Smart Economy

In Solar Cells, Tweaking the Tiniest of Parts -Quantum dots Yields Big Jump in Efficiency

Company led by university researchers employs charged quantum dots to increase the efficiency of solar cell technology

-- Researchers from the University at Buffalo, Army Research Laboratory and Air Force Office of Scientific Research have developed a new, nanomaterials-based technology that has the potential to increase the efficiency of photovoltaic cells up to 45 percent.

-- Specifically, the researchers have shown that embedding charged quantum dots into solar cells can improve electrical output by enabling the cells to harvest infrared light, and by increasing the lifetime of photoelectrons. The technology can be applied to many different photovoltaic structures.

-- A new company the researchers founded, OPtoElectronic Nanodevices LLC. (OPEN LLC), is commercializing this technology.

BUFFALO, N.Y. -- By tweaking the smallest of parts, a trio of University at Buffalo engineers is hoping to dramatically increase the amount of sunlight that solar cells convert into electricity.

With military colleagues, the UB researchers have shown that embedding charged quantum dots into photovoltaic cells can improve electrical output by enabling the cells to harvest infrared light, and by increasing the lifetime of photoelectrons.

The research appeared online last May in the journal Nano Letters. The research team included Vladimir Mitin, Andrei Sergeev and Nizami Vagidov, faculty members in UB's electrical engineering department; Kitt Reinhardt of the Air Force Office of Scientific Research; and John Little and advanced nanofabrication expert Kimberly Sablon of the U.S. Army Research Laboratory.

Mitin, Sergeev and Vagidov have founded a company, OPtoElectronic Nanodevices LLC. (OPEN LLC.), to bring the innovation to the market.

The idea of embedding quantum dots into solar panels is not new: According to Mitin, scientists had proposed about a decade ago that this technique could improve efficiency by allowing panels to harvest invisible, infrared light in addition to visible light. However, intensive efforts in this direction have previously met with limited success.

The UB researchers and their colleagues have not only successfully used embedded quantum dots to harvest infrared light; they have taken the technology a step further, employing selective doping so that quantum dots within the solar cell have a significant built-in charge.

This built-in charge is beneficial because it repels electrons, forcing them to travel around the quantum dots. Otherwise, the quantum dots create a channel of recombination for electrons, in essence "capturing" moving electrons and preventing them from contributing to electric current.

The technology has the potential to increase the efficiency of solar cells up to 45 percent, said Mitin, a SUNY Distinguished Professor. Through UB's Office of Science, Technology Transfer and Economic Outreach (STOR), he and his colleagues have filed provisional patent applications to protect their technology.

"Clean technology will really benefit the region, the state, the country," Mitin said. "With high-efficiency solar cells, consumers can save money and providers can have a smaller solar field that produces more energy."

Mitin and his colleagues have already invested significant amounts of time in developing the quantum dots with a built-in-charge, dubbed "Q-BICs." To further enhance the technology and bring it to the market, OPEN LLC is now seeking funding from private investors and federal programs.

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.

Related Stories:

Vladimir Mitin Among Three UB Faculty Members Named SUNY Distinguished Professors: http://www.buffalo.edu/news/9243

Novel alloy could produce hydrogen fuel from sunlight

Using advanced theoretical computations, a team of Kentucky scientists has derived a means to "tweak" an inexpensive semiconductor to function as photoelectrochemical catalyst.

Scientists from the University of Kentucky and the University of Louisville have determined that an inexpensive semiconductor material can be "tweaked" to generate hydrogen from water using sunlight.

The research, funded by the U.S. Department of Energy, was led by Professors Madhu Menon and R. Michael Sheetz at the UK Center for Computational Sciences, and Professor Mahendra Sunkara and graduate student Chandrashekhar Pendyala at the UofL Conn Center for Renewable Energy Research. Their findings were published Aug. 1 in the Physical Review Journal (Phys Rev B 84, 075304).

The researchers say their findings are a triumph for computational sciences, one that could potentially have profound implications for the future of solar energy.

Using state-of-the-art theoretical computations, the UK-UofL team demonstrated that an alloy formed by a 2 percent substitution of antimony (Sb) in gallium nitride (GaN) has the right electrical properties to enable solar light energy to split water molecules into hydrogen and oxygen, a process known as photoelectrochemical (PEC) water splitting. When the alloy is immersed in water and exposed to sunlight, the chemical bond between the hydrogen and oxygen molecules in water is broken. The hydrogen can then be collected.

