Editing Tidal power (section)

=== Tidal lagoon ===
A new tidal energy design option is to construct circular retaining walls embedded with turbines that can capture the potential energy of tides. The created reservoirs are similar to those of tidal barrages, except that the location is artificial and does not contain a pre-existing ecosystem.<ref name="Tethys" />
The lagoons can also be in double (or triple) format without pumping<ref>{{cite web |url=https://www.youtube.com/watch?v=lnHwb8BKJzU |title=Hydrological Changing Double Current-typed Tidal Power Generation |website=[[YouTube]] |date=23 September 2012 |format=video |access-date=2015-04-15 |url-status=live |archive-url=https://web.archive.org/web/20151018074420/https://www.youtube.com/watch?v=lnHwb8BKJzU |archive-date=2015-10-18 }}</ref>  or with pumping<ref>{{cite web |url=http://www.inference.phy.cam.ac.uk/sustainable/book/tex/Lagoons.pdf |title=Enhancing Electrical Supply by Pumped Storage in Tidal Lagoons |access-date=2014-03-13 |url-status=live |archive-url=https://web.archive.org/web/20150924034732/http://www.inference.phy.cam.ac.uk/sustainable/book/tex/Lagoons.pdf |archive-date=2015-09-24 }}</ref> that will flatten out the power output. The pumping power could be provided by excess to grid demand renewable energy from for example wind turbines or solar photovoltaic arrays. Excess renewable energy rather than being curtailed could be used and stored for a later period of time. Geographically dispersed tidal lagoons with a time delay between peak production would also flatten out peak production providing near baseload production at a higher cost than other alternatives such as district heating renewable energy storage. The cancelled [[Tidal Lagoon Swansea Bay]] in Wales, United Kingdom would have been the first tidal power station of this type once built.<ref>{{cite web|url=http://www.renewableenergyfocus.com/view/42607/green-light-for-worlds-first-tidal-lagoon/|title=Green light for world's first tidal lagoon|author=Elsevier Ltd, The Boulevard, Langford Lane, Kidlington, Oxford, OX5 1&nbsp;GB, United Kingdom|website=renewableenergyfocus.com|access-date=26 July 2015|url-status=live|archive-url=https://web.archive.org/web/20150818213310/http://www.renewableenergyfocus.com/view/42607/green-light-for-worlds-first-tidal-lagoon/|archive-date=18 August 2015}}</ref>