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Algae deliver hydrogen at a 5 times higher efficiency

Algae deliver hydrogen at a 5 times higher efficiency | Amazing Science | Scoop.it
Hydrogen as a regenerative fuel produced in gigantic water tanks full of algae, which need nothing more than sunlight to produce the promising green energy carrier: a great idea in theory, but one that fails due to the vast amount of space required for the production process. Scientists from the Max Planck Institutes for Chemical Energy Conversion and Coal Research) in Mülheim an der Ruhr, and from the research group Photobiotechnology at Ruhr-Universität Bochum (RUB) have now discovered a way of increasing the efficiency of hydrogen production in microalgae by a factor of five. If the algae can generate the fuel more efficiently, it can be produced in a smaller area and in quantities suitable for practical use. This approach also dispenses with the need for rare and expensive precious metals, which are used to split the energy-rich gas is technically from water.

Living organisms need electrons in many places, as they use them to form chemical compounds. Algae and other organisms which carry out photosynthesis release electrons from water with the help of sunlight and then distribute them in the cell. The ferrous protein PETF is responsible for this: It transports the electrons in particular to ferredoxin-NADP+ oxidoreductase (FNR), so that NADPH is formed and carbohydrates are finally synthesised from carbon dioxide. The production of hydrogen through hydrogenases is among the many other processes, for which PETF provides the necessary electrons.

Hydrogenases are very efficient enzymes that contain a unique active centre comprising six iron atoms, where the electrons supplied by PETF are bound to protons. Molecular hydrogen is produced in this way.

With the help of nuclear magnetic resonance spectroscopy, on which magnetic resonance imaging in medicine is also based, the scientists working with Sigrun Rumpel, a post doc at the Max Planck Institute for Chemical Energy Conversion in Mülheim, investigated the components of PETF – or more precisely amino acids – that interact with the hydrogenase and those that interact with FNR. It emerged that only two amino acids of PETF are important for binding FNR. When the researchers modified these two amino acids and the enzyme FNR, PETF was no longer able to bind FNR as efficiently. Thus, the enzyme transferred less electrons to FNR and more to the hydrogenase. In this way, the scientists increased the hydrogen production by a factor of five.


“For a technically feasible hydrogen production with the help of algae, its efficiency must be increased by a factor of 10 to 100 compared to the natural process,” says Sigrun Rumpel. “Through the targeted modification of PETF and FNR we have taken a step towards achieving this objective.” Up to now, the production of hydrogen from renewable energy carriers involved the electrolytic splitting of water. Expensive and rare precious metals like platinum are currently required for this purpose. Sigrun Rumpel and other researchers are therefore working on finding a way of enabling algae to efficiently produce the fuel. Microalgae produce the gas naturally, but in very small volumes. Thus, if cars were to be powered one day using hydrogen rather than petrol or diesel, to come anywhere near covering Germany’s fuel requirements, gigantic areas with tanks full of algal cultures would have to be set up.


“These results represent a path to the economically-viable regenerative production of fuels with the help of microalgae,” says Sigrun Rumpel. The change of electron transfer pathways could further improve hydrogen production in future. The researchers therefore now want to combine different modifications with each other.

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Hybrid materials could smash the solar efficiency ceiling by extracting electrons from dark triplet excitons

Hybrid materials could smash the solar efficiency ceiling by extracting electrons from dark triplet excitons | Amazing Science | Scoop.it
Researchers have developed a new method for harvesting the energy carried by particles known as ‘dark’ spin-triplet excitons with close to 100% efficiency, clearing the way for hybrid solar cells which could far surpass current efficiency limits.


The team, from the University of Cambridge, have successfully harvested the energy of triplet excitons, an excited electron state whose energy in harvested in solar cells, and transferred it from organic to inorganic semiconductors. To date, this type of energy transfer had only been shown for spin-singlet excitons. The results are published in the journal Nature Materials.


In the natural world, excitons are a key part of photosynthesis: light photons are absorbed by pigments and generate excitons, which then carry the associated energy throughout the plant. The same process is at work in a solar cell.


In conventional semiconductors such as silicon, when one photon is absorbed it leads to the formation of one free electron that can be extracted as current. However, in pentacene, a type of organic semiconductor, the absorption of a photon leads to the formation of two electrons. But these electrons are not free and they are difficult to pin down, as they are bound up within ‘dark’ triplet exciton states.

Excitons come in two ‘flavours’: spin-singlet and spin-triplet. Spin-singlet excitons are ‘bright’ and their energy is relatively straightforward to harvest in solar cells. Triplet-spin excitons, in contrast, are ‘dark’, and the way in which the electrons spin makes it difficult to harvest the energy they carry.


“The key to making a better solar cell is to be able to extract the electrons from these dark triplet excitons,” said Maxim Tabachnyk, a Gates Cambridge Scholar at the University’s Cavendish Laboratory, and the paper’s lead author. “If we can combine materials like pentacene with conventional semiconductors like silicon, it would allow us to break through the fundamental ceiling on the efficiency of solar cells.”

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Boundary Dam Power Plant: Let the Clean Coal Era Begin

Boundary Dam Power Plant: Let the Clean Coal Era Begin | Amazing Science | Scoop.it

On October 2, the Boundary Dam power plant in Saskatchewan became the first full-sized coal-fired boiler tocapture the copious carbon dioxide that had previously billowed from its smokestack, preventing the greenhouse gas from entering the atmosphere. On the resulting invisible stream of hot smoke ride the hopes of combating climate change while still burning fossil fuels.


Such CO2 capture and storage (CCS) “is the only known technology that will enable us to continue to use fossil fuels and also de-carbonize the energy sector,” said Maria van der Hoeven, executive director of the International Energy Agency, in a statement on the opening of the Boundary Dam plant. “As fossil fuel consumption is expected to continue for decades, deployment of CCS is essential.”


