1. Future Projections: Tidal Power in the UK Alice Sheppard 24 th February 2005

2. Proposals 2 options: 1.Tidal barrage 2.Turbines Tidal Energy at 10 most promising sites 36 TWh/year (House of Commons, 2001). Total resource ~50TW/year (1994) Severn Barrage: 17TWh/year (1994) Bi-direction turbines, capacity 60MW, cost £79m

3. Hopes for Tidal Power £348m allocated towards R&D over 4 years (Patricia Hewitt) Technology still “in infancy”: –>30 years ago predictions made for 10MW turbines –43 wind farms operating in 1997 Technological barriers “could be overcome” if engineering funded (House of Commons) Lifetime ~ 120 years for barrage Low maintenance cost (0.5%/year) More predictable than wind Could promote local employment and recreation

4. Potential Disadvantages Construction costs –Severn Barrage: at least £800m (1981), 7% overheads cost –Electricity price could be 14p/kWh (1994) –“Limited scope for cost reduction” (1994) No output until construction complete Adverse effect on local area: –Redirecting/treating sewage effluent ~£120-230m –Additional sea defence ~£10m Essentially long-term project so undesirable to “market forces”; “no significant economies of scale” After £12.1m allocated to DTI/DE programme funding before March 1993 & 150 projects, none commissioned

5. Optimistic Projections: Turbines In theory, could install 20 turbines/day. Installation 3-4 weeks, so say 20 every 3 weeks, starting from March this year, each 1MW: 2005=220MW=6.93PJ/year 2010=2920MW=91.98PJ/year 2015=5720MW=180.18PJ/year 2020=8520MW=268.28PJ/year 2030=11,320MW=356.58PJ/year

6. Pessimistic Projection: Turbines Energy Papers 46 and 62 do not even mention turbines: worst possible outcome 0PJ/year. What is most likely? Depends upon: –Future use of nuclear fuel –Willingness of government to invest in R&D –Engineering –Success in other countries

7. Optimistic Projection: Barrages 30 potential sites have been identified in the UK, 90% of generation to take place at 8 sites Total resource 50TWh. If all this could be used by 2030, 180PJ/year could be produced. Gross Energy Consumption projected in 2030: 15,894PJ (assuming a 1.7% yearly growth since 2003) In theory, therefore possible to supply 20% of current energy consumed in England and Wales (1994) No information available on rates of construction, or start/finish dates. Projection assumes finish date 2030.

8. Pessimistic Projection: Barrage Energy Paper 62, March 1994: Predicts zero construction between 2005 and 2025: “limited scope for cost reduction”, “no significant economies of scale” etc. May be 0 PJ generated by 2030. Assuming construction starts 2025, no electricity would be generated that year If the Severn Barrage was completed by 2030, generating 17TWh: 61.2PJ/year, or <4% of projected energy demand by 2030 Realistic scenario: Probably pessimistic - no development plans at present or change from intention to delay any construction until 2025.