"Previous research on PEC has focused on complex materials," Menon said. "We decided to go against the conventional wisdom and start with some easy-to-produce materials, even if they lacked the right arrangement of electrons to meet PEC criteria. Our goal was to see if a minimal 'tweaking' of the electronic arrangement in these materials would accomplish the desired results."

Gallium nitride is a semiconductor that has been in widespread use to make bright-light LEDs since the 1990s. Antimony is a metalloid element that has been in increased demand in recent years for applications in microelectronics. The GaN-Sb alloy is the first simple, easy-to-produce material to be considered a candidate for PEC water splitting. The alloy functions as a catalyst in the PEC reaction, meaning that it is not consumed and may be reused indefinitely. UofL and UK researchers are currently working toward producing the alloy and testing its ability to convert solar energy to hydrogen.

Hydrogen has long been touted as a likely key component in the transition to cleaner energy sources. It can be used in fuel cells to generate electricity, burned to produce heat, and utilized in internal-combustion engines to power vehicles. When combusted, hydrogen combines with oxygen to form water vapor as its only waste product. Hydrogen also has wide-ranging applications in science and industry.

Because pure hydrogen gas is not found in free abundance on Earth, it must be manufactured by unlocking it from other compounds. Thus, hydrogen is not considered an energy source, but rather an "energy carrier." Currently, it takes a large amount of electricity to generate hydrogen by water splitting. As a consequence, most of the hydrogen manufactured today is derived from non-renewable sources such as coal and natural gas.

Sunkara says the GaN-Sb alloy has the potential to convert solar energy into an economical, carbon-free source for hydrogen.

"Hydrogen production now involves a large amount of CO2 emissions," Sunkara said. "Once this alloy material is widely available, it could conceivably be used to make zero-emissions fuel for powering homes and cars and to heat homes."

Menon says the research should attract the interest of other scientists across a variety of disciplines.

"Photocatalysis is currently one of the hottest topics in science," Menon said. "We expect the present work to have a wide appeal in the community spanning chemistry, physics and engineering."

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For more information, please contact Keith Hautala at the University of Kentucky at (859) 323-2396 or keith.hautala@uky.edu. At the University of Louisville, please contact Judy Hughes at (502) 852-6171 or judy.hughes@louisville.edu.

Graphite + Water = your next battery

A combination of two ordinary materials – graphite and water – could produce energy storage systems that perform on par with lithium ion batteries, but recharge in a matter of seconds and have an almost indefinite lifespan.

Dr. Dan Li, of the Monash University Department of Materials Engineering, and his research team have been working with a material called graphene, which could form the basis of the next generation of ultrafast energy storage systems.

“Once we can properly manipulate this material, your iPhone, for example, could charge in a few seconds, or possibly faster.” said Dr. Li.

Graphene is the result of breaking down graphite, a cheap, readily available material commonly used in pencils, into layers one atom thick. In this form, it has remarkable properties.

Graphene is strong, chemically stable, an excellent conductor of electricity and, importantly, has an extremely high surface area.

Dr. Li said these qualities make graphene highly suitable for energy storage applications.

“The reason graphene isn’t being used everywhere is that these very thin sheets, when stacked into a usable macrostructure, immediately bond together, reforming graphite. When graphene restacks, most of the surface area is lost and it doesn’t behave like graphene anymore.”

Now, Dr. Li and his team have discovered the key to maintaining the remarkable properties of separate graphene sheets: water. Keeping graphene moist – in gel form – provides repulsive forces between the sheets and prevents re-stacking, making it ready for real-world application.

“The technique is very simple and can easily be scaled up. When we discovered it, we thought it was unbelievable. We’re taking two basic, inexpensive materials – water and graphite – and making this new nanomaterial with amazing properties,” said Dr. Li.

When used in energy devices, graphene gel significantly outperforms current carbon-based technology, both in terms of the amount of charge stored and how fast the charges can be delivered.

Dr. Li said the benefits of developing this new nanotechnology extend beyond consumer electronics.

“High-speed, reliable and cost-effective energy storage systems are critical for the future viability of electricity from renewable resources. These systems are also the key to large-scale adoption of electrical vehicles.

“Graphene gel is also showing promise for use in water purification membranes, biomedical devices and sensors.”