That deployment is beginning to happen in fits and starts, and with lots of government support. For example, the Mississippi-based Kemper Facility, a power plant that will turn brown coal to gas and strip off the CO2 in the process, is due online in 2015—a year behind schedule and at a of cost $5.6 billion, more than twice its initial estimate. And the U.S. Environmental Protection Agency has approved plans by Archer Daniels Midland (ADM) to inject CO2 captured at its ethanol fermentation facility in Illinois into a saltwater aquifer deep underground.


The Boundary Dam also burns brown coal, the most polluting form of the most polluting fossil fuel. Saskatchewan has an estimated 300-year supply of the dirty fuel to burn at present rates of consumption. The unit uses amines—a nitrogen-based molecule that can bond with CO2—to capture a projected 1 million metric tons of the leading greenhouse gas each year. The amine captures the CO2 and then when further heated releases it again, meaning it takes away some of the plant’s power to take away the plant’s CO2. The captured CO2, compressed and liquefied, will then travel 66 kilometers via pipeline to the nearby Weyburn oil fields and join the CO2 captured at a plant that turns brown coal into a gas in North Dakota. At Weyburn, the CO2 will be used to scour more oil out of the ground. Of course, the eventual burning of this oil will also release CO2 into the atmosphere.

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World's first "solar battery" runs on light and air and stores its own power

World's first "solar battery" runs on light and air and stores its own power | Amazing Science | Scoop.it

Researchers at The Ohio State University have invented a solar battery -- a combination solar cell and battery -- which recharges itself using air and light. The design required a solar panel which captured light, but admitted air to the battery. Here, scanning electron microscope images show the solution: nanometer-sized rods of titanium dioxide (larger image) which cover the surface of a piece of titanium gauze (inset). The holes in the gauze are approximately 200 micrometers across, allowing air to enter the battery while the rods gather light. Image courtesy of Yiying Wu, The Ohio State University.


When the battery discharges, it chemically consumes oxygen from the air to re-form the lithium peroxide. An iodide additive in the electrolyte acts as a “shuttle” that carries electrons, and transports them between the battery electrode and the mesh solar panel. The use of the additive represents a distinct approach on improving the battery performance and efficiency, the team said.


The mesh belongs to a class of devices called dye-sensitized solar cells, because the researchers used a red dye to tune the wavelength of light it captures.


In tests, they charged and discharged the battery repeatedly, while doctoral student Lu Ma used X-ray photoelectron spectroscopy to analyze how well the electrode materials survived—an indication of battery life.


First they used a ruthenium compound as the red dye, but since the dye was consumed in the light capture, the battery ran out of dye after eight hours of charging and discharging—too short a lifetime. So they turned to a dark red semiconductor that wouldn’t be consumed: hematite, or iron oxide—more commonly called rust.


Coating the mesh with rust enabled the battery to charge from sunlight while retaining its red color. Based on early tests, Wu and his team think that the solar battery’s lifetime will be comparable to rechargeable batteries already on the market.


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Solar power with a view: Transparent luminescent solar concentrators

Solar power with a view: Transparent luminescent solar concentrators | Amazing Science | Scoop.it
Researchers have developed a new type of solar concentrator that when placed over a window creates solar energy while allowing people to actually see through the window. It is called a transparent luminescent solar concentrator and can be used on buildings, cell phones and any other device that has a flat, clear surface.


Research in the production of energy from solar cells placed around luminescent plastic-like materials is not new. These past efforts, however, have yielded poor results -- the energy production was inefficient and the materials were highly colored.


"No one wants to sit behind colored glass," said Lunt, an assistant professor of chemical engineering and materials science. "It makes for a very colorful environment, like working in a disco. We take an approach where we actually make the luminescent active layer itself transparent."


The solar harvesting system uses small organic molecules developed by Lunt and his team to absorb specific nonvisible wavelengths of sunlight. "We can tune these materials to pick up just the ultraviolet and the near infrared wavelengths that then 'glow' at another wavelength in the infrared," he said.


The "glowing" infrared light is guided to the edge of the plastic where it is converted to electricity by thin strips of photovoltaic solar cells. "Because the materials do not absorb or emit light in the visible spectrum, they look exceptionally transparent to the human eye," Lunt said.

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Scientists develop pioneering new spray-on solar cells

Scientists develop pioneering new spray-on solar cells | Amazing Science | Scoop.it

A team of scientists at the University of Sheffield is the first to fabricate perovskite solar cells using a spray-painting process – a discovery that could help cut the cost of solar electricity.


Experts from the University’s Department of Physics and Astronomy and Department of Chemical and Biological Engineering have previously used the spray-painting method to produce solar cells using organic semiconductors - but using perovskite is a major step forward.


Efficient organometal halide perovskite based photovoltaics were first demonstrated in 2012. They are now a very promising new material for solar cells as they combine high efficiency with low material costs. The spray-painting process wastes very little of the perovskite material and can be scaled to high volume manufacturing – similar to applying paint to cars and graphic printing.


Lead researcher Professor David Lidzey said: “There is a lot of excitement around perovskite based photovoltaics. “Remarkably, this class of material offers the potential to combine the high performance of mature solar cell technologies with the low embedded energy costs of production of organic photovoltaics.”


While most solar cells are manufactured using energy intensive materials like silicon, perovskites, by comparison, requires much less energy to make. By spray-painting the perovskite layer in air the team hope the overall energy used to make a solar cell can be reduced further. Prof. Lidzey said: “The best certified efficiencies from organic solar cells are around 10 per cent.


“Perovskite cells now have efficiencies of up to 19 per cent. This is not so far behind that of silicon at 25 per cent - the material that dominates the world-wide solar market.” He added: “The perovskite devices we have created still use similar structures to organic cells. What we have done is replace the key light absorbing layer - the organic layer - with a spray-painted perovskite.


“Using a perovskite absorber instead of an organic absorber gives a significant boost in terms of efficiency.” The Sheffield team found that by spray-painting the perovskite they could make prototype solar cells with efficiency of up to 11 per cent.


Professor Lidzey said: “This study advances existing work where the perovskite layer has been deposited from solution using laboratory scale techniques. It’s a significant step towards efficient, low-cost solar cell devices made using high volume roll-to-roll processing methods.”


