Feeds:
Posts
Comments

Posts Tagged ‘Biomimicry’

MendoCoastCurrent, March 14, 2011

Dear President Obama,

Continuing to hear comments that you, your administration and your cabinet members consider nuclear power as a clean, renewable solution is most alarming.

Mr. President, let’s consider the nuclear event occurring in Japan right now and learn the simple truth that any safe renewable energy portfolio DOES NOT include nuclear energy.

The ramifications of the current Japanese nuclear trauma will be felt worldwide as will the fall-out, for months and possibly years to come.

Mr. President, I strongly encourage your team to change course, hit the ground running in alternative, renewable and sustainable energy r&d right now.

Here’s a solution that may be started TODAY ~ http://bit.ly/t7ov1

I call it Mendocino Energy and am not attached to the name, yet very passionate about this important safe, renewable energy development concept. Time has come for us to get rolling!

Mendocino Energy ~ At this core energy technology incubator, energy policy is created as renewable energy technologies and science move swiftly from white boards and white papers to testing, refinement and implementation.

The Vision

Mendocino Energy is located on the Mendocino coast, three plus hours north of San Francisco, Silicon Valley. On the waterfront of Fort Bragg, utilizing a portion of the now-defunct Georgia-Pacific Mill Site to innovate in best practices, cost-efficient, safe renewable and sustainable energy development – wind, wave, solar, bioremediation, green-ag/algae, smart grid and grid technologies, et al.

The process is collaborative in creating, identifying and engineering optimum, commercial-scale, sustainable, renewable energy solutions with acumen.

Start-ups, utility companies, universities (e.g. Precourt Institute for Energy at Stanford), EPRI, the federal government (FERC, DOE, DOI) and the world’s greatest minds gathering at this fast-tracked, unique coming-together of a green work force and the U.S. government, creating responsible, safe renewable energy technologies to quickly identify best commercialization candidates and build-outs.

The campus is quickly constructed on healthy areas of the Mill Site as in the past, this waterfront, 400+ acre industry created contaminated areas where mushroom bioremediation is underway.

Determining best sitings for projects in solar thermal, wind turbines and mills, algae farming, bioremediation; taking the important first steps towards establishing U.S. leadership in renewable energy and the global green economy.

With deep concern & hope,

Laurel Krause

Read Full Post »

Scientific Computing, Advantage Business Media, November 2009

The ocean is a potentially vast source of electric power, yet as engineers test new technologies for capturing it, the devices are plagued by battering storms, limited efficiency and the need to be tethered to the seafloor. Now, a team of aerospace engineers is applying the principles that keep airplanes aloft to create a new wave energy system that is durable, extremely efficient and can be placed anywhere in the ocean, regardless of depth.

While still in early design stages, computer and scale model tests of the system suggest higher efficiencies than wind turbines. The system is designed to effectively cancel incoming waves, capturing their energy while flattening them out, providing an added application as a storm wave breaker.

The researchers, from the U.S. Air Force Academy, presented their design at the 62nd annual meeting of the American Physical Society’s Division of Fluid Dynamics on November 24, 2009.

“Our group was working on very basic research on feedback flow control for years,” says lead researcher Stefan Siegel, referring to efforts to use sensors and adjustable parts to control how fluids flow around airfoils like wings. “For an airplane, when you control that flow, you better control flight — for example, enabling you to land a plane on a shorter runway.”

A colleague had read an article on wave energy in a magazine and mentioned it to Siegel and the other team members, and they realized they could operate a wave energy device using the same feedback control concepts they had been developing.

Supported by a grant from the National Science Foundation, the researchers developed a system that uses lift instead of drag to cause the propeller blades to move.

“Every airplane flies with lift, not with drag,” says Siegel. “Compare an old style windmill with a modern one. The new style uses lift and is what made wind energy viable — and it doesn’t get shredded in a storm like an old windmill. Fluid dynamics fixed the issue for windmills, and can do the same for wave energy.”

Windmills have active controls that turn the blades to compensate for storm winds, eliminating lift when it is a risk, and preventing damage. The Air Force Academy researchers used the same approach with a hydrofoil (equivalent to an airfoil, but for water) and built it into a cycloidal propeller, a design that emerged in the 1930s and currently propels tugboats, ferries and other highly maneuverable ships.

The researchers changed the propeller orientation from horizontal to vertical, allowing direct interaction with the cyclic, up and down motion of wave energy. The researchers also developed individual control systems for each propeller blade, allowing sophisticated manipulations that maximize (or minimize, in the case of storms) interaction with wave energy.

Ultimately, the goal is to keep the flow direction and blade direction constant, cancelling the incoming wave and using standard gear-driven or direct-drive generators to convert the wave energy into electric energy. A propeller that is exactly out of phase with a wave will cancel that wave and maximize energy output. The cancellation also will allow the float-mounted devices to function without the need of mooring, important for deep sea locations that hold tremendous wave energy potential and are currently out of reach for many existing wave energy designs.

While the final device may be as large as 40 meters across, laboratory models are currently less than a meter in diameter. A larger version of the system will be tested next year at NSF’s Network for Earthquake Engineering Simulation (NEES) tsunami wave basin at Oregon State University, an important experiment for proving the efficacy of the design.

Compelling images of the cycloidal turbine:

The view from the far downstream end into the test section of the U.S. Air Force Academy water tunnel. Three blades of the cycloidal turbine are visible at the far end. Engineer Stefan Siegel and his colleagues test the turbine using the tunnel, with both steady and oscillating flow conditions simulating a shallow-water wave-flow field. Courtesy of SSgt Danny Washburn, U.S. Air Force Academy, Department of Aeronautics

 

A cycloidal turbine is installed on top of the test section of the U.S. Air Force Academy water tunnel. In the background, Manfred Meid (left) and Stefan Siegel (right) operate the turbine. Courtesy of SSgt Danny Washburn, US Air Force Academy, Department of Aeronautics

 

 

 

A cycloidal turbine prototype with three blades (translucent, at bottom of image), is shown lifted out of the tunnel. One of the blade pitch control servo amplifiers is visible in the foreground, and the servo motors can be seen in the top portion of the image. Courtesy of SSgt Danny Washburn, US Air Force Academy, Department of Aeronautics

Read Full Post »

JESSICA MARSHALL, Discovery.com News, November 30, 2009

The patterns that schooling fish form to save energy while swimming have inspired a new wind farm design that researchers say will increase the amount of power produced per acre by at least tenfold.

“For the fish, they are trying to minimize the energy that they consume to swim from Point A to Point B,” said John Dabiri of the California Institute of Technology in Pasadena, who led the study. “In our case, we’re looking at the opposite problem: How to we maximize the amount of energy that we collect?”

“Because both of these problems involve optimizing energy, it turns out that the model that’s useful for one is also useful for the other problem.”

