Although there are no large tidal energy projects that currently generate electricity in the UK, the idea to use tidal power is not a new one; at one time there were 200 tide mills operating in the British Isles!

Mike Case
Head of Turbines

History of tidal range technology in the UK

Tidal lagoons, like their forerunners tidal mills, produce energy by creating an artificial impoundment and exploiting the difference in water levels between the external tide range and the basin level i.e. the head difference.  With a large tidal range you can create a large operating head and, as with conventional hydropower, the greater the head difference the greater the potential energy that can be extracted.  The mega tidal ranges experienced around the British Isles and in particular the Severn Estuary give the UK one of the greatest tidal range energy resources in the world.

UK millers were harnessing the power of our tides almost 1,000 years ago, so tidal lagoons are a modern interpretation of a very old, simple and natural idea.  The UK’s first tide mill was recorded in Nendrum Monastery Northern Ireland in 619 AD.  The first tide mill in England, located in Dover, was recorded in the Doomsday book in 1086 AD.  By the 18th Century it is estimated that there were over 700 tide mills operating along the Atlantic coastline of Europe and the US, with 200 operating in the UK, of which 140 were in London. The last working mill was at Woodbridge. Watch

Tidal Mill Pembrokeshire

Carew Tide Mill Pembrokeshire

The high tidal range of the Severn Estuary has long been an obvious choice for siting tidal power plants and plans for a Severn Barrage were initially proposed by Thomas Fulijames in 1849.  Since then, a number of proposals have subsequently been put forward.

619 AD

UK’s first tide mill, Nendrum Monastery Northern Ireland, taps the power of our tides to grind grain.


The first recorded tide mill in England, located in Dover, was recorded in the Doomsday book.


The first proposal for a tidal power station in the Severn Estuary was recorded.


Severn Barrage committee chaired by Lord Brabazon recommended a barrage from English stones but work was interrupted by WWII.


Central Electricity Generating Board (CEGB) propose barrage plans developed by Professor Wilson including lagoons.


Severn Barrage ‘Bondi’ committee set up following Iran oil crisis recommended a Lavenock point to Brean Down barrage which led to the setting up of the Severn Tidal Power Group (STPG).


The STPG published the five volume ‘Severn Barrage Project Detailed Report’, funded equally by the STPG, the Department of Energy and the Central Electricity Generating Board.


The Sustainable Development Commission (SDC) began a strategic overview of tidal power in the UK including barrage and non-barrage proposals for the Severn Estuary.


Department of Energy and Climate Change (DECC) published the Severn Tidal Power Feasibility Study, an extensive analysis of barrage and non-barrage schemes. None were recommended to progress. However the ensuing debate, including an Energy & Climate Change Committee inquiry and report, concluded that a more incremental approach using alternative technologies, such as tidal lagoons, may represent a lower risk and lower impact option than a Severn Barrage.


Tidal Lagoon Power initiates work on a national fleet of UK power stations.

History of tidal range technology worldwide

Since medieval times, millers around the globe have harnessed the power of the tides.  Tide mills once dotted the coasts of France, Portugal, Spain, Belgium, The Netherlands, Germany, Denmark, Canada, the United States and China.


Tide Mill, Morbihan Gulf, Brittany

Serious investigation of the potential to generate electricity from tidal range began in France in the 1920s, culminating in the completion of the world’s first such project, a tidal barrage at La Rance, in 1966.  The 240MW plant, owned and operated by Électricité de France (EDF), is now celebrating 50 years of unbroken operation and generates some of the cheapest electricity in Europe.

La Rance Power Station, Brittany, France (source EDF)

La Rance Power Station, Brittany, Franc: source EDF

A number of smaller projects followed, including in the Soviet Union, Canada and China.  In 2011, the Sihwa Lake Tidal Power Plant in South Korea became the world’s largest tidal power installation to date, with an installed capacity of 254MW.

C. 10th AD

Tide mills are first recorded in the Persian Gulf.


The earliest known mill was built in The Netherlands at Zuicksee.


The first tide mill in France is recorded at Veulves, Normandy.


The idea of constructing a tidal power plant on the Rance is first raised by Gerard Boisnoer.


The Society for the Utilisation of the Tides begins its investigation of tidal power sites and schemes in France.


The Rance Tidal Power Station enters construction.


La Rance, a 240MW tidal barrage, generates its first electricity.


The 1.7MW Kislaya Guba Tidal Power Station in Russia is first operated.


Construction of the Jiangxia Tidal Power Station, a 3.2MW tidal barrage and the first tidal range power plant in Asia, is completed.


The first tidal range power plant in North America, a 20MW tidal barrage, opens at Annapolis Royal, Nova Scotia.


Sihwa Tidal Power Plant, a 254MW tidal barrage in South Korea, completes construction and becomes the world’s largest tidal power station.


Tidal Lagoon Power begins work to assess the potential to deploy tidal lagoon infrastructure in international waters.

Tidal Lagoon Plc


T: +44 (0)1452 303892

A: Pillar & Lucy House
Merchants Road
The Docks

Tidal Lagoon (Swansea Bay) Plc


T: +44 (0)1792 274006

A: Suite 6
J Shed
Kings Road

© Tidal Lagoon Plc and Tidal Lagoon (Swansea Bay) Plc. | Designed and Developed by Spindogs