Solar power is becoming an increasingly important component of the world-wide renewables energy market and continues to grow at a remarkable rate despite the difficult economic environment.

Professor Lidzey said: “I believe that new thin-film photovoltaic technologies are going to have an important role to play in driving the uptake of solar-energy, and that perovskite based cells are emerging as likely thin-film candidates. “

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Nanostructured metal-oxide catalyst efficiently converts CO2 to methanol

Nanostructured metal-oxide catalyst efficiently converts CO2 to methanol | Amazing Science | Scoop.it

Scanning tunneling microscope image of a cerium-oxide and copper catalyst (CeOx-Cu) used in the transformation of carbon dioxide (CO2) and hydrogen (H2) gases.


Scientists at Brookhaven National Laboratory have discovered a new catalytic system for converting carbon dioxide (CO2) to methanol — a key commodity used to create a wide range of industrial chemicals and fuels. With significantly higher activity than other catalysts now in use, the new system could make it easier to get normally unreactive CO2 to participate in these reactions.


“Developing an effective catalyst for synthesizing methanol from CO2 could greatly expand the use of this abundant gas as an economical feedstock,” said Brookhaven chemist Jose Rodriguez, who led the research. “It’s even possible to imagine a future in which such catalysts help capture CO2 emitted from methanol-powered combustion engines and fuel cells, and recycling it to synthesize new fuel,” he said.

That future, of course, will be determined by a variety of factors, including economics.


The research team, which included scientists from Brookhaven, the University of Seville in Spain, and Central University of Venezuela, describes their results in the August 1, 2014, issue of the journal Science.


Because CO2 is normally such a reluctant participant in chemical reactions, interacting weakly with most catalysts, it’s also rather difficult to study. The new studies required the use of newly developed in-situ (or on-site, meaning under reaction conditions) imaging and chemical “fingerprinting” techniques.


These techniques allowed the scientists to peer into the dynamic evolution of a variety of catalysts as they operated in real time. The scientists also used computational modeling at the University of Seville and the Barcelona Supercomputing Center to provide a molecular description of the methanol synthesis mechanism.


The team was particularly interested in exploring a catalyst composed of copper and ceria (cerium-oxide) nanoparticles, sometimes also mixed with titania. The scientists’ previous studies with such metal-oxide nanoparticle catalysts have demonstrated their exceptional reactivity in a variety of reactions. In those studies, the interfaces of the two types of nanoparticles turned out to be critical to the reactivity of the catalysts, with highly reactive sites forming at regions where the two phases meet.


To explore the reactivity of such dual particle catalytic systems in converting CO2 to methanol, the scientists used spectroscopic techniques to investigate the interaction of CO2 with plain copper, plain cerium-oxide, and cerium-oxide/copper surfaces at a range of reaction temperatures and pressures. Chemical fingerprinting was combined with computational modeling to reveal the most probable progression of intermediates as the reaction from CO2 to methanol proceeded.


These studies revealed that the metal component of the catalysts alone could not carry out all the chemical steps necessary for the production of methanol. The most effective binding and activation of CO2 occurred at the interfaces between metal and oxide nanoparticles in the cerium-oxide/copper catalytic system.


“The key active sites for the chemical transformations involved atoms from the metal [copper] and oxide [ceria or ceria/titania] phases,” said Jesus Graciani, a chemist from the University of Seville and first author on the paper. The resulting catalyst converts CO2 to methanol more than a thousand times faster than plain copper particles, and almost 90 times faster than a common copper/zinc-oxide catalyst currently in industrial use.

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Eric Chan Wei Chiang's curator insight, August 2, 11:21 PM

The transformation of CO2 into alcohols or other hydrocarbon compounds is challenging because catalysing the formation of carbon-carbon bonds is very difficult. To illustrate, Victor Grignard won the Nobel Prize in 1912 for developing reagents which forms carbon-carbon bonds.


Nonetheless, this technology has vast implications in space exploration and sustainable energy:

http://www.scoop.it/t/world-of-tomorrow/?tag=Space+Exploration

http://www.scoop.it/t/aquascaping-and-nature/?tag=Sustainable+Energy

 

On carbon fixation, an artificial leaf devised using real chloroplast is described here: http://sco.lt/7MI8mX

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Steam from the sun: New sponge-like material converts 85% of solar energy into steam

Steam from the sun: New sponge-like material converts 85% of solar energy into steam | Amazing Science | Scoop.it

A new material structure developed at MIT generates steam by soaking up the sun. The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.


The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation. What’s more, the setup loses very little heat in the process, and can produce steam at relatively low solar intensity. This would mean that, if scaled up, the setup would likely not require complex, costly systems to highly concentrate sunlight.


Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, says the spongelike structure can be made from relatively inexpensive materials — a particular advantage for a variety of compact, steam-powered applications.


“Steam is important for desalination, hygiene systems, and sterilization,” says Ghasemi, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”


Ghasemi and mechanical engineering department head Gang Chen, along with five others at MIT, report on the details of the new steam-generating structure in the journal Nature Communications.


Today, solar-powered steam generation involves vast fields of mirrors or lenses that concentrate incoming sunlight, heating large volumes of liquid to high enough temperatures to produce steam. However, these complex systems can experience significant heat loss, leading to inefficient steam generation.


Recently, scientists have explored ways to improve the efficiency of solar-thermal harvesting by developing new solar receivers and by working with nanofluids. The latter approach involves mixing water with nanoparticles that heat up quickly when exposed to sunlight, vaporizing the surrounding water molecules as steam. But initiating this reaction requires very intense solar energy — about 1,000 times that of an average sunny day.


By contrast, the MIT approach generates steam at a solar intensity about 10 times that of a sunny day — the lowest optical concentration reported thus far. The implication, the researchers say, is that steam-generating applications can function with lower sunlight concentration and less-expensive tracking systems.  