Both designs rely on individuals capturing energy from their neighbors to operate more efficiently.”If there was just one fish swimming, it kicks off energy into the water, and it just gets wasted,” Dabiri said, “but if there’s another fish behind, it can actually use that kinetic energy and help it propel itself forward.”

The wind turbines can do the same thing. Dabiri’s wind farm design uses wind turbines that are oriented to rotate around the support pole like a carousel, instead of twirling like a pinwheel the way typical wind turbines do.

Like the fish, these spinning turbines generate a swirling wake. The energy in this flow can be gathered by neighboring turbines if they are placed close enough together and in the right position. By capturing this wake, two turbines close together can generate more power than each acting alone.

This contrasts with common, pinwheel-style wind turbines where the wake from one interferes with its neighbors, reducing the neighbors’ efficiency. The vortexes occur in the wrong orientation for the neighboring turbines to capture them.

For this reason, such turbines must be spaced at least three diameters to either side and 10 diameters up — or downwind of another, which requires a lot of land.

Although individual carousel-style turbines are less efficient than their pinwheel-style counterparts, the close spacing that enhances their performance means that the amount of power output per acre is much greater for the carousel-style turbines.

Dabiri and graduate student Robert Whittlesey calculated that their best design would generate 100 times more power per acre than a conventional wind farm.

The model required some simplifications, however, so it remains to be seen whether tests of an actual wind farm produce such large gains. That will be the team’s next step. “Even if we’re off by a factor of 10, that’s still a game changer for the technology,” Dabiri noted.

In the end, schooling fish may not have the perfect arrangement. The pair found that the best arrangement of wind turbines did not match the spacing used by schooling fish.

“If we just mimic the fish wake, we can do pretty well,” Dabiri said. “But, as engineers, maybe we’re smarter than fish. It turns out that for this application there is even better performance to be had.”

This may be because fish have other needs to balance in their schooling behavior besides maximizing swimming efficiency. They seek food, avoid predators and reproduce, for example.

“I think that this is a very interesting possibility,” said Alexander Smits of Princeton University, who attended a presentation of the findings at a meeting of the American Physical Society Division of Fluid Dynamics in Minneapolis last week.

But a field test will show the idea’s real potential, he noted: “You have to go try these things. You can do a calculation like that and it might not work out. But it seemed like there was a very large reduction in the land usage, and even if you got one half of that, that would be pretty good.”

Read Full Post »

WENDEE HOLTCAMP, National Wildlife, December/January 2010

Frank Fish was browsing in a Boston sculpture shop a few years ago when he noticed a whale figurine. His first thought was, “This isn’t right. It’s got bumps on the leading edge of its flipper. It’s always a straight edge.”

Fish, a West Chester University professor specializing in the dynamics of locomotion, was surprised because all flippers he knew of had straight edges—including those of dolphins, penguins and even most whales. The straight-edge blade is also shared by ceiling fans and most industrial blades and rotors. But the store manager showed him a photo of a humpback whale, and sure enough, it had tubercles on its flippers. Humpbacks have a unique habit of catching fish in a bubble net that they create by diving deep and swimming in a spiraling circle, and Fish speculated that the tubercles may somehow give them a hydrodynamic advantage.

Turns out he was right. After testing a scaled-down flipper replica in a wind tunnel, Fish and colleagues Loren Howle and Mark Murray found the tubercles reduced drag by 32% and increased lift by 6% compared with a smooth-edge flipper. The bumps have the same effect on rotors and blades in air—a revolutionary discovery in aerodynamics. Fish co-patented so-called “Tubercle Technology” and in 2005 he helped found Whale Power, a company that is building energy-efficient windmills using scalloped-edge blades. The technology could eventually improve energy-efficiency for any machine that uses turbines, fans or pumps.

Fish is among an increasing number of scientists, inventors and companies turning to the natural world to help them create better, more sustainable products and to find solutions to some of humanity’s most vexing problems. The concept is called biomimicry and the idea behind it is simple: Over the millennia, living organisms in the natural world already have tested and solved many of the challenges humans are grappling with today.

“People are looking for ways to reduce material use, get away from toxic substances and reduce energy use. When they hear about biomimicry, they realize it’s an R&D program that’s been going on for 3.8 billion years,” says biologist Janine Benyus of the Biomimicry Guild, a Montana-based consulting firm that provides research and guidance on natural solutions for some of the country’s largest companies and government agencies.

In her landmark 1997 book Biomimicry: Innovation Inspired by Nature, Benyus issued a call to action, urging people to engage not just in shallow biomimicry—copying nature’s forms—but to push for deep biomimicry where manufacturing processes follow nature’s lead of sustainability. The ideal industrial loop, she says, would work as seamlessly as a redwood forest, where one’s processed wastes become food or input for another and nothing is wasted. In the book, Benyus also compiled dozens of examples of how people are emulating natural processes.

Velcro, for example, one of the most famous products to come from mimicking nature, was created by a Swiss engineer in the 1940s after observing how cockleburs got stuck in his dog’s fur. Three decades later, a German botanist discovered that lotus leaves contain tiny waxy bumps that cause water to bead up and run off the surface, washing and cleaning the leaves in the process. The discovery has since inspired a number of waterproof products including Lotusan, a self-cleaning paint that keeps the outsides of buildings free of algae and fungi.

More recently, scientists from the University of New South Wales discovered a revolutionary antibacterial compound in a type of red algal seaweed that lives off the coast of Australia. Bacteria form slimy biofilms but require a “quorum” to congregate, and so they constantly communicate with one another. The seaweed stays bacteria-free by emitting the compound furanone, which jams the bacteria’s communication sensors. Mimicking that natural action, the Australian company Biosignal created cleaning fluids that keep surfaces bacteria-free without killing them, which is a breakthrough because its use does not lead to the evolution of antibiotic resistance, as has happened with the proliferation of so many antibacterial cleaning compounds. So far, furanone works on various bacteria, including staphylococcus and vibrio, which causes cholera. It also works on the bacteria that corrode pipes, leading to oil spills.

In another flip on tradition, Mercedes-Benz recently modeled an ecologically friendly, fuel-efficient concept vehicle called the Bionic Car after the yellow boxfish, a squarish tropical creature found in reefs in the Pacific and Indian Oceans. Traditionally, aerodynamic cars have been built long and lean, but it turns out the boxfish has a drag coefficient nearly equal to that of a drop of water, which has one of the lowest drags possible. The automobile company not only borrowed from the boxfish’s boxy but aerodynamic shape but also from its unique skeletal structure that protects the animal from injury, making the car safer by putting extra material in certain parts of its frame and economizing by lightening up the load elsewhere.

Another product, the UltraCane, was developed not long ago as a result of research at the University of Leeds in Great Britain to help the blind “see” by utilizing the echolocation systems of bats. The cane emits an ultrasonic sound that bounces off objects, allowing vision-impaired people to develop a mental picture of where and how far away objects are—and hence better navigate around them.

