● OPERATIONAL / PE−HX−01
HELIOS−1.
A 200 MWₜ spherical tokamak. The smallest production-grade fusion reactor anyone is building.
Thermal
200 MW
Fuel
D−T
Footprint
0.4 ha
Status
Online
NOW OPERATING / TEST REACTOR HELIOS−PRIMEEST. 2019 · PASADENA · ABU DHABI · OSAKA
POWER
THE IMPOSSIBLE.
EVERYTHING ELSE
IS WALLPAPER.
We're building compact, dispatchable fusion reactors — small enough to sit beside a datacenter, hot enough to run a city. Limitless. Clean. Commercial by 2031.
FROM THE FOUNDER
“The old grid was designed for the world that existed in 1962. We're not retrofitting it. We're replacing it. If that sounds arrogant, wait until you see the data.”
— Dr. Yara Kessler, Co−founder & CEO
11.4MW
Net thermal output, Helios−Prime test article (Q1 2026)
$842M
Total committed capital, Series C-2 (closed Mar 2026)
317
Engineers, plasma physicists & reactor technicians across three sites
LIVE FEED · HELIOS−PRIMEPLASMA TEMP 152 M KCONFINEMENT τₑ 3.4 sNET Q 1.62SHOT #04,178TRITIUM LOOP NOMINALCRYO −268.4 °CNEXT MAINTENANCE WINDOW 14 MAY 2026
LIVE FEED · HELIOS−PRIMEPLASMA TEMP 152 M KCONFINEMENT τₑ 3.4 sNET Q 1.62SHOT #04,178TRITIUM LOOP NOMINALCRYO −268.4 °CNEXT MAINTENANCE WINDOW 14 MAY 2026
/ 01 — OUR PURPOSE
Humanity's energy budget will 3× by 2055. The grid that delivers it doesn't exist yet. We're building it.
Planet Energy designs and operates compact magnetic-confinement fusion reactors. Each unit produces a sustained 50–200 MW of dispatchable thermal energy, with a physical footprint smaller than a regulation football pitch. No fission. No long-lived waste. No carbon. Available wherever load wants it — beside hyperscale compute, desalination, hydrogen synthesis, or grid balancing.
/ 02 — WHAT WE BUILD
THREE
SYSTEMS.
ONE GRID.
A vertically-integrated stack: the reactor that makes the heat, the turbine block that converts it, and the orchestration layer that sells it onto the grid in millisecond increments.
● SHIPPING Q4 2027 / PE−TX−02
PULSE.
Closed-loop sCO₂ turbine block. Replaces a 1970s steam hall with a shipping-container-sized power conversion island.
Conversion
52%
Working fluid
sCO₂
Footprint
24 m²
Status
In production
● PILOT — TX ERCOT / PE−GX−03
GRID−X.
Real-time dispatch and settlement engine. Every joule we make is sold before it leaves the reactor.
Latency
12 ms
Markets
9 ISOs
Cleared
$117 M
Status
Pilot
152M K
Sustained plasma core temperature — 10× the surface of the sun
1.62Q
Energy gain ratio. Net−positive for 38 of the last 42 shots
0g
Long-lived radioactive waste per gigawatt−year of operation
$31/MWh
Projected unsubsidised LCOE at first commercial unit, 2031
/ 03 — WHAT THEY'RE SAYING
“Planet Energy is doing in a decade what the public sector said would take half a century. The implications for industrial policy are not subtle.”
— THE ECONOMIST, ENERGY BRIEF · NOV 2025
As featured in
BLOOMBERG
The Economist
WIRED
MITTECH REVIEW
REUTERS
FTENERGY
Backed by
Lowercase Capital · Founders Fund · Khosla Ventures Breakthrough Energy · Temasek · ARK Invest · Octopus Energy
/ 04 — TALK TO US
LET'S MAKE
A REACTOR
YOUR PROBLEM.
We sell heat, electrons, and the orchestration that gets them to load. If you operate a datacenter, a port, a fab, a desalination plant, or a small country — we should talk.