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A new solution for storing hydrogen fuel for alternative energy

A new solution for storing hydrogen fuel for alternative energy | Amazing Science | Scoop.it

Turning the "hydrogen economy" concept into a reality, even on a small scale, has been a bumpy road, but scientists are developing a novel way to store hydrogen to smooth out the long-awaited transition away from fossil fuels. Their report on a new solid, stable material that can pack in a large amount of hydrogen that can be used as a fuel appears in the ACS journal Chemistry of Materials.

Umit B. Demirci and colleagues explain that storing hydrogen in solids is a recent development and a promising step toward building a hydrogen economy. That's the idea originated in the 1970s and promoted by former President George W. Bush that we replace fossil fuels with hydrogen, which can serve as a clean fuel. Although a promising alternative to conventional energy sources, hydrogen has posed a number of technological challenges that scientists are still overcoming. One of those issues has to do with storage


Previously, researchers were focused on developing hydrogen-containing liquids or compressing it in gas form. Now, solid storage is showing potential for holding hydrogen in a safe, stable and efficient way. In the latest development on this front, Demirci's team looked to a new kind of material.


They figured out a way to make a novel crystal phase of a material containing lithium, boron and the key ingredient, hydrogen. To check how they could get the hydrogen back out of the material, the scientists heated it and found that it released hydrogen easily, quickly and only traces of unwanted by-products.


More information: "Lithium Hydrazinidoborane: A Polymorphic Material with Potential for Chemical Hydrogen Storage" Chem. Mater., Article ASAP. DOI: 10.1021/cm500980b

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Superelastic lithium-ion batteries can be woven into textiles for wearable devices

Superelastic lithium-ion batteries can be woven into textiles for wearable devices | Amazing Science | Scoop.it

Huisheng Peng and colleagues at Fudan University made the superelastic batteries by winding two carbon nanotubes–lithium oxide composites yarns, which served as the positive and negative electrodes, onto an elastomer substrate and covering this with a layer of gel electrolyte. The batteries owe their stable electrochemical performance under stretching to the twisted structure of the fibre electrodes and the stretchability of the substrate and gel electrolyte, with the latter also acting as an anchor. When the batteries were stretched, the spring-like structure of the two electrodes was maintained.


Previous stretchable batteries have generally been produced in a planar format, which has been an obstacle for their development for small, lightweight, wearable electronics. ‘Our fibre-shaped batteries can easily be scaled-up to an appropriate length and woven into clothing that can adapt to the body’s movement,’ says Peng.


The battery recorded a specific capacity of 91.3mAh/g and this was maintained at over 88% after stretching by 600%.


Ray Baughman, an electrochemical device expert at the University of Texas at Dallas, US, says the superelasticity achieved for the operating battery is fascinating. ‘A future challenge will be to dramatically increase the volume fraction of energy-storing material in the total elastomeric structure and to the decrease overall diameter to those conventionally used for weaving, while still maintaining a useful degree of rubber-like elasticity.’


Reference: Y Zhang et alJ. Mater. Chem. A, 2014, DOI: 10.1039/c4ta01878h

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World first: Australian solar plant has generated “supercritical” steam that rivals fossil fuels’

World first: Australian solar plant has generated “supercritical” steam that rivals fossil fuels’ | Amazing Science | Scoop.it
A CSIRO test plant in Australia has broken a world record and proved solar power could efficiently replace fossil fuels.


A solar thermal test plant in Newcastle, Australia, has generated “supercritical” steam at a pressure of 23.5 mpa (3400 psi) and 570°C (1,058°F). CSIRO is claiming it as a world record, and it’s a HUGE step for solar thermal energy.


"It's like breaking the sound barrier; this step change proves solar has the potential to compete with the peak performance capabilities of fossil fuel sources," Dr Alex Wonhas, CSIRO’s Energy Director, said.


The Energy Centre uses a field of more than 600 mirrors (known as heliostats) which are all directed at two towers housing solar receivers and turbines, Gizmag reports.


This supercritical steam is used to drive the world’s most advanced power plant turbines, but previously it’s only been possible to produce it by burning fossil fuels such as coal or gas.


"Instead of relying on burning fossil fuels to produce supercritical steam, this breakthrough demonstrates that the power plants of the future could instead be using the free, zero emission energy of the sun to achieve the same result,” Dr Wonhas explained.


Currently, commercial solar thermal or concentrating solar power power plants only operate a “subcritical” levels, using less pressurised steam. This means that they’ve never been able to match the output or efficiency of the world’s best fossil fuel power plants - until now.


The commercial development of this technology is still a fair way off, but this is an important first step towards a more sustainable future.

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Marc Kneepkens's curator insight, June 8, 6:11 PM

Renewable energy is catching up quickly.

Eric Chan Wei Chiang's curator insight, June 9, 1:50 AM

Supercritical water have properties between those of a gas and a liquid. Generating supercritical water is not an easy task as very high temperatures and pressures are required i.e. more than 374 °C and 218 atm.

 

Power plants can extract ten times more energy from supercritical water as compared to typical steam or hot water.

 

Icelandic scientists previously tried to generate supercritical water from geothermal means http://sco.lt/7mbwvZ

 

Annenkov's curator insight, June 9, 5:12 AM

Технический прорыв в единстве с местными условиями?

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Tokelau: An Island 100% Powered By Solar Energy

Tokelau: An Island 100% Powered By Solar Energy | Amazing Science | Scoop.it

Tokelau (population: 1,500) is an island nation in the South Pacific, made up of three atolls whose highest point is only five meters above sea level. Even though the New Zealand protectorate’s contribution to climate change is miniscule, it faces grave threats to its very existence. In 2011, at the Durban Climate conference, Foua Toloa, the head of Tokelau, said the island would be using 100 percent renewable energy by 2012. By October of that year residents accomplished their goal, becoming the first country in the world to produce 100 percent of its electricity from the sun.


