- Email: [email protected]
Efficient conversions
NEWS For more information contact: Isofotón, SA C/ Caleta de Vélez, 52 Polígono Industrial, Santa Teresa 29006, Málaga, Spain. Tel: +34 952 243790. Email: [email protected]
Sharp’s US manufacture Sharp Corporation in Japan will start making solar modules in the US from next April, to help expand its business. Sharp expects its sales of solar modules to reach ¥49bn ($405.1m) this year from ¥31.5bn last year, said Takashi Tomita, GM of the Solar Systems division. Sharp, with total annual sales of about ¥2 trillion ($16.5bn), held 19.2% or the largest share of the world solar battery market in 2001. Tomita said 30% of Sharp’s sales were generated outside Japan in the fiscal year to March, but the company aims to raise that to 50% by 2003/4. It will spend up to ¥500m ($4m) on facilities in Memphis, Tennessee. Consultancy Yano Research Institute said in July that the value of solar shipments in Japan rose to ¥73.01bn in 2001/2, from ¥59.33bn a year earlier, helped by rising exports. For more information go to: www.sharp-usa.com/ sharp-usa/be-sharp/SolarLanding/0,2060,,00.html
Efficient conversions Fullerenes Virginia Tech researchers are putting polymers and fullerenes together using ultra thin fullerenes to act as electron acceptors, which has been found to increase the efficiency of the organic solar cells. The problem nanotechnology solves is the distance between the materials that are electron doners and acceptors. The fullerene has to be within 10 nm of where the light is absorbed so it can create a current. ‘We believe we can improve the efficiency by factors of 5 or 10 through nanoscale control of composition and thickness’ said James R Heflin, associate physics professor at Virginia Tech. ‘We expect organic solar cells to be at least as efficient as silicon within five years.’ For more information contact: Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. Tel: +1 540 231 6000.
Nanotubes Efficient photovoltaic conversion devices may be made from carbon nanotubes. The University of Tokushima and Japan Gain the Summit Co, a Tokyo venture firm, have a device based on carbon nanotubes emitting
September 2002
electrons from the tip when energy is applied from external sources. The prototype is two plate-like electrodes separated by a gap and inside an evacuated glass bottle. The top carbon electrode has numerous nanotube protrusions on the underside. Solar energy absorbed by this causes the nanotubes to emit electrons, picked up by the bottom stainless steel electrode. A wire between electrodes closes the circuit. The prototype energy conversion efficiency is nearly 8% – not particularly high, but proving the concept. For more information contact: University of Tokushima, 2-24 Shinkura-cho, Tokushima 770-850, Japan. Email: [email protected] Or go to: http://www.jgs-g.co.jp
Corrugations The Thin Film Photonics Group, University of Exeter has researched measurement of photoluminescence from corrugate thin films of light-emitting polymers. They found that emission into guided modes, otherwise trapped in the polymer, may Bragg-scatter off corrugations to produce useful, far-field radiation. They compared the efficiency with which radiation is produced by planar and corrugated structures, finding corrugated structures up to a factor of 2.6 more efficient, and indicating how to improve the efficiency of devices based on light emitting thin films. For more information contact: University of Exeter, Northcote House, Queen’s Drive, Exeter EX4QJ, UK. Tel: +44 1392 661000. Email: [email protected]
Down-converter Solar cells could get an efficiency boost of 30%. Martin Green at the University of New South Wales and colleagues say ‘downconverters’ could connect to existing solar cells to double the ‘useful’ photons they capture. A down-converter splits high-energy photons into two lower-energy photons. When a photon reaches the down-converter, it excites an electron into a higher energy level. But the electron returns to its ground state via an intermediate energy level, and emits a lowerenergy photon at each stage. By tuning a downconverter to emit photons with a wavelength corresponding to the energy gap of a solar cell, one high-energy photon could be split into two ‘useful’ photons. This could increase the efficiency of solar cells from the current maximum of about 30% to almost 40%. For more information contact: Martin Green, Centre for Photovoltaic Engineering, University of NSW. Tel:
