Zap Energy is part of the race to produce commercially viable energy by smashing together and fusing light atoms, releasing power.
Zap completed construction of its Century System, which includes a plasma-producing device and other key power-making technologies.
Current investors in its recent Series D of $130m include Addition, Chevron Technology Ventures, Breakthrough Energy Ventures, Shell Ventures, Summer Impact Partners, big-name philanthropist organizations, and new investors Mizuho and Plynth Energy.
Century creates a case study of successfully integrating technologies for power plants.
The company's objective is to deliver a commercial power plant, not just prove a science experiment.
Zap uses sheared-flow-stabilized Z-pinch technology, compressing material to produce sufficient fusion conditions.
Zap demonstrated more than 1,000 consecutive plasmas in three hours but further adjustments are required.
Japan's Mizuho Bank and Abu Dhabi government-owned energy fund Plynth Energy are the two new strategic investors, Conway says.
Zap Energy is one of eight Milestone-Based Fusion Development Programme recipients selected by the US Department of Energy.
Fusion could be a solution for a growing clean energy demand due to expanding data centres, among other things, if and when it is commercialized.