1. Oceanic Energy Professor S.R. Lawrence Leeds School of Business University of Colorado Boulder, CO 80305

2. Renewable Hydro Power Wind Energy Oceanic Energy Solar Power Geothermal Biomass Sustainable Hydrogen & Fuel Cells Nuclear Fossil Fuel Innovation Exotic Technologies Integration Distributed Generation Course Outline

3. Overview Tidal Power Technologies Environmental Impacts Economics Future Promise Wave Energy Technologies Environmental Impacts Economics Future Promise Assessment Oceanic Energy Outline

4. Overview of Oceanic Energy

5. Sources of New Energy Boyle, Renewable Energy, Oxford University Press (2004)

6. Global Primary Energy Sources 2002 Boyle, Renewable Energy, Oxford University Press (2004)

7. Renewable Energy Use – 2001 Boyle, Renewable Energy, Oxford University Press (2004)

8. Tidal Power

9. Tidal Motions Boyle, Renewable Energy, Oxford University Press (2004)

10. Tidal Forces Boyle, Renewable Energy, Oxford University Press (2004)

11. Natural Tidal Bottlenecks Boyle, Renewable Energy, Oxford University Press (2004)

12. Tidal Energy Technologies 1. Tidal Turbine Farms 2. Tidal Barrages (dams)

13. 1. Tidal Turbine Farms

14. Tidal Turbines (MCT Seagen) • 750 kW – 1.5 MW • 15 – 20 m rotors • 3 m monopile • 10 – 20 RPM • Deployed in multi-unit farms or arrays • Like a wind farm, but • Water 800x denser than air • Smaller rotors • More closely spaced MCT Seagen Pile http://www.marineturbines.com/technical.htm

15. Direct drive to generator No gearboxes Gravity base Versus a bored foundation Fixed pitch turbine blades Improved reliability But trades off efficiency Tidal Turbines (Swanturbines) http://www.darvill.clara.net/altenerg/tidal.htm

16. Deeper Water Current Turbine Boyle, Renewable Energy, Oxford University Press (2004)

17. Oscillates up and down 150 kW prototype operational (2003) Plans for 3 – 5 MW prototypes Oscillating Tidal Turbine http://www.engb.com Boyle, Renewable Energy, Oxford University Press (2004)

18. Vertical turbine blades Rotates under a tethered ring 50 m in diameter 20 m deep 600 tonnes Max power 12 MW Polo Tidal Turbine Boyle, Renewable Energy, Oxford University Press (2004)

19. Power from Land Tides (!) http://www.geocities.com/newideasfromtelewise/tidalpowerplant.htm

20. Advantages of Tidal Turbines • Low Visual Impact • Mainly, if not totally submerged. • Low Noise Pollution • Sound levels transmitted are very low • High Predictability • Tides predicted years in advance, unlike wind • High Power Density • Much smaller turbines than wind turbines for the same power http://ee4.swan.ac.uk/egormeja/index.htm

21. Disadvantages of Tidal Turbines • High maintenance costs • High power distribution costs • Somewhat limited upside capacity • Intermittent power generation

22. 2. Tidal Barrage Schemes

23. Definitions • Barrage • An artificial dam to increase the depth of water for use in irrigation or navigation, or in this case, generating electricity. • Flood • The rise of the tide toward land (rising tide) • Ebb • The return of the tide to the sea (falling tide)

24. Potential Tidal Barrage Sites Only about 20 sites in the world have been identified as possible tidal barrage stations Boyle, Renewable Energy, Oxford University Press (2004)

