Wave power refers to the energy of ocean surface waves and the capture of that energy to do useful work — including electricity generation, desalination, and the pumping of water (into reservoirs). Wave power is a form of renewable energy. Renewable energy effectively uses natural resources such as sunlight, wind, rain, tides and geothermal heat, which are naturally replenished. Renewable energy technologies range from solar power, wind power, hydroelectricity/micro hydro, biomass and biofuels for transportation. Though often co-mingled, wave power is distinct from the diurnal flux of tidal power and the steady gyre of ocean currents. Wave power generation is not currently a widely employed commercial technology although there have been attempts at using it since at least 1890. The world’s first commercial wave farm is based in Portugal, at the Aguçadora Wave Park, which consists of three 750 kilowatt Pelamis devices. The pros and cons surrounding wave revolve around some of the following questions. Is wave power a clean, renewable resource that is a good tool in combating global climate change? Does wave power harm local ecosystems and marine wildlife? Is wave power bad for fishers? How much energy is required in producing and transporting wave energy systems? Can wave power produce a significant enough amount of energy? Are there many locations in the world where wave power systems make sense? Does wave power supply a consistent supply of energy? Is wave power too young an industry? Is wave power generally viable economically and as an industry? Are wave power farms aesthetic or do they violate pristine coastal views? Do wave power systems diminish wave power, and impair quality surfing in coastal areas?
See Wikipedia’s wave power article for greater background.
The most important contemporary environmental concern is that an energy source emits greenhouse gases into the atmosphere. Wave energy addresses this concern, emitting not greenhouse gases in the process of generating electricity.
Wave power provides clean power with no emissions that is fully renewable. Waves will never stop crashing, and so there is no limit to the amount of clean-power that can be extracted from waves. This compared favorably to fossil fuels and other non-renewable sources of power. Wave power is also free in this sense.
“I’m not prepared to take new risks unless we’re conserving and respecting the energy we already have.”
It requires substantial energy to produce wave power generating systems, such as the Pelamis. The system is made from a significant quantity of metal and must be shipped out and installed in coastal areas. This requires substantial energy, much of which comes by burning fossil fuels. This means that constructing and transporting wave power systems can release a significant quantity of carbon dioxide into the atmosphere.
“Marine life forms are more intelligent than what people make of them and can easily avoid such devices. Wave energy devices [generally] will not affect migratory patterns. They can only have positive environmental effects when deployed away from ecologically sensitive areas. Greenpeace has campaigned strongly and effectively for wave energy, which shows their view of its environmental credentials.”
Philip D. Moeller, a member of the Federal Energy Regulatory Commission and a supporter of wave and tidal energy projects, said to the New York Times in 2007 that the government was “not allowing these [wave power generators] to go into sensitive areas. We haven’t defined sensitive area, but the point is we’ll be cognizant of that.”
“It is noteworthy that even these environmental impacts are far less than those of most fossil fuel plants.”
“Off shore ocean wave generators need anchors to hold them to the sea floor. These generators may actually be beneficial to sea life because of the subsurface structure they provide.”
Migrating fish and whales can potentially run into wave power generators. The violent bobbing up-and-down of these systems presents some risks.
“Because it is a diffuse energy source we can expect to see environmental impacts on par with those experienced by large power dams or wind turbines.”
“some environmentalists and fishermen worry that the recent rush for renewable energy is more about politics, big business and the next big thing than it is about clean energy. They warn that too little is known about what effect wave farms might have on migrating fish and whales.”
The transmission of electricity from wave power systems through cables to the shore has the risk of transmitting electro-magnetic energy into the water, harming animals.
“[A]ccording to our Environmental Science textbook, if problem occurs, equipment can be removed quickly (as opposed to dams)”
“‘I don’t want it in my fishing grounds,’ said Mr. Martinson, 40, who docks his 74-foot boat, Libra, here at Yaquina Bay, about 90 miles southwest of Portland. ‘I don’t want to be worried about driving around someone else’s million-dollar buoy.'”
Many other sources of power, such as solar and tidal power, provide energy only at certain times of the day. Wave power, however, provides a much more consistent and reliable supply of energy. This means it supplies more energy and that its electricity-supply can be more easily integrity into the grid system.
Wave power has the potential to provide 5-10% of US energy supply, according to the New York Times.
“Economically usable worldwide resources add up to a significant amount of power. The NREL site noted above shows that we have economical global ocean wave energy resources of about 2,000 TWh annually, roughly 12% of world electrical output, if we can find acceptable ways to utilize it.”
“A potentially highly efficient wave-to-electricity conversion ratio[…]The sheer force/density of water compared to wind equates to far fewer generators being required compared with wind turbines.”
“Alas, harnessing it has proved to be unexpectedly difficult. In recent years wind farms have sprouted on plains and hilltops, and solar panels have been sprinkled across rooftops and deserts. But where the technology of wind and solar power is established and steadily improving, that of wave power is still in its infancy. The world had to wait until October 2007 for the first commercial wave farm, consisting of three snakelike tubes undulating with the Atlantic swell off the coast of Portugal.”
“Wave energy has the potential to provide as much renewable energy as the wind industry. However, wave technology is currently at the same level of development as the wind industry was 10 years ago.”
“Wave energy is intermittent and variable. Even in the most active wave areas, there are many days with little wave activity. On days that have good wave activity, wave levels can vary. As explained on the Pros and Cons of Wind Power page, resolving intermittency problems to attain reliable energy output can double and even triple the cost of power.”