daily menu » rate the banner | guess the city | one on oneforums map | privacy policy | DMCA | news magazine | posting guidelines

Go Back   SkyscraperCity > Fun Forums > Space, Science & Technology

Space, Science & Technology shaping tomorrow's world



Global Announcement

As a general reminder, please respect others and respect copyrights. Go here to familiarize yourself with our posting policy.


Reply

 
Thread Tools
Old January 23rd, 2013, 06:50 PM   #1
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865

Renewable Energy Thread

__________________

VelesHomais liked this post
ramanujann no está en línea   Reply With Quote

Sponsored Links
 
Old January 23rd, 2013, 06:54 PM   #2
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865

Quote:
Make solar energy economical

As a source of energy, nothing matches the sun. It out-powers anything that human technology could ever produce. Only a small fraction of the sun’s power output strikes the Earth, but even that provides 10,000 times as much as all the commercial energy that humans use on the planet.


Why is solar energy important?

Already, the sun’s contribution to human energy needs is substantial — worldwide, solar electricity generation is a growing, multibillion dollar industry. But solar’s share of the total energy market remains rather small, well below 1 percent of total energy consumption, compared with roughly 85 percent from oil, natural gas, and coal.

Those fossil fuels cannot remain the dominant sources of energy forever. Whatever the precise timetable for their depletion, oil and gas supplies will not keep up with growing energy demands. Coal is available in abundance, but its use exacerbates air and water pollution problems, and coal contributes even more substantially than the other fossil fuels to the buildup of carbon dioxide in the atmosphere.

For a long-term, sustainable energy source, solar power offers an attractive alternative. Its availability far exceeds any conceivable future energy demands. It is environmentally clean, and its energy is transmitted from the sun to the Earth free of charge. But exploiting the sun’s power is not without challenges. Overcoming the barriers to widespread solar power generation will require engineering innovations in several arenas — for capturing the sun’s energy, converting it to useful forms, and storing it for use when the sun itself is obscured.

Many of the technologies to address these issues are already in hand. Dishes can concentrate the sun’s rays to heat fluids that drive engines and produce power, a possible approach to solar electricity generation. Another popular avenue is direct production of electric current from captured sunlight, which has long been possible with solar photovoltaic cells.


How efficient is solar energy technology?

But today’s commercial solar cells, most often made from silicon, typically convert sunlight into electricity with an efficiency of only 10 percent to 20 percent, although some test cells do a little better. Given their manufacturing costs, modules of today’s cells incorporated in the power grid would produce electricity at a cost roughly 3 to 6 times higher than current prices, or 18-30 cents per kilowatt hour [Solar Energy Technologies Program]. To make solar economically competitive, engineers must find ways to improve the efficiency of the cells and to lower their manufacturing costs.

Prospects for improving solar efficiency are promising. Current standard cells have a theoretical maximum efficiency of 31 percent because of the electronic properties of the silicon material. But new materials, arranged in novel ways, can evade that limit, with some multilayer cells reaching 34 percent efficiency. Experimental cells have exceeded 40 percent efficiency.

Another idea for enhancing efficiency involves developments in nanotechnology, the engineering of structures on sizes comparable to those of atoms and molecules, measured in nanometers (one nanometer is a billionth of a meter).

Recent experiments have reported intriguing advances in the use of nanocrystals made from the elements lead and selenium. [Schaller et al.] In standard cells, the impact of a particle of light (a photon) releases an electron to carry electric charge, but it also produces some useless excess heat. Lead-selenium nanocrystals enhance the chance of releasing a second electron rather than the heat, boosting the electric current output. Other experiments suggest this phenomenon can occur in silicon as well. [Beard et al.]

Theoretically the nanocrystal approach could reach efficiencies of 60 percent or higher, though it may be smaller in practice. Engineering advances will be required to find ways of integrating such nanocrystal cells into a system that can transmit the energy into a circuit.


How do you make solar energy more economical?

Other new materials for solar cells may help reduce fabrication costs. “This area is where breakthroughs in the science and technology of solar cell materials can give the greatest impact on the cost and widespread implementation of solar electricity,” Caltech chemist Nathan Lewis writes in Science. [Lewis 799]

A key issue is material purity. Current solar cell designs require high-purity, and therefore expensive, materials, because impurities block the flow of electric charge. That problem would be diminished if charges had to travel only a short distance, through a thin layer of material. But thin layers would not absorb as much sunlight to begin with.

One way around that dilemma would be to use materials thick in one dimension, for absorbing sunlight, and thin in another direction, through which charges could travel. One such strategy envisions cells made with tiny cylinders, or nanorods. Light could be absorbed down the length of the rods, while charges could travel across the rods’ narrow width. Another approach involves a combination of dye molecules to absorb sunlight with titanium dioxide molecules to collect electric charges. But large improvements in efficiency will be needed to make such systems competitive.


How do you store solar energy?

However advanced solar cells become at generating electricity cheaply and efficiently, a major barrier to widespread use of the sun’s energy remains: the need for storage. Cloudy weather and nighttime darkness interrupt solar energy’s availability. At times and locations where sunlight is plentiful, its energy must be captured and stored for use at other times and places.

Many technologies offer mass-storage opportunities. Pumping water (for recovery as hydroelectric power) or large banks of batteries are proven methods of energy storage, but they face serious problems when scaled up to power-grid proportions. New materials could greatly enhance the effectiveness of capacitors, superconducting magnets, or flyweels, all of which could provide convenient power storage in many applications. [Ranjan et al., 2007]

Another possible solution to the storage problem would mimic the biological capture of sunshine by photosynthesis in plants, which stores the sun’s energy in the chemical bonds of molecules that can be used as food. The plant’s way of using sunlight to produce food could be duplicated by people to produce fuel.

