Nanotechnology simplifies hydrogen production for clean energy

In the first-ever experiment of its kind, researchers have demonstrated that clean energy hydrogen can be produced from water splitting by using very small metal particles that are exposed to sunlight. In the article, “Outstanding activity of sub-nm Au clusters for photocatalytic hydrogen production”, published in the journal Applied Catalysis B: Environmental, Alexander Orlov, PhD, an Assistant Professor of Materials Science & Engineering at Stony Brook University, and his colleagues from Stony Brook and Brookhaven National Laboratory, found that the use of gold particles smaller than one nanometer resulted in greater hydrogen production than other co-catalysts tested.
Experimental and theory predicted optical properties of supported sub-nanometer particles.
Experimental and theory predicted optical properties of supported sub-nanometer particles.
“This is the first ever demonstration of the remarkable potential of very small metal nanoparticles [containing fewer than a dozen atoms] for making fuel from water,” said Professor Orlov.
Using nanotechnology, Professor Orlov’s group found that when the size of metal particles are reduced to dimensions below one nanometer, there is a tremendous increase in the ability of these particles to facilitate hydrogen production from water using solar light. They observed a “greater than 35 times increase” in hydrogen evolution as compared to ordinary materials.
Experimental and theory predicted optical properties of supported sub-nanometer particles. In order to explain these fascinating results, Professor Orlov collaborated with Brookhaven National Lab computational scientist Dr. Yan Li, who found some interesting anomalies in electronic properties of these small particles. Professor Orlov noted that there is still a tremendous amount of work that needs be done to understand this phenomenon.
“It is conceivable that we are only at the beginning of an extraordinary journey to utilize such small particles [of less than a dozen atoms in size] for clean energy production,” he said.
“In order to reduce our dependence on fossil fuels it is vital to explore various sustainable energy options,” Professor Orlov said. “One possible strategy is to develop a hydrogen-based energy economy, which can potentially offer numerous environmental and energy efficiency benefits. Hydrogen can conceivably be a promising energy source in the future as it is a very clean fuel, which produces water as a final combustion product. The current challenge is to find new materials, which can help to produce hydrogen from sustainable sources, such as water.”
Source: Stony Brook University

World Energy Outlook 2011

In the IEO2011 Reference case, which does not incorporate prospective legislation or policies that might affect energy markets, world marketed energy consumption grows by 53 percent from 2008 to 2035. Total world energy use rises from 505 quadrillion British thermal units (Btu) in 2008 to 619 quadrillion Btu in 2020 and 770 quadrillion Btu in 2035 (Figure 1). Much of the growth in energy consumption occurs in countries outside the Organization for Economic Cooperation and Development (non-OECD nations)2 where demand is driven by strong long-term economic growth. Energy use in non-OECD nations increases by 85 percent in the Reference case, as compared with an increase of 18 percent for the OECD economies

World Energy Consumption, 1990- 2035 (quadrillion Btu), source: eia.gov

Although the world continues to recover from the 2008-2009 global recession, the recovery is uneven. In advanced economies, recovery has been slow in comparison with recoveries from past recessions. Unemployment is still high among the advanced economies, and real estate markets and household income growth remain weak. Debt levels in a number of small economies of the European Union—Greece, Ireland, and Portugal—required European Union intervention to avert defaults. Concerns about fiscal sustainability and financial turbulence suggest that economic recovery in the OECD countries will not be accompanied by the higher growth rates associated with past recoveries. In contrast, growth remains high in many emerging economies, in part driven by strong capital inflows and high commodity prices; however, inflation pressures remain a particular concern, along with the need to rebalance external trade in key developing economies.

Beyond the pace and timing of the world’s economic recovery, other events have compounded the uncertainty associated with this year’s energy outlook. Oil prices rose in 2010 as a result of growing demand associated with signs of economic recovery and a lack of a sufficient supply response. Prices were driven even higher at the end of 2010 and into 2011 as social and political unrest unfolded in several Middle Eastern and African economies. Oil prices increased from about $82 per barrel3 at the end of November 2010 to more than $112 per barrel in day trading on April 8, 2011. The impacts of quickly rising prices and possible regional supply disruptions add substantial uncertainty to the near-term outlook. In 2011, the price of light sweet crude oil in the United States (in real 2009 dollars) is expected to average $100 per barrel, and with prices expected to continue increasing in the long term, the price reaches $108 per barrel in 2020 and $125 per barrel in 2035 in the IEO2011 Reference case.

