Stephen Hugh Salter, MBE, FRSE (7 December 1938 – 23 February 2024) was a South African-born Scottish academic who was Emeritus Professor of Engineering Design at the University of Edinburgh[1] and inventor of the eponymous Salter's duck wave energy device.[2][3] Salter was also a proponent of geoengineering and was responsible for creating the concept of the mechanical enhancement of clouds to achieve cloud reflectivity enhancement.[4]

Stephen Salter
Born(1938-12-07)7 December 1938
Died23 February 2024(2024-02-23) (aged 85)
Edinburgh, Scotland
EducationUniversity of Cambridge
Known forSalter's Duck
Cloud reflectivity enhancement
• Wave generation and absorption in wave tanks
AwardsMBE, FRSE
Scientific career
FieldsEngineering
Geoengineering
Fluid dynamics
InstitutionsUniversity of Edinburgh

The wide wave tank at the University of Edinburgh—a novel design and invention by Salter, built in 1977—was the world's first multi-directional wave tank equipped with absorbing wavemakers. Feedback control systems on the wavemaking flaps were used for the absorption of reflected waves, propagating along the water surface of the tank interior towards the 89 flaps.[5][6][7] These force-feedback wave paddles were further developed and commercialised by Edinburgh Designs, and are used in many facilities worldwide. Salter argued in 2001 that to properly test wave and tidal energy devices required a circular combined wave and current basin, which ultimately led to the construction of the FloWaveTT facility.[8]

Together with Win Rampen, Salter also played a key role in the development of digital-displacement pump-motors, later manufactured by Artemis Intelligent Power.[8][9] Salter was a Specialist Advisor at wave energy company Aquamarine Power advising on the development of the Oyster wave energy converter,[10] however the company ceased trading in 2015.

Salter was "one of the leading voices" of the marine cloud brightening movement.[11] Born in Johannesburg on 7 December 1938,[12] he died in Edinburgh on 23 February 2024, at the age of 85.[13]

Salter's duck edit

While historic references to the power of waves do exist, the modern scientific pursuit of wave energy was begun in the 1970s by Salter, in response to the oil crisis. His 1974 invention became known as Salter's Duck or Nodding Duck, although it was officially referred to as the "Edinburgh Duck". In small scale controlled tests, the Duck's curved cam-like body can stop 90% of wave motion and can convert 90% of that to electricity.[14] According to sworn testimony before the House of Parliament, The UK Wave Energy programme was shut down on 19 March 1982, in a closed meeting.[15][16] An analysis of Salter's Duck resulted in a miscalculation of the estimated cost of energy production by a factor of 10,[17] an error which was only recently identified. Some wave power advocates believe that this error, combined with a general lack of enthusiasm for renewable energy in the 1980s (after oil prices fell), hindered the advancement of wave power technology.[18]

Honours and awards edit

Salter was appointed Member of the Order of the British Empire (MBE) in the 2004 Birthday Honours for services to engineering.[19] In 2012 he received the Royal Academy of Engineering Sustained Achievement Award.[20] In 2021 he was inducted into the Scottish Engineering Hall of Fame.[21]

References edit

  1. ^ Harvie, Barbra (8 October 2007). "Professor Stephen Salter". School of Engineering. University of Edinburgh. Retrieved 1 March 2009.
  2. ^ McGrath, Jane (14 July 2008). "Could Salter's Duck have solved the oil crisis?". Green Science. HowStuffWorks. Retrieved 1 March 2009.
  3. ^ Salter, S.H. (1974). "Wave power". Nature. 249 (5459): 720–724. Bibcode:1974Natur.249..720S. doi:10.1038/249720a0. S2CID 4278688.
  4. ^ Bower, Keith; Choularton, Tom; Latham, John; Sahraei, Jalil; Salter, Stephen (2006). "Computational assessment of a proposed technique for global warming mitigation via albedo-enhancement of marine stratocumulus clouds". Atmospheric Research. 82 (1–2): 328–336. Bibcode:2006AtmRe..82..328B. doi:10.1016/j.atmosres.2005.11.013.
  5. ^ Salter, S.H. (1981). "Absorbing wave-makers and wide tanks". Conference on Directional Wave Spectra Applications. ASCE. pp. 185–202.
  6. ^ "Wide Wave Tank 1977 – 2001". University of Edinburgh. Retrieved 2 March 2009.
  7. ^ "Wave master". The Engineer. 10 April 2007. Retrieved 2 March 2009.
  8. ^ a b "Announcing the death of Professor Stephen Salter | School of Engineering". www.eng.ed.ac.uk. Retrieved 1 March 2024.
  9. ^ Ehsan, Md.; Rampen, W. H. S.; Salter, S. H. (26 June 1997). "Modeling of Digital-Displacement Pump-Motors and Their Application as Hydraulic Drives for Nonuniform Loads". Journal of Dynamic Systems, Measurement, and Control. 122 (1): 210–215. doi:10.1115/1.482444. ISSN 0022-0434.
  10. ^ "Aquamarine Power". Aquamarine Power. 13 November 2013. Retrieved 27 November 2013.
  11. ^ Smedley, Tim. "How artificially brightened clouds could stop climate change". www.bbc.com. Retrieved 1 March 2019.
  12. ^ Birse, Ronald M. (1983). Engineering at Edinburgh University: a short history, 1673–1983\. ISBN 9780950892009.
  13. ^ "Stephen Hugh Salter". The Times. 4 March 2024. Retrieved 4 March 2024.
  14. ^ "Edinburgh Wave Energy Project" (PDF). University of Edinburgh. Archived from the original (PDF) on 1 October 2006. Retrieved 22 October 2008.
  15. ^ "Memorandum submitted by Professor S H Salter, Department of Mechanical Engineering, University of Edinburgh". Parliament of the United Kingdom. 9 February 2001. Archived from the original on 1 March 2012. Retrieved 22 October 2008.
  16. ^ "Further Memorandum by S H Salter, Department of Mechanical Engineering, University of Edinburgh" (PDF). Parliament of the United Kingdom. 1 June 1988. Retrieved 29 December 2017 – via S.H. Salter online archive.
  17. ^ "Water Power Devices". Earth Science Australia. Retrieved 22 October 2008.
  18. ^ "The untimely death of Salter's Duck". Green Left Weekly. Archived from the original on 10 October 2008. Retrieved 22 October 2008.
  19. ^ "The London Gazette, Number 57315, Saturday 12 June 2004". London-gazette.co.uk. 12 June 2004. Retrieved 27 November 2013.
  20. ^ "Wave energy pioneer receives top Academy Award". Royal Academy of Engineering. Retrieved 25 February 2013.
  21. ^ "Scottish Engineering Hall of Fame". engineeringhalloffame.org. 2012. Retrieved 19 February 2022.

Further reading edit