Provided by Monash University

Conducting energy on a nano scale improves solar panels

'Doped' nanocrystals are the future of technology, says Tel Aviv University researcher

Tel Aviv — Modern electronics as we know them, from televisions to computers, depend on conducting materials that can control electronic properties. As technology shrinks down to pocket sized communications devices and microchips that can fit on the head of a pin, nano-sized conducting materials are in big demand.

Now, Prof. Eran Rabani of Tel Aviv University's School of Chemistry at the Raymond and Beverly Sackler Faculty of Exact Sciences, in collaboration with Profs. Uri Banin and Oded Millo at the Hebrew University, has been able to demonstrate how semiconductor nanocrystals can be doped in order to change their electronic properties and be used as conductors. This opens a world of possibilities, says Prof. Rabani, in terms of applications of small electronic and electro-optical devices, such as diodes and photodiodes, electric components used in cellular phones, digital cameras, and solar panels.

Solar panels are typically made from a pn junction. When they absorb light, the junction separates the negatively charged electrons and the positively charged holes, producing an electrical current, explains Prof. Rabani. "With this new method for doping nanocrystals to make them both p and n type, we hope that solar panels can be made not only more efficient, but cheaper as well," he says. This research has been published recently in the journal Science.

Crystal-clear progress

According to Prof. Rabani, the quest to electrically dope nanocrystals has been an uphill battle. The crystals themselves have the capacity to self-purify, which means that they cleanse themselves of dopants. Also, he adds, some of the synthetic methods for doping were problematic on the nano-scale – the crystals were unable to withstand doping techniques applicable to bulk semiconductors.

The key, explains Prof. Rabani, was to find a method for doping the nanocrystals without "bleaching" their optical properties – and therefore nullifying their absorption capabilities. If you can dope nanocrystals in this way, he says, it opens the door to many practical applications based on nanocrystalline materials. "Whatever you can do with nanocrystals, you can do with doped nanocrystals – and more by controlling their electronic properties."

These challenges were circumvented with the use of room temperature diffusion controlled reactions. The crystals were bathed in a solution that included the dopants, where slow diffusion allowed for impurities to find their way into the nanocrystal.

The researchers used a scanning tunneling microscope (STM), a device that images surfaces at an atomic level, in order to determine the success of their doping procedure. These measurements indicated how the Fermi energy of the nanocrystals changed upon doping, a key feature in controlling the electronic properties of electronic devices. The results, notes Prof. Rabani, indicate that the nanocrystals have been doped with both n-type dopants, indicating the presence of excess electrons in the nanocrystals, and p-type, which contribute positively charged holes to the semiconductors. This will allow for their use in electronics that require a pn junction, such as solar panels, light emitting diodes, and more.

Broadening the nanocrystal spectrum

Not only did Prof. Rabani and his fellow researchers succeed in doping nanocrystals without bleaching their optical properties, but they also were able to control the optical properties, namely, the color range that the nanocrystals produce. Once doped, the nanocrystal particles could change in color, becoming more red or blue. Prof. Rabani and his colleagues were able to develop a theory to explain these observations.

Prof. Rabani says that this technology can go a long way. Doping semiconductors, he explains, has been essential for the development of technology. "Parallel to this, we also know we want to make electrical components very small. A big portion of future electronics or optics is going to be based on doping nanoparticles."

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American Friends of Tel Aviv University (www.aftau.org) supports Israel's leading, most comprehensive and most sought-after center of higher learning. Independently ranked 94th among the world's top universities for the impact of its research, TAU's innovations and discoveries are cited more often by the global scientific community than all but 10 other universities.

Internationally recognized for the scope and groundbreaking nature of its research and scholarship, Tel Aviv University consistently produces work with profound implications for the future.

