Genrating Electricity From Ocean Waves

[crokett]

I was sitting on the beach today wondering why no one has built some sort of turbine that uses wave power to generate electricity. It is an infinitely renewable, inexhaustible supply of energy. Anyway I did some research and it looks like somebody is doing this:

http://www.wavegen.co.uk

[Ed62]

It sure seems like there would be a lot of potential to harvest electricity from waves and other running water. There's an awful lot of power out there.

Ed

[Rob25]

And, there are companys out there doing the same thing with tides going in and out to generate energy...

[iceman61]

I saw a spot on the History Channel where they already have the technology & were working on it off the coasts of England & Scotland. They were using long cylindrical bouys.

[LCHIEN]

tidal energy and wave energy are two different, but related items. The tide energy changes 1 to 2 times per day and in some places displaces 20-30 feet reliably.
Wave occur every 3-12 seconds and are limited in height and the height even varies from day to day.
The machinery built for one differs in scale from the other due to the differences in order of magnitudes of pressure head and how often it is refreshed.

[milanuk]

And in Washington state... hydro power is not considered 'green' power. Why? Because we have a metric butt-load of it.

The gov't decided it would be a Good Idea to require utilities to use a certain amount of 'green' power in their base load. Since we have hydro-power coming out our ears already, they opted to not consider it 'green' so as to force the local utilities to spend money on more costly solutions (to a problem we already have handled here locally) like wind generation.

The problem with tidal generation is that it is extremely low net-head - there is a lot of water moving, but the total difference in available energy from one side of a generating unit to the other side is very low. Its not an insurmountable problem per se - if the units can pass enough flow, and you have enough of them, you can generate a significant amount of electricity. But you also have to account for things like maintenance, scheduled and unscheduled outages (Mother Nature can be a real PITA on a *river*, I can only imagine how that might play out at the edge of an *ocean*) and suddenly you might not ever have *all* the units online and generating at the same time.

Fun and games, eh?

[atgcpaul]

This is probably not possible, but consider having wind or wave farms that
captured the energy of wind or water so efficiently that the result was no
more wind or waves coming out the other end. Just my hypochondriac mind
wondering if that would have some kind of negative effect--the net loss of
wind and waves around the world.

Hey, what can I say, it's a Monday.


Paul

[bruce hylton]

This is probably not possible, but consider having wind or wave farms that
captured the energy of wind or water so efficiently that the result was no
more wind or waves coming out the other end. Just my hypochondriac mind
wondering if that would have some kind of negative effect--the net loss of
wind and waves around the world.

Hey, what can I say, it's a Monday.


Paul

That would probably slow the turning of the earth on its axis and make for some great long summer days.

[BobSch]

That would probably slow the turning of the earth on its axis and make for some great long summer days.

Which would mean more A/C.

[jackellis]

A number of firms are attempting to commercialize power from waves, tides and ocean currents. None of them have proven that it is commercially feasible.

We had a bit of a catfight out here over rights to use waves and currents off the Northern California coast. Already squatters are lining up to secure the rights and keep others away. Predictable, environmental groups are also complaining about the impact on sea life.

There's no environmentally benign way to convert energy from one form to another. Clean coal is pretty dirty, natural gas is not renewable and releases a bunch of other stuff besides CO2, wind machines kill birds and spoil views, solar takes a lot of land and uses either chemical batteries or some other storage system that has impacts.....

Coffee. I need coffee.

[pierhogunn]

what I want to see is deep-dry rock closed loop geothermal. Something where a relatively small bore well is drilled incredibly deep, with a heat exchange unit dropped down the hole, and a circulation of molten salts transfer heat to a topside transfer unit

IIRC, some one at Duke or NCSU was working on this using a relatively new and much less expensive type of drilling technology to bring this tech forward... think about it, your own geothermal power plant, generating about 30 - 60 KW for you to use and sell back to the grid...

[Stytooner]

I think that all the "New" ways of getting voltage are pretty impressive. It does show signs of good possibilities for the future. I think if we can implement wave energy near the coastal regions and the possibly wind an solar energy in mid cont., then we have a decent shot at only using oil for a short time until the vehicles catch up. I do think we should tap some of natures forces rather than resources for our eventual power needs.

[jackellis]

More on using the tides and waves...

