可再生能源电解制氢成本分析

Cost analysis of hydrogen production by electrolysis of renewable energy

本文对可再生能源电解制氢成本进行了系统分析,对比了碱性与质子交换膜(PEM)电解制氢的平准化成本(LCOH),并考察了规模效应、氢气压力、压缩与液化及输入功率波动性对碱性与PEM电解制氢成本的影响。结果表明:规模增加可降低制氢成本,所考察的电解系统在规模由1 MW提高至40 MW后,装置的固定成本降幅40%以上,由于电费是主要成本,平准化成本(LCOH)降幅小于25%。在固定成本投入无明显增加的情况下高压电解制氢可明显降低制氢成本,随着电解氢气压力由1 atm (1 atm=101.325 k Pa)提高至30 atm,进一步压缩至700 atm的成本由1$/kg降至0.3$/kg;液化成本受规模影响显著,1 MW电解制氢增至40 MW时制氢并液化的平准化成本(LCOH)从8.7$/kg降至5.3$/kg;由于PEM对可再生能源波动具有良好的适应性,在波动性功率输入时,随着低功率(<20%额定功率)波动性的增加,PEM的LCOH成本可以优于碱性电解。随着碱性与PEM电解技术的进步,二者优劣仍需针对具体情况进行分析讨论。

In this paper, the cost of hydrogen production by renewable energy electrolysis was systematically analyzed, and the levelized cost of hydrogen(LCOH) from alkaline and PEM electrolyzers were compared. The effects of scale, hydrogen pressure, compression and liquefaction,and input power fluctuation on the cost of hydrogen production by alkaline and PEM electrolysis were investigated. The results showed that the cost of hydrogen production was reduced with the increase of scale. When the scale of our investigated electrolysis system was increased from 1 MW to 40 MW, its fixed cost was reduced by more than 40%, but its LCOH cost was reduced byless than 25% because electricity is the main cost. The LCOH cost of hydrogen production by high-pressure electrolysis can be significantly reduced without increasing the fixed cost. With the increase of electrolysis pressure from 1 atm to 30 atm, the cost of hydrogen further compression to 700 atm will be reduced from 1 $/kg to 0.3$/kg. The liquefaction cost was significantly affected by the scale, and the levelized cost of hydrogen production by electrolysis and liquefaction decreased from 8.7 $/kg to 5.3 $/kg with the increasing of scale from 1 MW to 40 MW. For PEM has good adaptability of renewable energy fluctuation, the LCOH cost of PEM could be lower than that of alkaline electrolysis with an increase of low power(<20% rated power) fluctuation. With the improvement of alkaline electrolysis and PEM electrolysis technology, which is better or worse should be discussed according to the specific situation.