If the present research program is successful, heavy-ion beams can be used to ignite targets and to produce high gain for yields of about 400 MJ. HYLIFE-II is a power plant design based on surrounding such targets with thick liquid Flibe, (Li2BeF4) so that the chamber and other apparatus can stand up to these bursts of energy at 6 Hz for 1 GWe without replacing components during the plant's 30-year life. With liquid protection the capacity factor will be increased and the cost of component replacement will be decreased. The design is robust to technology risks in the sense that if the performance of targets, drivers and other components fall short of predictions, the cost of electricity rises surprisingly little. For example at 2 GWe, if it takes twice as much energy to ignite a target as previously projected instead of only 1.5 times, the COE increases 9% from 4 ȼ/kWh, and if the driver cost is increased by 30%, the COE increases by 12%.

The design strategy we recommend is to use conventional engineering principles and known materials in an optimized way to obtain the lowest cost of electricity while keeping the design robust to short falls in predicted cost and performance of components. For a number of components with a high technology risk we have fall-back options. However, good target performance (Gain > 50 for driver energy < 7 MJ) and low cost drivers (<800 M$ direct at driver energy ≥ 7 MJ) would be helpful to achieving good economics.