Stretching from Perth to Tasmania is the best place to use wave energy resources.
Credit: Wikipedia
SYDNEY: If just 10% of the near-shore wave energy available along Australia's Southern coastline could be converted into electricity, half of the country's current electricity consumption would be met, say CSIRO scientists.
Committed to reducing greenhouse gas emissions by 60% of year 2000 levels by 2050, the Australian Government aims to produce 45,000 gigawatt-hours/year of additional renewable energy before 2020.
"This total energy quota could be achieved using wave energy alone," said lead author Mark Hemer of the CSIRO Wealth from Oceans Flagship, Melbourne, "if 10% of the available wave energy resource over a 1,000km section of the Southern Australian margin were converted to electricity."
Australia lags behind in encouraging wave energy
The World Energy Council identified Australia's southern margin as one of the world's most promising sites for wave-energy generation, but governmental policies are still relatively underdeveloped.
"Several countries, particularly in Europe, have much more advanced policies to support uptake of the wave energy industry. This research shows that Australia's wave energy resource is considerably larger than these other countries which are actively encouraging the industry," said Hemer.
"As an example, the UK's wave energy resource has been estimated to be about 50 TWh/yr. This study has shown that Australia's southern has a sustained wave energy resource of 1329 TWh/yr."
Finding Australia's best wave energy locations
The study used long-term archives from the U.S. National Oceanic and Atmospheric Administration (NOAA), an operational wave model called WaveWatch III to measure significant wave height, peak wave period and peak wave direction, and The Simulating Waves Near-shore (SWAN) wave model to measure the spatial distribution of wave energy.
Using the 10-year, six-hourly archives collected by WaveWatch III from 1997 to 2006, the researchers calculated spectral wave measurements along the South-Western Australian margin, which extends from Perth to Hobart to determine deep-water wave energy potential, publishing their findings in the Journal of Renewable Sustainable Energy.
Using the SWAN wave model to assess how shallow water processes such as refraction, shoaling and bottom friction can affect the spatial distribution of wave energy, they were able to quantify the near-shore wave energy potential of certain locations, identifying the optimal places for energy extraction.
Once operational, wave energy has the potential to provide a clean source of renewable energy whilst posing minimal impacts on the environment and no greenhouse gas emissions.
Unlike wind turbines and solar farms, which are highly visible and have been criticised for spoiling coastal areas for recreational value, wave energy conversion devices can be hidden entirely underwater, or can protrude only a few metres above the ocean surface, depending on the design.
However, there are still uncertainties as to the long-term affect of these wave energy converters on marine and coastal environments.
Question marks over cost
The research by Mark Hemer and David Griffith from CSIRO aim to inform governmental policy by providing estimates on Australia's near-shore wave energy potential, and to narrow the search for the most suitable locations for commercialised wave energy converters.
"A whole range of Government policies are required to support the wave energy industry including R&D, manufacturing and deployment."
"An independent, comprehensive map of the wave energy resource is just one component to support that process, and that is what this research aimed to do," said Hemer.
Technology still needed
While this research has identified wave energy as a massive low-carbon resource for Australia to use in the future, it doesn't address the economic or engineering feasibility of wave energy converting devices. CSIRO are currently working on this research.
"In terms of developing wave energy technologies, normally many renewable energy sites are far away from where the energy is needed and it looks to be the case here in Australia," said AbuBakr S. Bahaj from the University of Southampton.
"This will have implication to energy cost due to the large investment needed to bringing the generated energy to population centres."
