The aim of this study is to quantify and utilize waste heat from wind-farm-powered water electrolysers and ammonia cracking. The port of Rotterdam, as a case study, has been analyzed where the transport of 4.6 Mt hydrogen and water electrolysis, powered by wind farms, is planned. A dynamic model was developed to calculate waste heat from an electrolyser powered by fluctuating electricity inputs from offshore wind power. Moreover, thermal analysis of ammonia cracking process streams was conducted. It was observed that integrating water electrolysis waste heat into the ammonia cracking process is not only a promising novel application for the reuse of the electrolysis waste heat, but also it can potentially enhance cracking efficiency by 2 % while creating synergies within the hydrogen industry. Additionally, waste heat can be used for district heating saving more than 70 % of energy and reducing CO₂ by just as much. In parallel, cold utilisation from ammonia cracking was explored for CO₂ and H₂ compression, as well as industrial cold storage to observe that technical implementation is possible.