Tidal turbines• The power of the rise and fall of the sea level or tidal power, can be harnessed to

generate electricity.• Tidal turbines are relatively cheap to manufacture. Any number of turbines can be

built and installed at any time and so an underwater. • The tide moves a huge amount of water twice each day, and harnessing it could

provide a great deal of energy - around 20% of Britain's needs.

How it Works

• tidal energy is a direct result of tide shifting from low to high.• It is also considered to be inexhaustible because tides always rise and fall due to gravity.• Tidal turbines look like wind turbines. They are arrayed underwater in rows• Tidal energy is produced through the use of tidal energy generators. These large underwater

turbines are placed in areas with high tidal movements, and are designed to capture the kinetic motion of the ebbing and surging of ocean tides in order to produce electricity.

Table 1 Highest tides (tide ranges) of the global ocean

Country Site Tide range (m)• Canada Bay of Fundy 16.2• England Severn Estuary 14.5• France Port of Ganville 14.7• France La Rance 13.5• Argentina Puerto Rio Gallegos 13.3• Russia Bay of Mezen (White Sea) 10.0• Russia Penzhinskaya Gub

Environmental impacts• Underwater turbines are by definition out of sight and it is believed that their environmental

impact is negligible thanks to their slow rotation rates of just 10-30 revolutions per minute. In addition

• tidal turbines do not affect navigation or shipping and so there are no hidden extra costs to consider.

• http://www.darvill.clara.net/altenerg/tidal.htm• http://www.alternative-energy-news.info/technology/hydro/tidal-power/• http://www.solarfeeds.com/ecofriend/16720-in-focus-tidal-energy

Tidal Barrage

• the water flows through tunnels. The ebb and flow of the tides is used to turn a turbine, or can be used to push air through a pipe, which then turns a turbine.

Severn from Lavernock Poin