laboratoryequipment:

Nanoflowers Promise Energy Storage, Solar Cells

Researchers from North Carolina State Univ. have created flower-like structures out of germanium sulfide (GeS) – a semiconductor material – that have extremely thin petals with an enormous surface area. The GeS flower holds promise for next-generation energy storage devices and solar cells.

“Creating these GeS nanoflowers is exciting because it gives us a huge surface area in a small amount of space,” says Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a paper on the research. “This could significantly increase the capacity of lithium-ion batteries, for instance, since the thinner structure with larger surface area can hold more lithium ions. By the same token, this GeS flower structure could lead to increased capacity for supercapacitors, which are also used for energy storage.”

Read more: http://www.laboratoryequipment.com/news/2012/10/nanoflowers-promise-energy-storage-solar-cells

quantumaniac:

New Record Efficient Solar Cells 

Researchers from the University of Toronto (U of T) and King Abdullah University of Science & Technology (KAUST) have made a breakthrough in the development of colloidal quantum dot (CQD) films, leading to the most efficient CQD solar cell ever. Their work is featured in a letter published in Nature Nanotechnology. The researchers, led by U of T Engineering Professor Ted Sargent, created a solar cell out of inexpensive materials that was certified at a world-record 7.0% efficiency.

“Previously, quantum dot solar cells have been limited by the large internal surface areas of the nanoparticles in the film, which made extracting electricity difficult,” said Dr. Susanna Thon, a lead co-author of the paper. “Our breakthrough was to use a combination of organic and inorganic chemistry to completely cover all of the exposed surfaces.”

Quantum dots are semiconductors only a few nanometres in size and can be used to harvest electricity from the entire solar spectrum — including both visible and invisible wavelengths. Unlike current slow and expensive semiconductor growth techniques, CQD films can be created quickly and at low cost, similar to paint or ink. This research paves the way for solar cells that can be fabricated on flexible substrates in the same way newspapers are rapidly printed in mass quantities.

The U of T cell represents a 37% increase in efficiency over the previous certified record. In order to improve efficiency, the researchers needed a way to both reduce the number of “traps” for electrons associated with poor surface quality while simultaneously ensuring their films were very dense to absorb as much light as possible. The solution was a so-called “hybrid passivation” scheme.

“By introducing small chlorine atoms immediately after synthesizing the dots, we’re able to patch the previously unreachable nooks and crannies that lead to electron traps,” explained doctoral student and lead co-author Alex Ip. “We follow that by using short organic linkers to bind quantum dots in the film closer together.” The advance opens up many avenues for further research and improvement of device efficiencies, which could contribute to a bright future with reliable, low cost solar energy. 

Solar Powered Airplane Makes First Intercontinental Round-Trip Flight

A unique airplane has just completed a 6,000 km journey, making the first solar-powered intercontinental round-trip air journey. Traveling between Europe and Africa, the Solar Impulse experimental solar airplane landed in Payerne, Switzerland at 08:30 pm local time on July 24, 2012. The trip began two months ago, on May 24 and so was not a test to see how fast it could make the trip, but to assess the endurance and reliability of the craft, as well as bringing awareness to more people of energy issues.

“The goal of this airplane is not just to go from one point to another, but to fly as long as we wish, promote renewable energy and ambitious energy policies,” said pilot Bertrand Piccard, founder of Solar Impulse, during one leg of the intercontinental flight. “All of these have been so successful.”

Solar Impulse flew the eight-leg trip from Payerne to Morocco and back again, with Piccard and André Borschberg taking ook turns in the single-seat cockpit, flying for a total of 13 hours and 29 minutes. They flew Solar Impulse to Madrid,Spain; Rabat, Malta; Ouarzazate, Morocco; Toulouse, France and back to Payerne. The most challenging destination not only for this aircraft but for commercial ones as well was Ouarzazate, a region rich in turbulence and strong winds.

The plane flew during the day but often took off and landed at night to avoid areas of air turbulence called thermals. However, it was almost always brought back to the hangar with a full set of batteries, according to the team at Solar Impulse.

Originally built only to prove the possibility of flying day and night (it flew a 26-hour flight in 2010), the prototype airplane is now in the process of collecting a number of distance world records for solar aircrafts, such as straight distance, free distance and distance along a course.

“It’s been an extraordinary adventure not only for what we’ve achieved with this airplane, originally only designed to demonstrate the possibility of flying day and night with a purely solar energy, but also for what has resulted in a tightly fused team, confident in the project and in their capacity to make it happen,” said André Borschberg, CEO of Solar Impulse. “I am proud what we’ve been able to accomplish together, all of us, from the engineers that have built a fantastic airplane, to the Mission team experts that found a safe but successful strategy to the ground crew who had to operate in challenging conditions and multimedia team who under any circumstance brought the message of the project to the public. The world’s first intercontinental solar-powered flight would have never happened without the fantastic support provided by all people that crossed HB-SIA’s way.”