For example, sunlight could power the electrolysis of water, generating hydrogen as a fuel. Hydrogen could then power fuel cells, electricity-generating devices that produce virtually no polluting byproducts, as the hydrogen combines with oxygen to produce water again. But splitting water efficiently will require advances in chemical reaction efficiencies, perhaps through engineering new catalysts. Nature’s catalysts, enzymes, can produce hydrogen from water with a much higher efficiency than current industrial catalysts. Developing catalysts that can match those found in living cells would dramatically enhance the attractiveness of a solar production-fuel cell storage system for a solar energy economy.

Fuel cells have other advantages. They could be distributed widely, avoiding the vulnerabilities of centralized power generation.

If the engineering challenges can be met for improving solar cells, reducing their costs, and providing efficient ways to use their electricity to create storable fuel, solar power will assert its superiority to fossil fuels as a sustainable motive force for civilization’s continued prosperity.
http://www.engineeringchallenges.org/cms/8996/9082.aspx

Last edited by ramanujann; January 23rd, 2013 at 06:59 PM.
ramanujann no está en línea   Reply With Quote
Old January 23rd, 2013, 08:43 PM   #3
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865

Quote:
Multi-Junction Solar Cell to Break Efficiency Barrier?

U.S. Naval Research Laboratory scientists in the Electronics Technology and Science Division, in collaboration with the Imperial College London and MicroLink Devices, Inc., Niles, Ill., have proposed a novel triple-junction solar cell with the potential to break the 50 percent conversion efficiency barrier, which is the current goal in multi-junction photovoltaic development.



"This research has produced a novel, realistically achievable, lattice-matched, multi-junction solar cell design with the potential to break the 50 percent power conversion efficiency mark under concentrated illumination," said Robert Walters, Ph.D., NRL research physicist. "At present, the world record triple-junction solar cell efficiency is 44 percent under concentration and it is generally accepted that a major technology breakthrough will be required for the efficiency of these cells to increase much further."

In multi-junction (MJ) solar cells, each junction is 'tuned' to different wavelength bands in the solar spectrum to increase efficiency. High bandgap semiconductor material is used to absorb the short wavelength radiation with longer wavelength parts transmitted to subsequent semiconductors. In theory, an infinite-junction cell could obtain a maximum power conversion percentage of nearly 87 percent. The challenge is to develop a semiconductor material system that can attain a wide range of bandgaps and be grown with high crystalline quality.

By exploring novel semiconductor materials and applying band structure engineering, via strain-balanced quantum wells, the NRL research team has produced a design for a MJ solar cell that can achieve direct band gaps from 0.7 to 1.8 electron volts (eV) with materials that are all lattice-matched to an indium phosphide (InP) substrate.

"Having all lattice-matched materials with this wide range of band gaps is the key to breaking the current world record" adds Walters. "It is well known that materials lattice-matched to InP can achieve band gaps of about 1.4 eV and below, but no ternary alloy semiconductors exist with a higher direct band-gap."

The primary innovation enabling this new path to high efficiency is the identification of InAlAsSb quaternary alloys as a high band gap material layer that can be grown lattice-matched to InP. Drawing from their experience with Sb-based compounds for detector and laser applications, NRL scientists modeled the band structure of InAlAsSb and showed that this material could potentially achieve a direct band-gap as high as 1.8eV. With this result, and using a model that includes both radiative and non-radiative recombination, the NRL scientists created a solar cell design that is a potential route to over 50 percent power conversion efficiency under concentrated solar illumination.

Recently awarded a U.S. Department of Energy (DoE), Advanced Research Projects Agency-Energy (ARPA-E) project, NRL scientists, working with MicroLink and Rochester Institute of Technology, Rochester, N.Y., will execute a three year materials and device development program to realize this new solar cell technology.
http://www.sciencedaily.com/releases...0114111616.htm
ramanujann no está en línea   Reply With Quote
Old January 23rd, 2013, 08:56 PM   #4
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865



http://en.wikipedia.org/wiki/Solar_cell#Efficiency
ramanujann no está en línea   Reply With Quote
Old January 23rd, 2013, 09:03 PM   #5
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865

Quote:
Breakthrough for solar cell research



In the latest issue of Science, researchers from Lund University in Sweden have shown how nanowires could pave the way for more efficient and cheaper solar cells. "Our findings are the first to show that it really is possible to use nanowires to manufacture solar cells", says Magnus Borgstrom, a researcher in semiconductor physics and the principal author.

Research on solar cell nanowires is on the rise globally. Until now the unattained dream figure was ten per cent efficiency - but now Dr Borgstrom and his colleagues are able to report an efficiency of 13.8 per cent.

The nanowires are made of the semiconductor material indium phosphide and work like antennae that absorb sunlight and generate power. The nanowires are assembled on surfaces of one square millimetre that each house four million nanowires. A nanowire solar cell can produce an effect per active surface unit several times greater than today's silicon cells.

Nanowire solar cells have not yet made it beyond the laboratory, but the plan is that the technology could be used in large solar power plants in sunny regions such as the south-western USA, southern Spain and Africa.

The Lund researchers have now managed to identify the ideal diameter of the nanowires and how to synthesise them. "The right size is essential for the nanowires to absorb as many photons as possible. If they are just a few tenths of a nanometre too small their function is significantly impaired", explains Magnus Borgstrom.

The silicon solar cells that are used to supply electricity for domestic use are relatively cheap, but inefficient because they are only able to utilise a limited part of the effect of the sunlight. The reason is that one single material can only absorb part of the spectrum of the light.

Research carried out alongside that on nanowire technology therefore aims to combine different types of semiconductor material to make efficient use of a broader part of the solar spectrum. The disadvantage of this is that they become extremely expensive and can therefore only be used in niche contexts, such as on satellites and military planes.

