The Massachusetts-based CFS expects to have Sparc operational in late 2026 or early 2027. Later this decade, the company says it will begin construction on Arc, its commercial power plant that will produce 400 megawatts of electricity. The facility will be built near Richmond, Virginia , and Google has agreed to buy half its output .Sparc’s reactor is a tokamak design, which resembles a doughnut. The D-shaped cross section is wound with high-temperature superconducting tape , which, when energized, generate ...