a deuterium–helium-3 fuel cycle while testing other fuel mixtures.
Reviewed 17 October 2026. Design targets, experimental reports and issuer statements are distinguished below.
History and approach
Helion was founded in 2013 by David Kirtley, John Slough, Chris Pihl and George Votroubek.[1] It develops pulsed systems that merge and compress FRC plasmas, then seek to recover electrical energy through electromagnetic induction.[2] Its intended D–He-3 cycle includes neutron-producing side reactions and tritium management.[3]
Experimental programme
Polaris followed the Trenta prototype and was reported operating by January 2025.[4] In February 2026, Helion announced measurable D–T fusion and approximately 150 million °C plasma temperatures.[5] The current Polaris page defines its objective as converting some fusion energy into electricity stored in capacitor banks, explicitly revising the earlier use of “net electricity”. This is distinct from demonstrating a positive whole-facility electricity balance.[6]
Planned commercial projects
The 2023 Microsoft agreement targeted startup in 2028 and at least 50 MW after a one-year ramp-up.[7] Helion reports construction activity for Orion in Malaga, Washington.[5] Nucor announced a separate 500 MW development collaboration and $35 million investment.[8] These arrangements are not evidence of electricity already delivered. Remaining development requirements include repeatability, materials lifetime and fuel processing.[3]
Financing and funding records
These are traceable public records, not an exhaustive account of undisclosed financing. Investor lists are non-exhaustive. Early auxiliary records have weaker evidence.
| Announcement / disclosure | Type or round | Amount (original currency) | Disclosed investors | Basis and references (Chinese notes) |
|---|---|---|---|---|
| 2014-08 | 早期投资 / Early investment | USD 1.5 million | Y Combinator、Mithril | 同期媒体记录；早期轮次命名并不统一。[9] |
| 2015-07（辅助记录） | 早期融资 / Early financing | 约USD 10.6 million | 数据库仅列私人投资者 | Gaebler记录；未取得对应一手交割公告。[10] |
| 2016-01（辅助记录） | 数据库标注B轮 / Database-labelled Series B | 约USD 21.3 million | 未据一手文件确认完整名单 | 仅作为融资史补充线索，不据此推定缺失C轮或精确累计值。[11] |
| 2020-09-23 | D轮 / Series D | USD 40 million | Dustin Moskovitz领投 | 公司披露累计7780万美元；公告称于前一日完成交割。[12] |
| 2021-11-05 | E轮 / Series E | USD 500 million | Sam Altman领投；Dustin Moskovitz、Mithril、Capricorn等 | 另有17亿美元附里程碑条件的投资机会，不计为本轮已到账金额。[13] |
| 2023-09-27 | 战略投资 / Strategic investment | USD 35 million | Nucor | 伴随500 MW项目合作披露；不同于购电合同金额。[8] |
| 2025-01-28 | F轮 / Series F | USD 425 million | Lightspeed、SoftBank Vision Fund 2、大学捐赠基金及原有投资者 | 公告投后估值54.25亿美元，累计融资超过10亿美元。[4] |
| 2026-06-04；2026-09更新 | G轮 / Series G | 首关USD 465 million；最终USD 500 million | Thrive Capital领投；Alta Park、Anti Fund、BoxGroup、Lux、Peak XV及原有投资者 | 9月扩募后最终5亿美元，与首关4.65亿美元为同一轮；6月公告投后估值155亿美元。[14] |
The $465 million first close and $500 million final Series G close are the same round. The 2021 conditional $1.7 billion is not counted as cash received. The June 2026 cumulative $1.5 billion is rounded and is not recalculated into a purported exact September total.
References
- Reuters. Nuclear startup Helion hits $15.5 billion valuation in latest funding round. 2026-06-04. [独立通讯社] Accessed: 2026-10-17.
- Helion. Technology. 动态网页. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Frequently Asked Questions. 网页标注更新2026-05-18. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Helion Announces $425M Series F Investment. 2025-01-28. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Helion Achieves New Fusion Energy Milestones. 2026-02-13. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Polaris: Converting fusion energy into electricity. 动态网页. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Helion announces fusion energy purchase agreement with Microsoft. 2023-05-10. [机构或企业一手公告] Accessed: 2026-10-17.
- Nucor. Nucor and Helion to Develop Historic 500 MW Fusion Power Plant. 2023-09-27. [交易对方公告] Accessed: 2026-10-17.
- TechCrunch. Y Combinator And Mithril Invest In Helion, A Nuclear Fusion Startup. 2014-08-14. [独立科技媒体；本次核对限摘要] Accessed: 2026-10-17.
- Gaebler. Helion Energy Funding Round. 2015-07-07. [融资数据库；辅助来源] Accessed: 2026-10-17.
- Seedtable. Helion Energy Funding Rounds. 动态网页. [融资数据库；辅助来源] Accessed: 2026-10-17.
- Helion. Fusion Energy Startup Helion Energy Closes Latest Funding Round at $1.25B Valuation. 2020-09-23. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Helion Raises $500 Million, Targets 2024 for Demonstrating Net Electricity from Fusion. 2021-11-05. [机构或企业一手公告] Accessed: 2026-10-17.
- Helion. Helion Raises $465 Million Series G Funding Round（附2026年9月最终交割更新）. 2026-06-04；2026-09更新. [机构或企业一手公告] Accessed: 2026-10-17.