Marine renewable energy (ocean energy)

Introduction

• More energy required because of growth in population and 31.
• What's needed:
  • renewable energy sources
  • methods that won't create pollution

Wave energy

• Advantage: waves provide a 32. source of renewable energy
• Electricity can be generated using offshore or onshore systems
• Onshore systems may use a reservoir
• Problems:
  • waves can move in any 33.
  • movement of sand, etc. on the 34. of the ocean may be affected

Tidal energy

• Tides are more 35. than waves
• Planned tidal lagoon in Wales:
  • will be created in a 36. at Swansea
  • breakwater (dam) containing 16 turbines
  • rising tide forces water through turbines, generating electricity
  • stored water is released through 37., driving the turbines in the reverse direction
• Advantages:
  • not dependent on weather
  • no 38. is required to make it work
  • likely to create a number of 39.
• Problem:
  • may harm fish and birds, e.g. by affecting 40. and building up silt

Ocean thermal energy conversion

• Uses a difference in temperature between the surface and lower levels
• Water brought to the surface in a pipe