Abstract:
The transition toward renewable energy systems has intensified interest in green
hydrogen as a clean and sustainable energy carrier. Conventional hydrogen production
methods contribute approximately 830 million tons of CO2 emissions
annually, necessitating alternative zero-emission solutions. Sri Lanka’s national
target of achieving 70% renewable energy by 2030, supported by 1,358 MW of
planned solar capacity, highlights a critical need for effective energy storage to
mitigate solar intermittency. This study presents the design, fabrication, and experimental
validation of a cost-effective solar-powered alkaline electrolysis stack,
with the primary technical contribution being the development of an optimized
bipolar stack configuration with improved sealing and system integration suitable
for decentralized hydrogen production. An iterative design methodology was
adopted, progressing from single-cell prototype testing to a six-cell bipolar stack
configuration. Design-driven safety enhancements and material optimization significantly
improved system reliability and performance. The final electrolysis
stack achieved a hydrogen production rate of 85.856 cm3/min at 12 V, with a
total power consumption of 36 W. The system demonstrated an electrolysis efficiency
of 51%, defined as the effectiveness with which electrical energy supplied to
the electrolyzer is converted into chemical energy stored in the form of hydrogen,
and an energy efficiency of 59%. Successful integration with a photovoltaic power
supply, battery storage, and real-time monitoring validated stable operation under
variable solar conditions. The developed electrolysis stack demonstrates strong
potential for off-grid energy storage and decentralized renewable energy applications
in regions with high solar availability.
