تنوع و توقف تدریجی انرژی جاری جزر و مد در سراسر انگلستان

Tidal energy has the potential to play a key role in meeting renewable energy targets set out by the United Kingdom (UK) government and devolved administrations. Attention has been drawn to this resource as a number of locations with high tidal current velocity have recently been leased by the Crown Estate for commercial development. Although tides are periodic and predictable, there are times when the current velocity is too low for any power generation. However, it has been proposed that a portfolio of diverse sites located around the UK will deliver a firm aggregate output due to the relative phasing of the tidal signal around the coast. This paper analyses whether firm tidal power is feasible with ‘first generation’ tidal current generators suitable for relatively shallow water, high velocity sites. This is achieved through development of realistic scenarios of tidal current energy industry development. These scenarios incorporate constraints relating to assessment of the economically harvestable resource, tidal technology potential and the practical limits to energy extraction dictated by environmental response and spatial availability of resource. The final scenario is capable of generating 17 TWh/year with an effective installed capacity of 7.8 GW, at an average capacity factor of 29.9% from 7 major locations. However, it is concluded that there is insufficient diversity between sites suitable for first generation tidal current energy schemes for a portfolio approach to deliver firm power generation.

This study presents a high level analysis of the aggregate behaviour of the tidal current energy resource in the UK and credible scenarios for exploiting the resource using first generation tidal current technology. With due consideration to the environmentally acceptable limits to energy extraction identified, although not considering the physical response, the resource available at first generation sites was estimated to be 17 TWh/year for an installed capacity of 7.8 GW. Although this work aims to offer an improvement in further understanding the UK's tidal current resource, each stage of this analysis has considerable uncertainties and inaccuracy: • The datasets used to generate the time series • The metrics used to identify site suitable for this analysis • The site-and device characteristics • The accuracy of the technically unconstrained and TAP value Due to this uncertainty and lack of a feedback re-evaluation it is thought that first generation development will be less that 17 TWh/yr. Despite these uncertainties, the analysis is rigorous about the phase assessment of the different tidal sites. Unfortunately, the nature of tidal wave propagation around the west coast of the UK means that most tidal energy hot spots suitable for first generation technologies are largely in phase, with only the Race of Alderney in the Channel Isles differing significantly. It is concluded that there is insufficient diversity between the sites identified for first generation tidal current schemes to be considered as a firm power source.