Life cycle assessment can be used to determine whether electricity from ocean energy sources has a lower climate change impact than electricity from fossil energy sources. A mathematical model was developed to calculate GHG emissions of electricity from a tidal turbine across its life cycle processes, scaled to a functional unit of 1 kWh. It was applied to 23 “hotspots” sites on U.S. coasts. Daily peak tidal velocities were used to determine electricity generated over the turbine’s lifetime. The life cycle climate change impacts of electricity from tidal turbines varied significantly across deployment sites. For example, the carbon footprint for a tidal turbine in the Sitkinak Strait (AK) is over 11,000 percent higher than that of the East River (NY). This shows electricity from tidal turbines can have life cycle climate change impacts comparable to other renewable energy sources, fossil energy sources, or impacts even worse than fossil energy sources