Prior to 2012, Tokelau’s residents relied on three diesel-driven power stations, burning 200 liters per day at a cost of nearly $800,000 per year. Tokelauans only had electricity 15 to 18 hours per day. They now have three solar photovoltaic systems, one on each atoll. The 4,032 solar panels (with a capacity of around one megawatt), 392 inverters, and 1,344 batteries provide 150 percent of their current electricity demand, allowing the Tokelauans to eventually expand their electricity use. In overcast weather, the generators run on local coconut oil, providing power while recharging the battery bank. The only fossil fuels used in Tokelau now are for the island nation’s three cars.

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Maria Isabel Ramos's curator insight, June 1, 6:11 PM

Com o albedo de Castelo Branco podíamos estar como Tokelau.

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Microalgae-based biofuel can help to meet world energy demand, researchers say

Microalgae-based biofuel can help to meet world energy demand, researchers say | Amazing Science | Scoop.it

Microalgae-based biofuel not only has the potential to quench a sizable chunk of the world's energy demands, say Utah State University researchers. It's a potential game-changer.


"That's because microalgae produces much higher yields of fuel-producing biomass than other traditional fuel feedstocks and it doesn't compete with food crops," says USU mechanical engineering graduate student Jeff Moody.


With USU colleagues Chris McGinty and Jason Quinn, Moody published findings from an unprecedented worldwide microalgae productivity assessment in the May 26, 2014 Edition of the Proceedings of the National Academy of Sciences. The team's research was supported by the U.S. Department of Energy.


Despite its promise as a biofuel source, the USU investigators questioned whether "pond scum" could be a silver bullet-solution to challenges posed by fossil fuel dependence.


"Our aim wasn't to debunk existing literature, but to produce a more exhaustive, accurate and realistic assessment of the current global yield of microalgae biomass and lipids," Moody says.


With Quinn, assistant professor in USU's Department of Mechanical and Aerospace Engineering, and McGinty, associate director of USU's Remote Sensing/Geographic Information Systems Laboratory in the Department of Wildland Resources, Moody leveraged a large-scale, outdoor microalgae growth model. Using meteorological data from 4,388 global locations, the team determined the current global productivity potential of microalgae.


Algae, he says, yields about 2,500 gallons of biofuel per acre per year. In contrast, soybeans yield approximately 48 gallons; corn about 18 gallons.


"In addition, soybeans and corn require arable land that detracts from food production," Quinn says. "Microalgae can be produced in non-arable areas unsuitable for agriculture."


The researchers estimate untillable land in Brazil, Canada, China and the U.S. could be used to produce enough algal biofuel to supplement more than 30 percent of those countries' fuel consumption.

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Tekrighter's curator insight, May 29, 10:30 AM

Here's a way to produce biofuels that does not compete with food production.

Daniel LaLiberte's curator insight, May 29, 8:52 PM

Land that is not used for food can be used to produce algae-based biofuel to meet a large fraction of the world's energy needs.  But another alternative is vertical farming in urban areas, where we can create as much space as we need.  

Eric Chan Wei Chiang's curator insight, May 30, 2:50 AM

This study highlights the commercial viability of algae biofuels.


The game changing aspect of the technology is that it does not contribute to food insecurity http://sco.lt/5CifIH, a global issue aggravated by climate change http://sco.lt/86HUtl.


However, would we garner enough political will to wrest monopoly from oil and gas companies?

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"Nanograss" boosts the efficiency of organic solar cells

"Nanograss" boosts the efficiency of organic solar cells | Amazing Science | Scoop.it

Solar cells are built using two different types of semiconductors ("p-type" and "n-type"), each with a slightly different composition; when the two come in close contact, they form a so-called "PN junction." This junction is a critical component of any solar cell because it generates an electric field that causes charge inside the cell to flow in a set direction, creating a voltage. Voltage times current equals (solar) power.


After decades of trial and error, scientists now believe that the ideal geometry for a PN junction would consist of a series of vertical nanoscale pillars made from one type of semiconductor (either p- or n-type) and surrounded by a semiconductor of the opposite type. This shape is extremely effective at trapping light without reflecting it, resulting in a greater amount of charge being collected, while also allowing the use of cheaper, lower-grade materials in smaller volumes, which decreases the overall cost of the cell.


This "Holy Grail" structure has already been achieved in inorganic solar cells, but has been elusive for their organic counterpart due to some of the unique challenges they present. Now, however, a team led by Prof. Alejandro Briseno at UMass Amherst has developed a new simple and highly adaptable technique that can produce "nanograss" for use in organic solar cells, which could lead to a significant boost in their efficiency.

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Creating low-cost solar energy on bendable plastic films

Creating low-cost solar energy on bendable plastic films | Amazing Science | Scoop.it
Work by PhD student Alex Barker, under the supervision of Dr Justin Hodgkiss, a senior lecturer in the School of Chemical and Physical Sciences, is helping to improve the efficiency of next generation solar cells made from materials like plastics.


The research, published recently by the prestigious international Journal of the American Chemical Society, addresses the long-standing question of how light produces charge pairs far enough apart from each other that they are free to flow as current, rather than staying bound together and ultimately just releasing heat.


The technique used by the researchers was to freeze the solar cells to -263 degrees Celsius, where charge pairs get stuck together. They then used lasers to measure the how far apart they moved as the temperatures increase.


"We found that the efficiency of polymer, or plastic-based, solar cell is determined by the ability of charge pairs to rapidly escape from each other while they are still 'hot' from the light energy," says Dr Hodgkiss, a 2011 Rutherford Discovery Fellow.


He adds that understanding how plastic solar cells work will result in more efficient and cheaper conductive materials that overcome the limitations of conventional solar cells.


"Because they're plastic and flexible, they could be rolled out to cover a tent or used as semi-transparent filters on windows."


The findings of the research settle a long-standing debate about how polymer solar cells work, and offers potential to guide the design of cheaper and more efficient materials, by isolating the key step in their development.

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Ms. Moon's curator insight, October 9, 10:29 PM

Materials Science is a fascinating subject. Here someone thought outside conventional wisdom and created something new and better. That's what "innovation" is all about.

