To understand the commercial feasibility of chemoenzymatic photoreforming, technoeconomic analyses were carried out to compare a model chemoenzymatic photoreforming pilot plant with a reported model photoreforming plant with alkaline pre-treatment (see Supporting Discussion and Tables S8-S10 for details). The economic and environmental feasibility of the process was estimated using the established metrics: H2 production cost (₤ kgH2 -1 ; both with and without revenue obtained from TPA), carbon footprint (gCO2 MJH2 -1 ) and energy returned on energy invested (EROI).