“Helion remains on track to become the first fusion company in the world to generate electricity from its Polaris test reactor later in 2025: 'Early testing has been encouraging, and they expect to demonstrate electricity this year.'”

Helion EnergyCEO

Fusion energy startup (CEO David Kirtley); Microsoft's contracted fusion power supplier

No electricity demonstration was announced by the end of 2025. Polaris' announced milestones in February 2026 were measurable D-T fusion and 150 million °C plasmas, and by September 2026 Helion had softened its language and hedged on when it would sell fusion electricity.