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High Efficiency Achieved for Harvesting Hydrogen Fuel From the Sun using Earth-Abundant Materials

High Efficiency Achieved for Harvesting Hydrogen Fuel From the Sun using Earth-Abundant Materials | Amazing Science | Scoop.it

Today, the journal Science published the latest development in Michael Grätzel’s laboratory at EPFL: producing hydrogen fuel from sunlight and water. By combining a pair of solar cells made with a mineral called perovskite and low cost electrodes, scientists have obtained a 12.3 percent conversion efficiency from solar energy to hydrogen, a record using earth-abundant materials as opposed to rare metals.

The race is on to optimize solar energy’s performance. More efficient silicon photovoltaic panels, dye-sensitized solar cells, concentrated cells and thermodynamic solar plants all pursue the same goal: to produce a maximum amount of electrons from sunlight. Those electrons can then be converted into electricity to turn on lights and power your refrigerator.

At the Laboratory of Photonics and Interfaces at EPFL, led by Michael Grätzel, where scientists invented dye solar cells that mimic photosynthesis in plants, they have also developed methods for generating fuels such as hydrogen through solar water splitting. To do this, they either use photoelectrochemical cells that directly split water into hydrogen and oxygen when exposed to sunlight, or they combine electricity-generating cells with an electrolyzer that separates the water molecules.

By using the latter technique, Grätzel’s post-doctoral student Jingshan Luo and his colleagues were able to obtain a performance so spectacular that their achievement is being published today in the journal Science. Their device converts into hydrogen 12.3 percent of the energy diffused by the sun on perovskite absorbers – a compound that can be obtained in the laboratory from common materials, such as those used in conventional car batteries, eliminating the need for rare-earth metals in the production of usable hydrogen fuel.

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Russell R. Roberts, Jr.'s curator insight, October 7, 3:23 AM

This development  could be a game changer when it comes to alternate energy. The Michael Gratzel Laboratory at EPFL has produced hydrogen from sunlight and water.  By connecting a pair of solar cells made from a common material known as perovskite and low-cost electrodes, scientists "have obtained a 12.3% conversion from solar energy to hydrogen...a record using earth-abundant materials as opposed to rare metals."  The day is coming when common metals, such as those used  in automobile batteries, will be joined with solar panels to produce the most abundant fuel in the universe--hydrogen.  Hydrogen-powered vehicles are in development now by several car manufacturers, including Ford, GM, Nissan, Toyota, Honda, Mercedes, and BMW.  Current hybrid vehicles require expensive Lithium-Ion batteries and exotic metals available in only a few countries.  Once easily produced hydrogen fuel is available, our dependence on unfriendly regimes for key metals will diminish.  Couple that with a reduced demand for foreign oil, this country may adopt a more realistic, objective foreign policy.  Aloha, Russ.

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US has 4,200 gigawatts of offshore winds and studies show wind farms will not harm marine mammals and birds

US has 4,200 gigawatts of offshore winds and studies show wind farms will not harm marine mammals and birds | Amazing Science | Scoop.it
The United States has plenty of strong winds offshore, but it has struggled to harness them for energy. 


In theory, the potential is tremendous. Including harder-to-reach deep-water sites, the offshore territory of the United States has the capacity to generate an estimated 4,200 gigawatts of electricity, enough to supply four times the nation’s current needs. But before the field can take off, proponents will have to prove that offshore wind can compete financially against other energy sources, and can clear the thicket of state and federal regulations that govern projects in coastal waters.


“I don’t think we’re looking at easy street here,” says Walt Musial, a long-time offshore-wind researcher at the National Renewable Energy Laboratory in Louisville, Colorado. “We really need to demonstrate that it can be done.”


No project encapsulates the challenges facing offshore wind power better than Cape Wind, being developed by Energy Management of Boston, Massachusetts. The venture aims to take advantage of the strong winds and relatively calm waters of Nantucket Sound near Cape Cod, Massachusetts, some 350 kilometres southwest of Castine.


The plan for Cape Wind consists of 130 turbines, each standing nearly 80 metres tall, over an area of 65 square kilometres. Energy Management says that the completed wind farm will have a capacity of 468 megawatts, able to produce 75% of the electricity for Cape Cod and the nearby islands of Martha’s Vineyard and Nantucket.


But the project has faced strong opposition for more than a decade. Organizations including the non-profit group Save Our Sound have brought dozens of lawsuits against Cape Wind, claiming that the project would harm birds and other wildlife, increase electricity rates for consumers and endanger aeroplanes flying into local airspace.Except for one temporary decision, all of the judicial rulings have been in favour of Cape Wind. Spokes­person Mark Rodgers says that even with court appeals coming, the project intends to commence construction by spring 2015. “There are no merits to any of these legal complaints,” he says.


Cape Wind has already broken new ground by being the first US offshore wind project to complete a major environmental assessment. That study — thousands of pages long — and independent analyses have helped to appease some groups that were sceptical of the initial proposal.

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Recycling old car batteries into solar cells could convert dangerous waste into photovoltaics

Recycling old car batteries into solar cells could convert dangerous waste into photovoltaics | Amazing Science | Scoop.it

This could be a classic win-win solution: A system proposed by researchers at MIT recycles materials from discarded car batteries — a potential source of lead pollution — into new, long-lasting solar panels that provide emissions-free power. The system is described in a paper in the journal Energy and Environmental Science,co-authored by professors Angela M. Belcher and Paula T. Hammond, graduate student Po-Yen Chen, and three others. It is based on a recent development in solar cells that makes use of a compound called perovskite — specifically, organolead halide perovskite — a technology that has rapidly progressed from initial experiments to a point where its efficiency is nearly competitive with that of other types of solar cells.


“It went from initial demonstrations to good efficiency in less than two years,” says Belcher, the W.M. Keck Professor of Energy at MIT. Already, perovskite-based photovoltaic cells have achieved power-conversion efficiency of more than 19 percent, which is close to that of many commercial silicon-based solar cells. Initial descriptions of the perovskite technology identified its use of lead, whose production from raw ores can produce toxic residues, as a drawback. But by using recycled lead from old car batteries, the manufacturing process can instead be used to divert toxic material from landfills and reuse it in photovoltaic panels that could go on producing power for decades.


