1. Tidal Energy Potential & Future Contribution to UK Energy Mix
Pilar Castillo

2. Categories: Tidal Range
Vertical difference in height between high & low water.
Severn Estuary tidal range is 2nd highest in the world – up to 14 meters
53TWh/y exploitable potential
14% of UK electricity generation
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3. Categories: Tidal Range - Technologies
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4. Categories: Tidal Range - Severn
Barrages & Lagoons: Severn project
Existing hydro-electric technology
Barrage: huge dam from A-B
Generates energy ebb tide
Max output: 8.6GW
Unit cost electricity: 7.39p/KWh
Public/private investment
Added rail or road link
Greater environmental damage
Lagoon: rock walled enclosure
Generates on both ebb & flow
Max output: 4.5GW
Unit cost electricity : p/KWh
Privately funded
Less intrusive, less damage
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5. Categories: Tidal Stream
Kinetic energy of moving water to power turbines
Half the European resource
10-15% of the known global resource
12TWh/yr of UK Tidal Stream Resource economically exploited
Potentially up to 3% electricity demand
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6. Categories: Tidal Stream - Technologies
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7. Comparing tidal technologies
Tidal Range
Hybrid Lagoon barrage:
Costly £10-12b (Severn)
7-10 years construction time
Grid upgrading required
Intrusive
Predictable resource w/low maintenance
Cost effective flood & coastal erosion control
Strategic energy storage potential
Tidal Stream
Application of wind technology
Water turbines greater output capacity than wind – water higher density
Only one 1.2MW turbine installed in NI connected to grid generating full capacity
Less intrusive than barrages
Predictable
No storage capacity
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8. Assumptions – Best Scenarios
Tidal range:
Seven Estuary (from 2020 If decision reached this year)
- Middle Barrage B3 (Cardiff – Weston) – 17TWh/y
- Bridgewater Bay L3d – 2.64TWh/y
- Combined B3 & L3d = 70.7PJ (5.6% of UK energy needs, 350TWh per year)
Cut 18m tonnes of GHG/y
Tidal Stream:
2020 – 2GW total installed capacity
- 200 tidal stream farms (each 10.5MW) = PJ total
2030 – 3GW total installed capacity
- 300 tidal stream farms (each 10.5MW) = PJ total
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9. Projections Tidal range: Seven Estuary
– Middle Barrage (Cardiff – Weston): 7.39 pence per kilowatt hour
– Bridgewater Bay: 8.29 pence per kilowatt hour
Tidal Stream:
– Around 3-4 pence per kilowatt hour but cost will decrease once technology is deployed on a larger scale
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10. Thank you
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