Humans have long had the dream of using the constant movement and power of oceans as an energy resource to power daily life. With two-thirds of the earth’s surface covered in ocean water, this dream may soon become a reality.
Colossal waves and consistent tides represent one of our planet’s last untapped natural and renewable energy resources. To take advantage of these resources, urgent action plans according to the current climate of Environmental Policy around the world have specified the importance of reducing both carbon and greenhouse gas emissions as a main priority. According to an article in Nature magazine, countries around the world plan to reach net-zero emissions by 2050-2060. Although there has been some speculation and rumors about the feasibility of these projections, government leaders are continuing to push towards a more green and sustainable future for all. Currently, 20% of global power requirements are supplied by renewables, and hydropower accounts for 80% of renewable energy production. The question arises then: What is hydropower and why has it become so ubiquitous as a go-to energy producer?
The creation and widespread usage of hydropower technologies began with the Greeks about 2,000 years ago. Famed for their use of water wheels to grind wheat crops into flour, the Greeks took advantage of the natural water systems that surrounded the city. Similarly, the Egyptians, creating communities near the River Nile, continued to support a growing empire by taking advantage of the river’s predictable tides and floods. By establishing a stable irrigation system and deep water reservoirs, the Egyptian Empire excelled with the help of water flow. The real push towards energy producing technologies being established on a massive scale came in the mid-1700’s when French hydraulic and military engineer, Bernard Forest de Bélidor, wrote the famed, “Architecture Hydraulique.” This extensive, in-depth manual inspired architects and engineers to construct new projects that could increase energy yields from water flow. With Bélidor’s manual in hand, these engineers were able to construct large structures such as dams. Most famously, the Hoover Dam, constructed from 1931-1936, is well known for producing irrigation water and hydroelectric power. Built during the Great Depression, this dam is a testament to the hard work and dedication of the local government to create new forms of energy. Although dams have been a great source of renewable energy for generations, issues have arisen in recent years about the safety of the construction and maintenance of these super structures.
On the Yangtze River, in the Hubei Province of China, the world’s biggest hydropower project called the Three Gorges Dam, has received widespread criticism for alleged human rights violations. Fully operational in 2012, the Three Gorges Dam submerged 632 km2 of land and displaced 1.5 million people according to Power Technology. The origins of these complaints stem from the lack of transparency about planning and progress provided by the Chinese Government. Determined to be the cause of an increase in the frequency of landslides and earthquakes among communities near the newly constructed dam, this superstructure has residents increasingly worried about their safety and quality of life. The increasingly frequent landslides have also submerged multiple Chinese factories and waste dumps. Consequently, pollution of Chinese rivers has increased dramatically, which has threatened local fishers, native animal and plant species, and local markets. China is not alone, though, in receiving criticism for the creation of these massive dams.
A 2014 study by the University of Copenhagen showed that the construction and upkeep of hydropower dams would be a “serious threat” to freshwater biodiversity in South America, South East Asia, and Africa due to a 20% reduction in large free-flowing rivers, the habitat of freshwater species. This news comes in tandem with an expected doubling in hydropower generation capacity by 1,700GW globally over the next 20 years.
To further demonstrate the importance of maintaining the biodiversity of freshwater sources, Universitat Tubingen professor, Dr. Christiane Zarfl, and her colleagues conducted a study at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin that focused on biodiversity loss as a direct result of the construction and maintenance of dams. Professor Zarfl specifically mentions, “Hydropower is an integrated part of transitioning to renewable energy and currently the largest contributor of renewable electricity. However, it is vital that hydropower dams do not create a new problem for the biodiversity in the world’s freshwater systems, due to fragmentation and the expected changes in the flow and sediment regime.” As consequences loom over the continued construction of dams, new innovations that have reached the market may create less harmful inroads towards a more sustainable future.
For example, at Sydney’s famous Bondi Beach, surfers and beach-goers are not the only ones catching the waves, as the Perth-Based Carnegie Wave Energy Project has just set a world record for completing 14,000 hours of operations. Located off Garden Island, Western Australia, the CETO 5 and 6 marine energy producing systems have been generating “clean, renewable electricity and potable desalinated water” for the massive Australian army base, HMAS Stirling. The CETO Unit consists of a fully submerged buoy that is tethered to a pump on the seabed. Oscillating with the ocean waves, the CETO’s pump contracts and extends to create a pressurized system. Increasing the pressure of fluid located below the pump, CETO sends highly pressurized fluids to an offshore hydroelectric power plant. With a closed loop system, CETO technology produces zero emissions and can also desalinate ocean water. Large investments by The Australian Renewable Energy Agency (ARENA) of $13.1 million have contributed to the $40 million project, and the first array of wave power generators are in the process of being connected to local electrical grids. By creating green and renewable energy in a commercial sales form, The Perth Project takes an important step towards unlocking the vast potential of wave energy in Australia and internationally.Although the excitement and news surrounding technological developments in wave energy are sonorous, there are some issues to take into account. First, there is still too little research on the possible effects that current and future technological implementations may have on marine habitats and wildlife. Further, there is a significant amount of time that has to be spent maintaining these new innovations due to the harsh and powerful waves that some of these technologies encounter in deep water. The world’s electricity sector is certainly evolving, but as with any new technology, the potential consequences must be considered.
Australian Renewable Energy Agency (ARENA). (2020, November 19). Perth Wave Energy Project – Australian Renewable Energy Agency (ARENA). Australian Renewable Energy Agency. https://arena.gov.au/projects/perth-wave-energy-project/
Cho, R. (2017, February 17). Tapping into Ocean Power. State of the Planet. https://blogs.ei.columbia.edu/2017/02/14/tapping-into-ocean-power/
L.M. (2010, May 22). Energy and the Environment-A Coastal Perspective – Oscillating Water Column. Energy and the Environment-A Coastal Perspective. https://coastalenergyandenvironment.web.unc.edu/ocean-energy-generating-technologies/wave-energy/oscillating-water-column/
Nature Editorial. (2021, March 16). Net-zero emissions targets are vague: three ways to fix. Nature. https://www.nature.com/articles/d41586-021-00662-3?error=cookies_not_supported&code=6136db78-4c75-48d4-be60-85c0e1bda38a
Stauffer, N. (2008, December 17). Catch the wave. MIT News | Massachusetts Institute of Technology. https://news.mit.edu/2008/waves-portugal-tt1217
Unwin, J. (2020, February 6). The future of hydropower energy. Power Technology | Energy News and Market Analysis. https://www.power-technology.com/features/hydropower-energy-future/
U.S.D.E. (2016, July 26). Hydropower Vision: A New Chapter for America’s 1st Renewable Electricity Source. Energy.Gov. https://www.energy.gov/eere/water/articles/hydropower-vision-new-chapter-america-s-1st-renewable-electricity-source
U.S.D.I. (2009). Renewable Energy on the Outer Continental Shelf | Bureau of Ocean Energy Management. Boem.Gov. https://www.boem.gov/renewable-energy/renewable-energy-program-overview
Vyas, K. (2020, July 22). The Future of Ocean Energy Conversion. Interesting Engineering. https://interestingengineering.com/the-future-of-ocean-energy-conversion