Amazingly, because the perovskite photovoltaic material takes the form of a thin film just half a micrometer thick, the team’s analysis shows that the lead from a single car battery could produce enough solar panels to provide power for 30 households.

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New material combines two semiconductor sheets three atomic layers thick to create ultra-thin solar cells

New material combines two semiconductor sheets three atomic layers thick to create ultra-thin solar cells | Amazing Science | Scoop.it

Semiconductor heterostructures form the cornerstone of many electronic and optoelectronic devices and are traditionally fabricated using epitaxial growth techniques. More recently, heterostructures have also been obtained by vertical stacking of two-dimensional crystals, such as graphene and related two-dimensional materials. These layered designer materials are held together by van der Waals forces and contain atomically sharp interfaces. Here, we report on a type-II van der Waals heterojunction made of molybdenum disulfide and tungsten diselenide monolayers. The junction is electrically tunable, and under appropriate gate bias an atomically thin diode is realized. Upon optical illumination, charge transfer occurs across the planar interface and the device exhibits a photovoltaic effect. Advances in large-scale production of two-dimensional crystals could thus lead to a new photovoltaic solar technology.


Tungsten diselenide is a semiconductor which consists of three atomic layers. One layer of tungsten is sandwiched between two layers of selenium atoms. “We had already been able to show that tungsten diselenide can be used to turn light into electric energy and vice versa”, says Thomas Mueller. But a solar cell made only of tungsten diselenide would require countless tiny metal electrodes tightly spaced only a few micrometers apart. If the material is combined with molybdenium disulphide, which also consists of three atomic layers, this problem is elegantly circumvented. The heterostructure can now be used to build large-area solar cells. 

When light shines on a photoactive material single electrons are removed from their original position. A positively charged hole remains, where the electron used to be. Both the electron and the hole can move freely in the material, but they only contribute to the electrical current when they are kept apart so that they cannot recombine. 

To prevent recombination of electrons and holes, metallic electrodes can be used, through which the charge is sucked away - or a second material is added. “The holes move inside the tungsten diselenide layer, the electrons, on the other hand, migrate into the molybednium disulphide”, says Thomas Mueller. Thus, recombination is suppressed.

This is only possible if the energies of the electrons in both layers are tuned exactly the right way. In the experiment, this can be done using electrostatic fields. Florian Libisch and Professor Joachim Burgdörfer (TU Vienna) provided computer simulations to calculate how the energy of the electrons changes in both materials and which voltage leads to an optimum yield of electrical power.

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World's first artificial leaves uses chloroplasts from real plants and photosynthesis

World's first artificial leaves uses chloroplasts from real plants and photosynthesis | Amazing Science | Scoop.it

The Silk Leaf project uses chloroplasts from real plants suspended in silk proteins to create a hardy vehicle for photosynthesis.


The leaves, created by Royal College of Art student Julian Melchiorri, absorb water and carbon dioxide just like real plants but are made from tough silk proteins that could let them survive space voyages.


Melchiorri explains: "NASA is researching different ways to produce oxygen for long-distance space journeys to let us live in space. This material could allow us to explore space much further than we can now."


The Silk Leaf project was engineered in collaboration with Tufts University silk lab, which helped Melchiorri extract chloroplasts from real leaves and suspend them in a silk matrix.


"The material is extracted directly from the fibres of silk," explains Melchiorri. "This material has an amazing property of stabilising molecules. I extracted chloroplasts from plant cells and placed them inside this silk protein. As an outcome I have the first photosynthetic material that is living and breathing as a leaf does."


Chloroplasts are the parts of plant cells that conduct photosynthesis, using the energy of the sun to turn carbon dioxide and water to create glucose and oxygen.


Melchiorri’s creations are currently more conceptual than practical (the efficiency of the photosynthesis process hasn’t been tested for one) but he hopes they could be used in all manner of futuristic architectural projects, perhaps even deploying giant leaves as air filters, hanging them on the exterior of buildings to absorb CO2 and channel fresh air inside.

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Segway Inventor Dean Kamen Thinks His New Stirling Engine Will Get People Off The Grid For Under $10K

Segway Inventor Dean Kamen Thinks His New Stirling Engine Will Get People Off The Grid For Under $10K | Amazing Science | Scoop.it
"Ten years from today the probability that you are depending on wires hanging on tree branches is as likely as that you'll still be installing land lines for telephones. Close to zero."


Inventor Dean Kamen is planning a 2.5 kW home version of hisDeka Research Beacon 10 Stirling engine that could provide efficient around-the-clock power or hot water to a home or business, reports ForbesKamen says the current Beacon is intended for businesses like laundries or restaurants that use a lot of hot water. “With commercialization partner NRG Energy, he’s deployed roughly 20 of the machines and expects to put them into production within 18 months,” says Forbes.


But Kamen has bigger plans: feeding excess power to the grid by networking devices across a region together. Depending on the price of natural gas, “ten years from today the probability that you are depending on wires hanging on tree branches is as likely as that you’ll still be installing land lines for telephones,” he says. “Close to zero.”

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Organic solar cells reach manufacturing milestone

Organic solar cells reach manufacturing milestone | Amazing Science | Scoop.it

Complete roll-to-roll processing of flexible organic tandem solar cells achieved for the first time.


In an impressive feat of engineering, scientists in Denmark have devised a rapid, scalable and industrially viable way to manufacture large sheets of flexible organic tandem solar cells. Their successful application of roll-to-roll processing is a significant achievement for this emerging renewable technology.


An organic photovoltaic (OPV) solar cell is a polymer-based thin film solar cell. OPV solar cells have been the focus of much research as they are lightweight, flexible, inexpensive, highly tuneable and potentially disposable. They are also unparalleled in the number of times that they can pay back the energy used in their manufacture.


