[bobeau]

Any comments on this idea?

http://www.atsnn.com/story/104442.html

Note the comment "What he has done is to approach this idea from a new perspective creating a very simple device that also has the potential to extract hydrogen from water, which has value given the imperative of the Bush Administration to convert the US to hydrogen power."

(This kid actually went to my highschool. And Eddie Vedder's, lol).

[BiGG]

Each buoy could potentially produce 250 kilowatts of power, and the technology can be scaled up or down to suit a variety of energy needs. A fleet of about 200 such buoys could power the business district of downtown Portland.

Waves of Power

[Omnitir]

There doesn’t appear to be many threads covering wave power, but based on the recent results of a new design by an Australian company Energetech, wave power appears to be one of the most promising sustainable energy sources in development. The results of the Port Kembla project indicate that this design could even be competitive with fossil fuel sources.

http://www.energetech.com.au/

Some quotes from the site:

Past laboratory studies and the analysis of an earlier trial deployment at Port Kembla had indicated the Energetech technology was capable of producing an annual energy output of at least 500 MWh at Port Kembla. However, this latest trial indicates the technology is capable of producing more power and fresh water than has previously been claimed. Based on the recent test results, a full scale project should power up to 1500 homes, or produce three million litres of water per day per production unit.
This is very encouraging, as the outcome of the trial ensures the economics of the design will be competitive not only with other renewable energy forms, but also with full cost fossil fuel sources.
[…]
Moderately good wave climates should produce power using first generation systems at a cost of around 10 cents US per kWh, and ideal sites at a cost around 5 cents. Over time, on moderately good sites, with capital cost savings from second generation designs, we can see the technology regularly delivering electricity at around 4 cents US kWh
[…]
Wave energy is:
• truly renewable - inexhaustible and occurring from natural phenomenon
• the most consistent of the intermittent renewable energy sources
• non-emitting - no emissions of harmful pollutants result from its use
• consumes no fuel in the operation of the system
[…]
Ocean waves contain enormous amounts of energy, but the energy in each crest is generally spread out along it. If all the energy could be transported to one point it could be harnessed far more readily.
It is possible to focus all the energy of a plane surface gravity wave crest, the type you see breaking on the beach, on to a single point using a parabolic wave focusser. The section of the wave is reflected by a parabolic wall and converges on the focus of the parabola. As the wave converges, the crest height grows to a maximum in the focus area.
[…]
Approximating what the device will produce in the way of power depends on the amount of energy extracted based on sea conditions on a particular day.
An illustration, however, may be useful. Consider a parabolic focuser with dimensions of 40 metres width, 20 metres length, and a focal length of 5 metres. Assume a coastal wave crest amplitude of 1 metre. This would render in the vicinity of ten million joules of energy for extraction from each wave. This equates to between 1 and 2 megawatts of power.

[blackfrank]

there is a massive amount of power in waves more than we could ever use, but that is part of the problem any machine build to capture wave energy could also be destroyed in a storm
this has happened moer than once
there is another better way to get energy

[Omnitir]

any machine build to capture wave energy could also be destroyed in a storm

True, but the same could be said of wind power, yet there is still plenty of investment. Should we not try to develop wave power because we could occasionally loose a generator or two? Doesn't the potential economics, sustainability, saleability and environmental aspects of this technology make it well worth pursuing?

I look at the considerable technical achievements the oil industry has made in off shore oil rigs, and wonder why there is a strong perception that wave power technology will always be so fallible. Hasn’t it already been proven that things can be built capable of withstanding the elements?

The modest research put into wave power suggests it could be made sufficiently durable against large waves, and also a highly effective energy solution, not to mention a much needed source of fresh water.

[Doly]

Doesn't the potential economics, sustainability, saleability and environmental aspects of this technology make it well worth pursuing?

I have nothing against wave power in principle, but all the designs so far have produced little power. If somebody comes up with something that is far better than anything done before, I'm all for it.

