Monthly Archives: October 2010

Tidal Power: The Next Wave?

Over the next few years, we can expect to see huge advances in our ability to harness power from the ocean’s waves and tides, a new report from IHS Emerging Energy Research, a Cambridge, Mass., consulting firm, predicts.

Until recently, that sector has had limited popularity and mixed success, even as the number of installations generating power from other renewable resources like the wind, sun and biomass has grown rapidly. “The global ocean energy sector is at a turning point,” the company’s report says. More than 45 wave and tidal prototypes are expected to be ocean-tested in 2010 and 2011. Only nine were tested in 2009. More important, perhaps, while previous test projects tended to be operated by small, boutique firms, the giants of hydropower, which have decades of experience drawing power from rivers, are now getting into the ocean business.

Tides are particularly attractive sources of power because they are predictable, unlike sunshine and wind. Not surprisingly, countries with rough seas like Britain and Portugal are leading the way in exploring ocean power. Portugal, which now gets more than 40 percent of its electricity from renewable sources, was one of the first countries to install a commercial “wave farm.” There, several years ago, a British company used a snakelike device called the Pelamis system to absorb the energy of waves. The Portugal experiment met with mixed results before it was halted because of financial problems. One stumbling block was that the floating machines that absorbed wave energy quickly broke under the constant assault of the waves.

The European Energy Association estimates that, globally, the oceans could yield more than 100.000 terawatt hours a year if the technology to harness that power can be perfected. That is more than five times the electricity the world uses in a year.

 

Source:  The New York Times

UK fuel cell power plants come big step closer

Huge hydrogen fuel cell stacks capable of providing thousands of homes with green power may arrive in a few years thanks to cheaper component parts, according to developer AFC Energy.

Although hydrogen fuel cell technology has been around for decades, commercialization has been restricted as expensive platinum was needed to make the catalyst, a problem AFC said it has overcome by using low-cost ceramic minerals instead. “You can buy these ceramic catalyst materials, which used to be around 30 pounds a gram, at around 30 pence per gram, which has changed the economic argument,” AFC technical director Gene Lewis said. This compares to around 34.60 pounds per gram for platinum.

The alkaline fuel cell developer plans to test a 50 kilowatt block next year, which is designed to be connected to others to build huge stacks. AFC said it plans to demonstrate a stack with output capacity in the megawatt range in the next 18 months. “That leaves plenty of time to scale up. For tens of megawatts for the chloralkali industry in 2013, and hundreds of megawatts from 2015 onwards,” AFC founder Howard White said. “We see no reason why it can’t be commercialized by next year.”

Through a chemical process, fuel cells generate electricity without producing climate-warming carbon emissions by consuming hydrogen, with heat and water as byproducts. Hydrogen can be produced from processing natural gas — with the carbon removed and buried — and is also produced in some chemical manufacturing such as the chloralkali process.

AFC, based in Cranleigh in south England with a staff of around 25, estimated the capital cost of the fuel cell will be under 400,000 pounds ($635,300) per megawatt hour of output.”This is substantially less than a fossil fuel turbine based plant,” White said.

AFC is part of two consortiums that are developing large fuel cell power projects in Britain. One, with clean technology company B9 Coal and utility Powerfuel, aims to install up to 300 megawatts (MW) at Powerfuel’s planned 900 MW integrated gasification combined-cycle (IGCC) Hatfield power plant. Powerfuel intends to convert coal into a carbon-less synthetic gas (syngas) to burn in the Hatfield plant as well as process it to produce hydrogen for the cells.

The other project with B9 Gas and Rio Tinto Alcan’s 500 megawatt Lynemouth coal-fired plant in northeast England would also use syngas from underground coal seams to make hydrogen to power the fuel cell.While there are a number of large above-ground commercial facilities that produce syngas from coal similar to the Hatfield project, there are only a few small underground syngas projects which the Lynemouth plant plans to use.

And although taking the carbon out of syngas to produce hydrogen is an established process, it involves high capital investment and also lowers the energy content of the resulting hydrogen compared to the source fossil fuel. Industry observers say the extra process may mean burning the syngas to rotate gas and steam turbines as a cheaper way to generate power unless the price of carbon — as traded through the European Emissions Trading Scheme (ETS) — is high enough to encourage hydrogen production to feed into fuel cells.

 

Source:  Reuters

Arizona physicists discover new way of turning waste heat into electricity

University of Arizona physicists have discovered a new way of harvesting waste heat and turning it into electrical power.

The research group led by Charles Stafford, associate professor of physics, published its findings in the September issue of the scientific journal, ACS Nano. Using a theoretical model of a so-called molecular thermoelectric device, the technology is said to hold great promise for enabling cars, power plants, factories, solar panels and so forth to be more efficient. In addition, more efficient thermoelectric materials would make ozone-depleting chlorofluorocarbons, or CFCs, obsolete.

“Thermoelectricity makes it possible to cleanly convert heat directly into electrical energy in a device with no moving parts,” said lead author Justin Bergfield, a doctoral candidate in the UA College of Optical Sciences.

Unlike existing heat-conversion devices such as refrigerators and steam turbines, the devices of Bergfield and Stafford require no mechanics and no ozone-depleting chemicals. Instead, a rubber-like polymer sandwiched between two metals acting as electrodes can do the trick. Car or factory exhaust pipes could be coated with the material, less than 1 millionth of an inch thick, to harvest energy otherwise lost as heat and generate electricity according to the researchers.

Their energy saving invention is currently only a simulation, but the team say they have been assured that nothing in their virtual version would be impossible to reproduce in the real world.

This technology sounds promising on paper, but no prototype has yet been built. It would be interesting to discover when they are going to develop it further and what the production costs and efficiency will be.

If you are interested in learning more about the technology, click here:

http://www.sciencedaily.com/releases/2010/09/100930154610.htm