September 05, 2006 - 02:13:20 AM
This posting provides some more info on some of the technology used by Dr. Thomas J. Goreau, namely the Biorock® Process. I wonder if he used geodesic and tensegrity structures as the frame for the Biorock(R) if there would be an advantage?
Biorock Technology, or mineral accretion technology is a method that applies safe, low voltage electrical currents through seawater, causing dissolved minerals to crystallize on structures, growing into a white limestone similar to that which naturally makes up coral reefs and tropical white sand beaches. This material has a strength similar to concrete. It can be used to make robust artificial reefs on which corals grow at very rapid rates. The change in the environment produced by electrical currents accelerates formation and growth of both chemical limestone rock and the skeletons of corals and other shell-bearing organisms.
The Biorock Process is owned by Biorock, Inc. and is licensed to GCRA for applicable projects.
Biorock methods speed up coral growth in damaged areas and restore authentic coral reef habitat and species. Biorock structures become rapidly colonized by a full range of coral reef organisms, including fish, crabs, clams, octopus, lobster, sea urchins. Species typically found in healthy reef environments are given an electrical advantage over the weedy organisms which often overgrow them in reefs stressed by humans. The advantages corals gain from mineral accretion are cancelled if they no longer receive current, at which point weeds will overgrow the corals. If the current is maintained, coral reefs can often be restored even in areas where water quality would prevent their recovery by any other method.
Biorock structures cement themselves to the hard bottom providing a physical wave barrier which over time, grows larger and stronger. Biorock materials are to an extent, structurally self healing. If a section is damaged, the cracks will fill making them ideal for breakwater shore protection.
Biorock projects can be powered by a wide range of electrical sources including renewable energy like windmills, photovoltaic solar panels and tidal current generators. This enables their construction in areas where conventional electric power is unavailable.
The mineral accretion process was first developed by architect Wolf Hilbertz in order to provide alternative construction materials. He and Tom Goreau of the Global Coral Reef Alliance later developed its use for reef restoration and shore protection.
Biorock® is a registered trademark of Biorock, Inc. The Biorock Process is owned by Biorock, Inc.
August 28, 2006 - 02:13:20 AM
The Boeing Company has signed a contract to provide 600,000 solar concentrator cells to SolFocus, Inc., a California-based renewable energy company that is developing renewable terrestrial energy alternatives.
Under the 12-month contract from SolFocus, Inc. of Palo Alto, Calif., Spectrolab will build and deliver 600,000 solar concentrator cells that will be used to convert the sun's rays into affordable electricity for homes and businesses. The cells produced for SolFocus will be capable of generating more than 10 megawatts of electricity, or enough to power about 4,000 U.S. homes. With the average solar cell efficiency above 35 percent at concentration, Spectrolab's concentrator photovoltaic cells generate electricity at a rate that can be more economical than electricity generated from conventional, flat panel photovoltaic systems.
A significant advantage of concentrator systems is that fewer solar cells are required to achieve a specific power output, thus replacing large areas of semiconductor materials with relatively inexpensive optics that provide optical concentration. The slightly higher cost of multi-junction cells is offset by the use of fewer cells. Due to the higher efficiency of multi-junction cells used in the concentrator modules, only a small fraction of the cell area is required to generate the same power output compared to crystalline silicon or thin-film, flat-plate modules.
August 28, 2006 - 02:13:20 AM
The Earth Institute at Columbia University, in cooperation with the New York Academy of Sciences, is pleased to announce the publication of a NYAS eBriefing based on the recent Earth Institute conference, State of the Planet 2006: Is Sustainable Development Feasible?
This free web-based report includes a comprehensive meeting summary, links to video and transcripts of the conference, a wide-ranging set of open questions, a rich library of related resources, and additional background information.
August 20, 2006 - 02:13:20 AM
A set of prototype solar concentrators installed in Lesotho. (Courtesy of Amy Mueller.)
Matthew Orosz, an MIT graduate student advised by Harold Hemond, professor of civil and environmental engineering are working on alternative approaches to solar-based electricity that could significantly cut costs compared to photovoltaics panels. Their goal is to put the ability to harvest electricity from the sun into the hands of villagers in poor countries.
According to Kevin Bullis of MIT's Technology Review the system works like this:
"The basic design of Orosz's solar generator system is simple: a parabolic trough (taking up 15 square meters in this case) focuses light on a pipe containing motor oil. The oil circulates through a heat exchanger, turning a refrigerant into steam, which drives a turbine that, in turn, drives a generator."
"The refrigerant is then cooled in two stages. The first stage recovers heat to make hot water or, in one design, to power an absorption process chiller, like the propane-powered refrigerators in RVs. The solar-generated heat would replace or augment the propane flame used in these devices. The second stage cools the refrigerant further, which improves the efficiency of the system, Orosz says. This stage will probably use cool groundwater pumped to the surface using power from the generator. The water can then be stored in a reservoir for drinking water."
"The design uses readily available parts and tools. For example, both the feed pump and steam turbine are actually power-steering pumps used in cars and trucks. To generate electricity, the team uses an alternator, which is not as efficient as an ordinary generator, but comes already designed to charge a battery, which reduces some of the complexity of the system. And, like power-steering pumps, alternators, including less-expensive reconditioned ones, are easy to come by."
"As a result, the complete system for generating one kilowatt of electricity and 10 kilowatts of heat, including a battery for storing the power generated, can be built for a couple thousand dollars, Orosz says, which is less than half the cost of one kilowatt of photovoltaic panels."
original article READ MORE »
August 20, 2006 - 02:13:20 AM
Chinese developers unveiled the world's first full-permanent magnetic levitation (Maglev) wind power generator at the Wind Power Asia Exhibition 2006 held June 28 in Beijing. Magnetic levitation, maglev, or magnetic suspension is a method by which an object is suspended above another object with no support other than magnetic fields. The electromagnetic force is used to counteract the effects of the gravitational force.
Regarded as a key breakthrough in the evolution of global wind power technology — and a notable advance in independent intellectual property rights in China—the generator was jointly developed by Guangzhou Energy Research Institute under China’s Academy of Sciences and by Guangzhou Zhongke Hengyuan Energy Science & Technology Co., Ltd. The Maglev generator is expected to boost wind energy generating capacity by as much as 20 percent over traditional wind turbines. This would effectively cut the operational expenses of wind farms by up to half, keeping the overall cost of wind power under 0.4 yuan ($US 5 cents), according to Guokun Li, the chief scientific developer of the new technology. Further, the Maglev is able to utilize winds with starting speeds as low as 1.5 meters per second (m/s), and cut-in speeds of 3 m/s, the chief of Zhongke Energy was quoted as saying at the exhibition. When compared with the operational hours of existing wind turbines, the new technology will add an additional 1,000 hours of operation annually to wind power plants in areas with an average wind speed of 3 m/s.
Photo Caption/Credit: Using magnetic levitation for a frictionless air bearing READ MORE »