[Omnitir]

Doesn't the potential economics, sustainability, saleability and environmental aspects of this technology make it well worth pursuing?

I have nothing against wave power in principle, but all the designs so far have produced little power. If somebody comes up with something that is far better than anything done before, I'm all for it.

Results from Energetech's new design:

This would render in the vicinity of ten million joules of energy for extraction from each wave

This seems to be far better then anything done before? 500 MWh from a signle generator is significant.

It seems to me like a promising solution for coastal communities, both for clean energy and for clean drinking water. I'm just wondering why interest in wave power isn't greater when it has such great potential. Especially in places like Australia where fresh water supplies are an issue.

[omegagarden]

this company Blue Energy www.bluenergy.com has been around for almost 20 years and the tech is pretty bullit proof and works with constant flow

[WildRose]

Wavegen and Ocean Power Delivery are two of the leaders in wave power. There are several different types of wave power structures that are currently being built and tested in many countries - Canada, Scotland, Britain, Portugal, Japan, Africa, Western Europe and the USA. Some of them are shoreline energy plants and others are built to float in harbors or across an inlet. If you google "Pelamis", you'll see a wave energy converter that consists of a bunch of cylinders linked together, and these can be arranged in a kind of "farm" in water away from the shore. The Pelamis is currently being used in Portugal (having been built in Scotland). The advantages of wave power are many - it's an energy resource that will never run out, will have minimal fuel price volatility in the future, and minimal to nil harmful emissions or waste products are produced. The disadvantages are mainly high initial cost of the plants and finding the right places to build them, where waves are continuous, also the structures have to be strong enough to resist corrosion.

[omegagarden]

i think that the tidal power thing wins out over the wave tech just because you don't need waves

[Heusdens]

Netherlands is building wind-turbines on see, they will have to be able to withstand the storms and salt water too.
I think it's possible.

[joelcolorado]

Can this be a piece of the solution. We have a lot of coastline and the technology is being used in Denmark already. Input?

[lawnchair]

For generating electricity, sure. We have quite a few options (albeit increasingly more expensive) for that. For liquid fuels for automobiling and flying and eternal growth thereof? No.

[btu2012]

Joel,

Take some time to read the posts on this website. This and other issues where discussed at length in the past.

Btu

[GREENE31]

A major portion of the earth is comprised of the ocean and the water bodies. The ocean water carries tremendous amounts of energy within itself. Owing to the realization of the ocean power, there has been a huge rise in the Ocean Energy Investment. The energy present in the ocean water is in three forms: the tides, the waves and the ocean water temperature variation.

The energy from the tides can be converted into electricity through tidal dams and ocean current. The tides, which are caused by the gravitational effect of the moon on the ocean surface, carry a great amount of force. This tidal energy can turn turbine fans and generate electricity.

Waves of the ocean also carry energy, which is estimated to be as large as 2-3 million megawatts. This is captured using point absorbers from the ocean surface or from the pressure fluctuations below the surface of the water.

The third form is the ocean water temperature difference. The difference between the temperatures of the ocean water carries energy which can be used for electricity generation. The more is the difference in temperature, the more is the energy generated using this difference.

[Tanada]

You know I really wish someone would put some of these plans together into a working 1 GWe power plant somewhere, it would go a very long way towards silencing the critics.

[johnsmithh]

Ocean energy is a used to describe the renewable energy derived from the sea including wave energy, tidal energy, river current, ocean current energy, offshore wind, salinity gradient energy and ocean thermal gradient energy. Ocean waves are generated by the influence of the wind on the ocean surface first causing ripples. As the wind continues to blow, the ripples become chop, fully developed seas and finally swells.

[Tanada]

Well the cost of renewables (especially OTEC) is only an issue because, from an energy standpoint, we are trying to convert lead into gold. In other words, trying to convert dilute sunlight and whimsical winds into that always-on, invisible does-it-all servant we call electricity, or corn stalks and garbage into liquid fuel good enough to burn in a modern computer-controlled engine to keep us rolling in our sanctuaries-on-wheels.

