Comparative life cycle greenhouse gas emission and cost assessment of hydrogen fuel and power for Singapore

Abstract

To identify lower-carbon and cost-effective hydrogen supplies for fuel and power generation in Singapore, we assessed the cradle-to-gate greenhouse gas (GHG) emissions and the landed costs of over fifty supply chains from Malaysia and Australia with current and emerging blue, turquoise, and green hydrogen production and carrier technologies. We found that with current technologies the total life cycle global warming potential of local H₂ production using steam methane reforming with carbon capture (4.47 kg CO₂e/kg H₂) is lower than importing solar-generated green H₂ from Australia transported as NH₃ (6.48 kg CO₂e/kg H₂) due to large emissions from conversion and transportation processes in the latter supply chain. When also considering emerging technologies, turquoise H₂ produced with the thermal decomposition of methane locally or in Malaysia is the most economical solution, while wind-generated H₂ from Australia transported as liquefied H₂ or NH₃ produce the least GHG emissions. In addition, we projected the impacts of the Singapore carbon tax, methane abatement in NG production, and reduction of renewable energy embodied emissions and costs on the supply chains in the year 2030. We estimated that with the expected renewable energy improvements, the emissions and costs of power generated from imported solar-powered H₂ could drop by as much as 74 % and 70 % respectively.