Tidal Energy Potential & Future Contribution to UK Energy Mix Pilar Castillo 16.3.2010

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 2/21/2019

Categories: Tidal Range - Technologies 2/21/2019

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 : 2-2.5-12-15p/KWh Privately funded Less intrusive, less damage 2/21/2019

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 2/21/2019

Categories: Tidal Stream - Technologies 2/21/2019

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 2/21/2019

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) = 0.0072PJ total 2030 – 3GW total installed capacity - 300 tidal stream farms (each 10.5MW) = 0.011 34PJ total 2/21/2019

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 2/21/2019

Thank you 2/21/2019