However, this is not the case with nanowires. Because of their small dimensions, the same sort of material combinations can be created with much less effort, which offers higher efficiency at a low cost. The process is also less complicated. In the Science article, the researchers have shown that the nanowires can generate power at the same level as a thin film of the same material, even if they only cover around 10 per cent of the surface rather than 100 per cent.

The research has been carried out as part of an EU-funded project, AMON-RA, coordinated by Knut Deppert, Professor of Physics at Lund University (www.amonra.eu).

"As the coordinator of the project, I am very proud of such a great result - it has well exceeded our expectations. We will of course continue the research on nanowire solar cells and hope to achieve an even higher level of efficiency than the 13.8 per cent that we have now reported", says Knut Deppert.
http://www.solardaily.com/reports/Br...earch_999.html
ramanujann no está en línea   Reply With Quote
Old January 25th, 2013, 11:13 AM   #6
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865

Quote:
Wind and Solar Power Paired With Storage Could Power Grid 99.9 Percent of the Time

Renewable energy could fully power a large electric grid 99.9 percent of the time by 2030 at costs comparable to today's electricity expenses, according to new research by the University of Delaware and Delaware Technical Community College.


A well-designed combination of wind power, solar power and storage in batteries and fuel cells would nearly always exceed electricity demands while keeping costs low, the scientists found.

"These results break the conventional wisdom that renewable energy is too unreliable and expensive," said co-author Willett Kempton, professor in the School of Marine Science and Policy in UD's College of Earth, Ocean, and Environment. "The key is to get the right combination of electricity sources and storage -- which we did by an exhaustive search -- and to calculate costs correctly."

The authors developed a computer model to consider 28 billion combinations of renewable energy sources and storage mechanisms, each tested over four years of historical hourly weather data and electricity demands. The model incorporated data from within a large regional grid called PJM Interconnection, which includes 13 states from New Jersey to Illinois and represents one-fifth of the United States' total electric grid.

Unlike other studies, the model focused on minimizing costs instead of the traditional approach of matching generation to electricity use. The researchers found that generating more electricity than needed during average hours -- in order to meet needs on high-demand but low-wind power hours -- would be cheaper than storing excess power for later high demand.

Storage is relatively costly because the storage medium, batteries or hydrogen tanks, must be larger for each additional hour stored.

One of several new findings is that a very large electric system can be run almost entirely on renewable energy.

"For example, using hydrogen for storage, we can run an electric system that today would meeting a need of 72 GW, 99.9 percent of the time, using 17 GW of solar, 68 GW of offshore wind, and 115 GW of inland wind," said co-author Cory Budischak, instructor in the Energy Management Department at Delaware Technical Community College and former UD student.

A GW ("gigawatt") is a measure of electricity generation capability. One GW is the capacity of 200 large wind turbines or of 250,000 rooftop solar systems. Renewable electricity generators must have higher GW capacity than traditional generators, since wind and solar do not generate at maximum all the time.

The study sheds light on what an electric system might look like with heavy reliance on renewable energy sources. Wind speeds and sun exposure vary with weather and seasons, requiring ways to improve reliability. In this study, reliability was achieved by: expanding the geographic area of renewable generation, using diverse sources, employing storage systems, and for the last few percent of the time, burning fossil fuels as a backup.

During the hours when there was not enough renewable electricity to meet power needs, the model drew from storage and, on the rare hours with neither renewable electricity or stored power, then fossil fuel. When there was more renewable energy generated than needed, the model would first fill storage, use the remaining to replace natural gas for heating homes and businesses and only after those, let the excess go to waste.

The study used estimates of technology costs in 2030 without government subsidies, comparing them to costs of fossil fuel generation in wide use today. The cost of fossil fuels includes both the fuel cost itself and the documented external costs such as human health effects caused by power plant air pollution. The projected capital costs for wind and solar in 2030 are about half of today's wind and solar costs, whereas maintenance costs are projected to be approximately the same.

"Aiming for 90 percent or more renewable energy in 2030, in order to achieve climate change targets of 80 to 90 percent reduction of the greenhouse gas carbon dioxide from the power sector, leads to economic savings," the authors observe.
http://www.sciencedaily.com/releases...1210133507.htm
ramanujann no está en línea   Reply With Quote
Old January 25th, 2013, 11:28 AM   #7
ramanujann
Registered User
 
ramanujann's Avatar
 
Join Date: May 2011
Location: Ukraine
Posts: 1,119
Likes (Received): 865

Quote:
"Artificial photosynthesis" turns water into hydrogen

Researchers at Spain’s Jaume I University develop semiconductor ‘leaf’ that needs only sunlight to release hydrogen from water.

A novel “leaf-like” semiconductor device that produces hydrogen gas from water just by the action of sunlight has been developed by scientists from the Photovoltaic & Optoelectronic Devices group at Universitat Jaume I (“UJI”), Castellón de la Plana, Spain. The group led by Professor Juan Bisquert, has developed the artificial leaf using nanotechnology techniques.

This technology, which the researchers call “artificial photosynthesis”, was inspired by natural photosynthesis, in which plants use sunlight to release the chemical energy stored in the bonds of the molecule adenosine triphosphate (ATP), converting organic material into various compounds, such as sugars or carbohydrates and releasing oxygen gas.

Researcher Sixto Giménez, explains, “The efficient production of hydrogen using semiconductor materials and sunlight constitutes a crucial challenge to make a paradigm shift towards achieving sustainable energy technology, using inexhaustible resources that are environmentally friendly.”

"Although the energy efficiency of the device is currently not sufficient enough for us to consider marketing it, we are exploring various ways to improve its efficiency and to show that this technology represents a real alternative to meet the energy demands of the 21st century.”

