Iran has launched a programme aimed at developing a nuclear fusion reactor - an ambition long-cherished by Western nations, BBC reported.
Asghar Sediqzadeh, head of the fusion research institute, said initial studies would last for two years, and a reactor would take 10 years to build.
Fusion is used in hydrogen bombs, but scientists have been unable to harness the energy created in such reactions.
Iran is already under UN sanctions because of its nuclear activities.
The UN acted after Tehran ignored demands to halt its uranium-enrichment programme, amid fears in the West that the country is seeking atomic weapons.
Iran has always maintained its nuclear programme is intended only for peaceful purposes.
At a ceremony to mark the beginning of the fusion project, Mr Sediqzadeh said 50 scientists would be working on the research.
"Iran is one of the first countries to begin research in this field," he said.
"We built one installation about 30 years ago. We had some delays in the past 10 years, [but] we can quickly make up for this time."
Ali Akbar Salehi, the head of the Atomic Energy Organisation of Iran, said the institute would have a budget of 80bn rials (£5.2m; $8m).
He said it would take 20 or 30 years for a fusion plant to become commercially viable.
Scientists across the world have been trying for decades to harness the energy released by fusion reactions.
They believe fusion would be far more efficient and environmentally friendly than current methods of power generation.
Despite small-scale success in laboratories, no-one has yet developed an effective way of channelling energy from a fusion reaction.
The international community agreed to build a fusion facility in France in 2006.
But costs have soared from initial estimates of 5bn euros (£4.2bn; $6.5bn) to something closer to 15bn euros, and progress on construction has been slow.