If we used energy (and other resources) according to the level of quality required (Use the lowest quality necessary to complete the task), the cost would be lower. But it would often mean reverting to such arcane things as clotheslines, bicycles, houses oriented to use solar heat, compost piles, sawtooth roofs instead of electric lights and mechanical fans, placement of industries to use each other's waste heat and materials, etc.

I think many people see that as a submission to nature, a reversion of the progress which is measured by the domination over nature. The second law of thermodynamics doesn't care, however.

The good news is a lot of small users have been putting combined cycle systems in to improve their efficiency, for example a company in Toledo, Ohio makes a good profit out of selling small gas turbine electric generators to point users like hospitals and factories that use natural gas heating. Their systems burn the gas in a turbine generator, then use the exhaust heat to provide heating supply for the hospital or factory in question. The cost in saved electricity has a payback time of 3 to 5 years in the applications where they are economical to install.

See http://www.naturalgas.org/overview/comb ... ystems.asp for a basic rundown of how these systems work.

[vtsnowedin]

[hink of it this way, you put a large diameter pipe from 3000 feet depth up to your shore lagoon facility. Have the pipe attach to the low end of the artificial lagoon you are using with a sealed structure. Enclose the lagoon from the open ocean with a dike. Pump the water in the lagoon over the dike into the surface waters. As you reduce the water level in the impounded lagoon the pressure goes down and creates a differential at the mouth of the pipe, the cold bottom water then flows up the pipe to replace the volume you are pumping out into the surface waters. Because of natural forces you only have to use enough energy to pump water as high as the top of the dike, nature abhors a vacuum and will replace the volume you remove through the only available pathway, up the deep pipe to the lagoon at the surface.

If that seems too complex for you, you can also run the system in reverse. Pump warm surface waters over the dike into the lagoon. What happens? The water level in the lagoon will go up until the pressure exceeds the density differential between the warm surface water and the cold bottom water. That is not actually very much, a few inches of elevation will do it, after which time the warm surface waters will be forced down the pipe to the cold bottom level. Put your thermocouples around the bottom of the pipe where the warm water exits and all you need are surface pumps pulling water into the impounded lagoon. For max efficiency use insulated pipe so that the waters maintain temperature all the way to the other end.

I prefer pulling the bottom water up because it is nutrient rich and when you dump it into the surface waters you will draw in all sorts of plankton, which in turn will bring in fish and other life. Either way let nature do the heavy lifting of filling the partial vacuum you create, don't do all the work mechanically.

Where to begin? First pumping water is very hard work, the definition of foot pound being to raise a pound of (water) one foot from where it is now.Any water pump worth mentioning has a very large diesel engine roaring away on the other end of the shaft. Your typical fire truck has a three hundred and fifty horse diesel attached to a pump with a six or eight inch inlet pipe and can pump just a thousand gallons a minute. And that is adjusted by both how high above the water the pump sits and how high the outlet end of the pipe is.
Any system that requires you to pump water through or (much worse) over a dike is a loser.
However you can build your system using just the tides to do the pumping for you if your in an area that has significant tides. All that is needed is a discharge pipe through the dike that has a one way valve on it to allow water to flow out but not in. At low tide the pond would be empty. As the tide raises sea level water would flow into the pond from your 3000 foot pipe pushed in by the rising sea level over the inlet of the pipe. You could run this water over turbine blades on the way in. The one way valve on your pipe through the dike would keep warm surface water from coming in that way. At high tide you would have a full pool of nutrient rich cold water . As the tide goes out the water would flow out through the drain and over another set of turbine blades. You might add other valves or gates to hold the water back until the tide was mostly out or in to increase the working head but reduce your flow time. Your limited of course by the size of the pond you can build and the size of the pipe bringing in the water from the deep.

[Newfie]

Saw this or something very similar at another board.

Seems the original post was by some kind of bot???