Water as fuel?

Hydrogen is an extremely abundant element on the Earth’s surface, but mainly in strongly-bonded combination with oxygen as water, H2O. The diatomic hydrogen molecule H2 contains a great deal of energy that can be released when burned due to the reaction with atmospheric oxygen, creating environmentally-friendly water as the result of this combustion process.

Giménez adds that in order to convert water into H2 “fuel”, the H2O must be broken down into its constituents. For this process can be carried out in a renewable way (without using fossil fuels), it is necessary to use a device which relies on solar power – with no other assistance – to provoke the chemical reactions to break the water and form hydrogen in a way similar to plant leaves in nature. “That is why we have called these devices artificial leaves.”

The semiconductor device is submerged in an aqueous solution, which, when illuminated with a light source, forms hydrogen gas bubbles. Initially, the research group used a solution with an oxidizing agent and studied the evolution of hydrogen produced by photons.

“Now the biggest challenge”, comments Iván Mora, a member of the team working on the project, “is to understand the physical-chemical process which is produced by the semiconductor material and its interface with the aqueous medium in order to streamline our device process.”

Material challenge

The team says that the development of the artificial leaf has been a “great scientific challenge” due to the difficulty choosing materials for the process that would working continuously and not decompose.

Currently, the UJI Photovoltaic & Optoelectronic Devices team is one of the few research groups working at an international level that has shown the viability of a device with these characteristics, along with North American laboratories from MIT, Boston, and NREL, Denver.

Research group leader, Juan Bisquert, adds, “in comparison to other devices, that which has been developed by the UJI has the advantage of low production costs and a large collection of incident photons of light, used in the production of hydrogen photons in the infrared spectrum”.

The research group’s hydrogen generation process video can be seen here:

http://optics.org/news/3/6/7
ramanujann no está en línea   Reply With Quote
Old January 26th, 2013, 02:20 AM   #8
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

Quote:
Blade Dynamics to make first 100-meter wind turbine blades?



The Energy Technologies Institute in the United Kingdom has announced that UK-based wind turbine blade manufacturer Blade Dynamics has been awarded a contract that will see the creation of the world's longest turbine blades, between 80 and 100 meters (262 and 328 feet) in length. Currently, the longest turbine blades are for offshore wind farms, maxing out at 75 meters (246 feet).



Unlike current mega-blades, Blade Dynamics will make its blades from carbon fiber rather than fiberglass, making them up to 40 percent lighter. These will be assembled from smaller components, which can be manufactured more cheaply and accurately than molding single-piece blades.



Current 75-meter blades are fitted to wind turbines with a capacity of up to 6 MW. With the new blades, the Energy Technologies Institute is aiming for a peak of 8 to 10 MW per turbine. The company claims that blades longer than 100 meters are perfectly viable for offshore purposes, and could offer 20 years of reliable performance. It says that the larger turbines enabled by the greater rotor size enable the generation of wind energy at lower cost.



After a period of prototyping, the blades should enter full production towards the end of 2014.
http://www.gizmag.com/worlds-longest...e-blade/25750/
Ulpia-Serdica no está en línea   Reply With Quote
Old January 30th, 2013, 04:33 AM   #9
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

Quote:
Norwegians trap sunlight with microbeads, produce solar cells that are 20 times thinner, cheaper



Researchers from the University of Oslo have used a bunch of “wonderful tricks” to produce silicon solar cells that are twenty times thinner than commercial solar cells. This breakthrough means that solar cells can be produced using 95% less silicon, reducing production costs considerably — both increasing profits (which are almost nonexistent at the moment), and reducing the cost of solar power installations.

Standard, commercial photovoltaic solar cells are fashioned out of 200-micrometer-thick (0.2mm) wafers of silicon, which are sliced from a large block of silicon. This equates to around five grams of silicon per watt of solar power, and also a lot of wastage — roughly half of the silicon block is turned into sawdust by the slicing process. With solar cells approaching 50 cents per watt (down from a few dollars per watt a few years ago), something needs to change.

Reducing the thickness of solar cells obviously makes a lot of sense from a commercial point of view, but it introduces another issue: As the wafer gets thinner, more light passes straight through the silicon, dramatically reducing the amount of electricity produced by the photovoltaic effect. This is due to wavelengths: Blue light, which has a short wavelength (450nm), can be captured by a very thin wafer of silicon — but red light, with a longer wavelength (750nm), can only be captured by thicker slabs of silicon. This is part of the reason that current solar cells use silicon wafers that are around 200 micrometers — and also why they’re mirrored, which doubles the effective thickness, allowing them to capture more of the visible spectrum.

In essence, the University of Oslo researchers have devised methods for trapping those longer wavelengths, even when the silicon wafers are just 10 micrometers thick. The first trick is using microbeads — very small plastic spheres, uniform in size, that create an almost perfect periodic pattern on the silicon. These beads force the sunlight to “move sideways,” increasing the apparent thickness of the silicon by 25 times.

The University of Oslo is also experimenting with asymmetric microindentations on the back of the silicon wafer. ”Cylinders, cones and hemispheres are symmetrical shapes. We have proposed a number of structures that break the symmetry. Our calculations show that asymmetrical microindentations can trap even more of the sunlight”, says Erik Marstein, one of the researchers involved with the work.

