1. Tidal Power Projections Tom Beagan 24 th February 2005

2. The Tidal Resource The UK has a significant proportion of the world’s tidal power It can be harnessed in 2 forms: Tidal Barrage Tidal Stream

3. Tidal Barrage Requires a tidal basin –at least 5m tidal difference Few suitable sites in the world La Rance (right) only large one, 240MW capacity Potential for an 8460 MW barrage across the Severn

4. Tidal Barrage Benefits Continuous electricity source Pollution free (except construction) Low cost after completion Limitations High capital cost (resulting in high cost of electricity) Environmental impact: sediment flows, species migration Hinders navigation Visual impact Can’t control peak generation time

5. Tidal Stream The newer method of tidal generation Devices placed in strong tidal streams around UK Possible devices: –‘Seagen’ (right) up to 1MW –Stingray (aerofoil) 150KW

6. Tidal Stream Benefits Small environmental and visual impact Large Potential resource in UK waters No pollution Limitations Technology in early stage of development Devices expensive = expensive electricity Tidal streams are a long way from large populations Electricity loss through transmission Low load factor 39% average (carbon trust)

7. The Future for Tidal Barrage Artists impression of the proposed Severn barrage Hmmm!

8. The Future for Tidal Barrage There are 3 large barrage proposals in UK The Severn – 8640 MW by far the largest in UK The Mersey – 700MW Orkney Churchill Barriers – 300MW Several smaller proposals Duddon estuary (Cumbria) – 100MW Wyre estuary (Lancashire) – 63.6 MW Conwy (North Wales) – 33.4 MW Loughor (Swansea) – 5 MW

9. Why aren’t they being built? Mainly financial reasons –Severn 8.6GW scheme ‘uneconomical’ –High capital costs and few jobs after completion –Electricity will be too expensive Environmental reasons –Large opposition from pressure groups –Extent of possible damage unknown –Big risk Turn towards Tidal Stream –Interest is building –Acquiring more funding and investment

10. What can we expect from barrage? Unlikely to be any sizeable schemes between now and 2030 except maybe Orkney (existing barrier) To increase likelihood Need a reduction in capital costs Improvement in power capture efficiency Possible tidal lagoon in Severn? FOE Projection 2010 – 0 MW 2015 – 0 MW 2020 – Up to 300 MW if Orkney gets go ahead 2030 – 300 MW

11. The Future for Tidal Stream

12. The future is bright! Size of resource 22 TWH/yr most recent prediction Most advanced design is double turbine ‘seagen’ capable of over 1 MW capacity 300 KW single turbine being tested in Bristol Channel currently outperforming expectations by 27% Problem? High cost of technology currently over £2M for a single unit Funding gap, businesses can’t afford to build prototypes

13. The Future for Tidal Stream Solution Aug ’04 Marine Renewables Development Fund to be set up Grants of £5M to suitable investors Result 1 MW prototype  Tests and technological improvements Grid connected ‘farm’ of 3-5 devices  Tests Tidal farm will grow to 20+ devices  Tests Several farms will be created in different sites Improved technology will bring prices down, large growth

14. Tidal Stream Projections

15. Carbon trust total tidal stream extractable: 22 TWh/year That requires a 2.5 GW supply This will need 6435 double turbines (LF 39%) Can we do this by 2030? That’s 257 Seagen a year from now until 2030 I don’t think so!!!

16. What can we expect? 2010 – 1 Seagen (1MW) probably grid installed –0.39 MW = 0.01 PJ 2015 – 25 Seagen grid operational –9.75 MW = 0.31 PJ 2020 – 100 operational –39 MW = 1.23 PJ Capital cost cheaper, Each unit now 1.5 MW 2025 – 350 operational (around 50 per year) –205 MW = 6.46 PJ 2030 – 750 operational (around 80 per year) –439 MW = 13.8 PJ

17. Stream plus Barrage Orkney tidal barrage (300MW) likely by 2020 Load factor around 23% Therefore 69 MW = 2.18 PJ 2020 – 3.14 PJ 2025 – 8.46 PJ 2030 – 16 PJ But this is an optimistic projection!

18. Conclusion Large margin for error Projections rely on results of testing Transmission costs not accounted for Hydrogen? Main barrier FINANCIAL