A new wind turbine blade design that researchers at Sandia National Laboratories developed in partnership with Knight & Carver (K&C;) of San Diego promises to be more efficient than current designs.
It should significantly reduce the cost-of-energy (COE) of wind turbines at low-wind-speed sites.
Named “STAR“ for Sweep Twist Adaptive Rotor, the blade is the first of its kind produced at a utility-grade size. Its most distinctive characteristic is a gently curved tip, termed “sweep,“ which unlike the vast majority of blades in current use, is specially designed for low-wind-speed regions like the Midwest.
The sites targeted by this effort have annual average wind speeds of 5.8 meters per second, measured at 10-meter height. Such sites are abundant in the US and would increase by 20-fold the available land area that can be economically developed for wind energy, E4engineering.com said.
Sized at 27.1 meters--almost three meters longer than the baseline it will replace Ñ the blade improves energy capture at lower wind speeds. Instead of the traditional linear shape, the blade features a curvature toward the trailing edge, which allows the blade to respond to turbulent gusts in a manner that lowers fatigue loads on the blade. It is made of fibreglass and epoxy resin.
“This design allows the blade to twist more than traditional designs, thus relieving some of the effects of gusty turbulent wind on blade life,“ says Tom Ashwill, who leads Sandia’s blade research efforts. “This then allows us to grow the blade length for the same rotor, providing for increased energy capture of 5-10 percent and yet retaining the same expected fatigue life.“
The K&C; contract is part of the Low Wind Speed Technology (LWST) project that targets wind sites that are not the strongest but plentiful. In late 2005 the Department of Energy (DOE) and Sandia awarded Knight & Carver the $2 million contract that includes $800,000 in K&C; cost share. Because of budget reallocations, this project was the only one of several LWST projects to receive 2007 funding.
Sandia’s role in the project has been in directing design and test planning. The K&C; team provided the detailed design and blade fabrication.
The first STAR blade was tested in January at Knight & Carver’s fabrication facility in San Diego to determine its bending and twist behavior due to static loads. Natural frequencies were also measured.
This data will be compared to design simulations to determine how well the design concept performs. Four additional blades will be fabricated in the first quarter of 2007--three of which will be flight-tested on a turbine in Iowa.
Other members of the design team are Dynamic Design of Davis, CA; MDZ Consulting of Clear Lake Shores, TX; University of California, Davis; and NSE Composites of Seattle, WA.
“The DOE interest and funding are a big step for us,“ Ashwill says. “We’ve been pushing for the incorporation of innovative concepts into utility-scale blades for some time now as a way of reaching program goals of lowered cost of energy.“
He adds that the continued increase in the average size of utility-grade wind turbines may come to an end before all efficiencies are wrung out unless blade weight growth (which is nonlinear) can be reined in. The challenge is to develop new concepts that reduce the rate of weight growth, such as the swept STAR blade.

(Clockwise) Brookhaven Lab researchers Kotaro Sasaki, Junliang Zhang, Eli Sutter, and Radoslav Adzic view gold clusters on a single-crystal platinum surface using a scanning tunneling microscope.

Platinum might outweigh gold in the jewelry market, but as part of an ongoing effort to produce efficient and affordable fuelcells, scientists at the US Department of Energy’s (DOE) Brookhaven National Laboratory are studying how gold atoms might enhance the value of the pricier metal. Specifically, they’re looking for ways to use gold to prevent the destruction of platinum in the chemical reactions that take place in fuelcells. Brookhaven chemist Radoslav Adzic will describe this research during the 233rd National Meeting of the American Chemical Society at 2 p.m. Central Time (3 p.m. Eastern Time) on Tuesday, March 27, 2007, in room S405A, Level 4, at McCormick Place South, Chicago, Illinois.