The researchers are in talks with industrial partners to investigate whether these methods can be scaled up to industrial production. The researchers seem quite confident that their technology could come to market within five to seven years.
http://www.extremetech.com/extreme/1...hinner-cheaper
Ulpia-Serdica no está en línea   Reply With Quote
Old April 4th, 2013, 02:14 AM   #10
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

Quote:
EWICON bladeless wind turbine generates electricity using charged water droplets



Wind energy may be one of the more sustainable sources of power available, but the spinning blades of conventional wind turbines require regular maintenance and have attracted criticism from bird lovers. That might explain why we've seen wind turbine prototypes that enclose the blades in a chamber or replace them entirely with a disc-like system. But researchers in the Netherlands set out to eliminate the need for a mechanical component entirely and created the EWICON, a bladeless wind turbine with no moving parts that produces electricity using charged water droplets.

Where most wind turbines generate electricity through mechanical energy, the EWICON (short for Electrostatic WInd energy CONvertor) creates potential energy with charged particles – in this case, water droplets. The current design consists of a steel frame holding a series of insulated tubes arranged horizontally. Each tube contains several electrodes and nozzles, which continually release positively-charged water particles into the air. As the particles are blown away, the voltage of the device changes and creates an electric field, which can be transferred to the grid for everyday use.



Dutch researchers have developed the EWICON, a bladeless windmill with no moving parts that produces electricity by pushing charged water droplets into the wind

Energy output would be dependent not only on the wind speed, but also the number of droplets, the amount of charge placed on the droplets, and the strength of the electric field.

According to the developers, the system could easily be installed on land or sea, much like regular wind turbines, but the design is particularly suited to urban areas. Expansive wind farms usually aren't feasible in big cities due to a lack of space, but one or more EWICONs could be incorporated into existing architecture just by altering it's shape. Also, with a lack of moving parts, it would require less maintenance while producing less noise and no flickering shadows.



The designers of the EWICON windmill incorporated it into the sign on top of the Stadstimmerhuis 010 building in Rotterdam

So far, only a few small-scale prototypes of the EWICON have been produced: two that are incorporated into a sign on top of the Stadstimmerhuis 010 building in Rotterdam and another standalone version that was erected on the Delft Technical University campus. The designers are currently testing the device's capabilities, but are trying to gather funding for a larger model that could produce more power.

The EWICON was designed by architecture firm Mecanoo using technology developed by Delft Technical University researchers Johan Smit and Dhiradj Djairam.
SOURCE: http://www.gizmag.com/ewicon-bladele...turbine/26907/
Ulpia-Serdica no está en línea   Reply With Quote
Old April 4th, 2013, 06:12 PM   #11
Argh
Registered User
 
Argh's Avatar
 
Join Date: Jun 2010
Location: Kraków
Posts: 593
Likes (Received): 219

Maybe you have heard of DESERTEC.



and first real achievment



What do you think about this whole initiative? Brilliant way to create alternative power source for euro-asia-africa region or just an excuse for expansion of Big european energy companies?
__________________
Salus rei publicae suprema lex esto
http://osom.org.pl/przestrzen-miasta - wesprzyj swoje miasto!
Argh no está en línea   Reply With Quote
Old April 4th, 2013, 07:38 PM   #12
TowerVerre:)
Registered User
 
TowerVerre:)'s Avatar
 
Join Date: Dec 2012
Location: Stuttgart
Posts: 616
Likes (Received): 838

I love this kind of ideas. That would be a good solution for the energy problem. Of course we have to note the interests of native people there. But it would be much more sustainable then to build all this solar cells in germany. The only problem I see is that they have to built this lines. But if they solve this problem and INVOLVE the native poeple then it will be a great success. The only thing what is needed is cooperation.

PS: Maybee it is a good idea to start a own treat for Desertec ?!
TowerVerre:) no está en línea   Reply With Quote
Old April 5th, 2013, 08:45 AM   #13
Argh
Registered User
 
Argh's Avatar
 
Join Date: Jun 2010
Location: Kraków
Posts: 593
Likes (Received): 219

Well, what is crucial to this project, is at least three subjects:
1. Problem of lines on the bottom of the sea, which requires a lot of money and agreement with at least two countries, to which the sea area belongs.
2. Matter of internal affairs of arab countires, the north africa seems to be highly unstable area, therefore it limitate number of countries in which energy investment can take place.
3. Logically, such operation as the one Desertec plan, requires a lot of good will and funding from energy companies from europe. the TurNur investment in Tunis will be critical- if it will pay off, then consequently the other investment should follow.

Still, I think it may be a little to early for independent thread. Let's watch Desertec progress for some time, and see if it's worth it
__________________
Salus rei publicae suprema lex esto
http://osom.org.pl/przestrzen-miasta - wesprzyj swoje miasto!

TowerVerre:) liked this post
Argh no está en línea   Reply With Quote
Old April 7th, 2013, 09:09 PM   #14
Argh
Registered User
 
Argh's Avatar
 
Join Date: Jun 2010
Location: Kraków
Posts: 593
Likes (Received): 219

Interesting find, right from desertec fanpage Not exactly about solar energy, but still renewable and possible to impelement in europe and surroundings.

__________________
Salus rei publicae suprema lex esto
http://osom.org.pl/przestrzen-miasta - wesprzyj swoje miasto!

gramercy liked this post
Argh no está en línea   Reply With Quote
Old April 9th, 2013, 11:56 AM   #15
_BPS_
678 999 8212
 
_BPS_'s Avatar
 
Join Date: Feb 2005
Location: Mrs.GaGa
Posts: 2,285
Likes (Received): 973

Scientists a step closer toward creating biofuels directly from atmospheric CO2
mongabay.com
March 29, 2013

Read more at http://news.mongabay.com/2013/0329-c...tIG3iEbp5kr.99


Researchers have taken a step closer to using atmospheric carbon dioxide as a biofuel, potentially helping mitigate climate change while at the same time meeting rising energy demand, according to a study published in the Proceedings of the National Academy of Sciences.

