Abstract
Tidal range schemes (TRS) remain controversial as their sustainability issues are poorly understood. This study presents a first comprehensive life cycle assessment (LCA) of small, medium and large-scale TRS, considering their dual roles for electricity generation and storage. This is coupled with a discussion of their socio-economic implications and public acceptability. When used solely for electricity generation, tidal power has significantly lower environmental impacts than natural gas, wind and solar photovoltaics, but shows higher values against hydro and nuclear power. When used for both electricity generation and storage, TRS outperform wind electricity coupled with pumped hydro, batteries, compressed air or liquid air energy storage. If only half of the 20 proposed TRS replace natural gas and battery storage by 2050, they could reduce the climate change impact of grid electricity by 71%, saving up to 4.4 Mt CO2 eq./y. Most other environmental impacts would be reduced by up to 24%. In addition, hundreds of thousands of jobs could be created, along with billions in gross value added. However, high costs and low public acceptability hinder the deployment. It is hoped that the findings of this study will contribute toward a better understanding of the sustainability of this emerging technology.