The future energy landscape is expected to increasingly rely on green hydrogen as a carrier for variable renewable energy

particularly to facilitate the decarbonization of hard-to-abate sectors. Off-grid hydrogen production has emerged as a promising solution

offering a pathway to minimize carbon intensity while ensuring the economic viability of hydrogen generation. This study simulates the operation of an isolated power system by integrating wind

solar

and hydrogen production

utilizing real-time weather data to explore the wind–solar capacity ratio for maximizing the operational hours of hydrogen electrolysers. The levelized cost of electricity and the levelized cost of hydrogen (LCOH) for these off-grid systems are evaluated across four representative locations in northern China and compared with fossil-based hydrogen (steam methane reforming/coal gasification). The findings indicate that

in northern China

the optimal wind-to-solar capacity ratio for maximizing hydrogen production falls within the range of 2.0–2.75. Under this configuration

the lowest achievable LCOH is 27.17 CNY/kg (∼3.77 USD/kg)

offering a significant advantage in terms of negligible carbon emissions compared with fossil-based hydrogen. Furthermore

a 40% reduction in the unit fixed costs of wind turbines

solar photovoltaic systems

and electrolysers is projected to lower the LCOH by 8.33 CNY/kg (23.29%)

3.12 CNY/kg (8.73%)

and 2.54 CNY/kg (7.10%)

respectively. These findings underscore the potential of off-grid wind–solar hybrid hydrogen production as a viable and sustainable alternative. Greater policy support and increased investment are essential to accelerating the deployment of such systems and realizing their full potential in the clean-energy transition.