Scientists at the University of Georgia and the North Carolina State University are working with the bacteria Pyrococcus furiosus to convert CO2 into directly biofuels.

"Basically, what we have done is create a microorganism that does with carbon dioxide exactly what plants do-absorb it and generate something useful," said study co-author Michael Adams of the the University of Georgia. "What this discovery means is that we can remove plants as the middleman. We can take carbon dioxide directly from the atmosphere and turn it into useful products like fuels and chemicals without having to go through the inefficient process of growing plants and extracting sugars from biomass."
Read more at http://news.mongabay.com/2013/0329-c...tIG3iEbp5kr.99


Pyrococcus furiosus. Image from the Missouri University of Science and Technology
Read more at http://news.mongabay.com/2013/0329-c...tIG3iEbp5kr.99


Pyrococcus furiosus is a microorganism that lives in super-heated ocean waters near geothermal vents. Adams and colleagues manipulated the bacteria's genome so it feeds on CO2 at much lower temperatures.

A press release from the University of Georgia explains the next steps of the process for potentially using the extremophile bacteria to convert the potent greenhouse gas into fuel.

The research team then used hydrogen gas to create a chemical reaction in the microorganism that incorporates carbon dioxide into 3-hydroxypropionic acid, a common industrial chemical used to make acrylics and many other products.

With other genetic manipulations of this new strain of P. furiosus, Adams and his colleagues could create a version that generates a host of other useful industrial products, including fuel, from carbon dioxide.

When the fuel created through the P. furiosus process is burned, it releases the same amount of carbon dioxide used to create it, effectively making it carbon neutral, and a much cleaner alternative to gasoline, coal and oil.

Adams called the development "an important first step that has great promise as an efficient and cost-effective method of producing fuels."

"In the future we will refine the process and begin testing it on larger scales."

The study did not evaluate the economic viability of the approach.


CITATION: Matthew W. Keller et al (2013). Exploiting microbial hyperthermophilicity to produce an industrial chemical, using hydrogen and carbon dioxide. PNAS Online Early Edition for the week of March 25, 2013-March 29, 2013.
Read more at http://news.mongabay.com/2013/0329-c...tIG3iEbp5kr.99
__________________
Roma | Firenze | Pisa | Vatican City
New York City | Atlantic City
Montreal | Ottawa | Quebec City | Toronto | Niagara Falls
Havana
Jerusalem | Amman
_BPS_ no está en línea   Reply With Quote
Old April 9th, 2013, 05:39 PM   #16
joshsam
JR
 
joshsam's Avatar
 
Join Date: Jul 2009
Location: Sint-Truiden
Posts: 5,245
Likes (Received): 2082

Quote:
'Artificial leaf' widens reach with self-healing capacity




The world's first practical "artificial leaf” can now self-heal damage that occurs during production of energy.
The innovation means the leaf, which mimics the ability of real leaves to produce energy from nothing other than sunlight and water, can now be run on dirty water making it even more suitable for providing people in developing countries and remote areas with electricity.

Daniel Nocera, described the advance during the "Kavli Foundation Innovations in Chemistry Lecture" at the 245th National Meeting and Exposition of the American Chemical Society, which runs until Thursday.

Nocera, leader of the research team, explained the device is a simple catalyst-coated wafer of silicon, rather than a complicated reproduction of the photosynthesis mechanism in real leaves.

Dropped into a jar of water and exposed to sunlight, catalysts in the device break water down into its components, hydrogen and oxygen and those gases bubble up and can be collected and used as fuel to produce electricity in fuel cells.

"Surprisingly, some of the catalysts we've developed for use in the artificial leaf device actually heal themselves," Nocera said. "They are a kind of 'living catalyst.' This is an important innovation that eases one of the concerns about initial use of the leaf in developing countries and other remote areas."

Nocera, who is the Patterson Rockwood Professor of Energy at Harvard University, explained that the artificial leaf would probably find its first uses in providing "personalized" electricity to individual homes in areas that lack traditional electric power generating stations and electric transmission lines.

Less than one quart of drinking water, for instance, would be enough to provide about 100 watts of electricity 24 hours a day.

And while earlier versions of the leaf required pure water, because bacteria eventually formed biofilms on the leaf's surface shutting down production, the new “self-healing” design means it can be used in the natural environment.

"Self-healing enables the artificial leaf to run on the impure, bacteria-contaminated water found in nature," Nocera said. "We figured out a way to tweak the conditions so that part of the catalyst falls apart, denying bacteria the smooth surface needed to form a biofilm. Then the catalyst can heal and re-assemble."

Nocera said that about 3 billion people today live in areas that lack access to traditional electric production and distribution systems and about 1 billion people in the developing world already lack reliable access to clean water.

"It's kind of like providing 'fast-food energy,'" he noted. "We're interested in making lots of inexpensive units that may not be the most efficient, but that get the job done. It's kind of like going from huge mainframe computers to a personal laptop. This is personalized energy."

Earlier devices used rare, costly metals and other materials, involved complicated wiring and were expensive to manufacture, but Nocera's artificial leaf uses less-expensive materials and incorporates a design — called a "buried junction" — that is simple and would be inexpensive to mass produce.

And the leaf has advantages over solar panels, which are costly and produce energy only during daylight hours, as the leaf's hydrogen and oxygen can be stored and used at night.

"A lot of people are designing complicated, expensive energy-producing devices, and it is difficult to see them being adopted on a large scale," he said. "Ours is simple, less expensive, and it works. And with that, I think we've changed the dialog in the field."

Among the team's priorities for further development of the device is integrating it with technology for converting the hydrogen into a liquid fuel that could run traditional portable electric generators or even cars.