In Zimbabwe, the architectural design firm Arup Associates modeled the country’s largest office complex, Eastgate Centre, after the passive cooling system used by African termites in their mounds. Termites farm fungus that they must keep at a precise 87 degrees F, while outside air varies from 35 degrees at night to 104 by day. To accomplish this amazing feat, termites constantly plug and unplug cooling vents that create convection currents, drawing air through the mound as needed. The Eastgate Centre builders copied this model, using fans and chimneys to shunt hot air out, and ground-level cavities to allow cooler air in—a concept known as passive cooling. Without any modern heating or air conditioning, the facility uses only 10% of the electricity of a conventional building its size. The energy-cost savings trickle down to tenants, who pay 20% lower rent than in neighboring buildings.

Elsewhere, scientists are turning to Mother Nature for inspiration for other energy-related materials. To increase the amount of sunlight that is absorbed by solar panels, for instance, a University of Florida researcher is developing a coating for the panels based on the structure of moth eyes, which reflect little light. In China and Japan, scientists are modeling more efficient solar cells after the scales on butterfly wings, which serve as highly effective, microscopic solar collectors.

The benefits humans gain as a result of such research provide a strong argument for conserving wildlife. “Protecting plant and animal habitats means also preserving the wellspring of ideas for the next industrial revolution,” says Benyus, who in 2007 was named by Time magazine as one of its “International Heroes of the Environment.”

That same year, she also founded the nonprofit Biomimicry Institute, which urges companies to donate a percentage of their profits to the habitat from which their biomimicry-inspired products come from. “We must become nature’s apprentice at this point,” she says, “and part of that path has to be preserving the wild places we now realize are the homes of geniuses.”

Read Full Post »

MendoCoastCurrent, November 16, 2009

For centuries humanity has gazed at the sea, rivers and rambling brooks in awe of water currents and the energy potential they hold. With increasingly critical demand for safe renewable energy solutions, our ability to capture water power has been an abstruse, distant choice for mitigating our dependence on fossil fuels.

Now with Peak Oil and Climate Change concerns igniting our interest in renewable energies, our brightest, most creative thinkers the world-over turn their attention and intention toward creating efficient, sustainable and safe renewable energy capture devices. It’s understood best bets for generating constant electricity straddle natural energy sources: the sun, the wind and the tides, with the energy captured from water and the tides currently garnering longest odds.

Water power, known more formally as hydrokinetic energy, is based on hydro, meaning water, and kinetic with roots in Greek, κίνηση, or kinesis, meaning motion. The motion of water and study of it includes capturing its power. At the heart of this energy is spinning and flowing, ironically a strikingly dissimilar concept from capture.

Whether extracted, converted, captured or transformed, hydrokinetic energy may well be the ‘holy grail’ of renewable energy, especially when considering the math:

  • ‘One foot of tidal change, when funneled through the natural orifices of the coastal inlets, has the potential to generate pure, clean, green energy and all with absolutely no carbon footprint.’
  • Thus, as an example, one Florida inlet having an average tidal change between 2” up to 1’ carries 75 trillion Cu-Ft of fast moving water every tide.

Furthermore, hydrokinetic energy offers consistent yields and potentials unknown and possibly undiscoverable from other naturally-sourced energy. Wind power faces insufficient, constant wind to return the capital investment, even with government subsidies, and robust solar energy opportunities are mostly located in far, off grid locales.

Traditional hydrokinetic solutions include tidal turbines, wave buoys, wave hubs, tethered ocean, buoyant/flexible wave snakes and tidal stream machines that generate electricity yet also create gross negative impacts on marine wildlife and the environment.

These solutions must overcome fundamental issues like potential fish or turtle kill, corrosion and tethering issues, repair distance and processes, long-term durability in water/weather, noise pollution and super expensive grid connections that are also environmentally damaging.

Seems that when we embrace and mimic nature in creating organically-derived energy capture tools, the harmonious capacity of the design inherently overcomes the problems of other inelegant hydrokinetic systems.

Over the last two years, W. S. “Scotty” Anderson, Jr. may have either consciously or unconsciously designed along these lines as he victoriously led his team to invent and build the ECO-Auger™. You’ll find information on this and other cool inventions at Anderson’s laboratory, www.smartproductinnovations.com.

As a lifelong fisherman, Anderson designed his hydrokinetic system to convert energy from moving water, delivering renewable, sustainable energy, while completely safe for fish and marine wildlife.

The tapered helix permits fish and other marine life to pass through with absolutely no sharp edges to injure them. Even turtles can swim through or are gently pushed aside as the ECO-Auger generally rotates under 100 rpm. The tapered design also permits debris to pass.

First thoughts of the ECO-Auger came to Anderson in 2008 as he was fishing the waters of the fast-moving Kenai River in Alaska. His mind focused on capturing the river’s energy; here are his notes: “I got the vision of a screw turning in the river current and generating electricity on the river bank. The screw would turn a flexible shaft and drive an electric generator outside the water.”

The ECO-Auger is a double-helix, auger-shaped spinner regulated by the size of the radius and the strength of the water current. “It’s easy to array, bi-directional and housed in an individual, streamlined single form,” Anderson points out.

Anderson originally envisioned the ECO-Auger “simply installed under bridges between the arches of bridges, housed on the ECO-Sled, a sort of a pontoon boat like a floating dry-dock.” This permits easy launch and retrieval for maintenance or if/when the ice gets too thick.

Over the next year Anderson built and tested prototypes, refining his hydrokinetic system completely from U.S. materials, requiring that each generation of the ECO-Auger be “very reasonable to build, deploy, easy to service and inexpensive to array.”

In describing his invention, Anderson said, “the ECO-Auger does not have blades, straight or twisted like other devices, and is environmentally-friendly to all marine wildlife. The fish are not harmed and swim through the organic design. With no electrical generation under or in water, there also is no danger to transmitting vibrations or naval sonar to whales and dolphins.”

This novel approach is so very different to existing technology. So very different and innovative that in late September 2009 Anderson’s team won First Place in the ConocoPhillips Energy Prize, a joint initiative of ConocoPhillips and Penn State University recognizing new ideas and original, actionable solutions that help improve the way the US develops and uses energy.

The prize-winning ECO-Auger was described as “a hydrokinetic energy capturing device that converts moving water from river and ocean currents to renewable electric energy using the constant hydraulic pressure and storage to maintain continuous energy output regardless of tidal current strength.”

How the ECO-Auger Works:

The ECO-Auger rotates in either direction from the moving water and current and is directly transferred through planetary gears to a high-pressure hydraulic pump located in the machine’s nose cone. The nose cone, which is physically tethered to bridges by cables, or anchored in moving water, stabilizes the torque generated from the rotation and transfers it to a hydraulic pump. The pump supplies variable volumes of high-pressure fluid at controlled, set pressure, regardless of the direction or speed of rotations. This pressure turns an oil-driven electric generator that delivers stable electrical current. Thus, constant power is generated through the ECO-Auger’s unique hydraulic circuit.

