By Simon Jessop
LONDON, Oct 6 (Reuters) - US start-up Type One Energy has raised $200 million from investors including the venture unit of Germany's Siemens Energy, as it vies to build the world's first commercial fusion reactor, its chief executive told Reuters.
The Series-B round, which takes total funding to-date to more than $400 million, is the third-biggest sector Series B raise over the last five years, data from industry tracker PitchBook showed. The company did not disclose its valuation.
Fusion energy has been researched for decades. A wave of firms has launched in recent years as advances in magnets, computing and materials have fuelled hopes fusion technology could one day provide abundant clean power across the globe.
Type One is backed by Bill Gates' Breakthrough Energy Ventures and Clutterbuck Capital. It is developing a stellarator, a type of fusion reactor that uses complex magnetic fields to contain superheated plasma, partnering with engineering, construction and other companies to speed up delivery and reduce costs.
Chief Executive Christofer Mowry said the funds would help further develop its technology, including the deployment of an engineering prototype machine, Infinity One.
"It's not an experimental science project... the only thing that we want to learn is that our design for the fusion machine in the power plant works as advertised."
Project Infinity is based at Bull Run in Tennessee and Type One hopes to launch the commercial plant, Infinity Two, within a decade. It aims to work towards a manufacturing partnership with Siemens.
Enrique Gonzalez Zanetich, partner at Siemens Energy Ventures, said in a statement that the deal strengthened his company's position in fusion "as we continue to explore the technologies and collaborations that can help advance commercialization".
New investors alongside Siemens included Lowercarbon Capital, co-founded by early Uber backer Chris Sacca, and SiteGround Capital.
(Reporting by Simon Jessop; Editing by Susan Fenton)
