This paper discusses the results of computational fluid dynamics (CFD) modeling of hydrogen releases anddispersion outdoors during venting of hydrogen storage in real environment and geometry of a hydrogenrefueling or energy station for a given flow rate and dimensions of vent stack. The PHOENICS CFDsoftware package was used to solve the continuity, momentum and concentration equations with theappropriate boundary conditions, buoyancy model and turbulence models. Also, thermal effects resultingfrom potential ignition of flammable hydrogen clouds were assessed using TNO ?Yellow Book?recommended approaches. The obtained results were then applied to determine appropriate clearancedistances for venting of hydrogen storage for contribution to code development and station designconsiderations. CFD modeling of hydrogen concentrations and TNO-based modeling of thermal effects haveproven to be reliable, effective and relatively inexpensive tools to evaluate the effects of hydrogen releases.