Nocera acknowledged research funding from the National Science Foundation, the Department of Energy and the Air Force Office of Scientific Research.
from: http://eandt.theiet.org/news/2013/ap...icial-leaf.cfm
__________________
WxWxHxC
BRUSSELS | the good, the bad and the ugly
joshsam no está en línea   Reply With Quote
Old April 11th, 2013, 12:21 AM   #17
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

Sol Voltaics unveils SolInk nanomaterial to boost PV module performance by 25%



Sol Voltaics AB of Ideon Science Park, Lund, Sweden has unveiled SolInk, a nanomaterial that promises to boost the efficiency of crystalline silicon or thin-film solar modules by up to 25%, leading to solar power plants and rooftop solar arrays that can generate far more electricity than the best systems currently available commercially, it is claimed.

The firm reckons that the increase in efficiency will allow SolInk-enhanced panels to deliver power at prices that can compete directly against electricity from fossil-fuel plants while improving the economics for manufacturers. Global demand for solar energy is expected to grow from 29.8GW of new solar installations in 2012 to 50.8GW in 2016, according to Greentech Media.

“About two-thirds of the cost of commercial solar systems revolves around land, labor costs and other factors that solar developers cannot directly control,” says Sol Voltaics’ CEO David Epstein. “By raising the efficiency of solar modules, we give solar manufacturers the opportunity to sell more valuable, higher-margin products and solar developers the opportunity to generate more power ‐ at a lower price - with essentially the same physical assets,” he adds.



Sol Voltaics’ strategy revolves around two fundamental technologies: gallium arsenide nanowires measuring 1-2 microns in length and 100-200nm in diameter (the active ingredient in SolInk) and Aerotaxy (a process for producing nanowires created by company founder and Lund University professor Lars Samuelson).

GaAs has been used in solar for years (e.g. in orbiting satellites) because of its reliability and high energy conversion efficiencies, but GaAs solar cells typically cost far more to produce than crystalline silicon or thin-film cells, confining the material to niche market segments, says the firm.

SolInk reduces the cost by minimizing materials: less than a gram of nanowires is added to the surface of crystalline silicon panels. With SolInk, module makers can make commercially feasible, high-efficiency GaAs solar modules or multi‐junction solar modules combining GaAs nanowires on top of crystalline silicon, reckons the firm.



SolInk also enables light concentration without the use of optics or mechanical components, Sol Voltaics adds. Nanowires need to cover only a small portion of the surface area of a crystalline silicon or thin-film solar cell to achieve substantially all of the benefits of adding GaAs. In the academic journal Science earlier this year, Lund University and Sol Voltaics researchers demonstrated that indium phosphide (InP) nanowires covering just 12% of the substrate surface produced a solar cell with an efficiency of 13.8%. The results were certified by Germany’s Fraunhofer Institute. The phenomenon, called wave concentrated photovoltaics (WCPV), combined with the other advantages of GaAs nanowires leads to the high performance of SolInk, it is claimed.

Aerotaxy manufacturing method

Nanowires and nanotubes are typically produced via a process of epitaxial crystal growth on a substrate. But because of the inherent physical limits of the epitaxial process, nanoparticles often need to be grown in place or harvested and sorted in batch processes that can be both time-consuming and expensive.

Instead, Aerotaxy creates nanomaterials by suspending and mixing active materials in carrier gas streams. The active materials bond to form larger, uniform structures while in flight: nanowires are literally grown in air. Aerotaxy can hence generate tens of billions of nanowires per second on a continuous basis. The finished nanowires can be integrated into a solar panel or other products, or can be stored indefinitely. A paper published in Nature late last year details how professor Samuelson and his team used Aerotaxy to manufacture GaAs nanowires (‘Continuous gas-phase synthesis of nanowires with tunable properties’ by Magnus Heurlin et al, Nature, 492, 90–94 (6 December 2012); doi:10.1038/nature11652).

“The results have been far better than we ever expected,” says Samuelson. “We understand how different materials react or bond to one another,” he adds. “With Aerotaxy, we essentially create an atmosphere where we can better harness those physical and chemical properties.”

Business model: selling SolInk, rather than modules



Rather than produce modules or sell capital equipment, Sol Voltaics will produce and sell SolInk to solar cell and module makers. Hence a single, relatively small manufacturing facility will be able to provide megawatts worth of materials, it is reckoned. Module makers likewise will be able to integrate new materials into their products without replacing existing production lines, the firm adds.

Sol Voltaics expects to produce functional solar cells with GaAs nanowires for demonstration by the end of 2013. Commercial production of SolInk-enhanced modules should begin in 2015 and move into volume production in 2016. Total invested capital to get into high‐volume commercial production will come to less than $50m, the firm estimates.

Founded in 2008, Sol Voltaics has previously raised $11m from private investors including Stockholm-based venture capital firm Industrifonden, Foundation Asset Management AB of Sweden, Teknoinvest AS, Provider, Nano Future Invest and Scatec Energy of Norway. The firm has also received public funding from the European Union, Vinnova, Nordic Innovation Center, and others. Sol Voltaics aims to raise $10-20m this year.

The firm reckons that other potential applications for Aerotaxy include producing nanomaterials for power electronics, LEDs, batteries and energy storage.

“The promise of nanotechnology has been held back by complexity, low yields and cost,” says Scatec’s chairman Alf Bjorseth. “Aerotaxy paves the way for integrating new materials into products in a streamlined manner.”

SOURCE: http://www.semiconductor-today.com/n...ICS090413.html
Ulpia-Serdica no está en línea   Reply With Quote
Old April 15th, 2013, 03:43 AM   #18
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

Nanowires Show Promise to Develop New Generation of Solar Panels



Imagine a solar panel more efficient than today’s best solar panels, but using 10 000 times less material. This is what EPFL researchers expect given recent findings on these tiny filaments called nanowires.

