Canada

Green hydrogen stands as a promising clean energy carrier with potential net-zero greenhouse gas emissions. However different system-level configurations for green hydrogen production yield different levels of efficiency cost and maturity necessitating a comprehensive assessment. This review evaluates the components of hydrogen production plants from technical and economic perspectives. The study examines six renewable energy sources—solar photovoltaics solar thermal wind biomass hydro and geothermal—alongside three types of electrolyzers (alkaline proton exchange membrane and solid oxide electrolyzer cells) and five hydrogen storage methods (compressed hydrogen liquid hydrogen metal hydrides ammonia and liquid organic hydrogen carriers). A comprehensive assessment of 90 potential system configurations is conducted across five key performance indicators: the overall system cost efficiency emissions production scale and technological maturity. The most cost-effective configurations involve solar photovoltaics or wind turbines combined with alkaline electrolyzers and compressed hydrogen storage. For enhanced system efficiency geothermal sources or biomass paired with solid oxide electrolyzer cells utilizing waste heat show significant promise. The top technologically mature systems feature combinations of solar photovoltaics wind turbines geothermal or hydroelectric power with alkaline electrolyzers using compressed hydrogen or ammonia storage. The highest hydrogen production scales are observed in systems with solar PV wind or hydro power paired with alkaline or PEM electrolyzers and ammonia storage. Configurations using hydro geothermal wind or solar thermal energy sources paired with alkaline electrolyzers and compressed hydrogen or liquid organic hydrogen carriers yield the lowest life cycle GHG emissions. These insights provide valuable decision-making tools for researchers business developers and policymakers guiding the optimization of system efficiency and the reduction of system costs.

This study investigates hydrogen (H2) as a supplementary fuel in heavy-duty diesel engines using pre-manifold injection. A H2-diesel dual-fuel (H2DF) system was implemented on a commercial class-8 heavy-duty diesel truck without modifying the original diesel injection system and engine control unit (ECU). Tests were conducted on a chassis dynamometer at engine speeds between 1000 and 1400 rpm with driver-demanded torques from 10 to 75%. The hydrogen energy fraction (HEF) was strategically controlled in the range between 10 and 30%. Overall CO2 reduction (comparable to the HEF level) was achieved with similar brake-specific energy consumption (BSEC) at all loads and speeds. To maintain the same shaft torque the driver-demanded torque was reduced in H2DF operation which resulted in a lower boost pressure. At higher loads engine-out BSNOx slightly decreased while BSCO and black carbon (BC) increased significantly due to lower oxygen concentration resulting from the lower boost pressure. At lower loads engine-out BSCO and BSBC decreased moderately while NO2/NO ratio increased substantially in H2DF operation. Deliberate air path and diesel injection control are expected to enable higher HEF and GHG reductions.