Obama Seeks Funding Cuts for Wave, Tidal Energy Research

May 31 - McClatchy Washington Bureau


The Obama administration has proposed a 25 percent cut in the research and development budget for one of the most promising renewable energy sources in the Northwest - wave and tidal power.
At the same time the White House sought an 82 percent increase in solar power research funding, a 36 percent increase in wind power funding and a 14 percent increase in geothermal funding, it sought to cut wave and tidal research funding from $40 million to $30 million.
The decision to cut funding for tidal and wave power came only weeks after the Interior Department suggested that wave power could emerge as the leading offshore energy source in the Northwest and at a time when efforts to develop tidal power in Puget Sound are attracting national and international attention.
By some estimates, wave and tidal power could eventually meet 10 percent of the nation's electricity demand, about the same as hydropower currently delivers. Some experts have estimated that if only 0.2 percent of energy in ocean waves could be harnessed, the power produced would be enough to supply the entire world.
In addition to Puget Sound and the Northwest coast, tidal and wave generators have been installed, planned or talked about in New York's East River, in Maine, Alaska, Hawaii and off Atlantic City, N.J. However, they would generate only small amounts of power.
The Europeans are leaders when it comes to tidal and wave energy, with projects considered, planned or installed in Spain, Portugal, Scotland, Ireland and Norway. There have also been discussions about projects in South Korea, the Philippines, India and Canada's Maritime provinces.
The proposed cut, parts of the president's budget submitted to Congress, has disappointed Sen. Patty Murray, D-Wash.
"Wave and tidal power holds great promise in helping to meet America's long-term energy needs," Murray said, adding that Washington state is a leader in its development. "It's time for the Department of Energy to focus on this potential. But playing budget games won't get the work done."
In addition to cutting funds in its budget proposal, Murray's staff said that while $16.8 billion in the recently passed stimulus bill is reserved for renewable energy and energy efficiency, none of it is earmarked for wave and tidal power.
Energy Department spokesman Tom Welch, however, said the Obama administration is asking for 10 times more for tidal and wave power than the Bush administration did.
"The trend line is up," Welch said. "The department is collaborating with industry, regulators and other stakeholders to develop water resources, including conventional hydro."
Murray sees it differently. Congress appropriated $40 million for the current year, so the Obama administration proposal actually would cut funding by a fourth.
Utility officials involved in developing tidal energy sources said the administration's approach was shortsighted.
"We need all the tools in the tool belt," said Steve Klein, general manager of the Snohomish County, Wash., Public Utility District. "It's dangerous to anoint certain sources and ignore others."
The Snohomish PUD could have a pilot plant using three tidal generators installed on a seabed in Puget Sound in 2011. The tidal generators, built by an Irish company, are 50 feet tall and can spin either way depending on the direction of the tides. The units will be submerged, with 80 feet of clearance from their tops to the water's surface. They'll be placed outside of shipping channels and ferry routes.
The pilot plant is expected to produce one megawatt of electricity, or enough to power about 700 homes. If the pilot plant proves successful, the utility would consider installing a project that powered 10,000 homes.
"A lot of people are watching us," Klein said.
The Navy, under pressure from Congress to generate 25 percent of its power from renewable sources by 2025, will install a pilot tidal generating project in Puget Sound near Port Townsend, Wash., next year.
In Washington state, law requires that the larger utilities obtain 15 percent of their electricity from renewable sources by 2020. The law sets up interim targets of 3 percent by 2012 and 9 percent by 2016.
Most of the attention so far has focused on developing large wind farms east of the Cascade Mountains. Because wind blows intermittently, however, the region also needs a more reliable source of alternative energy. Tidal and wave fit that need. Also, at least with tidal, the generators would be closer to population centers than the wind turbines in eastern Washington.
"The potential is significant and (tidal and wave) could accomplish a large fraction of the renewable energy portfolio for the state," said Charles Brandt, director of the Pacific Northwest National Laboratory's marine sciences lab in Sequim, Wash.

[JR]

This is probably not possible, but consider having wind or wave farms that captured the energy of wind or water so efficiently that the result was no more wind or waves coming out the other end.

There is a proposal for a generator off the coast at Eureka, using technology from a Vancouver company. The first to raise their hands with concerns was a local surfer's group.

JR

[Alex Franke]

I was sitting on the beach today wondering why no one has built some sort of turbine that uses wave power to generate electricity. It is an infinitely renewable, inexhaustible supply of energy.

There's some discussion on this realted thread, too: http://www.bt3central.com/showthread.php?t=43962