Abengoa’s Gigantic “Salt Battery” Stores Utility-Scale Solar Energy

It is also the first solar plant in the U.S. with thermal energy storage, in the form of a molten salt system. The storage capacity is about six hours. That enables the plant to keep generating electricity from solar energy well into the early evening hours, when demand in the region typically peaks out.

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Plasmonic nanostructures could prove a boon to solar cell technology

Researchers at the University of Pennsylvania have found a way to harvest energy from sunlight more efficiently, with the help of so-called plasmonic nanostructures. The new findings suggest that plasmonic components can enhance and direct optical scattering, creating a mechanism that is more efficient than the photoexcitation that drives solar cells. The development could therefore provide a real boost to solar cell efficiency and lead to faster optical communication.

http://www.gizmag.com/plasmonic-nanostructures-solar/29067/

Solar Cell Advance...perovskite cells

The Oxford team has demonstrated that perovskite cells are just as efficient if they are constructed in the same flat design, and using the same method—known as vapor deposition—as cheap thin-film silicon cells. “Having started with a complicated nanostructure, we’ve reduced it to a thin film,” Snaith says. “It’s amusing, I agree!”

http://news.sciencemag.org/physics/2013/09/flat-out-major-advance-emerging-solar-cell-technology

Rooftop Solar Panels Become Growing Threat to Firefighters

Thursday, 05 Sep 2013 02:31 PM

 http://www.newsmax.com/US/solar-panels-firefighters-danger/2013/09/05/id/524042#ixzz2e3Z47Stq 

Spray-On Solar Cells — New, Inexpensive Nanoparticles Lower Solar Cell Manufacturing Costs

Relatively inexpensive, easy-to-manufacture, nanoparticle-based solar cells can be created with materials that are abundantly common throughout the Earth’s crust, according to new work from researchers at the University of Alberta. The new nanoparticle-based solar cells — which could be mass-manufactured using simple methods, such as roll-to-roll printing or spray-coating — are possible thanks to a new type of nanoparticle designed by the researchers.

The researchers think that the new design/discovery — which according to them has been several years in the making — “is an important step forward in making solar power more accessible to parts of the world that are off the traditional electricity grid or face high power costs, such as the Canadian North.”

Read more at http://cleantechnica.com/2013/09/01/spray-on-solar-cells-new-inexpensive-nanoparticles-lower-solar-cell-manufacturing-costs/#ct5yMRvLSHdcUY7g.99

A Material Could Make Solar Panels "Dirt Cheap"

A new type of solar cell, made from a material that is dramatically cheaper to obtain and use than silicon, could generate as much power as today’s commodity solar cells.

Researchers developing the technology say that it could lead to solar panels that cost just 10 to 20 cents per watt. Solar panels now typically cost about 75 cents a watt, and the U.S. Department of Energy says 50 cents per watt will allow solar power to compete with fossil fuel.

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50% Solar Cell Efficiency?

Is the 50% efficient solar cell on the horizon?

by Amanda Alvarez

 

9 HOURS AGO

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SUMMARY:

Is there a solar panel coming that can convert an unheard-of 50 percent of the suns light into electricity. Some early research indicates that yes, it’s possible, though it might take many more years to commercialize.

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The summer sunshine is upon us, at least here on the East Coast, which means it’s the perfect time to think about how best to harness those golden rays for clean energy. The solar industry’s power players put their newest tech on display at last week’s Intersolar North America conference in San Francisco, despite the industry’s slightly depressed showing this year (see Ucilia Wang’s report from the trade show floor).

Nonetheless, despite these recent business shadows, there have been glimmers of research progress. At the conference Alta Devices, for example, presented technology that can boost solar cell efficiency to between 30 percent and an unprecedented 50 percent or more, using both materials and optical advances.

Best research photovoltaic cell efficiencies Rev. 06-2013

Besides the solar market slump, constraints imposed purely by physics have also been the bane of solar cell manufacturers. Many modern commercial cells hover around the 10-20 percent efficiency mark, and boosting efficiency is a major R&D focus for many companies. There are lots of reasons why solar cells can’t reach 100 percent efficiency: blackbody radiation (think of it as ambient energy evaporation), the PV materials used, and their capacity to accommodate electrons. Oddly, photons themselves can also be a roadblock to optimal efficiency.

Traditional solar cells can only collect one wavelength of light and are constrained by the Shockley-Queisser limit, which dictates that the maximum efficiency of an ideal solar cell can never exceed 33.7 percent. That’s because in traditional single-junction solar cells, the bandgap between two semiconductor materials defines how well the photons are converted into electrons within the cell. In this scenario, capturing photons whose energy is well-matched to the materials’ specific bandgapis crucial.

Fortunately, silicon and other semiconducting materials are pretty well-matched in their bandgaps to harness the sun’s natural spectral distribution. But spreading your photonic net across wavelengths could yield more energy-producing photons. That’s what multi-junction or tandem cells, like those from Alta Devices, aim to do.

In March, Alta Devices announced their solar cells had exceeded 30 percent efficiency, and at Intersolar last week founder and Caltech professor Harry Atwater outlined how the company plans to break the 50 percent efficiency barrier. Photon recycling and epitaxial lift-off (check out this earlier story for an explainer) are the two main factors distinguishing Alta’s cells, whose super thin gallium arsenide films are currently more efficient than traditional PV materials like silicon. They are, however, also more expensive, and may thus best serve niche markets where performance requirements trump cost. Alta is focusing on mobile deployments of its tech, from unmanned aerial vehicles to transportable solar arrays.

According to Atwater, simulations indicate that efficiencies in multi-junction cells can continue to increase, provided the structure of the cells is appropriately tweaked. The stacking of thin film layers and using tuned materials to cover the entire wavelength spectrum are some of the main considerations. By iterating and improving the PV design over these parameters, efficiencies of 50 percent or greater should be achievable.

Spectrum splitting – using optical methods to reflect and redirect incident light to appropriate layers – and using lenses or mirrors as concentrators are two accessory ways to further improve solar efficiency that Alta and others are pursuing. With light concentrators, the argument is that fewer solar cells are then needed, leading to potential cost and area savings. The snag is that you need a device, like the QBotix robot, to track the sun, and you need to funnel the energy of hundreds of suns into the system. Companies that use solar concentrators, like Solar Junction, have achieved over 40 percent efficiency with their cells in this way.

The future for solar efficiency is thus bright, in theory, but materials costs and technical hurdles related to manufacturing intricate multi-junction cells may keep these advances from being fully realized for the time being.

http://gigaom.com/2013/07/18/is-the-50-efficient-solar-cell-on-the-horizon/