Is the ocean Florida’s untapped energy source?

By Azadeh Ansari - CNN

Imagine if your utility company could harness the ocean’s current to power your house, cool your office, even charge your car.

Researchers at Florida Atlantic University are in the early stages of turning that idea into reality in the powerful Gulf Stream off the state’s eastern shore.

“If you can take an engine and put it on the back of a boat or propel a ship through water, why not take a look at the strength of the Gulf Stream and determine if that can actually turn a device and create energy?” asked Sue Skemp, executive director at Florida Atlantic University’s Center for Ocean Energy Technology.

The demand for energy in Florida — the fourth most populous state, with an estimated 19 million residents — is quickly outpacing the capacity to create it, according to experts.

“Right now in Florida, we are at the cusp of an energy crisis. Our energy demand keeps growing,” said Frederick Driscoll, director of Florida Atlantic University’s Center of Excellence in Ocean Energy Technology.

Beginning in the Caribbean and ending in the upper-North Atlantic, the Gulf Stream lies on the eastern shore of Florida.

Its powerful currents have been used by many fishermen, sailors and explorers to expedite their passage in the Atlantic north and east to Europe, but scientists say the energy within its currents could propel Florida out of its potential energy crisis, powering 3 million to 7 million Florida homes — or supplying the state with one-third of its electricity.

“The predictions at this point estimate that the strength of the Gulf Stream could generate anywhere between four to 10 gigawatts of power, the equivalent of four to 10 nuclear power plants,” said Skemp.

“The Gulf Stream is the strongest current in the world, so we want to harness our greatest resource. It’s renewable, emission free and reliable,” said Jeremy Susac, executive director of the Florida Energy and Climate Commission.

At the university’s Center for Ocean Energy Technology in Boca Raton, Florida, ocean engineers are working with marine, environmental and material scientists to develop cost-competitive technologies to commercialize the energy within the Gulf Stream.

Though it has been considered for more than a century, harnessing the energy of the Gulf Stream is no easy task, and no sustainable system has been implemented.

“First we have to do a resource assessment and understand how much energy is in the Gulf Stream current on a minute-to-minute, day-to-day, hour-to-hour and yearly basis,” said Driscoll.

In April, researchers at the center deployed four acoustic Doppler current profilers in the Atlantic off the east coast of Florida.

Using high frequency, low-power sonar, these large orange ball-shaped objects measure the speed of the ocean currents.

“We are looking at how much energy we can safely extract — what is the sensitivity of extraction versus the environmental effects?” said Driscoll.

The vision for the pilot program is to develop and test a 20-kilowatt underwater turbine by spring 2010.

Sound familiar?

The concept behind underwater turbines is similar to that of wind turbines on land.

As water flows by the turbine, it turns a rotor blade. As the rotor blade turns, energy is generated.

That energy can be transmitted from a generator inside the turbine to electrical conducting cables, where it’s captured, harnessed and distributed for future use.

Researchers also are looking at ways to use the electricity that is generated underwater to generate and store hydrogen in the ocean. The hydrogen could be used to fuel clean-running cars and trucks.

“Because it’s such a new endeavor, there’s a lot of knowledge gaps not only in terms of the technology side but also on the ecological side of things,” said Driscoll.

Completely reliant

Florida is completely reliant on out-of-state fuel sources (coal and natural gas), but generates more than 90 percent of its own electricity, according to the Florida Energy and Climate Commission. It ranks third nationally in total energy consumption.

So how much will this endeavor cost? And what kind of impacts will it have on the local marine environment?

“Those are the questions we don’t have answers to,” said Skemp.

There are some hurdles that need to be cleared before the technology can get approval and become commercially available.

“This area is so new, we’re still finding out what needs to be done,” said Skemp.

“It’s not like an established industry, like the aerospace industry or the automotive industry or others, where you have models which you could base cost on,” added Skemp.

So far, the state of Florida has allocated $13.75 million in grants toward research and development of the pilot project, but the cost to implement the project on a large scale could be much higher.

Before a project like this can go forward, the Federal Energy Regulatory Commission will have to look at a whole range of factors, from the effects it will have on wild and marine life to recreation activities and shipping, said an environmental specialist with the commission.

If the pilot program is successful, it could take another five to 10 years before the technology can be implemented.

Salty water power

Researcher proposes new, cheaper way to get energy from salt water and fresh water

By Jenny Lauren Lee

A new way to get electricity out of water could prove to be worth its salt. Mixing salt water and fresh water in a container with carbon electrodes can produce clean, renewable energy, reports Doriano Brogioli of the University of Milano–Bicocca in Italy.

The reaction’s main by-product is brackish water that could be dumped back into the sea, Brogioli says in a paper to be published online in Physical Review Letters.

If further developed, the idea could be the basis for a new type of power plant that could be built in coastal areas, where natural sources of salt water and fresh water already exist, Brogioli says. A device developed using the method could have the potential to produce 1 kilowatt of electric power — enough to power a house, he says.

The idea is feasible but “still in the early stages of development,” says materials scientist Yury Gogotsi of Drexel University in Philadelphia. It will take more research to “bring it to a stage where it can be made … into a large device that could handle cubic meters of water flow,” Gogotsi says.

Brogioli likens his concept to the reverse of desalination, in which electricity is consumed to separate salt ions from seawater. In his method, the combination of fresh and salt water generates electricity when the ions diffuse through water.

In the first stage of the process, salt water is pumped into a container with two charged carbon electrodes. Salt ions — positively charged sodium and negatively charged chloride — are attracted to the surface of one of the two carbon electrodes, depending on the ions’ charge. Next, fresh water is pumped into the container, and the salt ions diffuse away from the surface of the electrodes and mix in the fresh water. Like pulling a rubber band taut, pulling the salt ions away from the charged electrodes creates increased energy in the system — the potential for work.

The amount of energy generated is similar to that harnessed through existing techniques that use fresh and salt water to produce electricity, but at a fraction of the cost, Brogioli says.

Since the 1970s, people have been exploring ways of getting energy from salt water. But many of those methods produce energy from the flow of water across membranes that separate fresh from salt water.

Yet making and maintaining the membranes has proved expensive compared to other sources of renewable energy. The field did not receive attention again until recently, when advances in materials and a drive to find renewable energy resources made the process a popular line of research, Gogotsi says.

Even if a device designed from Brogioli’s method could be used only in areas with a natural abundance of salt water and fresh water, Gogotsi says, it would be a welcome addition to existing renewable energy options such as solar and wind power. Given the limited amounts of fossil fuels in the Earth, “we will have to move to renewable energy sources one way or another,” he says.

Wave & Tidal Energy

A variety of technologies have been proposed to capture the energy from waves. Some of the more promising designs are undergoing demonstration testing at commercial scales.

Wave technologies have been designed to be installed in nearshore, offshore, and far offshore locations. The OCS Alternative Energy Programmatic EIS is concerned primarily with offshore and far offshore wave technologies. Offshore systems are situated in deep water, typically of more than 40 meters (131 feet). Read more