As the ECO-Auger rotates, the high-pressure oil flows through check valves to an array of standard air oil accumulators that are connected directly in line to the oil motor driving the electric generator. The oil to the electric generator is sized below the maximum gallons per minute of the ECO-Auger’s hydraulic pump, allowing the pumped oil to be supplied to the motor, while the excess volume is stored in the accumulator. A computer-monitored storage system assures maximum energy stability, storing energy and supplying the generators during the slow down of tidal flow.

Guide for Installation Opportunities:

Since the ECO-Auger is bi-directional, it is well-suited for high velocity, coastal ocean and bay locations. Near the ocean, the generation hydraulic system uses nitrogen-over-oil accumulators to maintain power generation during ebb tides or slack tidal movement under 1 knot (0.5m/s).

Each potential installation of the ECO-Auger is unique, requiring the water velocity and profile or depth of the installed area to be fully studied and documented. Anderson recommends a month-long study to support 30-year energy capture forecasts and projections.

River installations of the ECO-Auger are successful when current is in excess of 3 kts (1.5 meters/sec). The accumulators mentioned above are not required in mono-flow installations and installation reflects this cost savings. With the mono-directional ECO-Auger, electricity can be generated already existing power dams, downstream in any dam outlet, discharge from municipal water treatment facility, cooling water discharge and many river bridge options.

The ECO-Auger in its recent First Place win in the 2009 ConocoPhillips Energy Prize, a joint initiative of ConocoPhillips and Penn State University — won specifically for its new, original idea improving the way the U.S. creates and uses energy.

Anderson and his team are up to this important challenge and set their sights on installing this remarkable fish-friendly, economical, high-yielding hydrokinetic solution in a river, alongside a bridge or coastal inlet near you.

Read Full Post »

MIKE CHINO, Inhabitat, July 27, 2009

48_group-2-1Although electric vehicle use is on the rise, we’re certainly not out of the woods yet in terms of providing them with a steady supply of clean energy – that’s why designer Neville Mars has conceived of an incredible EV charging station that takes the form of an evergreen glade of solar trees. His photovoltaic grove serves a dual function, acting as a go-to source for clean renewable energy while providing a shady spot for cars to park as they charge.

Each of the trees in Neville Mars’s solar forest is composed of a set of photovoltaic leaves mounted on an elegantly branching poll. The base of each trunk features an power outlet that can be used to juice up your eco ride as you run errands.

Neville told Inhabitat that the tree and leaf design wasn’t a goal but came naturally as they tried to maximize the shaded surface that the structures provide. Although the efficiency of overlapping photovoltaic panels initially raised some concerns, Neville went on to explain that the leaves rotate with the sun to ensure maximum efficiency. The solar forest is certainly an aesthetic step up from your standard sun-baked concrete parking lot, and serves as great inspiration for integrating solar technology with natural forms.

Read Full Post »

TYLER HAMILTON, CleanBreak.ca, February 17, 2009

humpback_finToronto-based WhalePower, maker of the tubercle-lined turbine blades inspired by humpback whale flippers, got the results back from its first independent study in the field. 

The blade design was tested on a 25-kilowatt Wenvor Technologies turbine at the Wind Energy Institute of Canada. The institude found that annualized energy production from the retrofitted blade increased by an estimated 20%.

You can find the data here and analysis here. “Rated power was attained at 12.5 metres per second versus the 15 meters per second previously published performance for the unmodified Wenvor turbine. (Caveat: it’s an estimate because the test of the retrofitted blade followed International Electro-Technical Commission standards, while the benchmark data did not).

“An improvement of just 1% or 2% in AEP is significant,” said Stephen Dewar, WhalePower’s director of R&D. “Here we have about 20% with low noise. We’re thrilled by this result.”

The next step is to perform a more comprehensive apples-to-apples test on a larger turbine. These results may help the company raise the capital it needs to take its testing to the next level. Perhaps at some point it will begin catching the attention of some of the bigger wind-energy players.

Read Full Post »

DAVID FOGARTY, Reuters Climate Change Correspondent, February 5, 2009

ceto-overview1For millennia, Australia’s rugged southern coast has been carved by the relentless action of waves crashing ashore.

The same wave energy could soon be harnessed to power towns and cities and trim Australia’s carbon emissions.

“Waves are already concentrated solar energy,” says Michael Ottaviano, who leads a Western Australian firm developing a method to turn wave power into electricity.

“The earth has been heated by the Sun, creating wind, which created the swells,” he told Reuters from Perth, saying wave power had the potential to supply all of Australia’s needs many times over.

Ottaviano heads Carnegie Corp, which has developed a method of using energy captured from passing waves to generate high-pressure sea water. This is piped onshore to drive a turbine and to create desalinated water.

A series of large buoys are tethered to piston pumps anchored in waters 15 to 50 metres deep (49 to 131 feet). The rise and fall of passing waves drives the pumps, generating water pressures of up to 1,000 pounds per square inch (psi).

This drives the turbine onshore and forces the water through a membrane that strips out the salt, creating fresh water in a process that normally requires a lot of electricity.

The CETO (named after a mythical Greek sea creature) pumps and buoys are located under water, differing from some other wave power methods, for example, those that sit on the surface.

The CETO concept was invented in the 1970s by a Western Australian businessman Alan Burns and initial development began in 1999, followed by completion of a working prototype by 2005.

Ottaviano says the company, which works in partnership with British-based wind farm developer Renewable Energy Holdings and French utility EDF, is in the process of selecting a site for its first commercial demonstration plant in Australia.

The 50 megawatt plant, enough to power a large town, would cost between A$300 million to A$400 million ($193 million to $257 million) and cover about 5 hectares (12.5 acres) of seabed.

Funding could be raised from existing or new shareholders, he believes.

Several sites in Western Australia, including Albany in the south and Garden Island off Perth, looked promising.

“There’s significant interest in these sorts of projects, even in the current financial environment,” he added.

And a 50 MW plant was just a drop in the ocean.

He pointed to a study commissioned by the company that said wave power had the potential to generate up to 500,000 MW of electricity along the southern half of Australia’s coast at depths greater than 50 metres (165 feet).

At shallower depths, the potential was 170,000 MW, or about four times Australia’s installed power generation capacity.

Interest in renewable energy in Australia and elsewhere is being driven by government policies that enshrine clean energy production targets as well as state-backed funding programmes for emerging clean-tech companies.

“Australia is going to be one of those markets because of what the government is doing to drive investment in this sector. For starters, there’s quite a bit of direct government funding for projects like this,” he said.

The federal government has also set a renewable energy target of 20% by 2020, which is expected to drive billions of dollars worth of investment in Australia over the next decade, with much of it going into wind farms.

