General Fusion raises $20 million to further develop its plasma confinement approach for fusion energy. The company aims to achieve fusion using synchronized pistons to set up shock waves in plasma at an estimated cost of $0.04 per kilowatt-hour. Several options for advancing energy production are discussed, including carbon sequestration, fission, and various fusion technologies like dense plasma focus devices. Multiple companies and research institutions around the world are conducting research into practical fusion energy production through different confinement approaches.