Ocean Energy Poten.al and Research Projects at Stellenbosch South African Ocean Energy Network Wednesday 10 October 2012 Cape Town
Prof JL (Wikus) van Niekerk Director: Centre for Renewable and Sutainable Energy Studies Stellenbosch University 1/22 Centre for Renewable and Sustainable Energy Studies
Contents •  Ocean Energy Resources in South Africa –  Wave Energy Resources –  Agulhas Current Data •  Stellenbosch Research Projects –  Wave Energy –  Ocean Current •  Conclusions and Way Forward •  QuesOons 2/22 Centre for Renewable and Sustainable Energy Studies
Wave Energy Resource of South Africa 3/22 Centre for Renewable and Sustainable Energy Studies
Wave Energy Resource in the Western Cape Mean annual average
wave power (kW/m)
0
25
50km
Scale
0000
St Helena Bay
N
63
59
55
0000
51
Saldanha Bay
47
43
39
Dassen Island
35
0000
31
27
23
Table Bay
19
15
0000
11
Hout Bay
7
3
False Bay
0000
Cape Point
150000
4/22 200000
250000
Hangklip
300000
-10
(Geustyn, 1983)
The Cape southwest coast has the best documented wave energy resource along the SA coastline. (Joubert 2008)
Modelled the annual average wave power using hindcast wave data Centre for Renewable and Sustainable Energy Studies
Ocean Current Resource around South Africa 5/22 Centre for Renewable and Sustainable Energy Studies
Agulhas Ocean Current Data 6/22 Centre for Renewable and Sustainable Energy Studies
Agulhas Ocean Current Data •
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Eskom measurements are available Few other sources, Lutjeharms, satellite data, etc. Average current speed 1.2 m/s -­‐ 1.5 m/s Max current speed 2.5 m/s Depth 20 m (or very near the surface!) Distance from shore, approx 10 km Water depth, approx 100 m Natal pulses, reversals! Occasional large waves Extended periods of low velocity flow 7/22 Centre for Renewable and Sustainable Energy Studies
Agulhas Ocean Current Measurements •  Measured in 3 month periods with ADCPs at numerous sites. •  Data accuracy ? •  Discrepancies ? •  Availability? •  InterpretaOon? 8/22 Centre for Renewable and Sustainable Energy Studies
Agulhas Ocean Current Reversal 9/22 Centre for Renewable and Sustainable Energy Studies
Stellenbosch Wave Energy Research •  Stellenbosch University acOve since 1978 •  Numerous Masters and PhD •  SWEC 10/22 Centre for Renewable and Sustainable Energy Studies
Stellenbosch Wave Energy Converter Wave Crest
Under-Sea Cable to Shore
Turbine and Generator
Air-Chambers
Openings with Valves
High Pressure Duct
Low Pressure Duct
11/22 Centre for Renewable and Sustainable Energy Studies
ShoreSWEC in Granger Bay 12/22 Centre for Renewable and Sustainable Energy Studies
ShoreSWEC 13/22 Centre for Renewable and Sustainable Energy Studies
South African Wave Energy Research •  Stellenbosch University (2007-­‐present) –  James Joubert (PhD) – Design and development of the ShoreSWEC through numerical modelling and experimental tests –  Jacques du Plessis (MSc.Eng) – Design and tesOng of a model point absorber with hydraulic power take-­‐off system –  Paul Ackerman (MSc.Eng) – Numerical airflow model and turbine design –  Bavesh Kooverji (MSc.Eng) – Development and tesOng of system to measure bidirecOonal airflow of an OWC –  Felipe Guerrero (MSc. Civil Eng) Focussing wave basin –  James Joubert (MSc. Civil Eng) – Resource assessment of the South African southwest coast –  Linear generator development and tesOng for a point absorber(Electrical Engineering) •  University of Cape Town –  Jonathan Frick (MSc.Eng) -­‐ Environmental and regulatory requirements for wave energy projects on the South African coast •  University of the Witwatersrand –  Linear synchronous generator 14/22 Centre for Renewable and Sustainable Energy Studies
Stellenbosch Wave Energy Projects •  Ship-­‐integrated WEC for semi-­‐staOonary vessels – for De Beers Marine •  Feasibility studies on various WECs –  Wave Air Generator –  OEMP –  Roman Bay 15/22 Centre for Renewable and Sustainable Energy Studies
Stellenbosch Ocean Current Research •  Since 2007 5 final year projects; 2 x M.Sc.Eng. •  Sea Renewable Energy (Pty) Ltd –  Tethered wing with two trailing turbines –  Rotordiameter 21 m –  LCOE R 2.34/kWh to R 3.42/kWh 16/22 Centre for Renewable and Sustainable Energy Studies
Stellenbosch Ocean Current Research •  Simple shroud, twice the power •  OpOmised shroud, 3.5 Omes the power 17/22 Centre for Renewable and Sustainable Energy Studies
Stellenbosch Ocean Current Research 1.6 1.4 1.2 OpOmised diffuser (Bahaj rotor) Cp 1 OpOmised diffuser (Stanford rotor) 0.8 0.6 Straight wall diffuser (Bahaj rotor) 0.4 Bare turbine (Bahaj rotor) 0.2 0 1 18/22 2 3 4 5 6 7 8 TSR 9 10 11 12 13 Centre for Renewable and Sustainable Energy Studies
Open InnovaOon Challenge •  Stellenbosch University entered with consorOum partners SRE and Minesto •  Asked to submit full proposal for second round 19/22 Centre for Renewable and Sustainable Energy Studies
Conclusions and Way Forward •  SA has an ahracOve wave and ocean current energy resources that can be exploited for electricity generaOon •  Wave Energy: Converters are sOll under development, commercial systems are sOll a few years off; Wave energy complements wind energy in the Western Cape •  Ocean Current: Suitable converters are not currently available; “24/7” operaOon is vey ahracOve for base load; surface current and distance to shore poses unique challenges. •  Wave and Ocean Current technologies sOll need to be supported by R&D grants and then by subsidies (FITs) to develop commercially viable converters in future 20/22 Centre for Renewable and Sustainable Energy Studies
Acknowledgements •
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21/22 Josh Reinecke Prof TW von Backström James Joubert Jacques du Plessis Centre for Renewable and Sustainable Energy Studies
QuesOons ? www.crses.sun.ac.za 22/22 Centre for Renewable and Sustainable Energy Studies