A second company, BioPower Systems, is developing underwater wave and tidal power systems and expects to complete pilot projects off northern Tasmania this year.

The company’s bioWAVE system is anchored to the sea bed and generates electricity through the movement of buoyant blades as waves pass, in a swaying motion similar to the way sea plants, such as kelp, move.

Tidal power, in which electricity is generated by turbines spinning to the ebb and flow of tides, has not taken off in Australia, partly because of cost, but is expected to be a big provider of green power in Britain in coming years.

Last week, Britain announced five possible projects to generate power from a large tidal area in south-west England. The largest of the projects could generate 8,600 MW and cost 21 billion pounds ($29 billion).

CONSTANT

Ottaviano believes wave power is one of the few green technologies that can provide steady, or baseload power.

Wind and solar photovoltaic panels can only operate at 25 to 30% efficiencies because neither the wind nor the sun are permanently available.

Government policies should promote the development of technologies that delivered large-scale, high-availability clean power competitively, he said.

“If you look from an outcome point of view and leave it up to the market to work out how that is going to be achieved, it comes down to geothermal certainly being one of the potential technologies because (of) its high availability and also potentially cost-competitive and harnessable at large scale,” Ottaviano said.

Australia has large geothermal potential in remote central and northern areas.

“Wave is another logical one because it is high availability. It is 90 to 100% available in most sites around southern Australia.”

“You could power the country 10 times over.”

Read Full Post »

MendoCoastCurrent, November 29, 2008

Ann Arbor, Michigan — Slow-moving ocean and river currents could be a new, reliable and affordable alternative energy source. A University of Michigan engineer has made a machine that works like a fish to turn potentially destructive vibrations in fluid flows into clean, renewable power.

The machine is called VIVACE. A paper on it is published in the current issue of the quarterly Journal of Offshore Mechanics and Arctic Engineering.

VIVACE is a device that may harness energy from most of the water currents around the globe because it works in flows moving slower than 2 knots (about 2 miles per hour.) Most of the Earth’s currents are slower than 3 knots. Turbines and water mills need an average of 5 or 6 knots to operate efficiently.

VIVACE stands for Vortex Induced Vibrations for Aquatic Clean Energy. It doesn’t depend on waves, tides, turbines or dams. It’s a unique hydrokinetic energy system that relies on “vortex induced vibrations.”

Vortex induced vibrations are undulations that a rounded or cylinder-shaped object makes in a flow of fluid, which can be air or water. The presence of the object puts kinks in the current’s speed as it skims by. This causes eddies, or vortices, to form in a pattern on opposite sides of the object. The vortices push and pull the object up and down or left and right, perpendicular to the current.

These vibrations in wind toppled the Tacoma Narrows bridge in Washington in 1940 and the Ferrybridge power station cooling towers in England in 1965. In water, the vibrations regularly damage docks, oil rigs and coastal buildings.

“For the past 25 years, engineers—myself included—have been trying to suppress vortex induced vibrations. But now at Michigan we’re doing the opposite. We enhance the vibrations and harness this powerful and destructive force in nature,” said VIVACE developer Michael Bernitsas, a professor in the U-M Department of Naval Architecture and Marine Engineering.

Fish have long known how to put the vortices that cause these vibrations to good use.

“VIVACE copies aspects of fish technology,” Bernitsas said. “Fish curve their bodies to glide between the vortices shed by the bodies of the fish in front of them. Their muscle power alone could not propel them through the water at the speed they go, so they ride in each other’s wake.”

This generation of Bernitsas’ machine looks nothing like a fish, though he says future versions will have the equivalent of a tail and surface roughness a kin to scales. The working prototype in his lab is just one sleek cylinder attached to springs. The cylinder hangs horizontally across the flow of water in a tractor-trailer-sized tank in his marine renewable energy laboratory. The water in the tank flows at 1.5 knots.

Here’s how VIVACE works: The very presence of the cylinder in the current causes alternating vortices to form above and below the cylinder. The vortices push and pull the passive cylinder up and down on its springs, creating mechanical energy. Then, the machine converts the mechanical energy into electricity.

Just a few cylinders might be enough to power an anchored ship, or a lighthouse, Bernitsas says. These cylinders could be stacked in a short ladder. The professor estimates that array of VIVACE converters the size of a running track and about two stories high could power about 100,000 houses. Such an array could rest on a river bed or it could dangle, suspended in the water. But it would all be under the surface.

Because the oscillations of VIVACE would be slow, it is theorized that the system would not harm marine life like dams and water turbines can.

Bernitsas says VIVACE energy would cost about 5.5 cents per kilowatt hour. Wind energy costs 6.9 cents a kilowatt hour. Nuclear costs 4.6, and solar power costs between 16 and 48 cents per kilowatt hour depending on the location.

“There won’t be one solution for the world’s energy needs,” Bernitsas said. “But if we could harness 0.1% of the energy in the ocean, we could support the energy needs of 15 billion people.”

The researchers recently completed a feasibility study that found the device could draw power from the Detroit River. They are working to deploy one for a pilot project there within the 18 months.

This work has been supported by the U.S. Department of Energy, the Office of Naval Research, the National Science Foundation, the Detroit/Wayne County Port Autrhority, the DTE Energy Foundation, Michigan Universities Commercialization Initiative, and the Link Foundation. The technology is being commercialized through Bernitsas’ company, Vortex Hydro Energy.

Read Full Post »

CHRIS GOODALL, Guardian/U.K, November 27, 2008

Myth 1: Solar energy is too expensive to be of much use

In reality, today’s bulky and expensive solar panels capture only 10% or so of the sun’s energy, but rapid innovation in the US means that the next generation of panels will be much thinner, capture far more of the energy in the sun’s light and cost a fraction of what they do today. They may not even be made of silicon. First Solar, the largest manufacturer of thin panels, claims that its products will generate electricity in sunny countries as cheaply as large power stations by 2012.

Other companies are investigating even more efficient ways of capturing the sun’s energy, for example the use of long parabolic mirrors to focus light on to a thin tube carrying a liquid, which gets hot enough to drive a steam turbine and generate electricity. Spanish and German companies are installing large-scale solar power plants of this type in North Africa, Spain and the south-west of America; on hot summer afternoons in California, solar power stations are probably already financially competitive with coal. Europe, meanwhile, could get most of its electricity from plants in the Sahara desert. We would need new long-distance power transmission but the technology for providing this is advancing fast, and the countries of North Africa would get a valuable new source of income.

Myth 2: Wind energy is too unreliable

Actually, during some periods earlier this year the wind provided almost 40% of Spanish power. Parts of northern Germany generate more electricity from wind than they actually need. Northern Scotland, blessed with some of the best wind speeds in Europe, could easily generate 10% or even 15% of the UK’s electricity needs at a cost that would comfortably match today’s fossil fuel prices.

