Showing posts with label could. Show all posts
Showing posts with label could. Show all posts

Sunday, October 10, 2010

Then regular solar energy: antenna made carbon nanotubes could make solar cells more efficient

ScienceDaily (Sept. 13, 2010) - with carbon nanotubes (hollow tubes carbon atoms), more than one regular photovoltaic cell found with chemical engineers, to concentrate solar energy 100 times a way. Make such nanotubes could antennas that capture and could potentially allow light energy to focus much smaller and more powerful solar arrays.

Rather than your whole roof a photovoltaic cell, could little spots must you tiny photovoltaic cells, with antennas the photons in you were, would go, says Michael Strano, Charles and Hilda Roddey Associate Professor of chemical engineering and Director of the research team.

Strano and his students describe their new carbon nanotube antenna or "solar funnel," in the Sept. 12 online issue of the journal nature are Materials.Lead authors of the paper postdoctoral associate Jae-Hee Han and graduate student Geraldine Paulus.

Your new antennas may be also useful required goggles or telescopes for another application that focuses light, such as night vision.

Solar panels generate electricity by photons (packets of light energy) in electric current transform. Strano's nanotube antenna increases the number of photons can be captured and turned the light into energy, which be channelled in a solar cell.

The antenna consists of a fibrous rope 10 microns (1,000,000th meters) long and four microns thick, with about 30 million - carbon - nanotubes. Strano's team built, for the first time made a fiber from two layers of nanotubes with different electrical property-specifically, various Bandgaps.

Electrons at different energy levels can exist in any material. When a photon hits the surface, it attracts an electron to a higher energy level, which is specific to the material. The interaction between the energized electron and hole leaves it means an exciton and the difference in energy levels between the hole and the electron is known as the energy gap.

The inner layer of the antenna contains nanotubes with a small energy ratio and nanotubes in the outer layer have a higher energy pitch.This is important, because Exzitonenbildung like flow of high to low energy. In this case means that the Exzitonenbildung in the outer layer River on the inner level where they can be present in a lower (but still excited) power state.

Therefore, if strikes, light energy material are all in the middle of fiber where you focused the Exzitonenbildung.Strano and his team have not built yet a photovoltaic device with the antenna, but you want.In such a device, the antenna would focus photons before the photovoltaic cell could in an electric current konvertiert.Dies from the antenna to create a core of semiconducting material.

The interface between the semiconductor and the nanotubes would the electron from the hole with electrons at an electrode touching the inner semiconductor collected and the nanotubes trennen.Dieses covered holes that touch on an electrode system would then electricity animations.the materials for the electrode, according to the researchers would depend on the efficiency of a solar cell.

Strano's team is the first to construct nanotube fibres in which you can control the properties of the different layers, an achievement, made possible by recent advances in the separation of nanotubes with different properties.

While the cost of carbon nanotubes was once prohibitive, it has in recent years down been build as their production companies."" Sometime in the near future, probably for a few pennies per pound, carbon nanotubes are sold how polymers are sold,"says Strano.""With these costs, which in addition could be negligible costs of the cell to a solar cell compared to manufacturing and raw material, as coatings and polymer components are small components of the costs of a photovoltaic cell."

Strano's team now works on ways to minimize the energy lost as Exzitonenbildung flow through the fiber and opportunities, more than an Exciton per photon to generieren.Die nanotube bundle that lose material paper described around in the nature 13 percent of the energy you record, but the team is working on new antennas that would lose only 1 percent.

Funding: Career award of the National Science Foundation, MIT Sloan fellow, MIT DuPont Alliance and the Korea Research Foundation.

Story source:

The above story is from materials available provided by Massachusetts Institute of technology (with editorial adjustments of ScienceDaily staff) abgedruckt.Der original article was written by Anne Trafton, MIT News Office.