Platinum is the most efficient electrocatalyst for accelerating chemical reactions in fuelcells. However, in reactions during the stop-and-go driving of a fuelcell-powered electric car, the platinum dissolves. In accelerated tests, as much as 45 percent of the catalyst can be lost during five days. “Platinum is by far the best single component catalyst for the oxygen reduction reaction, and we have to find a way to protect it,“ Adzic said. Under lab conditions that imitate the environment of a fuelcell, Adzic and a team of Brookhaven researchers, including Junliang Zhang, Kotaro Sasaki, and Eli Sutter, added gold clusters to a platinum electrocatalyst, which kept it intact during an accelerated stability test that simulates stop-and-go driving in an electric car, Fuelcellsworks.com said.
The details: A fuelcell converts hydrogen and oxygen into water and, as part of the process, produces electricity. Hydrogen is oxidized at the device’s anode (the terminal where current flows in) when electrons are released and hydrogen ions are formed; the released electrons supply current for an electric motor. These electrons flow to the cathode (the terminal where current flows out) to reduce oxygen, and in a reaction with hydrogen ions, water, the only byproduct of a fuelcell reaction, is produced. Platinum electrocatalysts are used to speed up the oxidation and reduction reactions involved in this process, but as a result, they, too, are oxidized (lose electrons) and dissolve.
In the unique method used at Brookhaven, researchers place gold on carbon-supported platinum nanoparticles by displacing a single layer of copper and subject it to several sweeps of voltage. The copper is needed to reduce the charged gold particles to neutral atoms; it then conveniently forms a monolayer of platinum by an adsorption process, the binding of molecules or particles to a surface. Using x-rays as probes at Brookhaven’s National Synchrotron Light Source, a scanning transmission microscope at Brookhaven’s Center for Functional Nanomaterials, and electrochemical techniques in the laboratory, the scientists can show that less platinum is oxidized with this method. As predicted, during laboratory testing, the platinum electrocatalyst remains stable when under conditions mimicking stop-and-go driving conditions. Next, researchers will test the catalyst in real fuelcells at the DOE’s Los Alamos National Laboratory in New Mexico.
“The very promising properties of fuelcells have been known for many decades,“ Adzic said. “But it’s only now that we can look at the activities and qualities of the catalysts and find something stable enough to be used in cars or residential applications.“
This research is funded through the US Department of Energy’s Hydrogen Program, which implements the President’s Hydrogen Fuel Initiative, a five-year program that began in 2003 to sponsor research, development, and demonstration of hydrogen and fuelcell technologies. Specifically, the funding derived from DOE’s Office of Basic Energy Sciences and its Office of Energy Efficiency and Renewable Energy.

Uganda’s geothermal electricity potential is not as much as it was originally thought to be by age-old studies.
A new study has showed that only 40MW of geothermal power generating capacity may be developed economically.
While the study looked at the economic and financial evaluation study of the 250MW Bujagali hydropower project, it highlighted Uganda’s geothermal potential in the hot springs of western Uganda.
“We have made a detailed review of the geothermal potential of Uganda and conclude that the resource may be substantially lower than previously estimated,“ the report, which majorly dwells on Bujagali, reads in part.
“It is considered that only approximately 40MW of geothermal power generating capacity may be developed economically on the basis of present knowledge.“ Power Planning Associates Limited of the United Kingdom, an independent consulting firm did the study.
Studies that were done in the 1950s and 1970’s indicated an initial estimate for the potential of 450MW of geothermal electrical generation at the three locations of Katwe, Buranga and Kibiro in the now oil-rich Albertine basin.
Subsequent exploration activity has failed to confirm the 450MW estimate with only three potentially viable prospects identified, Allafrica.com said.
In spite of the long history of interest in the potential of the geothermal resources in Uganda for commercial power generation, the exploration of these resources even today stands at a pre-feasibility level of investigation the study noted.
However, the 40MW potential at Katwe would need an investment of US$133.7 million. The purpose of the study was to evaluate the economic viability of Bujagali and to determine whether it’s commissioning in 2011 is the least cost strategy for Uganda. The study concluded that the commissioning of Bujagali in 2011, with a generation capacity of 250MW, is part of the least-cost expansion plan for power generation in Uganda.
The power supply generated from Bujagali would enable the 50-100MW of expensive, oil-fueled thermal generation capacity to be retired.
