WASHINGTON: Global fusion energy investment growth fell for a second year, an industry group said in an annual survey on Tuesday, amid difficulties in raising capital for a technology that one day could revolutionize the energy industry but has major hurdles.

Investments rose more than $900 million this year to a total of about $7.1 billion, the Washington-based Fusion Industry Association said. But the growth in new investments is lower than the jump of $1.4 billion in last year's survey and the leap of $2.8 billion in 2022, it said.

"The growth seen in the last 12 months is positive, but will not be enough to deliver fusion’s ambitious goals," said Andrew Holland, the head of FIA. Fusion "needs continued support from public and private investors if it is to continue to innovate," he said.

Fusion, which fuels the sun and stars, is in the experimental stage on Earth, but could one day generate enormous amounts of energy that emits virtually no greenhouse gas and without generating large amounts of long-lasting radioactive waste.

Physicists in government and private labs are working to replicate fusion reactions by forcing together light atoms with technology including lasers or giant magnets. Hurdles include getting reactions to occur almost continuously, lowering the amount of energy needed to kick off reactions, and building systems to capture the energy and send it to power grids.

In the survey, 89% of the companies said that fusion will provide electricity to the grid by the end of 2030s, about the same level they predicted in 2021, the first year of the survey. But about 66% of the respondents said they believe funding will be a barrier to success. The survey included 45 fusion companies, up two from last year.

A bright spot was global public funding into private fusion companies which jumped about 57% to $426 million, FIA said. Countries including the United States, China, Japan, the UK and Germany are pursuing fusion.

(Reporting by Timothy Gardner in Washington Editing by Matthew Lewis)