Roger Falconer and Chris Binnie - Sustainable Severn Forum 2017
Download as PPTX, PDF1 like318 views
This document discusses opportunities for tidal energy generation in the Bristol Channel and Severn Estuary. It provides details on existing tidal power installations like the La Rance Tidal Barrage in France. It also describes current designs for proposed tidal projects in the region like the Swansea Bay Tidal Lagoon, including the lagoon area, number of turbines, and expected annual energy generation. The document analyzes potential impacts of tidal projects like cumulative impacts from multiple close schemes and wake effects from turbine and sluice gate layout. It also discusses interactions between barrage and lagoon designs being considered for the Severn Estuary.
Roger Falconer and Chris Binnie - Sustainable Severn Forum 2017
- 1. Tidal Energy Opportunities in the Bristol Channel and Severn Estuary Roger Falconer1 and Chris Binnie2 1Hydro-environmental Research Centre, Cardiff University 2Independent Water Consultant 1
- 2. 2 Key details: • Completed in 1966 • 24 x 5.5m dia. bulb turbines & 6 sluices • Turbine trials ebb- only (+ pumping) • Generate 0.54TWh/y • Energy cost €20/MWh cheapest in EU • No baseline studies prior to construction La Rance Tidal Barrage Scheme
- 3. 3 Swansea Bay Lagoon - Current Design Key details: • Wall 9.7km long • Area 11.6km2 • 16 x 7.3m diam bulb turbines & 8 sluices • Turbines: two-way + pumping HW & LW • Generate 0.54TWh/y • Potential for large wakes and eddies
- 4. 4 Swansea Lagoon - Current Predictions 0 EBB FLD Turbining 0 LW HW Sluicing
- 5. 5 Annapolis Barrage - Sluice Gate Wake Wake from 2 Sluices and 1 x 20 MW turbine
- 6. LEGE ND Order limits X:JOBS3513_SWANSEA7CADDRAWINGSDCOPLANSPLANNING PLANS3513_PL_001_MASTERPLAN_KEY_PLAN.DWG Sources Ordnance Survey This drawing may contain: Ordnance Survey material by permission of Ordnance Survey on behalf of the Controller of Her Majesty's Stationery Office © Crown Copyright 2013. All rights reserved. Reference number 0100031673 OS Open data / © Natural England / © DEFRA / © DECC / © English Heritage. Contains Ordnance Survey data © Crown copyright and database right 2013 I Aerial Photography REFER TODRAWING NUMBER 3513/PL/002.3 Plan 3of6 REFER TODRAWING NUMBER 3513/PL/002.1 Plan 1of6 REFER TODRAWING NUMBER 3513/PL/002.4 Plan 4of6 REFER TODRAWING NUMBER 3513/PL/002.6 Plan 6of6 REFER TODRAWING NUMBER 3513/PL/002.2 Plan 2of6 T: 01865 887050 North SCALE@A0 1:10,000 STATUS Planning REV. DESCRIPTION APP. DATE DOC REF NO: 2.4.1 No dimensions are to be scaled from this drawing. All dimensions are to be checked on site. Area measurements for indicative purposes only. © LDA Design Consulting LLP. Quality Assured to BS EN ISO 9001 : 2008 PR OJ EC T TI TLE TIDAL LAGOON SWANSEA BAY PROJECT D R A W I N G T I T L E Masterplan Key Plan DATE 06.02.2014 DRAWN JH CHECKED LJ APPROVED AK ISSUED BY Oxford DWG. NO 3513_PL_001 10.5 9.5 5.2 1.0 0.0 5.5 4.5 0.2 Highest Astronomical Tide (HAT) Mean High Water Springs (MHWS) Mean Sea Level (MSL) -4.0 Mean Low Water Springs (MLWS) -5.0 Lowest Astronomical Tide (LAT) 10.0 9.0 N/A 1.5 5.0 4.0 N/A -3.5 Highest Astronomical Tide (HAT) Mean High Water Springs (MHWS) Mean Sea Level (MSL) Mean Low Water Springs (MLWS) Tidal bar - Outside of the lagoon (NTS) 0.5 -4.5 Lowest Astronomical Tide (LAT) Tidal bar - Inside of the lagoon (NTS) Chart Datum (m) Ordnance Datum (m) Chart Datum (m) Ordnance Datum (m) Turbine location: Option B REFER TODRAWING NUMBER 3513/PL/002.5 Plan 5of6 Turbine location: Option A (refer to inset for option B) Swansea Bay - Design Modification 1
- 7. 7 Swansea Bay - Design Modification 1 Revert turbine/sluice location to Option B - submitted to DCO Wake would be parallel to, and away from, dredged channel
- 8. 8 Swansea Bay - Design Modification 2 Focusing turbines and sluice gates leads to high wake/jet effects Flow through turbines emptying 2 Olympic swimming pools/sec https://www.ice.org.uk/ICEDevelopmentWebPortal/media/.../6-Ioan-Jenkins.pdf
