To determine economically optimal operating strategies for alkaline water electrolysis systems, this study developed a 

comprehensive electrochemical and techno-economic model. The model incorporates stack performance, balance-of-plant 

(BOP) energy consumption, and variable capital and electricity costs. Simulation results show that system utilization rate 

is the most infl uential factor in reducing the levelized cost of hydrogen (LCOH). High utilization and full-load operation 

signifi cantly lower hydrogen production costs, particularly when electricity prices are high and system capital expenditures 

(CAPEX) are low. Under certain conditions, such as when electricity prices are high and system costs are low, an optimal 

partial-load operation point can be found that minimizes the LCOH by balancing stack effi ciency with operating expenses. 

The study also explores trade-off s associated with increasing the number of electrolyzer cells to improve effi ciency. It is 

found that the benefi ts of improved effi ciency off set the additional capital and maintenance costs only when electricity 

prices are suffi ciently high and system costs suffi ciently low. These results suggest that appropriate load management and 

system design optimization are essential to achieving economically viable hydrogen production via alkaline electrolysis, 

especially in regions with high electricity prices and fl uctuating renewable energy supply. Distinct from conventional TEA 

studies that rely on fi xed stack effi ciency or simplifi ed BOP assumptions, this work provides an electrochemical-modelbased,

stack–BOP coupled framework to determine economically optimal operating regimes and design trade-off s.