Dutch researchers analyzed the two most promising solar-assisted technologies to produce green hydrogen, based on the average cost of hydrogen. They found that photovoltaics produced hydrogen at the lowest cost at $6.22 per kilogram, with a solar-to-hydrogen efficiency ratio of 10.9%.
A research team at Utrecht University in the Netherlands compared two of the most promising technologies for solar-assisted hydrogen production: photoelectrochemical (PEC) systems that directly convert solar radiation into hydrogen gas and off-grid photovoltaic-powered electrolysers (PV- E).
They published their research in the International Journal of Hydrogen Energy: A Techno-Economic Comparison of Photovoltaic Cells and Photovoltaic Electrolysis for Renewable Hydrogen Production. They concluded that the potential techno-economic benefits of photoelectrochemistry with respect to electrolyzers are uncertain and limited.Also read:12v 300ah lithium ion battery
The scientists calculated the horizontal cost of hydrogen (LCOH) for both technologies by considering standard electrolyzer designs and anticipated photoelectrochemical designs for future large-scale applications.
"Despite intensive and promising research on photoelectrochemical technology over the past few years, no system is currently commercially available," the researchers said. Electrolysis of solar energy to produce hydrogen."
The group calculates the minimum cost of the technology based on investment expenses, revenues and costs over the life of the plant, discounted to a reference date. The production rate of the two systems is set at 10 tons per day, and the time frame for hydrogen production is 20 years.
They performed the demonstration in Daggett, California, where the daily irradiance is 6.19 kilowatt-hours per square meter. Installation costs are assumed to be 20% of the capital cost of both systems.
"The installation of the electrolyzer system requires more cables and installation of the electrolyser. On the other hand, the photoelectrochemical system requires more piping, in addition to installing a compressor," the academics said.
The electrolyser system is designed to balance the high cost of the electrolyser by optimizing the size of the photovoltaic generator and the size of the electrolyser. The demonstrated electrolyser has an overall efficiency of 10.9%.
Regarding the photoelectrochemical system, the researchers chose a non-concentrating panel with an efficiency of 10%. It is based on a single-fluid-consolidation design, with one side of the photoelectrode immersed in the electrolyte. "One part of the solar panel has to withstand electrochemical reactions and corrosion, while the other part has to be in contact with the ambient air," the researchers said.
The researchers showed that the electrolyzer system could achieve LCOH of $6.22 per kilogram. They conclude that balance of system (BoS) costs for electrolyzers may fall again in the future due to economies of scale.
"The cost of the electrolyzer is higher than that of the photovoltaic system, and the gap would be even greater if the scale of the two plant components were not optimized," the researchers said. View more details:48v 200ah lifepo4 battery
The researchers also said that if BoS costs and PV module prices drop by another 50%, LCOH could reach $3.76/kg in the future. The LCOH of the photoelectrochemical system was $2 higher than that of the photoelectrochemical system at $8.43/kg, and the photoelectrochemical module accounted for almost half of the total system cost.