Green Wombat

New Effort to Harness Tidal Power in San Francisco Bay

photo: Doogie Boogie
California utility PG&E, the city of San Francisco and a green energy company will collaborate on a study to determine the potential for tapping tidal power in San Francisco Bay by placing turbines on the sea floor below the Golden Gate Bridge.  Earlier studies estimated that tidal power could provide greenhouse gas-free electricity to as many as 40,000 homes in San Francisco. PG&E (PCG) will kick in $1.5 million for the study by outside experts, which will be completed in about a year. Depending on the outcome of the research, it could be three to five years before a tidal project goes online. Golden Gate Energy of Washington, D.C., currently holds the federal permits  to conduct tidal power studies in San Francisco Bay and has committed $346,000 to the effort, according to PG&E. The joint study - the latest of several - will be only the first step in a complicated regulatory dance, complicated by a likely tussle over who ultimately wins the right to develop tidal power. The San Francisco Board of Supervisors recently voted to determine the feasibility of pulling the plug on PG&E and securing its own electricity supplies from renewable sources. A 400-megawatt tidal power plant would obviously help the city achieve that goal.

Starbug: New breed of robot to monitor oceans, coral reefs

Anyone who has read Elizabeth Kolbert's recent New Yorker article on the impact of global warming on the world's oceans knows there's an apocalyptic sea change under way, wrought by climate change, over-fishing and coral bleaching. Next year an inexpensive but technologically advanced autonomous underwater robot is expected to hit the market to boost scientists' efforts to monitor an area that covers two-thirds of the planet's surface. The Starbug will keep tabs on water quality, map fish habitat and survey threatened coral reefs. Starbug's designer, scientist Matthew Dunbabin, told Green Wombat that the little yellow robot also could be deployed to monitor fish populations and detect over-fishing as well as for use in underwater gas and oil exploration and to patrol harbors. Developed by Dunbabin's team at the Australian Commonwealth Scientific and Industrial Research Organisation, the 4-foot-long (1.2 meter) Starbug (CSIRO photo above) is highly manueverable thanks to innovative thruster technology that lets it explore coral reefs and other areas off limits to traditional - read big and heavy - submersibles. That means the Starbug doesn't have to be tethered to a boat and can operate independently without human intervention. Another breakthrough: the Starbug "sees" its surroundings, using robotic vision to navigate rather than expensive sonar. Its cameras and the onboard Linux operating system also allow the Starbug to identify and count, for instance, the invasive crown-of-thorns starfish. The marine pest is killing off parts of the Great Barrier Reef, an ecological cash cow that generates $11 billion annually in tourism revenues. Given that the Great Barrier Reef covers some 135,000 square miles (349,000 square kilometers), detecting outbreaks of crown-of-thorns starfish is an impossible and prohibitively expensive job for human divers. Dunbabin envisions fleets of Starbugs launched from small boats that will swim around the Great Barrier Reef, transmitting data back to base.  For monitoring of bays and harbors, the Starbug can be launched from shore. The Starbug's estimated cost of around $US 24,000 should fall with mass production. Dunbabin's team is now building the next generation Starbug and will use the robot to conduct two habitat mapping trials early next year. "Currently we are talking with local and international companies for the commercialization of Starbug," says Dunbabin, pictured below with a Starbug prototype.

"Air Shower" Saves Water, Makes Money

Australian scientists have developed a showerhead device they say cuts water use by 30 percent by injecting tiny air bubbles into water droplets. "The Aerated Showerhead creates the sensation of having a full and steady stream of water even though the water is now more like a wet shell around a bubble of air," according to the Commonwealth Scientific and Industrial Research Organisation, the  Australian government's super science agency that created the technology. While aerated showerheads have been around for awhile, the CSIRO nozzle-like gadget is a new technology the agency claims could save the average household 15,000-20,000 liters (about 4,000 to 5,300 gallons) of water annually. Jie Wu, the CSIRO scientist who lead development of the "air shower," says the nozzle is expected to sell for about $15 and can be installed by homeowners. Part of CSIRO's mandate is to commercialize its technology and it often works with investors and startups on spin-offs or licensing deals. The person to see in this case is Dilip Manuel, the business development manager for CSIRO Manufacturing & Materials Technology. Given its low rainfall, frequent droughts and desert environment, it's no surprise that Australia leads when it comes to inventing water-saving technology. With a global water crisis looming, such technology will inevitably be in demand.