In the context of global warming and climate change, Hydrogen energy is seen as a way of reducing carbon dioxide emissions. Hydrogen technologies (using fuel cells) seem to offer a 'green' solution to supplying power for transportation, heating for buildings, and for portable devices (mobile phones, laptops). However, there are many risks and uncertainties. In addition to safety concerns, there are knowledge-gaps about the production, storage and distribution of hydrogen. How ordinary citizens will accept hydrogen energy, and use it in their everyday lives is a problematic question. This lecture will address some of these issues from a sociological standpoint.