How does a tidal lagoon power plant work — Transcript

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1. 0:00the Restless Tides flowing in and out
2. 0:04four Tides a day a firm thinks it's time
3. 0:07to harness all that energy this is
4. 0:10Swansea Bay Wales the tidal range here
5. 0:13is enormous the firm plans to build a
6. 0:16sea wall over 5 m long to enclose a vast
7. 0:20body of water into a lagoon here in
8. 0:23Swansea Bay large power generating
9. 0:27turbines will be set in the seaw wall
10. 0:30here's how it works on the left here is
11. 0:33the Open Sea its height increasing from
12. 0:36low tide to high tide the seaw wall
13. 0:39holds the rising tide out of the Lagoon
14. 0:41on the right then a wicked gate is
15. 0:44opened to let the high tide flow in that
16. 0:47makes
17. 0:48electricity when the Lagoon fills up the
18. 0:51tide goes out and the whole process is
19. 0:53reversed to make energy once
20. 0:56more we're about a mile and a half out
21. 0:59to sea now and it's right down beneath
22. 1:01me that the turbines will go and you can
23. 1:04see the vast amount of water that'll be
24. 1:07held back by that
25. 1:13wall the notion of lagoons is let's
26. 1:15use that free Power it's created by the
27. 1:18dance between the Moon and the planet
28. 1:20and let's generate electricity for the
29. 1:21next 120 years very certainly little bit
30. 1:24expensive to start off with very cheap
31. 1:26for a very long
32. 1:28time environment group groups say the
33. 1:30Lagoon shouldn't disturb Wildlife too
34. 1:32much they say it'll make much needed
35. 1:35clean energy there's one great thing
36. 1:38about tidal power unlike energy from the
37. 1:40Sun or the wind it is utterly
38. 1:43predictable so from here at high tide to
39. 1:47way down here at low tide Engineers can
40. 1:50calculate exactly how much water has
41. 1:53been moved and exactly how much energy
42. 1:56that will generate and the power firms
43. 1:58really value that
44. 2:01certainty but one group is concerned the
45. 2:04Anglers what about the impact of the
46. 2:06Lagoon on local Rivers we're very
47. 2:09worried about tidal lagoons because they
48. 2:13have the potential to chop up lots of
49. 2:15fish and the positioning of lots of
50. 2:17lagoons near the mouth of rivers is very
51. 2:20alarming for us there's another drawback
52. 2:22the Lagoon will have to be subsidized by
53. 2:25Bill payers and it is looking very
54. 2:28expensive the developers claim a second
55. 2:31Lagoon they want to make at Cardiff will
56. 2:33provide energy for about the same cost
57. 2:35as nuclear and much more
58. 2:37safely ministers are committed to
59. 2:40getting almost all our electricity from
60. 2:42low carbon sources they hope a fleet of
61. 2:45lagoons round the coasts of Britain will
62. 2:47prove affordable as well as reliable
63. 2:50Roger harabin BBC News Swansea