So far, the economic assessments of tidal stream energy have been conducted from a sectorial, spatially dimensionless point of view; or in other words, on the basis of mean values obtained as representative of the average across the tidal industry. However, as this marine technology progresses, such assessments will need to be performed on a per-project basis, which inevitably requires the consideration of site-related variables: from the tidal resource to the local topography and accessibility. With this in view, this thesis develops a new methodology to include the spatial dimension into the economic analysis of tidal stream energy projects, and more specifically into the LCOE, in a continuous manner – thereby allowing for macro-micro linkages: impacts of a project over an entire region and vice versa. The methodology is materialised in the form of a new ad hoc tool and illustrated through a case study in the Bristol Channel and Severn Estuary (UK), a region with one of the greatest potentials for tidal power development in the world. As a result, spatial cost patterns over the study domain, together with environmental and socioeconomic constraints for project deployment are showed. They constitute the basis on which informed decisions on public and private funding allocation should be taken, for a further sustainable development of tidal stream energy hotspots and an integrated coastal management of the regions of interest.