Journal reference:

Jae-Hee Han, Geraldine L. C. Paulus, Ryuichiro Maruyama, Daniel A. Heller, Woo-Jae Kim, Paul W. barons, Chang young Lee, Jong Hyun Choi, Moon Ho ham, Changsik song, C. Fantini, Michael S. Strano.Exciton antennas and concentrators core-shell and corrugated board carbon nanotube filaments of homogeneous composition.Natur materials, 2010; DOI: online nmat2832

Note: If no author is specified, instead cites the source.


View the original article here

Friday, October 8, 2010

U.S. CO <sub>2</sub> emissions from coal could eliminate in 20 years, experts say

ScienceDaily (May 2, 2010) – the USA could complete carbon dioxide emissions from coal-electric Kraftwerke-- a decisive step for controlling global warming - 20 years using technology already exists or within a decade after a group of scientists, engineers and architects commercially available could be.

This is the conclusion of an article online, along with a news article on the subject in the American Chemical Society's semi-monthly journal environmental science & technology (ES & T) published. both are planned for the June print edition of the ES & t.

Pushker Kharecha and Kollegen--by the NASA Goddard Institute for space studies, Columbia University Earth Institute, the national renewable energy laboratory and 2030 Inc. / Architecture 2030--say that the global climate change problem is manageable only if the company quickly employs carbon dioxide emissions from the combustion of coal in electrical power plants.

"The only practical way to a planet, the similar to the world of the nearby (today) to preserve with relatively stable coastlines and conservation of the species, it is rapidly, phase out coal emissions and prevent emissions from unconventional fossil fuels such as oil shale and tar sands" tell.

The authors describe this exit strategies possible box.you include the abolition of subsidies for fossil fuels; putting increasing prices on carbon emissions; substantial improvements of power transmission and the energy efficiency of homes, commercial buildings and equipment; replace coal with biomass, geothermal, wind, Sun and third-generation nuclear power; and after successful demonstration at commercial scales, deploying advanced (fourth generation) nuclear power plants; and carbon capture and storage on remaining coal plants.

Story source:

The above story is reprinted (with editorial adjustments of ScienceDaily personnel) of materials provided by the American Chemical Society, via EurekAlert!, a service of AAAS.

Journal references:

Pushker A. Kharecha, Charles F. Carter, James E. Hansen and Edward Mazria.Options for near term use phaseout of CO2 emissions from coal in the United States .Environmental Science & Technology, 2010; DOI: 10.1021/es903884aKellyn bed.Can the U.S. phase out coal's greenhouse gas emissions by 2030?Environmental science & technology, 2010; DOI: 10.1021/es101320m

Note: If no author is specified, instead cites the source.


View the original article here

Thursday, October 7, 2010

Solar power in Ontario could produce almost as much power as all U.S. nuclear reactors, to find the studies

ScienceDaily (Apr. 16, 2010)-solar energy in South-Eastern Ontario has the potential to almost the same amount of power as to produce all the nuclear reactors in the United States, two studies under the authority of the Queens's University applied sustainability research group based in Kingston, Canada.

These studies led by Queen's mechanical engineering professor Joshua Pearce, are solar energy potential.Professor Pearce first explore of the region was surprised how many gigawatt could be produced.

"We came up with enormous numbers and we were conservative.""There about 95 gigawatt potential performance in Southeastern Ontario-only that it shows massive potential", says Professor Pearce, solar photovoltaic materials and applied sustainability.

Computer urban discovered environment and systems, which accepts a study for publication in the journal, orientation and shades that if roof tops in Southeastern Ontario with solar panels covered option, you produce five gigawatt or around five per cent of Ontario's energy konnte.In of study were umbrella in account.

"To put this in perspective, all the coal plants in all Ontario produce well six gigawatt."The sun always seems not so if you could teach solar power with other renewable energy sources such as wind, hydropower and biomass, Southeastern Ontario easily cover its own energy needs, ", says Professor Pearce.

