Future Projections:
Tidal Power in the UK
Alice Sheppard
24th February 2005
Proposals
2 options:
1. Tidal barrage
2. Turbines
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•
•
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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
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
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
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:
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•
•
•
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2005
2010
2015
2020
2030
=220MW
=2920MW
=5720MW
=8520MW
=11,320MW
=6.93PJ/year
=91.98PJ/year
=180.18PJ/year
=268.28PJ/year
=356.58PJ/year
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
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.
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.