Contact: George Hunka; ghunka@aftau.org; 212-742-9070; American Friends of Tel Aviv University

When will the Recession End? Part 239 Russia hits the wall in 2012 with Peak Oil/Gas, production drops after that

'The IEA forecasts that Russia's oil and condensate production is set to peak at 10.57 million bpd next year and then start declining' - at least partly due to high taxes, which in Russia take 78% of oil profits and 56% of gas profits.  Rosneft, Transneft, Surgutneftegaz and TGK-2 are all complaining to the government about a new bill containing measures that would grant minor shareholders more rights to company information ('All four companies are in conflicts with their minority shareholders', and Alexei Navalny is on the boards of Rosneft and Transneft).  [..].  Negotiations between Gazprom and E.ON on the commercial terms of their supply contracts are expected to continue until the end of the year, and could be transferred to an international arbitration court if they do not reach a conclusion.  The German chair of the EU Committee on the Environment wants to restrict the expansion of shale gas exploration in Europe over concerns about damage caused by fracking; Poland, in its upcoming role as EU president, will obstruct any attempts to regulate shale gas development.  China is holding its first licensing round for shale gas production.

from http://www.robertamsterdam.com/2011/07/energy_blast_-_july_6_2011.htm

 

Nanotechnology pushes battery life to eternity

Let your fingers do the charging A simple tap from your finger may be enough to charge your portable device, thanks to a  discovery by Australian National University researchers, using piezoelectric thin films.

The technology could allow for an iPad that recharges every time you press the screen, or a pacemaker powered by your own blood pressure.

Ref.: Madhu Bhaskaran, et al., Energy Materials: Nanoscale Characterization of Energy Generation from Piezoelectric Thin Films, Advanced Functional Materials, first published online: June 16, 2011, [DOI: 10.1002/adfm.20119004112/2011]

When will the Recession End? Part 223 Investors flee Russia despite oil revenue boom

The Financial Express. Dhaka: Jun 6, 2011.

MOSCOW, June 6 -- The billions of investor dollars fleeing Russia each week offer a stark counterpoint to Moscow's aspirations of soon becoming a global financial centre linking London with Hong Kong.

The world's leading oil exporter finds itself in the odd position of being flooded with petrodollars and seeing remarkable ruble strength-two prime conditions for local investment-while also bleeding capital at record rates.

The outflow of investor money abroad reached $30 billion by the end of April to nearly match the 2010 total. The May figure is expected to approach $8 billion and a slowdown is not anticipated for some months.

"It is difficult to give a simple and clear explanation as to why this is happening," Russian Central Bank chairman Sergei Ignatyev acknowledged.

"But the main reason is a rather unfavourable Russian investment climate."

Investors may argue that Ignatyev was gilding over a graft problem so blatant it saw Russia rank 154 out of 178 countries on last year's Transparency International Corruption Index.

The World Bank says Russia is the world's second-most difficult country in which to get a construction permit while local entrepreneurs often treat law enforcement authorities and the courts as a part of the same system.

"When you talk to investors, that really is one of their biggest points," said chief UralSib strategist Chris Weafer.

"They say look, the Russians are taking their money out of the country. Why should I come to Russia when the Russians are coming out?"

The real mystery is why this scramble to get out of Russia is getting more frantic at precisely the moment when the government is pursuing one of its most market-friendly programmes in years.

President Dmitry Medvedev is now courting Westerners with a $10 billion joint investment fund and hoping to put meat on the bones of his modernisation effort by dislodging state appointees from their seats on company boards.

Both measures fold into a broader $60 billion privatisation programme aimed at giving Moscow its coveted status of being a centre of global finance.

Uncertainty over whether Medvedev or his mentor and predecessor, Prime Minister Vladimir Putin will head the Kremlin next year, may be one of the factors behind investors' latest spell of jitters.

But analysts note that Putin's return has been rumoured since the final day of his second term in 2008 and can hardly explain why the outflow of currency has nearly tripled in recent months.

There are other more technical factors also at play. Russia's inflation expectations are rising and squeezing holders of local currency bonds. But the help these investors have been getting from a stronger ruble will expire once oil prices climb off their recent highs.

"I think most of the capital flight is associated with this," said Renaissance Capital economist Ovanes Oganisyan in reference to ruble bond sales.

Other factors may be the record dividends-sometimes as much as 90 percent of profits-paid by such local giants as the British joint venture TNK- BP.

But analysts say that behind all these immediate variables is buried a more fundamental investor doubt about Russia as a future growth market.

The government is gradually raising tax rates on energy producers to cover the tens of billions of dollars in outlays it has promised ahead of the approaching elections.

Manufacturing growth slowed to just above stagnation level last month while Gross Domestic Product growth has barely reached half the rate seen before the global slump in 2008.

"People are starting to realise that the levels of growth we have seen in the past decade are not sustainable without major reforms and major investment," UralSib's Weafer said.

