Wave & Tide
The term "blue energy" refers to salinity gradient power – the energy retrieved from the difference in the salt concentration between seawater and river water. The power is generated using osmosis with ion-specific membranes. Jan Post, at Wageningen University in the Netherlands, has researched the global potential for electric power generated in this way. His research into the practical applicability, techniques and preconditions for large-scale energy generation from salinity gradients, has shown that very high yields are possible. In the laboratory, it is possible to recover more than 80% of the energy from salinity gradients. In practice, the technical feasibility … Continue Reading
Scientists in the Netherlands have previously succeeded in generating electricity at the point where salt and fresh water mix in an estuary using a membrane. Unfortunately, the membranes are expensive and delicate, making the technique costly. Now Doriano Brogioli of the University of Milan Bicocca in Monza, Italy, has published a paper in the Physical Review Letters which takes a different approach that promises to be much cheaper. Two carbon electrodes are placed in the salt water and given an initial electrostatic charge – one positive and the other negative. Positively charged sodium ions are attracted to the negative electrode … Continue Reading
A British company, Checkmate Seaenergy Ltd, has demonstrated a new wave energy device known as "Anaconda".. Its inventors claim the key to its success lies in its simplicity: Anaconda is little more than a length of rubber tubing filled with water. Waves in the water create bulges which travel along the tubing gathering energy. In effect, the bulge surfs the front of the wave. At the end of the tube, the surge of energy drives a turbine that generates electricity. The company has been testing a small-scale, 8 metre long prototype in a wave tank in Gosport, Hampshire, and is … Continue Reading
Last July, a Pelamis wave power generator was towed into the Atlantic about 5 kilometres off the coast of Aguçadoura in northern Portugal. In September, two more Pelamis uints were added. Each Pelamis unit was capable of generating about 750 megawatts of electricity – making this the world’s first commercial wave power project. The project was a joint venture between the Portuguese power utility Energias de Portugal, a Portuguese electrical engineering company Efacec, and the Australian asset manager Babcock & Brown. The first problem the project encountered was leaks in the foam-filled buoyancy tanks for the mooring installation. These were … Continue Reading
Google has filed a patent for a wave-powered data centre. The data centre would also use sea water for cooling. There are currently an estimated 44 million servers in use worldwide. These use about 0.5% of the world’s electricity – about the same amount as Argentina or the Netherlands. Google’s patent envisages using existing technology, such as the Pelamis wave energy converter, to generate electricity for large server arrays located at sea where the most wave energy is available. The Pelamis device consists of a series of semi-submerged cylindrical sections linked by hinged joints. Waves cause these sections to move … Continue Reading
A tidal turbine near the mouth of Strangford Lough in Northern Ireland has begun producing electricity at full capacity for the first time. The SeaGen system is generating 1.2MW, the highest level of power produced by a tidal system anywhere in the world, and is claimed to be the first truly commercial ocean tidal system to achieve full production. Martin Wright, managing director of SeaGen developers, Marine Current Turbines, said "There are no other tidal turbines of truly commercial scale; all the competitive systems so far tested at sea are quite small, most being less than 10% the rotor area … Continue Reading
For his doctoral project at Uppsala University, Rafael Waters, has designed and built a wave power facility on the bottom of the sea, two kilometers off the west coast of Sweden, near Lysekil. Electricity is produced using a linear generator that works with the slow movements of the waves. A conventional generator transforms rotational energy to electricity and it needs to turn at about 1500 rpm to be efficient – which means that the slow wave movement needs complicated gears of hydraulics to convert it into a rapid rotating movement. “Instead of trying to adapt conventional energy technology to the … Continue Reading
A British engineer, Alvin Smith, has developed a simple system, called Searaser, which uses ocean wave energy to produce electricity on demand – including so-called baseload power – even at times when the sea is calm. The system is based on a two-part pump. The bottom part of the pump is anchored to the ocean floor. The top part moves up and down with the motion of the waves and drives a piston within a cylinder in the bottom section. This action is used to pump water to a reservoir on a coastal cliff or hilltop. Water from the reservoir … Continue Reading
It has been estimated that their is sufficient energy in the world’s ocean currents to meet 3,000 times the current power needs of the the entire world’s population. The difficulty is in harnessing that energy. Turbines and watermills need water flowing at 5 to 6 knots to operate effectively. But most of the ocean currents flow at less than 3 knots. Michael Bernitsas, a professor in the University of Michigan, has now developed a device that works in water flowing at just 2 knots. The machine, called a VIVACE, relies on "vortex induced vibrations". These are undulations that a rounded … Continue Reading
The US Department of Energy has awarded Lockheed Martin a contract to construct a thermal piping system to capture the ocean’s absorbed solar heat. The energy produced could be used to generate electricity or to fuel desalination, and according to the company, the process would be harmless to the ocean’s environment. Lockheed Martin plans to create piping wide and long enough to stretch down thousands of feet under the ocean to harness the energy available from the temperature difference between the surface and the deep ocean. The temperature variant is relatively small, so large volumes of water are needed to … Continue Reading
Videos
Renewables News- New Aussie Technology to Clean Polluted WaterScientists from Deakin University, together with French colleagues, say that they have manufactured a lightweight and reusable material that can absorb up to 33 times its weight in a wide range of spilt oils, chemical solvents and dyes, while repelling … Continue Reading → […]
- Aussie Researchers Make Efficient Solar Cells from Low-grade SiliconResearchers at the University of New South Wales have found a way to make very high efficiency solar cells out of cheap, low-grade silicon. It has been known for several decades that hydrogen atoms can be introduced into the atomic … Continue Reading → […]
- First Aussie “Hot Rocks” Power Plant Begins ProducingThe first power plant in Australia to produce electricity using an enhanced geothermal ("hot rocks") system has begun producing electricity in the far north-east of South Australia. The one-megawatt Habanero pilot plant near outback Innamincka is operated by Geodynamics. Geodynamics … Continue Reading → […]
- New Aussie Technology to Clean Polluted Water
