Efficient STEP (solar thermal electrochemical photo) production of hydrogen – an economic assessment

详细信息    查看全文

• 作者：Stuart Licht ; Olivia Chitayat ; Harry Bergmann ; Andrew Dick ; Hina Ayub ; Susanta Ghosh
• 关键词：Hydrogen production ; Solar energy ; Water-splitting ; Electrolysis ; STEP
• 刊名：International Journal of Hydrogen Energy
• 出版年：2010
• 出版时间：October 2010
• 年：2010
• 卷：35
• 期：20
• 页码：10867-10882
• 全文大小：679 K

文摘

A consideration of the economic viability of hydrogen fuel production is important in the STEP (Solar Thermal Electrochemical Photo) production of hydrogen fuel. STEP is an innovative way to decrease costs and increase the efficiency of hydrogen fuel production, which is a synergistic process that can use concentrating photovoltaics (CPV) and solar thermal energy to drive a high temperature, low voltage, electrolysis (water-splitting), resulting in H₂ at decreased energy and higher solar efficiency. This study provides evidence that the STEP system is an economically viable solution for the production of hydrogen. STEP occurs at both higher electrolysis and solar conversion efficiencies than conventional room temperature photovoltaic (PV) generation of hydrogen. This paper probes the economic viability of this process, by comparing four different systems: (1) 10 % or (2) 14 % flat plate PV driven aqueous alkaline electrolysis H₂ production, (3) 25 % CPV driven molten electrolysis H₂ production, and (4) 35 % CPV driven solid oxide electrolysis H₂ production. The molten and solid oxide electrolysers are high temperature systems that can make use of light, normally discarded, for heating. This significantly increases system efficiency. Using levelized cost analysis, this study shows significant cost reduction using the STEP system. The total price per kg of hydrogen is shown to decrease from $5.74 to $4.96 to $3.01 to $2.61 with the four alternative systems. The advanced STEP plant requires less than one seventh of the land area of the 10 % flat cell plant. To generate the 216 million kg H₂/year required by 1 million fuel cell vehicles, the 35 % CPV driven solid oxide electrolysis requires a plant only 9.6 mi² in area. While PV and electrolysis components dominate the cost of conventional PV generated hydrogen, they do not dominate the cost of the STEP-generated hydrogen. The lower cost of STEP hydrogen is driven by residual distribution and gate costs.