The flight was in conjunction with events in Morocco that promoted investment in innovative projects for job creation and sustainable growth while also decreasing dependency on fossil fuels.

“The success of this mission was not only aeronautical: it also stands in the quantity of positive emotions we managed to bring to the cause of renewable energies,” said Piccard at the end of the flight today.

A Twisting Tale of Space Solar Power

The dream of clean, consistent and renewable space solar power may become a reality, thanks to new research being done at The University of Strathclyde in Glasgow, Scotland.

The concept of space solar power – gathering solar energy with satellites in low-Earth orbit and “beaming” it down to collection stations on the ground — has been around for decades, but technology restrictions and prohibitive costs have kept it in the R&D phases, with some doubting that it will ever happen at all.

Now, researcher Dr. Massimiliano Vasile, of the University of Strathclyde’s Department of Mechanical and Aerospace Engineering, has announced his team’s development of modular devices that could be used to gather solar energy in orbit, working atop an experimental “space web” structure developed by graduate students at the university’s Department of Mechanical and Aerospace Engineering.

“By using either microwaves or lasers we would be able to beam the energy back down to earth, directly to specific areas. This would provide a reliable, quality source of energy and would remove the need for storing energy coming from renewable sources on ground as it would provide a constant delivery of solar energy.”

– Dr. Massimiliano Vasile, University of Strathclyde

The web structure, part of an experiment called Suaineadh — which means “twisting” in Scottish Gaelic (and I believe it’s pronounced soo-in-ade but correct me if I’m wrong) — is made of a central hub that would go into orbit and release a square web of material that’s weighted at the corners. The whole apparatus would spin, keeping its shape via centrifugal force and providing a firm structure that other devices could build upon and attach to.

The Suaineadh experiment was successfully launched on March 19 aboard a Swedish sounding rocket and while it appears that the components worked as expected, communication was lost after ejection. As a result the central hub — with all its data — couldn’t be located after landing. A recovery mission is planned for this summer.

Meanwhile, Dr. Vasile is still confident that his team’s space solar project, called SAM, can help provide space solar power to remote locations.

“The current project, called SAM (Self-inflating Adaptable Membrane) will test the deployment of an ultra light cellular structure that can change shape once deployed,” Dr. Vasile explains. “The structure is made of cells that are self-inflating in vacuum and can change their volume independently through nanopumps.

“The independent control of the cells would allow us to morph the structure into a solar concentrator to collect the sunlight and project it on solar arrays. The same structure can be used to build large space systems by assembling thousands of small individual units.”

By collecting solar energy in space, where the constraints of day and night or weather variability are nonexistent, the satellites could ultimately beam clean energy down to otherwise off-the-grid locales.

“In areas like the Sahara desert where quality solar power can be captured, it becomes very difficult to transport this energy to areas where it can be used,” says Dr. Vasile. “However, our research is focusing on how we can remove this obstacle and use space based solar power to target difficult to reach areas.

“By using either microwaves or lasers we would be able to beam the energy back down to earth, directly to specific areas. This would provide a reliable, quality source of energy and would remove the need for storing energy coming from renewable sources on ground as it would provide a constant delivery of solar energy.”

If successful, the Suaineadh/SAM project could develop into a source of renewable energy for not only small, remote locations but also neighborhoods, towns and perhaps even entire cities.

“Initially, smaller satellites will be able to generate enough energy for a small village but we have the aim, and indeed the technology available, to one day put a large enough structure in space that could gather energy that would be capable of powering a large city,” Dr. Vasile says.

Read more on the University of Strathclyde Glasgow’s site here.

Image credits: The University of Strathclyde. The project is part of a NASA Institute for Advanced Concepts (NIAC) study. 

sustainableenergyz:

• Solar heating, or the use of sun’s energy for hot water heating, has been used for a far longer time than electric heating. Hence, this method has already been proven with regard to its effectiveness. Indeed it sounds simple, but solar heating is the one efficient way…

scanzen:

3500 mirrors of the Mont-Louis solar furnace, the first solar furnace in the world. In: LIFE Science Library - The engineer by C. C. Furnas, Joe McCarty and the Editors of TIME - LIFE BOOKS (hungarian edition by Műszaki Könyvkiadó,1972).

(via ikenbot)

socialuprooting:

from ZeitNews RSS

8bitfuture:

Printable solar cells could turn anything into an energy source.

A team at MIT has developed a process to ‘print’ solar cells onto almost any surface. Using chemical vapour deposition, the process uses “abundant organic molecules” to convert about 2 percent of the available energy into light. Typical solar panels are around 12-17% efficient, but the team thinks 10% efficiency is achievable.

The cost of installing panels keeps many people from adopting solar power, Barr says. By integrating it into ordinary materials, he thinks he can clear that hurdle. “You’re already hanging a curtain in your house,” he says. “Why not add some energy to that?”

(via theuniverseishuge)