25. Schematic of Tidal Barrage Boyle, Renewable Energy, Oxford University Press (2004)

26. Cross Section of a Tidal Barrage http://europa.eu.int/comm/energy_transport/atlas/htmlu/tidal.html

27. Tidal Barrage Bulb Turbine Boyle, Renewable Energy, Oxford University Press (2004)

28. Tidal Barrage Rim Generator Boyle, Renewable Energy, Oxford University Press (2004)

29. Tidal Barrage Tubular Turbine Boyle, Renewable Energy, Oxford University Press (2004)

30. La Rance Tidal Power Barrage • Rance River estuary, Brittany (France) • Largest in world • Completed in 1966 • 24×10 MW bulb turbines (240 MW) • 5.4 meter diameter • Capacity factor of ~40% • Maximum annual energy: 2.1 TWh • Realized annual energy: 840 GWh • Electric cost: 3.7¢/kWh Boyle, Renewable Energy, Oxford University Press (2004) Tester et al., Sustainable Energy, MIT Press, 2005

31. La Rance Tidal Power Barrage http://www.stacey.peak-media.co.uk/Brittany2003/Rance/Rance.htm

32. La Rance River, Saint Malo

33. La Rance Barrage Schematic Boyle, Renewable Energy, Oxford University Press (2004)

34. Cross Section of La Rance Barrage http://www.calpoly.edu/~cm/studpage/nsmallco/clapper.htm

35. La Rance Turbine Exhibit

36. Tidal Barrage Energy Calculations • R = range (height) of tide (in m) • A = area of tidal pool (in km2) • m = mass of water • g = 9.81 m/s2= gravitational constant • = 1025 kg/m3= density of seawater • 0.33 = capacity factor (20-35%) kWh per tidal cycle Assuming 706 tidal cycles per year (12 hrs 24 min per cycle) Tester et al., Sustainable Energy, MIT Press, 2005

37. La Rance Barrage Example • =33% • R = 8.5 m • A = 22 km2 GWh/yr Tester et al., Sustainable Energy, MIT Press, 2005

38. Proposed Severn Barrage (1989) Never constructed, but instructive Boyle, Renewable Energy, Oxford University Press (2004)

39. Proposed Severn Barrage (1989) • Severn River estuary • Border between Wales and England • 216 × 40 MW turbine generators (9.0m dia) • 8,640 MW total capacity • 17 TWh average energy output • Ebb generation with flow pumping • 16 km (9.6 mi) total barrage length • £8.2 ($15) billion estimated cost (1988)

40. Severn BarrageLayout Boyle, Renewable Energy, Oxford University Press (2004)

41. Severn Barrage ProposalEffect on Tide Levels Boyle, Renewable Energy, Oxford University Press (2004)

42. Severn Barrage ProposalPower Generation over Time Boyle, Renewable Energy, Oxford University Press (2004)

43. ~$15 billion (1988 costs) Severn Barrage ProposalCapital Costs Boyle, Renewable Energy, Oxford University Press (2004) Tester et al., Sustainable Energy, MIT Press, 2005

44. ~10¢/kWh (1989 costs) Severn Barrage ProposalEnergy Costs Boyle, Renewable Energy, Oxford University Press (2004)

45. Severn Barrage ProposalCapital Costs versus Energy Costs 1p  2¢ Boyle, Renewable Energy, Oxford University Press (2004)

46. Offshore Tidal Lagoon Boyle, Renewable Energy, Oxford University Press (2004)

47. Array of vertical axis tidal turbines No effect on tide levels Less environmental impact than a barrage 1000 MW peak (600 MW average) fences soon Tidal Fence Boyle, Renewable Energy, Oxford University Press (2004)

48. Promising Tidal Energy Sites http://europa.eu.int/comm/energy_transport/atlas/htmlu/tidalsites.html

49. Tidal Barrage Environmental Factors • Changes in estuary ecosystems • Less variation in tidal range • Fewer mud flats • Less turbidity – clearer water • More light, more life • Accumulation of silt • Concentration of pollution in silt • Visual clutter

50. Advantages of Tidal Barrages • High predictability • Tides predicted years in advance, unlike wind • Similar to low-head dams • Known technology • Protection against floods • Benefits for transportation (bridge) • Some environmental benefits http://ee4.swan.ac.uk/egormeja/index.htm