Petroleum and natural gas as the main sources of energy have played a critical role in the development of modern society. However, it also contributes to global warming and the associated climate change. Increasingly, renewable energy resources are being deployed to mitigate the impacts of climate change, with the goal of achieving carbon neutrality by 2050. Green and Blue Hydrogen are projected to replace natural gas as the main energy resource. As with the production of energy from traditional resources, water will continue to play a pivotal role in energy transition. In the face of an increasing shortage of freshwater alternative wastewater streams like treated wastewater, produced water, and seawater will become significant resources for the production of hydrogen.