From Austin Groener (March 8, 06)

Renewable Energy Resources - Tidal Generators.

 

ADVANTAGES

Once you've built it, tidal power is free.

It produces no greenhouse gases or other waste.

It needs no fuel.

It produces electricity reliably.

Not expensive to maintain.

Tides are totally predictable.

Offshore turbines and vertical-axis turbines are not ruinously expensive to build

   and do not have a large environmental impact.

 

DISADVANTAGES

A barrage across an estuary is very expensive to build, and affects a very wide area -

the environment is changed for many miles upstream and downstream. Many birds

rely on the tide uncovering the mud flats so that they can feed. There are few suitable

   sites for tidal barrages.

 

   Only provides power for around 10 hours each day, when the tide is actually moving in or out.

 

 

FUTURE SCEHEMES BEING CONSIDERED

Country

Place

Mean tidal range (m)

Area of basin (km2)

Installed capacity (MW)

Argentina

San Jose

5.9

-

6800

Australia

Secure Bay

10.9

-

?

Canada

Cobequid

12.4

240

5338

Cumberland

10.9

90

1400

Shepody

10

115

1800

India

Kutch

5.3

170

900

Cambay

6.8

1970

7000

Korea

Garolim

4.7

100

480

Cheonsu

4.5

-

-

Mexico

Rio Colorado

7-Jun

-

?

Tiburon

-

-

?

United Kingdom

Severn

7

520

8640

Mersey

6.5

61

700

Wyre

6

5.8

47

Conwy

5.2

5.5

33

United States

Passamaquoddy Bay

5.5

-

?

Knik Arm

7.5

-

2900

Turnagain Arm

7.5

-

6500

Russia

Mezen

9.1

2300

15000

Tugur

-

-

10000 or 7000

Penzhinskaya Bay

6

-

50000