Solar technology integrating nanowires could capture large quantities of light and produce energy with incredible efficiency at a much lower cost. This technology is possibly the future for powering microchips and the basis for a new generation of solar panels.

Despite their size, nanowires have tremendous potential for energy production. “These nanowires capture much more light than expected,” says Anna Fontcuberta i Morral about her research, published on 24 March 2013 in Nature Photonics.

Nanowires are extremely tiny filaments–in this case able to capture light–with a diameter that measures tens to hundreds of nanometers, where a nanometer is one millionth of a millimeter. These miniscule wires are up to 1000 times smaller than the diameter of human hair, or comparable in diameter to the size of viruses.

When equipped with the right electronic properties, the nanowire becomes a tiny solar cell, transforming sunlight into electric current. Anna Fontcuberta i Morral and her team built a nanowire solar cell out of gallium arsenide, a material which is better at converting light into power than silicon. They found that it actually collects more light than the usual flat solar cell–up to 12 times more–and more light means more energy.

The nanowire standing vertically essentially acts like a very efficient light funnel. Even though the nanowire is only a few hundred nanometers in diameter, it absorbs light as though it were 12 times bigger. In other words, it has a greater field of vision than expected.

Fontcuberta’s prototype is already almost 10% more efficient at transforming light into power than allowed, in theory, for conventional single material solar panels. Furthermore, optimizing the dimensions of the nanowire, improving the quality of the gallium arsenide and using better electrical contacts to extract the current could increase the prototype’s efficiency.

Arrays of nanowire solar cells offer new prospects for energy production. This study suggests that an array of nanowires may attain 33% efficiency, in practice, whereas commercial (flat) solar panels are now only up to 20% efficient. Also, arrays of nanowires would use at least 10 000 times less gallium arsenide, allowing for industrial use of this costly material. Translating this into dollars for gallium arsenide, the cost would only be $10 per square meter instead of $100 000.

Free to the engineer’s imagination to mount these nanowires onto a variety of substrate panels, be it lightweight, flexible or designed to withstand the harshest of conditions. In a world where energy consumption is on the rise, these nanowires may one day power everything from your favorite gadget to space missions to Mars.

SOURCE: http://www.azonano.com/news.aspx?newsID=27098
Ulpia-Serdica no está en línea   Reply With Quote
Old April 15th, 2013, 04:39 AM   #19
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

A Solution For Clean Energy On A 24/7 Basis

Critics of renewables have always claimed that sun and wind are only intermittent producers of electricity and need fossil fuel plants as back-up to make them viable. But German engineers have proved this is not so.

By skillfully combining the output of a number of solar, wind and biogas plants the grid can be provided with stable energy 24 hours a day without fear of blackouts, according to the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) in Kassel.

For Germany, which has turned its back on nuclear power and is investing heavily in all forms of renewables to reduce its carbon dioxide emissions, this is an important breakthrough.

The country has a demanding industrial sector that needs a large and stable electricity supply, and some doubted that this could be achieved in the long term without retaining nuclear or large fossil fuel plants.

Solving the problem is becoming urgent. The latest figures show that on some days of the year the electricity being generated from sun, wind, biomass, water and geothermal production already accounts for more than half of the load required in the country.

The research is funded by the German Federal Ministry of the Environment and is aimed at showing that the entire electricity grid could be run on renewable energy.

Dr. Kurt Rohrig, deputy director of IWES, said: “Each source of energy – be it wind, sun or biogas – has its strengths and weaknesses. If we manage to skillfully combine the different characteristics of the regenerative energies, we can ensure the power supply for Germany.”

The idea is that many small power plant operators can feed their electricity into the grid but act as a single power plant using computers to control the level of power.

Sharing the load

Scientists linked together 25 plants with a nominal power output of 120 megawatts. Surplus power could be used for charging electric vehicles and for pumped storage (pumping water uphill into a reservoir to produce hydropower later).

When many small producers work together, then regional differences when the wind blows or the sun is intermittent are balanced out in the grid and can be boosted by controllable biogas facilities.

If there is too much surplus energy then the power can also be used to create and store thermal energy to be used later.

Kasper Knorr, the project manager for the scheme, which is known as the Combined Power Plant2 research project, says the idea is to ensure that the consumer is supplied reliably with 230 volts at a frequency of 50 Hertz.

The current system of supplying the grid with electricity is geared to a few large producers. In the new system, with dozens of small producers, there will need to be extra facilities at intervals on the system to stabilize voltage. Part of the project is designed to find out how many of these the country will need.

The project has the backing of Germany’s large and increasingly important renewable companies and industrial giants like Siemans. Researchers will be demonstrating the system at the Hanover Trade Fair from April 8 to 13.

SOURCE: http://www.earthtechling.com/2013/04...n-a-247-basis/
Ulpia-Serdica no está en línea   Reply With Quote
Old April 15th, 2013, 04:41 AM   #20
Ulpia-Serdica
ipso facto&manu militari
 
Ulpia-Serdica's Avatar
 
Join Date: Oct 2011
Posts: 7,758
Likes (Received): 3149

At 75 meters each, for a total rotor diameter of 154 meters, the Siemens wind turbine's blades are the longest in the world in operation. The swept area is 18,600 square meters, or the equivalent of two and a half soccer fields.

http://www.siemens.com/press/en/feat...rotorblade.php











Ulpia-Serdica no está en línea   Reply With Quote


Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT +2. The time now is 02:11 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Feedback Buttons provided by Advanced Post Thanks / Like v3.2.5 (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.

SkyscraperCity ☆ In Urbanity We trust ☆ about us | privacy policy | DMCA policy

Hosted by Blacksun, dedicated to this site too!
Forum server management by DaiTengu