Orbach also discussed fusion energy, which is “incredibly energy productive,” he said. “But it takes place in the interior of stars, where the temperatures and pressures are a bit higher than those we have been able to achieve here on Earth.”
Fusion reactors use isotopes of hydrogen as an energy source, including deuterium and tritium, and “there is enough deuterium in a body of water the size of Lake Erie to meet the energy needs of this earth for a thousand years,” Orbach said. Fusion produces energetic particles and radiation that need to be captured in the wall of a reactor, which produces heat that can be used to generate electricity. It has been a very difficult process to master and cannot be mastered in the short term, but “we are entering a new era with ITER,” Orbach said. ITER is an experimental fusion reactor in which hot gas is confined in a donut-shaped vessel and heated to more than 100 million degrees. The facility, which is sited in France and is a joint project of six nations and the European Union, is designed to produce about 10 times as much energy as it uses (Figure 6.2). The next step beyond ITER, Orbach said, will be a demonstration power plant based on fusion.