The intermittency of wind power does mean that we would need to run our electricity grids in a very different way. To provide the most reliable electricity, Europe needs to build better connections between regions and countries; those generating a surplus of wind energy should be able to export it easily to places where the air is still. The UK must invest in transmission cables, probably offshore, that bring Scottish wind-generated electricity to the power-hungry south-east and then continue on to Holland and France. The electricity distribution system must be Europe-wide if we are to get the maximum security of supply.

We will also need to invest in energy storage. At the moment we do this by pumping water uphill at times of surplus and letting it flow back down the mountain when power is scarce. Other countries are talking of developing “smart grids” that provide users with incentives to consume less electricity when wind speeds are low. Wind power is financially viable today in many countries, and it will become cheaper as turbines continue to grow in size, and manufacturers drive down costs. Some projections see more than 30% of the world’s electricity eventually coming from the wind. Turbine manufacture and installation are also set to become major sources of employment, with one trade body predicting that the sector will generate 2m jobs worldwide by 2020.

Myth 3: Marine energy is a dead-end

The thin channel of water between the north-east tip of Scotland and Orkney contains some of the most concentrated tidal power in the world. The energy from the peak flows may well be greater than the electricity needs of London. Similarly, the waves off the Atlantic coasts of Spain and Portugal are strong, consistent and able to provide a substantial fraction of the region’s power. Designing and building machines that can survive the harsh conditions of fast-flowing ocean waters has been challenging and the past decades have seen repeated disappointments here and abroad. This year we have seen the installation of the first tidal turbine to be successfully connected to the UK electricity grid in Strangford Lough, Northern Ireland, and the first group of large-scale wave power generators 5km off the coast of Portugal, constructed by a Scottish company.

But even though the UK shares with Canada, South Africa and parts of South America some of the best marine energy resources in the world, financial support has been trifling. The London opera houses have had more taxpayer money than the British marine power industry over the past few years. Danish support for wind power helped that country establish worldwide leadership in the building of turbines; the UK could do the same with wave and tidal power.

Myth 4: Nuclear power is cheaper than other low-carbon sources of electricity

If we believe that the world energy and environmental crises are as severe as is said, nuclear power stations must be considered as a possible option. But although the disposal of waste and the proliferation of nuclear weapons are profoundly important issues, the most severe problem may be the high and unpredictable cost of nuclear plants.

The new nuclear power station on the island of Olkiluoto in western Finland is a clear example. Electricity production was originally supposed to start this year, but the latest news is that the power station will not start generating until 2012. The impact on the cost of the project has been dramatic. When the contracts were signed, the plant was supposed to cost €3bn (£2.5bn). The final cost is likely to be more than twice this figure and the construction process is fast turning into a nightmare. A second new plant in Normandy appears to be experiencing similar problems. In the US, power companies are backing away from nuclear because of fears over uncontrollable costs.

Unless we can find a new way to build nuclear power stations, it looks as though CO2 capture at coal-fired plants will be a cheaper way of producing low-carbon electricity. A sustained research effort around the world might also mean that cost-effective carbon capture is available before the next generation of nuclear plants is ready, and that it will be possible to fit carbon-capture equipment on existing coal-fired power stations. Finding a way to roll out CO2 capture is the single most important research challenge the world faces today. The current leader, the Swedish power company Vattenfall, is using an innovative technology that burns the coal in pure oxygen rather than air, producing pure carbon dioxide from its chimneys, rather than expensively separating the CO2 from other exhaust gases. It hopes to be operating huge coal-fired power stations with minimal CO2 emissions by 2020.

Myth 5: Electric cars are slow and ugly

We tend to think that electric cars are all like the G Wiz vehicle, with a limited range, poor acceleration and an unprepossessing appearance. Actually, we are already very close to developing electric cars that match the performance of petrol vehicles. The Tesla electric sports car, sold in America but designed by Lotus in Norfolk, amazes all those who experience its awesome acceleration. With a price tag of more than $100,000, late 2008 probably wasn’t a good time to launch a luxury electric car, but the Tesla has demonstrated to everybody that electric cars can be exciting and desirable. The crucial advance in electric car technology has been in batteries: the latest lithium batteries – similar to the ones in your laptop – can provide large amounts of power for acceleration and a long enough range for almost all journeys.

Batteries still need to become cheaper and quicker to charge, but the UK’s largest manufacturer of electric vehicles says that advances are happening faster than ever before. Its urban delivery van has a range of over 100 miles, accelerates to 70mph and has running costs of just over 1p per mile. The cost of the diesel equivalent is probably 20 times as much. Denmark and Israel have committed to develop the full infrastructure for a switch to an all-electric car fleet. Danish cars will be powered by the spare electricity from the copious resources of wind power; the Israelis will provide solar power harvested from the desert.

Myth 6: Biofuels are always destructive to the environment

Making some of our motor fuel from food has been an almost unmitigated disaster. It has caused hunger and increased the rate of forest loss, as farmers have sought extra land on which to grow their crops. However the failure of the first generation of biofuels should not mean that we should reject the use of biological materials forever. Within a few years we will be able to turn agricultural wastes into liquid fuels by splitting cellulose, the most abundant molecule in plants and trees, into simple hydrocarbons. Chemists have struggled to find a way of breaking down this tough compound cheaply, but huge amounts of new capital have flowed into US companies that are working on making a petrol substitute from low-value agricultural wastes. In the lead is Range Fuels, a business funded by the venture capitalist Vinod Khosla, which is now building its first commercial cellulose cracking plant in Georgia using waste wood from managed forests as its feedstock.

We shouldn’t be under any illusion that making petrol from cellulose is a solution to all the problems of the first generation of biofuels. Although cellulose is abundant, our voracious needs for liquid fuel mean we will have to devote a significant fraction of the world’s land to growing the grasses and wood we need for cellulose refineries. Managing cellulose production so that it doesn’t reduce the amount of food produced is one of the most important issues we face.

Myth 7: Climate change means we need more organic agriculture

The uncomfortable reality is that we already struggle to feed six billion people. Population numbers will rise to more than nine billion by 2050. Although food production is increasing slowly, the growth rate in agricultural productivity is likely to decline below population increases within a few years. The richer half of the world’s population will also be eating more meat. Since animals need large amounts of land for every unit of meat they produce, this further threatens food production for the poor. So we need to ensure that as much food as possible is produced on the limited resources of good farmland. Most studies show that yields under organic cultivation are little more than half what can be achieved elsewhere. Unless this figure can be hugely improved, the implication is clear: the world cannot feed its people and produce huge amounts of cellulose for fuels if large acreages are converted to organic cultivation.

