Jul 25

The Next Generation Of Turbines Go Underwater

The Next Generation Of Turbines Go Underwater, And They’re Coming Soon

BY MICHAEL J. CORENWed Jul 20, 2011

As the U.S. slowly abandons its dams, more and more pilot programs pop up for deriving power from tides and river currents. Welcome to a new age of water power.

Every day, enough water flows down America’s rivers and streams to power tens of millions of homes. With the era of big dams effectively over in the U.S., halted by the lack of suitable sites as much as environmental concerns, the time for hydrokinetic energy may just be dawning.

The ideas of using turbines, or other mechanical devices, to capture the energy of moving water is not a new one. Yet the technology for such hydrokinetic energy has met serious resistance from conditions below the surface. As water is 832 times denser than air, it poses tough engineering challenges for power generators who must contend with corrosion, stray electromagnetic fields, and rules to safeguard sealife.

“There’s a lot of electricity to be had from these device and probably fewer environmental impacts, says Glenn Cada, senior researcher at Oak Ridge National Laboratory, in the Department of Energy’s program to improve hydrokenetic technology and minimize the environmental impacts. “It’s not as easy as taking a taking a wind turbine and putting it under water. The forces are much greater. We are trying to understand how to make them sturdy enough to generate electricity from river currents.”

Demonstration projects in the Mississippi and New York’s East Rivers have been steadily perfecting the technology needed to capture this energy for almost a decade. Verdant Power’s Roosevelt Island Tidal Energy project in New York’s East River (soon to be expanded) has successfully operated six underwater turbines between 2006-2008, and delivering 70 megawatt hours to a nearby supermarket and parking garage in what the company called the “world’s first grid-connected array of tidal turbines.” Free Flow Power Power has installed its own turbines, resembling jet engines, in the Mississippi and is eying more than 50 expansion sites.

Now, everyone from state agencies to universities are racing to get into the game. Applications to the Federal Energy Regulatory Commission for new hydrokinetic sites have soared in the last three years: 79   have been approved since 2009 (almost double those as of 2008), and 145 more are awaiting final approval in  Missouri, Maine, Louisiana, New Jersey and other states.

Eventually, based on the ambitions of several energy developers, underwater fields of hundreds of turbines could generating enough megawatts to power cities around the country.

“We’re trying to prove these things right now,” says Cada.

[Image: Atlantis Resources Corporation]

Reach Michael J. Coren via Twitter or email.

Read More: World’s First Floating Wind Turbine Installed, Ready for Testing

Jun 22

Dire forecast of marine life catastrophe – San Francisco Chronicle

The world’s oceans are degenerating far faster than predicted and marine life is facing extinction due to a range of human impacts – from overfishing to climate change – a report compiled by international scientists warned Tuesday.

The cumulative impact of “severe individual stresses,” ranging from climate warming and sea-water acidification to widespread chemical pollution and overfishing, would threaten the marine environment with a catastrophe “unprecedented in human history.”

The conclusions were published by a panel of international scientists who reviewed recent research at a workshop at Oxford University in Britain. They will be presented to the United Nations in New York this week for discussions on reforming governance of the oceans.

The report warned that damage to marine life would harm its ability to support humans, and that entire ecosystems, such as coral reefs, could be lost in a generation. Coral deaths alone would be considered a mass extinction, according to study chief author Alex Rogers of Oxford University. A single bleaching event in 1998 killed one-sixth of the world’s tropical coral reefs.

Carl Lundin, director of global marine programs at the International Union for Conservation of Nature, which helped produce the report with the International Program on the State of the Ocean, pointed to deaths of 1,000-year-old coral in the Indian Ocean and called the situation “really unprecedented.”

Chemicals and plastics from daily life are also causing problems for sea creatures, the report said. Overall, the world’s oceans just can’t bounce back from problems – such as oil spills – as they used to, scientists said.

“Unless action is taken now, the consequences of our activities are at a high risk of causing, through the combined effects of climate change, overexploitation, pollution and habitat loss, the next globally significant extinction event in the ocean,” it said.

The marine scientists called for a range of urgent measures to cut carbon emissions, reduce overfishing, shut unsustainable fisheries, create protected areas in the seas and cut pollution.

“As we considered the cumulative effect of what humankind does to the ocean, the implications became far worse than we had individually realized,” Rogers said. “This is a very serious situation demanding unequivocal action at every level.”

A separate study released Monday provided the most detailed look yet of sea level rise from global warming. It found the world’s oceans have been rising significantly over the past century. The yearly rise is slightly less than one-tenth of an inch, but it adds up over decades. That study was published in this week’s Proceedings of the National Academy of Sciences.

The Associated Press contributed to this report. This article appeared on page A – 4 of the San Francisco Chronicle