¶¶Òõ´«Ã½ÔÚÏß

The figure, which was included in the association's report, saw 56 fusion companies surveyed and brings the total raised over the six years to USD14.24 billion.

Major contributors to this year's figure were Commonwealth Fusion Systems, which raised USD863 million, Proxima Fusion, which raised USD518 million, Helion ¶¶Òõ´«Ã½ÔÚÏß, which raised USD465 million, and Inertia Enterprises, which raised USD450 million.

Also featuring for the first time was investment in companies planning to go public, with TAE Technologies and General Fusion both having listed their shares on the Nasdaq stock market.

The Fusion Industry Association (FIA) report says that five companies have a power purchase agreement - including Microsoft with Helion ¶¶Òõ´«Ã½ÔÚÏß and Google with Commonwealth Fusion Systems - offtake agreement "or similar commercial commitment". Six have a siting agreement, with four more "evaluating options".

Among the 56 companies surveyed by the FIA, 48% are focusing on magnetic confinement, 21% on inertial confinement and 14% on magneto-inertial. And nearly three-quarters of the companies - 71% - expect to see a fusion power plant delivering power to the grid "by the 2030s".

The key short-term challenge identified was funding, with longer-term challenges led by the availability of neutron-resilient materials, power efficiency and tritium self-sufficiency.

Andrew Holland, CEO of the US-based Fusion Industry Association, which describes itself as the voice of the world's private fusion industry, said: "This year's report shows how far fusion has come - from being defined by national labs and government R&D programmes to being dominated by private fusion investment totalling over USD4 billion in just one year. I'm confident that the sector has the ability to deliver commercial fusion in the 2030s. The existence of siting agreements and power purchase agreements shows that commercial fusion energy is on the horizon.

"However, alongside private investment, fusion companies still need the support of governments to address common challenges including the availability of resilient materials and the fusion fuel cycle. The governments that update their programmes and funding priorities to meet the sector's needs today will be the ones to capitalise on this vital emerging industry."