Naser Al Wasmi for The National UAE: Masdar Institute scientists have published a breakthrough research into more efficient solar power – and they will not have to look far for the raw material needed.
Using sand, they hope to drive concentrated solar power technology to compete with the traditional photovoltaic method.
Named “Sandstock”, the research published at the Solar Power and Chemical Energy Systems Conference in South Africa yesterday, showed sand can withstand temperatures of up to 1,000°C.
Concentrated solar power, or CSP, uses mirrors to reflect heat from the sun to one point, most typically a tower filled with a material capable of storing heat and then converting it into electricity.
CSP’s benefit is that the energy derived is easy to store, but in recent years it has lost out to the more popular photovoltaics, which is more cost-efficient.
That may now change.
“Sand is really always a drawback in this country but in this project we wanted to use it as an advantage because it can withstand very high temperature, and of course it is very cheap here,” said Dr Nicolas Calvet, assistant professor of mechanical and materials engineering, and guide for the research project. Cont'd...
Anmar Frangoul for CNBC: A common sight in the British countryside, bracken -- a type of fern -- is now being hailed as the next big source of biofuel.
Based in the south west of England, Brackenburn produces "brackettes" – biomass pellets made from bracken that they shred and compress into briquettes which produce much more heat when burnt than oak.
"In our estimation there's 2.5 million acres of bracken in the UK… it's a huge area," Barry Smith, Brackenburn's marketing and sales director, told CNBC in a phone interview.
"Left unchecked, bracken encroaches by three percent a year… at the end of the day there's no use for it whatsoever," Smith added. "It's a nuisance and to call it a crop is kind of giving it a status it doesn't deserve." Cont'd...
Matthew Gunther for Chemistry World: Perovskite solar cells may one day rival silicon-based technologies, but their performance outside the laboratory has been a constant source of contention in the past year. Now, an international team of scientists has manufactured the first thin film perovskite solar cell with a reported efficiency that has beenofficially recognised by an accredited national test laboratory.1
Since their development in 2012, the performance of light-harvesting metal–organo halide structures has seemingly improved at a staggering rate, with their efficiency increasing by six percentage points in just two years – the same increase took multi-crystalline solar cells over two decades.
But their stability has been brought into question, with some international test centres taking issue with perovskite solar cells that are so unstable that they may degrade spontaneously in air, making it hard for them to assess their performance.
It’s a state of affairs that Michael Grätzel from the Ecole Polytechnique Fédérale de Lausanne in Switzerland has had trouble dealing with. ‘Conspicuously, you could see that from the very beginning there was very scarce information on the stability of these devices,’ comments Grätzel. ‘I have raised that issue many times – one would think that now everybody does stability work after this alarm was sounded, but not so.' Cont'd...
Invisibility cloaking may be a long way from reality, but the principle could help improve the performance of solar cells in the near term.
In a series of simulations, researchers at the Karlsruhe Institute of Technology have demonstrated how cloaks made of metamaterials or freeform surfaces could eliminate shadows cast by energy-harvesting components onto the active surfaces of solar cells.
Contact fingers, which extract electric current, cover up to one-tenth of the surface area of a solar cell. By guiding light around these features, more of the sun's energy could be captured by the solar cell.
"Our model experiments have shown that the cloak layer makes the contact fingers nearly completely invisible," said doctoral student Martin Schumann. Cont'd...
By Kelly Hodgkins for Digital Trends: A team of engineers from Stanford University have invented a cool way to improve the performance of solar panel arrays. A new material that the team produced literally will lower the temperature of solar cells even while they are operating in full-strength sunlight. As the solar cells cool, their efficiency will rise, leading to significant gains in the amount of energy harvested from the sun.
Solar panel technology has improved by leaps and bounds, but the technology has a flaw that limits the efficiency of the system. The panels must face the sun to operate, but the heat from this exposure diminishes their ability to convert light into energy. The hotter they get, the less efficient they become. This issue has perplexed the industry for years, but the Stanford team may have discovered a material that can help dissipate this excess heat without affecting the operation of the solar array.
