Subject : chemical engineering

Someone gives you an electrolyzer unit that is 50% energy efficient in producing H2from H2O. If electricity costs $0.05/kWh, and a reinforced storage tank for $50/kg can store 10% of its mass as H2 and lasts 100 storage cycles, and the H2 can be used at an efficiency of 70%, what is the effective $/(kWh-cycle) cost for this scheme