Anticipated coastal impacts: What water-users think of marine renewables and why

• Water-users anticipate different levels of coastal impact depending on the device.
• A conceptual model predicts the level of impact that is likely to be anticipated.
• Anticipated impact was often based on device properties such as form or siting.
• Anticipated impact was often uninfluenced by device extraction efficiency.
• Water-user support or opposition may differ for devices with similar power ratings.

This article explores the physical coastal impacts that are anticipated by coastal water-users in the lee of the Wave Hub marine renewables test facility (Cornwall, UK). In depth, semi-structured interviews were analysed using a grounded theory approach in order to explore contemporary anticipations as well as the process of opinion formation that has occurred for participants. The interviews focused on anticipated impacts to inshore wave conditions, beach sedimentation, rip current formation and beach safety. The results indicate that participants constructed their anticipations by weighing their perceptions of the technology against their perceptions of the coastal environment. A conceptual model is presented which allows the degree of anticipated coastal impact to be predicted, by categorizing technologies and coastal environments in terms of their perceived properties. The model indicates that wave energy deployments which are perceived to be large scale, close to shore, wide, stationary, or extracting high percentages of energy are likely to invoke anticipations of significant or severe coastal impacts. Conversely, those which are perceived to be small scale, far from shore, narrow, moving, or extracting low percentages of wave energy are more likely to invoke anticipations of insignificant or no coastal impact. Interestingly, the level of anticipated impact was most often based on device properties such as form or siting, and was rarely influenced by device extraction efficiency. The implications for future marine renewables deployments are discussed.