The tidal energy resource can be split into two categories: tidal current—the extraction of kinetic energy from fast moving tidal currents, and tidal range—the extraction of potential energy release from water at high level relative to low level.
The UK tidal energy programme that ran between 1978 and 1994 estimated the total resource available in the UK, for tidal range energy generation from reasonably exploitable estuaries with a mean tidal range of 3 metres or more, at around 50 tera
watt hours per year (around 15 per cent. of current UK demand). Nearly all of this potential resource is in England and Wales, with 90 per cent. located in eight large estuaries—the Severn, the Dee, the Mersey, Morecambe Bay, Solway Firth, the Humber, the Wash and the Thames. The remaining 10 per cent. is in 30-40 smaller estuaries.
A study undertaken in 20051 estimated the tidal-current resource at approximately 16 tera watt hours per year (around 5 per cent. of current UK demand).
1 Black and Veatch (2005). Tidal Stream—Phase II UK Tidal Stream Energy Resource Assessment. A report to the Carbon Trust's Marine Energy
The Department has also carried out a study called ATLAS2 that looks at the marine resource around the UK, including tidal power. A copy of the study can be found online at
http://www.dti.gov.uk/energy/sources/renewables/renewables-explained/wind-energy/page27403.html
2 ABPmer, The Met Office, Garrard Hassan and Proudman Oceanographic Laboratory (2004). Atlas of UK Marine Renewable Energy Resources:
Technical report. A report to the Department of Trade and Industry.
The Department has not assessed the proportion of UK energy supply that tidal power could be expected to provide in the next decade.