An Oliver Wyman financial service partner, who recently compared Moscow to other financial centres, showed the Russian capital ranking behind cities such as Manila and Jakarta.

The survey recommended "strengthening regulatory requirements and oversight, improving disclosure ... and modernising corporate governance standards," the agency's Robert Maciejko wrote in the Wall Street Journal.

"In the absence of efforts on the part of the Russian government to reduce the risks of investments in Russia, one can hardly expect private capital inflows into the country," the Gaidar Institute said in an annual report.

Analysts said the only silver lining was that capital flight was putting the breaks on runaway ruble appreciation.

"This is a comfortable situation for the government-they like the fact that something is keeping the ruble from gaining too much," said Oganisyan

Solar cells more efficient than photosynthesis -- for now

In a head-to-head battle of harvesting the sun's energy, solar cells beat plants, according to a new paper in Science. But scientists think they can even up the playing field, says researcher David Kramer at Michigan State University.

Plants are less efficient at capturing the energy in sunlight than solar cells mostly because they have too much evolutionary baggage. Plants have to power a living thing, whereas solar cells only have to send electricity down a wire. This is a big difference because if photosynthesis makes a mistake, it makes toxic byproducts that kill the organism. Photosynthesis has to be conservative to avoid killing the organisms it powers.

"This is critical since it's the process that powers all of life in our ecosystem," said Kramer, a Hannah Distinguished Professor of Photosynthesis and Bioenergetics. "The efficiency of photosynthesis, and our ability to improve it, is critical to whether the entire biofuels industry is viable."

While photosynthesis is less efficient on a pure energy basis, it has the advantage of producing high-energy liquid fuels. (It also makes all of our food, and is thus essential for life). The paper summarizes several specific approaches to improving photosynthesis, some likely achievable in the short term, some more involved.

In truth, the competition really isn't fair unless the term "efficiency" is first defined. At a bare minimum it isn't fair to compare plants that package the sun's energy in handy little stored-fuel vessels (carbon-based molecules) to solar cells that just take the first step of converting the sun's energy to jazzed-up electrons. Fairer would be to compare plants to solar cell arrays that also store energy in chemical bonds.

The point of the comparison is not to make us throw plants on the compost pile, the researchers said. For one, efficiency is only one consideration among many in the choice among energy technologies. More important are life-cycle costs, the capital cost and valuation of the environmental impact of a product from its creation to its destruction.

Still the comparison is useful because it's leading the exploration of why plants are so inefficient and what can be done to improve their efficiency. Genetic engineering and the more aggressive techniques of synthetic biology – the marriage of biology and engineering to design and construct systems and metabolic pathways not found in nature – could speed things up considerably.

The experts suggested, for example, replacing one of the two photosystems in plants that handle the light-dependent reactions with a photosystem from a species of cyanobacteria. The photosystems in most plants compete for the same piece of the solar spectrum, cutting the energy efficiency nearly in half. But some cyanobacteria absorb light from an entirely different part of the spectrum. Basically, it would be the biological equivalent of a tandem solar cell, which is very efficient.

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Kramer, who works in the MSU-Department of Energy Plant Research Laboratory, was part of a team of researchers led by Washington University in St. Louis.

Michigan State University has been working to advance the common good in uncommon ways for more than 150 years. One of the top research universities in the world, MSU focuses its vast resources on creating solutions to some of the world's most pressing challenges, while providing life-changing opportunities to a diverse and inclusive academic community through more than 200 programs of study in 17 degree-granting colleges

Walter Derzko

Smart Economy

Toronto

energy storage> Enhanced electrical energy storage from a new porus three-dimensional carbon that can be used as a greatly enhanced supercapacitor

Enhanced electrical energy storage may result from professor's research

Researchers at The University of Texas at Austin's Cockrell School of Engineering have created a new porous, three-dimensional carbon that can be used as a greatly enhanced supercapacitor, holding promise for energy storage in everything from energy grids and electric cars to consumer electronics.

The findings of the group, led by materials science and mechanical engineering Professor Rodney S. Ruoff, will be published May 12 by Science magazine in its online publication ScienceXpress.

The significance of the discovery by Ruoff's team, which included postdoctoral fellow Dr. Yanwu Zhu and graduate students Shanthi Murali and Meryl Stoller, is the potential it offers for enabling supercapacitors to deliver significantly more charge, opening the doors to many potential unprecedented uses for this type of electrical energy storage device.