According to the study, Uganda’s electricity demand is expected to grow by 7.6% per year on average between 2005 and 2020.
However, to help meet this demand between 2006 and 2010, Uganda will lease and commission 150MW of oil-fueled power generation as well as some generation from bagasse, a sugar cane derivative used for renewable power generation, and from small hydropower plants. The report also simulates a set of least-cost plans without Bujagali, including the Karuma site as a candidate plant from 2012, considered as the earliest feasible commissioning date.
Compared to this set of scenarios, the expansion plans that include Bujagali commissioning in 2011, yield an economic advantage in favour of Bujagali of $184 million in net present value terms.
According to the study, after the commissioning of Bujagali in 2011, the average cost of supply to end-users should drop by up to 10% compared to prevailing prices in constant money terms.
On the economy as a whole, the study found that the commissioning of Bujagali in 2011 would have a small but positive impact on economic growth, balance of payments and the fiscal balance, compared to a scenario that does not include Bujagali. The former scenario also allows an earlier end to load shedding and lower tariffs than the latter.
As far as the hydrology of the lake and power generation are concerned, Bujagali would generate 1,165 giga watt-hours (GWh) per year when the lake level is low while an estimated 1,991GWh per year would be generated in times when the water levels rise.

Once, palm oil was seen as an ideal biofuel, a cheap alternative to petroleum that would fight global warming.
But second thoughts are wracking the power industry. Can the fruit of the palm tree help save the planet--or contribute to its destruction?
Environmentalists have long warned that many plantations in Indonesia and Malaysia, where 85 percent of commercial palm oil is grown, were planted on cleared rain forest, threatening the home of endangered animals like the orangutan and the Sumatran tiger.
Now, amid global efforts to curb emissions of greenhouse gases, power companies have joined conservationists in calculating the carbon count of producing palm oil fuel--and found the balance increasingly negative. A few companies have put plans on hold to switch to palm oil.
A report late last year by a Netherlands-based research group claimed some plantations produce far more carbon dioxide than they save. Seeded on drained peat swamps, they unleash a warehouse of carbon from decomposed plants and animals that had been locked in the bogs for hundreds of million years, which one biologist described as “buried sunshine.“
“As a biofuel, it’s a failure,“ said Marcel Silvius, a climate change expert for Wetlands International, the institute that led the research team.
The palm oil debate is just one example of cold realism dampening enthusiasm for vegetable oils as substitutes for the fossil fuels that are widely blamed for the gradual warming of the Earth and potentially disastrous changes in climate.
In the United States, where farmers have diverted corn and sugar crops to ethanol production, food prices have soared. Environmentalists say the high energy cost of making ethanol, coupled with the degraded land and polluted water from heavily fertilized fields, have put a large question mark on its value as a biofuel, ENN.com said.
Palm oil is an ingredient in cooking oil, cosmetics, soaps, bread, chocolate--in fact, in about one in every 10 products on the supermarket shelf. It also is used as an industrial lubricant.
It is attractive for bioenergy because it is relatively abundant, cheap at about US$557 (euro419) per ton in mid-March, and more easily integrated into existing power stations than most other alternative fuels.
Unlike carbon-rich fossil fuels, production is considered carbon neutral, meaning the carbon emitted from burning palm oil is the same as that absorbed during growth.
But the surrounding environmental cost is becoming increasingly apparent.
The four-year study in Southeast Asia by a team from Wetlands, Delft Hydraulics and the Alterra Research Center of Wageningen University said 600 million tons of carbon dioxide seep every year into the air from drained peat swamps. Another 1.4 billion tons go up in smoke from rain forest fires deliberately set to clear new land for plantations, shrouding much of Singapore and Malaysia in an impenetrable haze for weeks at a time.
Together, those 2 billion tons of CO2 amount to 8 percent of the globe’s fossil fuel emissions, the report said.
Friends of the Earth called the report “astonishing,“ and said it shows that harvesting palm oil for fuel is counterproductive. “It undermines the whole project,“ said a climate specialist for the environment group, Anne van Schaik.
