Tidal and Wave Energy By Patrick Blomberg Adam

Tidal and Wave Energy By: Patrick Blomberg Adam Womack

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

How it Works – Tidal Barrages

How it Works – Tidal Barrages from http: //www. esru. strath. ac. uk/Eand. E/Web_sites/01 -02/RE_info/tidal 1. htm)

How it Works - Wave Energy • Many experimental technologies • Example: Pelamis Project from http: //www. worldenergy. org/wec-geis/publications/reports/ser/wave. asp

How it Works - Wave Energy • Offshore Turbines • Have gearboxes, anchored by a monopile from http: //www. marineturbines. com/technical. htm

How it Works - Wave Energy • Swanturbines • No gearboxes, anchored by concrete from http: //www. swanturbines. co. uk

How it Works - Wave Energy from http: //www. worldenergy. org/wec-geis/publications/reports/ser/wave. asp

Environmental – Tidal Barrages • Under Construction – – Essentially the barrage is a dam – Stagnating water – Increase in pollutants – Given time, returns to normal

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

Environmental – Wave Energy • Blade Speed 10 -20 rpm – Boat propeller up to 10 x faster • Monopile/Concrete – Easily Avoided • Other Designs – Stationary, surface • Vortex – Unsure, expected to be avoided Image from: http: //www. marineturbines. com/home. htm

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 / k. W • Nuklear estimated similarly at 25/k. W

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. 5 x Nuclear – Estimated lifespan – 120 years • Nuclear is about 60 • Alternate Design - Lifts

Economic – Wave Energy • MCT – About $16 million US – Plotted Velocities – 300 k. W design – 1 MW design • Other Estimates – ‘Cheaper than tidal’ – ‘About the same as wind’

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

Questions?