In the quest to improve the efficiency of OPVs, which, in addition to operational lifetime, is currently their key limitation, various new materials, processing methods and device architectures have been investigated. Among these is the tandem cell, where multiple junctions are stacked upon one another. This can increase the efficiency of the cell by not only increasing the number of junctions, but, along with careful selection of complimentary materials, can make it possible to harvest photons from a broader region of the spectrum. However, this more complicated architecture renders their manufacture significantly more challenging.


Frederik Krebs and his research team at the Technical University of Denmark are specialists in renewable energy technologies, particularly OPVs. For the first time they have demonstrated the successful roll-to-roll manufacture of tandem OPV modules, each comprised of a stack of 14 discrete layers, which are rapidly printed, coated or deposited one on top of another by a machine reminiscent of a printing press. The experiment was carried out in simple conditions and is extremely fast, with a single solar cell module being printed onto blank foil each second. Most importantly, the process is relatively cheap and completely scalable, with a high technical yield.

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Human urine can be a cheap, durable and effective alternative to platinum-carbon as a catalyst for fuel cells

Human urine can be a cheap, durable and effective alternative to platinum-carbon as a catalyst for fuel cells | Amazing Science | Scoop.it
Human urine, otherwise potentially polluting waste, is an universal unused resource in organic form disposed by the human body. We present for the first time “proof of concept” of a convenient, perhaps economically beneficial, and innovative template-free route to synthesize highly porous carbon containing heteroatoms such as N, S, Si, and P from human urine waste as a single precursor for carbon and multiple heteroatoms. High porosity is created through removal of inherently-present salt particles in as-prepared “Urine Carbon” (URC), and multiple heteroatoms are naturally doped into the carbon, making it unnecessary to employ troublesome expensive pore-generating templates as well as extra costly heteroatom-containing organic precursors. Additionally, isolation of rock salts is an extra bonus of present work. The technique is simple, but successful, offering naturally doped conductive hierarchical porous URC, which leads to superior electrocatalytic ORR activity comparable to state of the art Pt/C catalyst along with much improved durability and methanol tolerance, demonstrating that the URC can be a promising alternative to costly Pt-based electrocatalyst for ORR. The ORR activity can be addressed in terms of heteroatom doping, surface properties and electrical conductivity of the carbon framework.
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Springtime for the artificial leaf: Technology tries to improve on photosynthesis

Springtime for the artificial leaf: Technology tries to improve on photosynthesis | Amazing Science | Scoop.it

Researchers make headway in turning photons into fuel. Inside Caltech's Jorgensen Laboratory, however, more than 80 researchers are putting a lot of effort into doing the leaf's job using silicon, nickel, iron and any number of other materials that would be more at home inside a cell phone than a plant cell. Their gleaming new labs are the headquarters of the Joint Center for Artificial Photosynthesis (JCAP), a 190-person research programme funded by the US Department of Energy (DOE) with US$116 million over five years. The centre's goal is to use sunlight to make hydrogen and other fuels much more efficiently than real leaves ever made biomass.


The researchers are pursuing this goal with a certain urgency. Roughly 13% of greenhouse-gas emissions worldwide come from transportation, so phasing out polluting fuels is a key environmental target. One approach is to replace cars and light trucks with electric vehicles charged by solar cells or wind — but that cannot tackle the whole problem. Nathan Lewis, an inorganic chemist at Caltech and JCAP's scientific director, says that some 40% of current global transportation cannot be electrified. For example, barring a major breakthrough, there will never be a plug-in hybrid plane: no craft could hold enough batteries. Liquid fuels are unbeatable when it comes to convenience combined with compact energy storage


That is why funding agencies around the world — and at least a few private companies — are putting unprecedented resources into making fuels using power from the Sun, which is not only carbon-free but effectively inexhaustible. JCAP stands out not only for its scale, but also for its ambition. It is one of five Energy Innovation Hubs created by the DOE beginning in 2010 to focus on specific problems using basic research, applied research and engineering. JCAP has promised to deliver a working prototype of an artificial leaf by the time its initial grant runs out in 2015.


Although the centre has taken some important steps in that direction — including one recently reported1 — it is still a long way from delivering on that promise, “This is a really, really difficult, challenging problem,” says electrochemist John Turner of the US National Renewable Energy Laboratory in Golden, Colorado. “The payback would be huge, but it's not as simple as everyone wanted it to be when we started playing in this area 40 years ago.”


Still, the surge of funding and attention has given many researchers reason to hope for long-term success. “If you could sustain this type of effort for the next ten years,” says Michael Wasielewski, a chemist at Northwestern University in Evanston, Illinois, “it's conceivable you could have a practical solution.”

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Siemens provides 150 wind turbines for largest ever offshore project

Siemens provides 150 wind turbines for largest ever offshore project | Amazing Science | Scoop.it

The Gemini consortium has signed all construction, operations and financing contracts yesterday with a total construction budget of nearly EUR 3 billion. With more than 20 parties involved 70 percent of this budget will be provided on the basis of project financing – making Gemini the largest-ever project financed offshore wind farm. For the Gemini project Siemens will deliver 150 wind turbines with a capacity of 4 megawatts (MW) and a rotor diameter of 130 meters each.

The wind power plant is to be located in the North Sea, 85 km above the coast of Groningen. With an installed capacity of 600 MW in total Gemini will yield 2.6 terawatt hours (TWh) of electricity per year. The wind power plant will supply clean energy for one and a half million people after being fully commissioned. The amount of energy is equivalent to a reduction in the emission of CO2 by 1,25 million tons per year.


For Siemens this is the first order for an offshore wind power plant in Dutch waters. The innovative service concept banks on the ongoing presence of a service vessel and the steady ground readiness of a helicopter.


Siemens' 15-year service and maintenance agreement for the Gemini project is the largest service order ever for Siemens Energy Service. It will introduce a highly advanced logistics concept for offshore sites. For the first time, a helicopter will be available for a project at all times and a specially designed, purpose-built service operation vessel (SOV) will be based at the wind farm. To ensure increased turbine availability, maintenance work can be carried out at almost all times irrespective of the weather conditions or wave height.

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