Supercapacitors are known as the "sprinters" among electrical energy storage devices, able to deliver energy much faster and more efficiently than batteries, but usually holding much less electrical charge, while batteries are like marathon runners, delivering energy slowly, but steadily.

"We synthesized a new sponge-like carbon that has a surface area of up to 3,100 square meters per gram (two grams has a surface area roughly equivalent to that of a football field). It also has much higher electrical conductivity and, when further optimized, will be superb for thermal management as well," Ruoff said. "The processes used to make this porous carbon are readily scalable to industrial levels.

"After we realized that we had a new carbon with a highly novel structure that showed superb performance as an electrode, we knew that this direction of research — to create carbon materials that consist of a continuous three-dimensional porous network with single-atom-thick walls — was likely to yield the optimum electrode material for supercapacitors."

The University of Texas at Austin's Office of Technology Commercialization has filed a patent with the U.S. Patent Office on behalf of the inventors.

"Rod and his team define what we mean when we talk about innovation to address grand challenges," said Gregory L. Fenves, dean of the Cockrell School of Engineering. "This team of students, researchers and faculty has discovered a way to improve the efficiency of supercapacitor energy storage."

Ruoff's research team of about 40 people collaborated with faculty and students from The University of Texas at Dallas, scientific staff at Brookhaven National Laboratory in New York and staff members at QuantaChrome Instruments in Florida.

The process used by the university team to synthesize the carbon material involved using microwaves to exfoliate graphite oxide, followed by treatment with potassium hydroxide, which created a carbon full of tiny holes — essentially a sponge that, when combined with an electrolyte, can store a giant electrical charge. The team at Brookhaven then analyzed the atomic structure of the carbon material at the nanoscale using very high resolution electron microscopes. Their observations confirmed Ruoff's hypothesis that the carbon was a new three-dimensional material having highly curved, single-atom-thick walls that form tiny pores.

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Full text of article published in ScienceXpress.

When will the Recession End? Part 217 Quality of Russia's crude reserves deteriorating admits Russian ministry

Text of report by corporate-owned Russian news agency Interfax

Moscow, 25 April: The [Russian] Ministry of Natural Resources [and Ecology] reports a deterioration in the quality of Russian crude oil reserves.

 

 "The quality of oil reserves in Russia is gradually deteriorating. The main cause of this is the recovery of the highest-quality oil, which results in an outrunning growth of heavy crude reserves: in 2009, the proved reserves [of heavy crude] grew by 2.9 per cent across Russia, whereas those of light oil shrunk by 2.8 per cent," reads the ministry's report "On the state and use of mineral resources in Russia in 2009".

The non-licensed stock of prospects mainly lists small fields and mothballed facilities, as well as undeveloped horizons of producing fields whose reserves are negligible or difficult to recover.

The ministry also notes that license holders in 2009 sharply (by over 40 per cent) reduced spending on mineral replacement due to the financial and economic crisis. "Suffice it to say that of the 1,927 licenses whose terms and conditions envisaged prospecting for solid minerals, work was not conducted on 679 licenses, meaning that 35 per cent of all deposits were not prospected," the report states. According to preliminary data, a similar situation is expected to be reported for 2010. The financial and economic stabilization in the country and the world allows for hope that the situation will start improving from 2011, the ministry notes.

Prospective oil resources [as received] in 2009 were estimated at 12.2bn tonnes, and probable resources - at 44.26bn tonnes. Proved reserves grew by 139.2bn tonnes in 2009 as compared to 2008, and inferred reserves grew by 692m tonnes.

The reserves of non-associated gas in Russia stood at nearly 68,000bn cubic metres in 2009, the share of proved reserves (Categories A+B+C1) in them exceeding 70 per cent. The proved reserves of gas increased by 60.5bn cubic metres, or by 0.1 per cent, in 2009. The potential resources of natural gas are estimated at 162,800bn cubic metres. The most proven part of these - Category C3 inferred resources - amounts to less than 20 per cent.

The annual report is based on statistics from industry and state sources, on documents of the Ministry of Natural Resources, Rosnedra [Russian Federal Agency for Management of Subsurface Resources], industry institutes and oil and gas companies.

Credit: Interfax news agency, Moscow, in Russian 1549 25 Apr 11