A second study, solar energy, considered country in Southeastern Ontario, used for solar farms released in may issue of the journal. could the study as a country with little economic value-barren, Rocky, not farmable areas in the vicinity of electrical Netze-and closed it has the potential to produce 90 gigawatts.

"Nuclear power for all of the USA is about 100 gigawatt.Wir produce 90 on barren land with only solar in this tiny region, so that we don't talk about small potatoes,"says Professor Pearce.""

The Professor studies led solid numbers offer decision makers on solar energy potential and possible solar Park find locations for developers.

Queen's civil engineering were also contribute to the studies students Lindsay Wiginton and mechanical engineering HA Nguyen student.

Story source:

The above story is from materials from Queen's University reprinted provided (with editorial adjustments of ScienceDaily staff).

Journal references:

L.k. Wiginton h.t Nguyen, j.m. Pearce.To quantify the rooftop solar photovoltaic potential for regional renewable energy policy. computers, environment and urban systems, 2010; DOI: 10.1016/j.compenvurbsys.2010.01.001H.T.Nguyen, j.m Pearce.Estimating potential photovoltaic r.sun yield and the open source geographical resources analysis support system.Solar Energy 2010; 84 (5): 831 DOI: 10.1016/j.solener.2010.02.009

Note: If no author is specified, instead cites the source.


View the original article here

Wednesday, September 29, 2010

Solar power in Ontario could produce almost as much power as all U.S. nuclear reactors, to find the studies

ScienceDaily (Apr. 16, 2010)-solar energy in South-Eastern Ontario has the potential to almost the same amount of power as to produce all the nuclear reactors in the United States, two studies under the authority of the Queens's University applied sustainability research group based in Kingston, Canada.

These studies led by Queen's mechanical engineering professor Joshua Pearce, are solar energy potential.Professor Pearce first explore of the region was surprised how many gigawatt could be produced.

"We came up with enormous numbers and we were conservative.""There about 95 gigawatt potential performance in Southeastern Ontario-only that it shows massive potential", says Professor Pearce, solar photovoltaic materials and applied sustainability.

Computer urban discovered environment and systems, which accepts a study for publication in the journal, orientation and shades that if roof tops in Southeastern Ontario with solar panels covered option, you produce five gigawatt or around five per cent of Ontario's energy konnte.In of study were umbrella in account.

"To put this in perspective, all the coal plants in all Ontario produce well six gigawatt."The sun always seems not so if you could teach solar power with other renewable energy sources such as wind, hydropower and biomass, Southeastern Ontario easily cover its own energy needs, ", says Professor Pearce.

A second study, solar energy, considered country in Southeastern Ontario, used for solar farms released in may issue of the journal. could the study as a country with little economic value-barren, Rocky, not farmable areas in the vicinity of electrical Netze-and closed it has the potential to produce 90 gigawatts.

"Nuclear power for all of the USA is about 100 gigawatt.Wir produce 90 on barren land with only solar in this tiny region, so that we don't talk about small potatoes,"says Professor Pearce.""

The Professor studies led solid numbers offer decision makers on solar energy potential and possible solar Park find locations for developers.

Queen's civil engineering were also contribute to the studies students Lindsay Wiginton and mechanical engineering HA Nguyen student.

Story source:

The above story is from materials from Queen's University reprinted provided (with editorial adjustments of ScienceDaily staff).

Journal references:

L.k. Wiginton h.t Nguyen, j.m. Pearce.To quantify the rooftop solar photovoltaic potential for regional renewable energy policy. computers, environment and urban systems, 2010; DOI: 10.1016/j.compenvurbsys.2010.01.001H.T.Nguyen, j.m Pearce.Estimating potential photovoltaic r.sun yield and the open source geographical resources analysis support system.Solar Energy 2010; 84 (5): 831 DOI: 10.1016/j.solener.2010.02.009

Note: If no author is specified, instead cites the source.


View the original article here