MILAN, April 13 (Reuters) - Italian energy group Eni is considering stepping up its investment in nuclear fusion, potentially doubling down on a technology considered so uncertain that Eni remains the only global oil company prepared to place a bet on it.
Eni and bigger rivals such as Shell and BP have been looking at moving into renewable energy as climate change, the falling cost of solar and wind power and a shift to electric vehicles raise doubts over long-term demand for oil.
Eni last month committed 50 million euros ($62 million) to one of several projects aiming to produce energy by fusing atoms at temperatures as hot as the sun, a process seen by doubters as still closer to science fiction than commercial reality.
After the move, Eni's head of development operations and technology, Roberto Casula, said it might raise its investment in Commonwealth Fusion System, a firm created by the Massachusetts Institute of Technology (MIT), which is developing the project.
"After the transition to renewable energy, the real breakthrough technologically is nuclear fusion," Casula said, adding the process involved recreating the physics of the sun, producing heat but no emissions and very limited nuclear waste.
Casula estimates it will cost $3 billion to develop a 200-megawatt fusion reactor by 2033 and says Commonwealth Fusion System is looking to raise more funds and to draw up an overall investment agreement with a range of financiers.
Casula and MIT declined to give the size of Eni's current stake, and the Eni executive could not say at this stage how much it would be ready to invest. He said Eni had signed a deal giving it the right to use the project's intellectual property.
"The eventual stake we'll have in the company will be decided when there is an overall investment agreement, depending also on how much they will raise," Casula said.
The MIT project is vying with research teams in France, China and Britain to develop a reactor that can generate more energy than the enormous amount that fusion consumes, and can also safely contain a mass of super-hot gases or plasma.
Italy also recently entered the race, though Eni is sticking with MIT, saying the Boston project is unique in its aim to produce electricity, while others have scientific objectives.
All projects are based on a system known as tokamak, which uses superconducting magnets to hold the plasma at temperatures of up to 100 million degrees, suspending it inside a vacuum chamber without it touching the chamber's walls.
To make electricity, heat produced by the fusion of hydrogen isotopes is used to spin steam turbines in the conventional way.
The France-based ITER project is the largest endeavour, with a budget of around 20 billion euros. A collaboration between Europe, the United States, China, India, Japan, Russia and South Korea, it is more than halfway towards the first test of its super-heated plasma by 2025 and first full-power fusion by 2035.
Unlike the MIT project, the International Thermonuclear Experimental Reactor (ITER) team does not plan to generate electricity, saying this will be further in the future, and is being supported by governments rather than the private sector.
"Based on our experience with the ITER project, we feel the MIT timeline to a power plant in 15 years is very ambitious, if not overly ambitious," ITER chief scientist Tim Luce said.
"But if they succeed, we will celebrate their success."
ITER director Bernard Bigot said nuclear fusion research and development were being driven mainly by governments, likening it to the early days of space technology and suggesting the time had yet to arrive when private investors would take the lead.
"In fusion research we are only about in the 1960s, before anybody got to the moon," Bigot said.
MIT and Eni are more optimistic.
The Boston-based team, which has built a bedroom-sized experimental tokamak reactor, plans to develop a larger-scale system of superconducting magnets within three years and build a fusion reactor within eight before finally, within 15 years, completing a nuclear-fusion power plant generating electricity.
"Our goal is to do things even faster than that because it is a unique opportunity right now and with climate change we should be aggressive and ambitious," said Bob Mumgaard, chief executive of MIT project company Commonwealth Fusion System.
He said the MIT and ITER projects differed mainly in their magnet technologies, and that MIT's system enabled it to contain plasma in a smaller chamber.
"In fusion devices the magnetic field is very important and this will allow us to build a device which is one sixtieth the volume of ITER," Mumgaard said, adding that MIT's final-stage reactor would be the size of a basketball court.
Though research into nuclear fusion dates to the 1950s, some scientists doubt the technology can become a commercial energy source within MIT's 15-year timeframe.
"The ability to make these components work in the desired way in the presence of such intense fields of irradiation ... is a very big challenge," said Matteo Passoni, a nuclear engineer and expert on plasma physics at Milan's Polytechnic University.
For Eni, though, its investment in fusion represents a modest bet on a potentially big discovery, a familiar equation to its upstream division when it explores for oil and gas.
"Arriving within 15-16 years at a commercial reactor is exactly the timeframe we use in upstream," Casula said. ($1 = 0.8080 euros) (Additional reporting by Geert De Clercq in PARIS Editing by Mark Bendeich and Dale Hudson)