The study explores the economics of producing clean hydrogen from offshore wind farms using electrolysis, comparing different methods and scenarios. A novel techno-economic model is presented to determine the Levelised Cost of Hydrogen (LCOH) for offshore wind-driven electrolysis, incorporating geological salt-cavern storage. The model calculates lifetime costs and LCOH, which are then compared with conventional hydrogen production methods. Using the United Kingdom as a case study, the LCOH for alkaline electrolysis (AEL) is €8.68/kgH2, proton exchange membrane electrolysis (PEMEL) is €10.49/kgH2, and grid electricity backup is €10.88/kgH2. A stochastic Monte-Carlo model assesses cost uncertainties, identifying capital costs, electrolyser, and wind farm costs as key drivers. Reducing capital costs to levels comparable to current wind farms could lower AEL LCOH to €5.32/kgH2, making it competitive with conventional methods. The study highlights the potential of offshore wind and electrolysis for decarbonizing industries, heating, and transportation, while addressing the challenges of intermittent renewable energy sources and storage.The study explores the economics of producing clean hydrogen from offshore wind farms using electrolysis, comparing different methods and scenarios. A novel techno-economic model is presented to determine the Levelised Cost of Hydrogen (LCOH) for offshore wind-driven electrolysis, incorporating geological salt-cavern storage. The model calculates lifetime costs and LCOH, which are then compared with conventional hydrogen production methods. Using the United Kingdom as a case study, the LCOH for alkaline electrolysis (AEL) is €8.68/kgH2, proton exchange membrane electrolysis (PEMEL) is €10.49/kgH2, and grid electricity backup is €10.88/kgH2. A stochastic Monte-Carlo model assesses cost uncertainties, identifying capital costs, electrolyser, and wind farm costs as key drivers. Reducing capital costs to levels comparable to current wind farms could lower AEL LCOH to €5.32/kgH2, making it competitive with conventional methods. The study highlights the potential of offshore wind and electrolysis for decarbonizing industries, heating, and transportation, while addressing the challenges of intermittent renewable energy sources and storage.