Wetlands’ figures could not be independently verified by the UN Climate Change Secretariat in Bonn, Germany, by the World Resources Institute in Washington, D.C., nor by academic experts. But all said the research appeared credible.
Deforestation is the No. 2 cause of greenhouse gas emissions after the burning of fossil fuels, said Jeffrey Dukes, a biologist at the University of Massachusetts, and clearing peat swamps for plantations is “a double whammy.“
It not only releases carbon trapped over many millennia, Dukes said, but destroys the most efficient ecosystem on the planet for sucking carbon from the atmosphere and storing it underground.
“By converting these forests, we are essentially taking that buried sunshine and wasting it,“ he said. “It’s a terrible decision. Whether or not it’s consciously made, it’s society going in reverse.“
Next month, the Intergovernmental Panel on Climate Change, an authoritative UN network of 2,000 scientists, will publish its second in a series of four reports on the likely causes and potential impact of global warming.
Silvius, of Wetlands, said awareness of the vast amounts of carbon released from degraded peat lands is so new that the problem was not included in an early draft of the IPCC report. The group was pushing to include it in the final report and put it on the environmental agenda.
The first report, released in February, said with more certainty than before that mankind was responsible for global warming.
That report galvanized European leaders to approve a bold plan to cut greenhouse gas emissions by 20 percent from 1990 levels by 2020--and increase that to 30 percent if other countries join. Part of that goal would be achieved by converting at least 10 percent of Europe’s energy supplies to biofuels.
Despite pressure to replace coal, oil and gas with cleaner fuels, major power companies in Britain and the Netherlands have scrapped plans to partially convert electricity generation to palm oil.
“We spent more than a year investigating the sustainability issues with palm oil,“ said Leon Flexman, of RWE npower, Britain’s largest electricity supplier. The company decided against palm oil because it could not verify all its supplies would be free of the taint of destroyed rain forest or peat bogs, he said.

Brazil’s state-owned energy company Petrobras and its Ecuadorian counterpart Petroecuador signed an agreement on Wednesday, with the aim to exploit the Ishpingo-Tiputini-Tambococha (ITT) oil fields in the Yasuni National Park in Ecuadorian Amazon.
The oil deal, inked by Brazilian President Luiz Inacio Lula da Silva and visiting Ecuadorian President Rafael Correa, is similar to separate agreements signed by the Chilean National Petrol Company (ENAP) and SIPC, a subsidiary of Chinese state-owned company Sinopec, to exploit Ecuador’s Amazon region.
Petroecuador will provide environmental, social and economic reports on the field, while the other three companies will present joint plans for evaluating and developing reserves, Rigzone.com said.
ITT contains Block 31, already being exploited by Petrobras, which has invested 461 million US dollars in Ecuador in the last four years. ITT’s estimated 1 billion barrels of heavy crude is in the heart of Yasuni, one of Ecuador’s most important animal and plant reserves, 320 km north of the Ecuadorian capital of Quito.
Oil exploration in the region has been held back several times by environmental activists.
Petrobras and Petroecuador also signed a memorandum of understanding, aimed at launching a joint research by the Brazilian Agricultural Investigation Agency and Ecuador’s Ministry of Agriculture on the technical, economic and legal viability of biofuel production and distribution joint ventures in Ecuador.
At a press conference after the signing ceremony, Lula described Correa, who arrived here on Tuesday evening, as a “friend and colleague.“
“We want to face the challenge of transforming the world energy framework together,“ he said. “Even though we are self-sufficient exporters of petroleum, our nations are determined to promote this new clean and renewable energy revolution.“
Lula also asked Correa to expedite Ecuador’s change from associate member to full member status of the Southern Common Market (Mercosur), a regional trade bloc made up of Argentina, Brazil, Paraguay, Uruguay and Venezuela.
He also said he would work to reduce Brazilian tariffs on Ecuadorian goods as Ecuadorians have complained of Brazil’s large trade surplus with its smaller neighbor.