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.
any machine build to capture wave energy could also be destroyed in a storm
Omnitir wrote:Doesn't the potential economics, sustainability, saleability and environmental aspects of this technology make it well worth pursuing?
Doly wrote:Omnitir wrote: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.
This would render in the vicinity of ten million joules of energy for extraction from each wave
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
RankineCycle wrote: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.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Tanada wrote:[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.
Users browsing this forum: No registered users and 11 guests