- 9. 9 Wider distribution of turbines & sluices leads to weaker eddies 0 Original Modified Swansea Bay - Design Modification 2
- 10. General Findings: Larger impoundment size greater impact Multiple schemes in close proximity have cumulative impacts Impacts reduced by refined turbine/sluice design 10 Cumulative Impacts Studied Velocities Elevations 0 Velocities Elevations
- 11. 11 Tidal Lagoon - Barrage Interactions Various Barrage lines (STPG & Atkins) and Lagoons (Cardiff & Swansea) considered, with interactions studied: Note: Figures do not include effects of pumping Results show Barrage would reduce Cardiff output 60% and Cardiff would reduce Barrage output 13% Run Barrage/Lagoon Annual Energy* Alone (TWh/yr) Annual Energy* Combined 1 Severn (HRC) 19.82 17.184 2 Severn (Atkins) 19.77 17.141 (est) 3 Cardiff Lagoon 4.680 1.783 4 Swansea Lagoon 0.586 0.531
- 12. Sustainable Severn Forum 27th April 2017 Energy opportunity for the estuary Updating the Severn barrage By Prof Chris Binnie MA, DIC, HonDEng, FREng, FICE, FCIWEM [email protected]
- 13. DECC Severn tidal schemes
- 14. DECC ebb only generation. Level of water inside impoundment Option 1: Generate over ebb tide only
- 15. Conclusions of the DECC study from the Executive Summary • Half of the schemes, including the Cardiff lagoon, were judged to be unviable and were not included in the more detailed consideration. • The Welsh Grounds lagoon, (Newport lagoon), is no longer considered feasible. • The Cardiff-Weston, Severn, barrage, 15.6 TWh/y, offers the best value for money. • Combinations of smaller schemes do not offer cost or energy yield advantages over a single larger scheme between Cardiff and Weston.
- 16. Reasons the Severn barrage was not supported. • Enormous loss of inter-tidal habitat, 118-163 km2 • Birds. Reduction in SPA feeding ground, significant negative effect on 30 species • Land Drainage. area affected 372km2 • Fish mortality, SAC, possible local extinction of shad and salmon. • Navigation, • delays to ships transiting the barrage • BPC planned Deep Sea Container Terminal
- 17. Improvements to turbines and operation achieved by TLP, Andritz and GE. • Ebb/flood generation • Improved basin water levels and generation output • Pumping • Basin water levels become near normal • Triple Regulation • Improvement in energy generation • Non-synchronous generators • Reduced fish mortality • Smoother passageway • Reduced shear so greatly improved shad mortality
- 18. Severn Barrage on the Atkins line
- 19. Tidal curve with ebb/flood generation with pumping.
- 20. Statistics of the revised barrage • Energy increased from 15.6 TWh/y to 20.5 TWh/y • Low water at the barrage increased from 0.34m CD to 0.39m CD, an increase of 0.05m. • High water at the barrage reduced from 13.84m CD to 13.40m CD, a reduction of 0.44m. • Mean water level marginally reduced.
- 21. Revised impact • Loss of SAC inter-tidal habitat considerably reduced. • Loss of bird feeding ground considerably reduced. • Drainage issue eliminated. • Fish impact considerably reduced. • Navigation. Two new container terminals at Liverpool and London Gateway. BPC DSCT postponed.
- 22. Comparison of Cardiff and Updated Severn barrage • Cardiff and Newport lagoons about 8 TWh/y • Severn barrage about 20 TWh/y. • Loss of national energy source of about 10 TWh/y • Severn barrage impact much reduced but still more navigation and fish impact than lagoons. • Before proceeding, independently update the comparison?
- 23. • Welcome Hendry Review and support for Swansea Bay Lagoon as “Pathfinder Project”. • Swansea Lagoon needs to be successful and would suggest further consideration of two design aspects. • DECC 2010 Severn Barrage had high impact. • Tidal energy parameters now much improved. • Lagoon and barrage impact much reduced. • Need for independent updated comparison? Concluding Remarks