The solution, proposed by Stanford electrical engineering professor Shanhui Fan, research associate Aaswath P. Raman, and doctoral candidate Linxiao Zhu, uses a material that is able to capture and emit thermal radiation (heat) away from the solar call. While deterring heat buildup, the thin, patterned silica material does not block sunlight, allowing the photons to enter the solar panel where they are converted to energy. It’s a win-win situation, allowing the free flow of sunlight and the removal of excess heat from the system. Cont'd...
By Lucas Mearian for Computerworld: Manhattan has approximately 47,000 buildings with around 10.7 million windows, according to a 2013estimate from The New York Times.
Now imagine if just 1% -- or 100,700 -- of those windows could generate electricity through transparent photovoltaics.
That's the idea behind solar power windows, and at least two companies are hoping to sell the technology to window manufacturers, saying once installed in a building the technology will pay for itself in about a year.
"If you look at the glass that's manufactured worldwide today, 2% of it is used for solar panels; 80% of it is used in buildings. That's the opportunity," said Suvi Sharma, CEO of solar panel maker Solaria. Cont'd...
Megan Treacy for TreeHugger: When we think of antennas we mainly think of the type that transmit and receive radio waves, letting us listen to radio stations in our car or watch TV in our homes, but in this case the researchers are using the term to describe a new thin film material that captures more of the light spectrum, converting it into wavelengths of light that solar cells can convert into electricity.
Many scientists are working on building better solar cells, but researchers at the University of Connecticut wanted to figure out how to boost the efficiency of the technology we already have. Thus, the antenna.
As Phys.org reports, Challa V. Kumar, Ph.D and his team "built an antenna that collects those unused blue photons and converts them to lower energy photons that the silicon can then turn into current."
"Many groups around the world are working hard to make this kind of antenna, and ours is the first of its kind in the whole world," Kumar said. Cont'd...
By Michael McDonald for OilPrice.com: As the oil price bust continues, renewable energy and sustainability innovation is continuing unabated. For instance, an architecture company recently unveiled a set of plans for a smart floating farm project that helps preserve land space and improve food production efficiency. The plans are just hypothetical at this point and it is unclear if they will ever be built, but that’s not really the point. The project shows that, around the world, companies and individuals continue to devote time and resources to innovation in sustainable living.
In a similar vein for instance, in the solar field, small companies are creating a host of new innovative products like new inverters and module level electronics. Many of these innovations may seem trivial and iterative. And many are, but a series of trivial and iterative innovations can still lead to big change and that has solar proponents excited.
Big changes are also occurring on more visible systems. A company called Ripasso Energy is pushing its new, more efficient solar generators. In a highly visible effort, Tesla is pressing ahead with its home and business battery storage systems. Desalinization with solar and even solar planes are also on the horizon.
The vast majority of these innovations are too early stage for investors to make serious bets on, and even if an investor could be in on an individual technology, that approach is risky. Instead, investors are better off putting their dollars into firms that consistently show an innovative spirit and are pressing forward with a broad portfolio of product innovations. These kinds of broad sets of innovations are important to the future of the planet and they can generate serious returns for sage investors as well. Cont'd...
How SolarWindow is Bringing World's First-of-Their-Kind Electricity-Generating Windows to Market - August 20th Webcast
A team of researchers has come up with a solar cell that produces fuel rather than electricity. A material called gallium phosphide enables the solar cell to produce clean fuel hydrogen gas from liquid water.
To connect an existing silicon solar cell to a battery that splits the water may well be an efficient solution; but it is very expensive.
So, researchers were streamlining their search to a semi-conductor material that is able to both convert sunlight into an electrical charge and split water.
The team found gallium phosphide (GaP), a compound of gallium and phosphide, useful in this respect.
GaP has good electrical properties but the drawback is that it cannot easily absorb light when it is a large flat surface as used in GaP solar cells, said the study thatappeared in Nature Communications.
The researchers overcame this by making a grid of very small GaP nanowires, measuring five hundred nanometres (a millionth of a millimetre) long and ninety nanometres thick.
"That makes these kinds of cells potentially a great deal cheaper," said lead author Erik Bakkers from Eindhoven University of Technology, the Netherlands. Cont'd...
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