[amor de cosmos]

Electron ‘spin’ key to solar cell breakthrough
Published
07 Aug 2013

Latest research paves way for inexpensive, high performance cells

Organic solar cells, a new class of solar cell that mimics the natural process of plant photosynthesis, could revolutionise renewable energy - but currently lack the efficiency to compete with the more costly commercial silicon cells.

At the moment, organic solar cells can achieve as much as 12 per cent efficiency in turning light into electricity, compared with 20 to 25 per cent for silicon-based cells.

Now, researchers have discovered that manipulating the 'spin' of electrons in these solar cells dramatically improves their performance, providing a vital breakthrough in the pursuit of cheap, high performing solar power technologies.

http://www.cam.ac.uk/research/news/e...breakthrough-0

Report signals PV boom in the Middle East and North Africa
08. August 2013 | Top News, Global PV markets, Industry & Suppliers, Markets & Trends | By: Ilias Tsagas

A new report examining renewable energy in the MENA region finds that "PV is experiencing rapid growth due to its tremendous potential and continuously decreasing technology costs," with a current pipeline of 2.3 GW.

The International Renewable Energy Agency (IRENA), the Renewable Energy Policy Network for the 21st Century (REN21) and the United Arab Emirates' Directorate of Energy and Climate Change recently published a joint report examining the deployment of renewable energies in the Middle East and North Africa (MENA) region.

MENA region, the report says, is currently characterized by an increasing amount of renewable power investment and a burgeoning project pipeline to harness the region’s abundance of renewable energy resources

http://www.pv-magazine.com/news/deta...ica_100012330/

Self-Healing Solar Cells ‘Channel’ Natural Processes
For Immediate Release
Mick Kulikowski | News Services | 919.515.8387
Dr. Orlin Velev | 919.513.4318
Release Date: 08.07.13

To understand how solar cells heal themselves, look no further than the nearest tree leaf or the back of your hand.

The “branching” vascular channels that circulate life-sustaining nutrients throughout leaves and hands serve as the inspiration for solar cells that can restore themselves efficiently and inexpensively.

In a new paper, North Carolina State University researchers Orlin Velev and Hyung-Jun Koo show that creating solar cell devices with channels that mimic organic vascular systems can effectively reinvigorate solar cells whose performance deteriorates due to degradation by the sun’s ultraviolet rays. Solar cells that are based on organic systems hold the potential to be less expensive and more environmentally friendly than silicon-based solar cells, the current industry standard.

The nature-mimicking devices are a type of dye-sensitized solar cells (DSSCs), composed of a water-based gel core, electrodes, and inexpensive, light-sensitive, organic dye molecules that capture light and generate electric current. However, the dye molecules that get “excited” by the sun’s rays to produce electricity eventually degrade and lose efficiency, Velev says, and thus need to be replenished to reboot the device’s effectiveness in harnessing the power of the sun.

“Organic material in DSSCs tends to degrade, so we looked to nature to solve the problem,” Velev said. “We considered how the branched network in a leaf maintains water and nutrient levels throughout the leaf. Our microchannel solar cell design works in a similar way. Photovoltaic cells rendered ineffective by high intensities of ultraviolet rays were regenerated by pumping fresh dye into the channels while cycling the exhausted dye out of the cell. This process restores the device’s effectiveness in producing electricity over multiple cycles.”

http://news.ncsu.edu/releases/velev_solar_cell_channel/