tidal_wave_energy.ppt
This document discusses tidal and wave energy technologies. It describes how tidal barrages work by damming estuaries and using turbines to generate electricity as the tides flow in and out. For wave energy, it discusses experimental offshore turbines and devices like the Pelamis Project. The environmental impacts of tidal barrages include changes to tidal heights and flows that can affect habitats. Tidal barrages also have high upfront costs but provide energy for over 120 years. Wave energy devices have lower predicted impacts and costs estimated similar to wind power. In conclusion, wave energy has potential to meet over 10% of global energy needs due to large ocean areas while tidal barrages require careful site selection due to environmental impacts.
tidal_wave_energy.ppt
- 1. Tidal and Wave Energy By: Patrick Blomberg Adam Womack
- 2. How it Works – Tidal Barrages • Tidal Barrages • Dam an estuary • As water flows out or in, a turbine is spun • Electricity is generated by the turbine
- 3. How it Works – Tidal Barrages
- 4. from http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/tidal1.htm) How it Works – Tidal Barrages
- 5. How it Works - Wave Energy • Many experimental technologies • Example: Pelamis Project from http://www.worldenergy.org/wec-geis/publications/reports/ser/wave/wave.asp
- 6. How it Works - Wave Energy • Offshore Turbines • Have gearboxes, anchored by a monopile from http://www.marineturbines.com/technical.htm
- 7. How it Works - Wave Energy • Swanturbines • No gearboxes, anchored by concrete from http://www.swanturbines.co.uk
- 8. How it Works - Wave Energy from http://www.worldenergy.org/wec-geis/publications/reports/ser/wave/wave.asp
- 9. Environmental – Tidal Barrages • Under Construction – – Essentially the barrage is a dam – Stagnating water – Increase in pollutants – Given time, returns to normal
- 10. Environmental – Tidal Barrages • After Construction – Tidal height changed • Decrease in mud flats area during low tide • Unpredictable effect on bird migration (30-50%) • Outside high tide increase; excess flow – Turbidity decreases • Increase in phytoplankton • Unpredictable changes to food chain – Sediment gradient altered • Severn Estuary Solution
- 11. Environmental – Wave Energy • Blade Speed 10-20 rpm – Boat propeller up to 10x faster • Monopile/Concrete – Easily Avoided • Other Designs – Stationary, surface • Vortex – Unsure, expected to be avoided Image from: http://www.marineturbines.com/home.htm
- 12. Economic – Tidal Barrages • Historical Example – Rance Estuary – Cost about 530 Million Euros in today’s costs, not including inflation in mid 60’s – 240 MW output – Estimated energy cost (Not including startup) • 18 cents Euro / kW • Nuklear estimated similarly at 25/kW
- 13. Economic – Tidal Barrages • Severn Estuary – Estimated $12-16 million construction • About 3 Nuclear plants – 8640 MW Output • About 8 Nucler plants – Running costs about 1.5x Nuclear – Estimated lifespan – 120 years • Nuclear is about 60 • Alternate Design - Lifts
- 14. Economic – Wave Energy • MCT – About $16 million US – Plotted Velocities – 300 kW design – 1 MW design • Other Estimates – ‘Cheaper than tidal’ – ‘About the same as wind’
- 15. Conclusions • Wave Energy – More area for utilization – Promising research – Potential for higher than 10% of world need • Tidal Barrages – Widely varying environmental impact – Expensive, but long lasting – Very placement specific
- 16. Questions?