The aftermath of the devastating earthquake and tsunami that struck northeastern Japan on March 11, 2011—which resulted in extensive loss of life and infrastructure damage, including severe damage to several nuclear reactors at Fukushima Daiichi—provides another major source of uncertainty in IEO2011. The near-term outlook for Japan’s economy is lower than the already sluggish growth that was projected before the events, but the impact on the rest of Asia and on world economic health as a whole probably will be relatively small, given that Japan has not been a major factor in regional economic growth in recent years. However, the event may have more profound implications for the future of world nuclear power. The IEO2011 projections do not reflect the possible ramifications of Fukushima for the long-term global development of nuclear power or the policies that some countries have already adopted in its aftermath with respect to the continued operation of existing nuclear plants. more

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Bangkok Car Free Day this Sunday to raise awareness of global warming

Bangkok Metropolitan Administration (BMA) will be hosting Bangkok Car Free Day 2011 this Sunday with an aim to encourage the use of public transportation and reduce environmental impact from cars.

Deputy Bangkok Governor Mr. Theerachon Manomaipiboon presided over the launching of ‘Bangkok Car Free Day 2011’ today to raise the awareness of the global warming and encourage people to leave their cars at home and instead travel by public transportation or ride a bicycle on Sunday.

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Titanium Dioxide for Energy Storage Systems

Batteries could get a boost from an Oak Ridge National Laboratory discovery that increases power, energy density and safety while dramatically reducing charge time.

A team led by Hansan Liu, Gilbert Brown and Parans Paranthaman of the Department of Energy lab’s Chemical Sciences Division found that titanium dioxide creates a highly desirable material that increases surface area and features a fast charge-discharge capability for lithium ion batteries. Compared to conventional technologies, the differences in charge time and capacity are striking.

“We can charge our battery to 50 percent of full capacity in six minutes while the traditional graphite-based lithium ion battery would be just 10 percent charged at the same current,” Liu said.

Compared to commercial lithium titanate material, the ORNL compound also boasts a higher capacity – 256 vs. 165 milliampere hour per gram – and a sloping discharge voltage that is good for controlling state of charge. This characteristic combined with the fact oxide materials are extremely safe and long-lasting alternatives to commercial graphite make it well-suited for hybrid electric vehicles and other high-power applications.

The results, recently published in Advanced Materials, could also have special significance for applications in stationary energy storage systems for solar and wind power, and for smart grids. The titanium dioxide with a bronze polymorph also has the advantage of being potentially inexpensive, according to Liu.

At the heart of the breakthrough is the novel architecture of titanium dioxide, named mesoporous TiO2-B microspheres, which features channels and pores that allow for unimpeded flow of ions with a capacitor-like mechanism. Consequently, a lithium ion battery that substitutes TiO2-B for the graphite electrode charges and discharges quickly.

“Theoretical studies have uncovered that this pseudocapacitive behavior originates from the unique sites and energetics of lithium absorption and diffusion in TiO2-B structure,” the authors write in their paper, titled “Mesoporous TiO2-B Microspheres with Superior Rate Performance for Lithium Ion Batteries.”

Paranthaman noted that the microsphere shape of the material allows for traditional electrode fabrication and creates compact electrode layers. He also observed, however, that the production process of this material is complex and involves many steps, so more research remains to determine whether it is scalable.

Other authors of the paper are Zhonghe Bi, Xiao-Guang Sun, Raymond Unocic and Sheng Dai. The research was supported by DOE’s Office of Science, ORNL’s Laboratory Directed Research and Development program, and ORNL’s SHaRE User Facility, which is sponsored by Basic Energy Sciences.

Source

Google’s Electricity consumption

Internet search giant Google says that it consumed about 2.26 billion kilowatt hours of electricity last year, equal to the energy used in 200,000 homes. But while that represents an enormous amount of energy, Google says the services supported by its expanding data centers reduce energy use globally and allow users to improve their own energy efficiency. In its official blog, the company said the typical user of Google’s products — including search, Gmail, and YouTube — uses about 180 watt-hours monthly accessing those services, or less than “a light left on for three hours.” It’s the first time Google has shared information on its energy use and greenhouse gas emissions, an attempt to be more transparent as it expands its data center operations worldwide — including a new center in Finland — and promotes its cloud-based data services. The company also disclosed that it emitted about 1.46 million metric tons of carbon dioxide in 2010, but said that about one-quarter of its electricity came from renewable energy sources. The company also buys carbon offsets for its emissions.