Myth 8: Zero carbon homes are the best way of dealing with greenhouse gas emissions from buildings

Buildings are responsible for about half the world’s emissions; domestic housing is the most important single source of greenhouse gases. The UK’s insistence that all new homes are “zero carbon” by 2016 sounds like a good idea, but there are two problems. In most countries, only about 1% of the housing stock is newly built each year. Tighter building regulations have no effect on the remaining 99%. Second, making a building genuinely zero carbon is extremely expensive. The few prototype UK homes that have recently reached this standard have cost twice as much as conventional houses.

Just focusing on new homes and demanding that housebuilders meet extremely high targets is not the right way to cut emissions. Instead, we should take a lesson from Germany. A mixture of subsidies, cheap loans and exhortation is succeeding in getting hundreds of thousands of older properties eco-renovated each year to very impressive standards and at reasonable cost. German renovators are learning lessons from the PassivHaus movement, which has focused not on reducing carbon emissions to zero, but on using painstaking methods to cut emissions to 10 or 20% of conventional levels, at a manageable cost, in both renovations and new homes. The PassivHaus pioneers have focused on improving insulation, providing far better air-tightness and warming incoming air in winter, with the hotter stale air extracted from the house. Careful attention to detail in both design and building work has produced unexpectedly large cuts in total energy use. The small extra price paid by householders is easily outweighed by the savings in electricity and gas. Rather than demanding totally carbon-neutral housing, the UK should push a massive programme of eco-renovation and cost-effective techniques for new construction.

Myth 9: The most efficient power stations are big

Large, modern gas-fired power stations can turn about 60% of the energy in fuel into electricity. The rest is lost as waste heat.

Even though 5-10% of the electricity will be lost in transmission to the user, efficiency has still been far better than small-scale local generation of power. This is changing fast.

New types of tiny combined heat and power plants are able to turn about half the energy in fuel into electricity, almost matching the efficiency of huge generators. These are now small enough to be easily installed in ordinary homes. Not only will they generate electricity but the surplus heat can be used to heat the house, meaning that all the energy in gas is productively used. Some types of air conditioning can even use the heat to power their chillers in summer.

We think that microgeneration means wind turbines or solar panels on the roof, but efficient combined heat and power plants are a far better prospect for the UK and elsewhere. Within a few years, we will see these small power plants, perhaps using cellulose-based renewable fuels and not just gas, in many buildings. Korea is leading the way by heavily subsidising the early installation of fuel cells at office buildings and other large electricity users.

Myth 10: All proposed solutions to climate change need to be hi-tech

The advanced economies are obsessed with finding hi-tech solutions to reducing greenhouse gas emissions. Many of these are expensive and may create as many problems as they solve. Nuclear power is a good example. But it may be cheaper and more effective to look for simple solutions that reduce emissions, or even extract existing carbon dioxide from the air. There are many viable proposals to do this cheaply around the world, which also often help feed the world’s poorest people. One outstanding example is to use a substance known as biochar to sequester carbon and increase food yields at the same time.

Biochar is an astonishing idea. Burning agricultural wastes in the absence of air leaves a charcoal composed of almost pure carbon, which can then be crushed and dug into the soil. Biochar is extremely stable and the carbon will stay in the soil unchanged for hundreds of years. The original agricultural wastes had captured CO2 from the air through the photosynthesis process; biochar is a low-tech way of sequestering carbon, effectively for ever. As importantly, biochar improves fertility in a wide variety of tropical soils. Beneficial micro-organisms seem to crowd into the pores of the small pieces of crushed charcoal. A network of practical engineers around the tropical world is developing the simple stoves needed to make the charcoal. A few million dollars of support would allow their research to benefit hundreds of millions of small farmers at the same time as extracting large quantities of CO2 from the atmosphere.

Read Full Post »

JASPER COPPING, TELEGRAPH/U.K., November 29, 2008

oceancurrent4The technology can generate electricity in water flowing at a rate of less than one knot – about one mile an hour – meaning it could operate on most waterways and sea beds around the globe.

Existing technologies which use water power, relying on the action of waves, tides or faster currents created by dams, are far more limited in where they can be used, and also cause greater obstructions when they are built in rivers or the sea. Turbines and water mills need an average current of five or six knots to operate efficiently, while most of the earth’s currents are slower than three knots.

The new device, which has been inspired by the way fish swim, consists of a system of cylinders positioned horizontal to the water flow and attached to springs.

As water flows past, the cylinder creates vortices, which push and pull the cylinder up and down. The mechanical energy in the vibrations is then converted into electricity.

Cylinders arranged over a cubic meter of the sea or river bed in a flow of three knots can produce 51 watts. This is more efficient than similar-sized turbines or wave generators, and the amount of power produced can increase sharply if the flow is faster or if more cylinders are added.

A “field” of cylinders built on the sea bed over a 1km by 1.5km area, and the height of a two-storey house, with a flow of just three knots, could generate enough power for around 100,000 homes. Just a few of the cylinders, stacked in a short ladder, could power an anchored ship or a lighthouse.

Systems could be sited on river beds or suspended in the ocean. The scientists behind the technology, which has been developed in research funded by the US government, say that generating power in this way would potentially cost only around 3.5p per kilowatt hour, compared to about 4.5p for wind energy and between 10p and 31p for solar power. They say the technology would require up to 50 times less ocean acreage than wave power generation.

The system, conceived by scientists at the University of Michigan, is called Vivace, or “vortex-induced vibrations for aquatic clean energy”.

Michael Bernitsas, a professor of naval architecture at the university, said it was based on the changes in water speed that are caused when a current flows past an obstruction. Eddies or vortices, formed in the water flow, can move objects up and down or left and right.

“This is a totally new method of extracting energy from water flow,” said Mr Bernitsas. “Fish curve their bodies to glide between the vortices shed by the bodies of the fish in front of them. Their muscle power alone could not propel them through the water at the speed they go, so they ride in each other’s wake.”

Such vibrations, which were first observed 500 years ago by Leonardo DaVinci in the form of “Aeolian Tones”, can cause damage to structures built in water, like docks and oil rigs. But Mr Bernitsas added: “We enhance the vibrations and harness this powerful and destructive force in nature.

“If we could harness 0.1% of the energy in the ocean, we could support the energy needs of 15 billion people. In the English Channel, for example, there is a very strong current, so you produce a lot of power.”

Because the parts only oscillate slowly, the technology is likely to be less harmful to aquatic wildlife than dams or water turbines. And as the installations can be positioned far below the surface of the sea, there would be less interference with shipping, recreational boat users, fishing and tourism.

The engineers are now deploying a prototype device in the Detroit River, which has a flow of less than two knots. Their work, funded by the US Department of Energy and the US Office of Naval Research, is published in the current issue of the quarterly Journal of Offshore Mechanics and Arctic Engineering.

Read Full Post »

ANNE TRAFTON, MIT NEWS, July 31, 2008

Scientists mimic essence of plants’ energy storage system

In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn’t shine.

Until now, solar power has been a daytime-only energy source, because storing extra solar energy for later use is prohibitively expensive and grossly inefficient. With today’s announcement, MIT researchers have hit upon a simple, inexpensive, highly efficient process for storing solar energy.

Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. “This is the nirvana of what we’ve been talking about for years,” said MIT’s Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and senior author of a paper describing the work in the July 31 issue of Science. “Solar power has always been a limited, far-off solution. Now we can seriously think about solar power as unlimited and soon.”

Inspired by the photosynthesis performed by plants, Nocera and Matthew Kanan, a postdoctoral fellow in Nocera’s lab, have developed an unprecedented process that will allow the sun’s energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.

The key component in Nocera and Kanan’s new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity – whether from a photovoltaic cell, a wind turbine or any other source – runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.

Combined with another catalyst, such as platinum, that can produce hydrogen gas from water, the system can duplicate the water splitting reaction that occurs during photosynthesis.

The new catalyst works at room temperature, in neutral pH water, and it’s easy to set up, Nocera said. “That’s why I know this is going to work. It’s so easy to implement,” he said.

Giant Leap for Clean Energy

Sunlight has the greatest potential of any power source to solve the world’s energy problems, said Nocera. In one hour, enough sunlight strikes the Earth to provide the entire planet’s energy needs for one year.

James Barber, a leader in the study of photosynthesis who was not involved in this research, called the discovery by Nocera and Kanan a “giant leap” toward generating clean, carbon-free energy on a massive scale.

“This is a major discovery with enormous implications for the future prosperity of humankind,” said Barber, the Ernst Chain Professor of Biochemistry at Imperial College London. “The importance of their discovery cannot be overstated since it opens up the door for developing new technologies for energy production thus reducing our dependence for fossil fuels and addressing the global climate change problem.”

Just the Beginning

Currently available electrolyzers, which split water with electricity and are often used industrially, are not suited for artificial photosynthesis because they are very expensive and require a highly basic (non-benign) environment that has little to do with the conditions under which photosynthesis operates.

More engineering work needs to be done to integrate the new scientific discovery into existing photovoltaic systems, but Nocera said he is confident that such systems will become a reality.

“This is just the beginning,” said Nocera, principal investigator for the Solar Revolution Project funded by the Chesonis Family Foundation and co-Director of the Eni-MIT Solar Frontiers Center. “The scientific community is really going to run with this.”

Nocera hopes that within 10 years, homeowners will be able to power their homes in daylight through photovoltaic cells, while using excess solar energy to produce hydrogen and oxygen to power their own household fuel cell. Electricity-by-wire from a central source could be a thing of the past.

The project is part of the MIT Energy Initiative, a program designed to help transform the global energy system to meet the needs of the future and to help build a bridge to that future by improving today’s energy systems. MITEI Director Ernest Moniz, Cecil and Ida Green Professor of Physics and Engineering Systems, noted that “this discovery in the Nocera lab demonstrates that moving up the transformation of our energy supply system to one based on renewables will depend heavily on frontier basic science.”

The success of the Nocera lab shows the impact of a mixture of funding sources – governments, philanthropy, and industry. This project was funded by the National Science Foundation and by the Chesonis Family Foundation, which gave MIT $10 million this spring to launch the Solar Revolution Project, with a goal to make the large scale deployment of solar energy within 10 years.

Read Full Post »

DAVID EHRLICH, cleantech.com, February 18, 2008

Researchers at Pennsylvania State University have come up with a way to get hydrogen from water that tries to copy the system that plants use.

“It’s a conceptual advance, I think. Kind of a proof of principle that you can make something that uses molecules to sort of do what photosynthesis does,” Professor Thomas Mallouk told Cleantech.com.

Mallouk is the DuPont professor of materials chemistry and physics at Penn State.

The researchers worked in collaboration with Arizona State University and with backing from the U.S. Department of Energy.

The group developed a catalyst system that, combined with a dye, mimics the electron transfer and water oxidation processes that occur in plants during photosynthesis.

But don’t look for a commercial application to come out anytime soon. The technology right now is very inefficient, although Mallouk said plants aren’t doing much better.

“Photosynthesis is basically a failed system. Since it’s had a billion-plus years to evolve and has only got to 1 to 3 percent efficient,” he said.

“So we need to do better than that in whatever man-made systems we make, whether they’re molecular systems like ours or semiconductor systems like conventional solar cells.”

The researchers have so far achieved an efficiency of only about 0.3 percent. They reported the results of their experiments at the annual meeting of the American Association for the Advancement of Science over the weekend in Boston.

Current catalytic systems can make hydrogen using a so-called sacrificial reducing agent that provides the electrons needed, with the agent consumed in the process.

“What we wanted to do was do that without cheating, using water as the electron donor and make hydrogen on the reducing side and oxygen on the oxidizing side.”

The process uses a cluster of molecules about 2 nanometers in diameter with a center catalyst of iridium oxide molecules surrounded by orange-red dye molecules.

The university said the researchers picked orange-red dye because it absorbs sunlight in the blue range, which has the most energy.

When the dye is hit with visible light, the energy excites electrons in the dye, which, with the help of the catalyst, can split the water molecule.

Attempts at a similar process by other researchers have run into the problem of the hydrogen and oxygen recombining.

“If you’re driving a reaction uphill, it wants to go back downhill,” said Mallouk. “Any catalyst that is a good catalyst for doing that uphill reaction, is also a good catalyst for sending it the other way.”

“So you have a real problem. You have to somehow separate the products physically or you have to do very tricky catalyst design that will only catalyze a reaction in one direction and not the other.”

The researchers impregnated a titanium dioxide electrode with the catalyst complex for the anode and used a platinum cathode, immersing the electrodes in a salt solution, but separating them from each other to avoid the problem of the hydrogen and oxygen recombining.

While the system is a step forward in making a process that can split water without using a reducing agent, it’s still well behind current, commercially available technology.

“I don’t know if this kind of water photolysis would ever catch up with power generating solar cells hooked to electrolyzer systems,” said Mallouk.

“Those systems are pretty good and getting better, but the costs are still pretty high.”

Companies like New Jersey-based Renewable Energy International are working on a solar cell-to-electrolyzer system for residential use.

Scaling up the the Penn State system, with its iridium oxide catalyst, isn’t likely to be a cheaper proposition.

“Iridium occupies a unique position of being the most expensive element in the periodic table,” said Mallouk. “Can’t get any worse than that.”

But he did point out that nature can achieve its oxygen evolution reaction 50 times faster than they can, using manganese, which is a cheap element.

“So it’s not hopeless to make this kind of thing out of cheap materials, but it would be a long, tough road to make a fully molecular water splitting system that was really efficient and really economical.”

He said the molecular systems are interesting, from a fundamental science point of view, but that the smart money is probably on semiconductor-based nanosystems for making really efficient solar cells.

“You could picture a microscopic system that develops the voltage you need to split water and then the components of the electrolyzer right on that particle.”

Read Full Post »