There are multiple ways to tap the energy of the ocean, including its tides, thermal features, and salinity. But wave energy appears to be the most promising and closest to commercial production.
A new report from the Electric Power Research Institute (EPRI) suggests that generation of electricity from wave energy may be economically feasible in the near future. The study was carried out by EPRI in collaboration with the DOE’s National Renewable Energy Laboratory (NREL) and energy agencies and utilities from six states. Continue reading »
An early study of the European wave energy resource was performed which indicated that the average wave power in Europe is highest near the west of Ireland with an average wave power of 76kW occurring of the Irish coast.
Most Americans are familiar with the land-based wind energy turbine. Fewer are acquainted with its off-shore cousin. The ocean makes up 73% of the earth’s surface, hence off-shore wind energy potential is enormous—several times again the energy requirement of the entire world. A wind farm is unobtrusive, assuming placement of turbines 10 or 100 miles from shore. One wind farm complex alone—comprised of 250 or 300 wind turbines—can produce as much electricity as is produced annually in a nuclear power plant. Off-shore wind energy is clean and renewable. If implemented on a large scale, it alone could fulfill 100% of the energy requirement of the United States.
(Wind Farm)
What will this look like? If wind turbines are placed 2-3 miles offshore, they would still be very visible because of their size. The picture below is of the UK’s largest offshore wind farm at Scroby Sands, generating power for as many as 41,000 homes.
Example Wind Farm
Alternatively, turbines placed further out to sea would perfrom as effectively, while protecting the valuable appearance from out beloved coastlines.
Using a variety of innovative technologies, electricity is today being generated, via wave energy, in dozens of locations throughout the world. Wave energy is pollution-free and entirely, persistently, renewable. It has been estimated that ocean waves are capable of producing between 2,000 and 4,000 gigawatts of electricity, the latter according to UNESCO*. And, if that isn’t enough, every 15 seconds, or so, here comes another wave! (I like to look at wave energy in this way: In 2007, seven years into the 21st century, only one wave in every one-hundred-million-billion-gazillion, has ever been harnessed for purposes of electrical production! As anyone can plainly see, we’ve got quite a waves to go! Ha!)
Wave Power/Wave Energy (Ocean Surface Wave Energy).
[*] David Ross, now deceased, one of the preeminent authorities in the field, has stated, “Wave energy has been hailed as the most promising renewable source for maritime countries. It does no environmental damage and is inexhaustible – the waves go on forever. It is invariably popular with the public, which has a sentimental love of the sea… The potential resource is vast. It is usually estimated as being of the order of 2,000 gigawatts (GW), though UNESCO has put it at roughly double that amount. But what we need to estimate is how much can be gathered and delivered at an economic price.”
Seawater is 800 times denser than air; hence water traveling at 12 mph exerts force comparable to a 110-mile wind. This power can successfully be harnessed, via turbine. Ocean current is of two types, two-way (ocean tides) and one-way (i.e., the Gulf Stream, for example) and can be used to generate electricity. Experts contend the Gulf Stream alone transports some 1.5 petawatts of heat, equivalent to 100 times the world energy demand. A tidal fence (between two land masses) can serve as a conduit for autos and trains (picture a high-speed bullet train linking Miami, Houston, and San Diego, for example). With regard to future water scarcity issues (rivers like the Colorado drying up, drought, etc.), a tidal fence could also be used for transporting desalinated water to shore.
(Tidal Energy).
The largest tidal power station in the world (and the only one in Europe) is in the Rance estuary in northern France, near St. Malo. It was built in 1966.
A major drawback of tidal power stations is that they can only generate when the tide is flowing in or out – in other words, only for 10 hours each day. However, tides are totally predictable, so we can plan to have other power stations generating at those times when the tidal station is out of action.
The ocean is the largest solar collector in the world*. It is estimated that 300 times what the entire world consumes in electricity is available by tapping the upper layers of the tropical ocean. An added benefit of ocean solar power is the production, via desalinization, of fresh water.
(Ocean Thermal Energy Conversion, OTEC).
[*] With regard to the ocean, Mariette DiChristina has stated, “The world’s largest solar collector absorbs an awesome amount of the sun’s energy: equal to 37 trillion kilowatts annually – or 4,000 times the amount of electricity used by all humans on the planet. A typical square mile of that collector—otherwise known as the surface waters of Earth’s vast oceans—contains more energy than 7,000 barrels of oil.”
Marine farming can capture incredible amounts of solar energy. It has been estimated that large, open ocean farms planted with giant kelp (as one example) could potentially provide most if not all of the energy needs of the United States. As contrasted with combustion of fossil fuels, marine biomass energy removes carbon dioxide from the atmosphere and converts it, via photosynthesis, into chemical energy.
Wikipedia: Biomass
(Marine Farm or Ocean Food and Energy Farm, OFEF).