A new technique to store solar energy

Solar thermal systems use mirrors to focus sunlight, generating temperatures high enough to produce steam to drive a turbine. One of the advantages of the solar thermal approach, versus conventional photovoltaics that convert sunlight directly into electricity, is that heat can be stored cheaply and used when needed to generate electricity. In all solar thermal plants, some heat is stored in the fluids circulating through the system. This evens out any short fluctuations in sunlight and lets the plant generate electricity for some time after the sun goes down. But adding storage systems would let the plant ride out longer periods of cloud cover and generate power well into, or even throughout, the night. Such long-term storage could be needed if solar is to provide a large share of the total power supply.

BrightSource Energy has become the latest solar thermal power company to develop a system for generating power when the sun isn’t shining. The company says the technology can lower the cost of solar power and make it more reliable, helping it compete with conventional sources of electricity.

BrightSource is using a variation on an approach to storage that’s a decade old: heating up a molten salt—typically, a combination of sodium and potassium nitride—and then storing it in a tank. To generate electricity, the molten salt is pumped through a heat exchanger to generate steam. BrightSource CEO John Woolard says one big factor in making this technology economically attractive is the use of power towers—in which mirrors focus sunlight on a central tower—that generate higher temperatures than other solar thermal designs. That higher temperature makes it possible to store more energy using a smaller amount of molten salt. “It’s a much more efficient system and much more cost effective, overall”

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Cheaper, better solar cell Is full of holes

A new low-cost etching technique developed at the U.S. Department of Energy’s National Renewable Energy Laboratory can put a trillion holes in a silicon wafer the size of a compact disc.
As the tiny holes deepen, they make the silvery-gray silicon appear darker and darker until it becomes almost pure black and able to absorb nearly all colors of light the sun throws at it.
At room temperature, the black silicon wafer can be made in about three minutes. At 100 degrees F, it can be made in less than a minute.
The breakthrough by NREL scientists likely will lead to lower-cost solar cells that are nonetheless more efficient than the ones used on rooftops and in solar arrays today.
R&D Magazine recently awarded the NREL team one of its R&D 100 awards for Black Silicon Nanocatalytic Wet-Chemical Etch. Called “the Oscars of Invention,” the R&D 100 awards recognize the most significant scientific breakthroughs of the year.
Howard Branz, the principal investigator for the project, said his team got interested in late 2006 after he heard a talk by a scientist from the Technical University of Munich. The scientist described how his team had created black silicon by laying down a thin gold layer using a vacuum deposition technique. Quickly, NREL senior scientist Qi Wang and senior engineer Scott Ward gave it a try.
“We always ride on the shoulders of others,” Branz said. “We started by replicating the Munich experiment.”

Packets of Light, Golden Holes
Think of light as coming in little packets. Each packet is a photon, which potentially can be changed into an electron for solar energy. If the photon bounces off the surface of a solar cell, that’s energy lost. Some of the light normally bounces off when it hits an object, but a ‘black silicon’ wafer will absorb all the light that hits it.
The human eye perceives the wafer as black because almost no sunlight reflects back to the retina. And that is because the trillion holes in the wafer’s surface do a much better job of absorbing the wavelengths of light than a solid surface does.
It’s roughly the same reason that ceiling tiles with holes in them absorb sound better than ceiling tiles without holes. Scientists by the late 19th century had already done experiments to show that what works for absorbing sound also works for absorbing light.
The team from Munich used evaporation techniques that require expensive vacuum pumps to lay down a very thin layer of gold, perhaps 10 atoms thick, Branz said. When a mixture of hydrogen peroxide and hydrofluoric acid was poured on the thin gold layer, nanoparticles of gold bored into the smooth surface of the wafer, making billions of holes.
The NREL team knew right away that the vacuum pumps and evaporative equipment needed to deposit the gold were too costly to become commercially viable.