IN BRIEF Xof1 cross-Canada solar run delayed
The Xof1 solar car team, which was to hit the road in a bid to break distance records by crossing Canada twice, has been thrown off schedule by a technical problem and forced to postpone its trip. ‘The 16,000 km project will now take place during the summer of 2003,’ said team leader Marcelo da Luz ‘The change will allow us more time to properly test the vehicle.’ The problem originated with a tiny sensor embedded in a test model of the high-tech car. When the model was undergoing windtunnel testing a few months ago to fine-tune the car’s aerodynamics, the sensor failed. The delay to replace the sensor and get a new timeslot in the busy wind tunnel in Guelph, Ontario, put the group behind schedule. Xof1 – which stands for ‘power of one’ – is the first solar car project in Canada spearheaded by an individual rather than by formal scientific or research groups. It is is relying on private donations of time and material, and the volunteer group’s goal is to prove that alternative and renewable sources of energy are viable options, and that people who want to take a ‘greener’ approach to life can do so, without government and industry to solve their energy problems for them. The group is cooperating with Osram Sylvania to test a set of extremely bright and energyefficient LEDs to be used as turn signals and brake lights. Xof1 is also working with Shell to fine-tune solar panels to work more efficiently when bonded to the car’s highly curved, aerodynamic body.
Spires solar climbing Spire Corporation, a leading supplier of solar electric systems as well as manufacturing equipment, biomedical products and services, has reported sales of US$4.6m for the second quarter ended June 2002. This is a gain of 53% from the same prior year period. Spire’s Solar Energy revenues were $2.7m, a 50% increase from the same quarter of 2001. Gains were driven by strong growth in Spire Solar Chicago PV systems sales, which recorded $1.8m, an increase of 91% over the same prior year period.
+61 2 9385 4018. Email: [email protected]
Photovoltaics Bulletin
7
Sharp’s US manufacture Sharp Corporation in Japan will start making solar modules in the US from next April, to help expand its business. Sharp expects its sales of solar modules to reach ¥49bn ($405.1m) this year from ¥31.5bn last year, said Takashi Tomita, GM of the Solar Systems division. Sharp, with total annual sales of about ¥2 trillion ($16.5bn), held 19.2% or the largest share of the world solar battery market in 2001. Tomita said 30% of Sharp’s sales were generated outside Japan in the fiscal year to March, but the company aims to raise that to 50% by 2003/4. It will spend up to ¥500m ($4m) on facilities in Memphis, Tennessee. Consultancy Yano Research Institute said in July that the value of solar shipments in Japan rose to ¥73.01bn in 2001/2, from ¥59.33bn a year earlier, helped by rising exports. For more information go to: www.sharp-usa.com/ sharp-usa/be-sharp/SolarLanding/0,2060,,00.html
Efficient conversions Fullerenes Virginia Tech researchers are putting polymers and fullerenes together using ultra thin fullerenes to act as electron acceptors, which has been found to increase the efficiency of the organic solar cells. The problem nanotechnology solves is the distance between the materials that are electron doners and acceptors. The fullerene has to be within 10 nm of where the light is absorbed so it can create a current. ‘We believe we can improve the efficiency by factors of 5 or 10 through nanoscale control of composition and thickness’ said James R Heflin, associate physics professor at Virginia Tech. ‘We expect organic solar cells to be at least as efficient as silicon within five years.’ For more information contact: Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. Tel: +1 540 231 6000.
Nanotubes Efficient photovoltaic conversion devices may be made from carbon nanotubes. The University of Tokushima and Japan Gain the Summit Co, a Tokyo venture firm, have a device based on carbon nanotubes emitting
September 2002
electrons from the tip when energy is applied from external sources. The prototype is two plate-like electrodes separated by a gap and inside an evacuated glass bottle. The top carbon electrode has numerous nanotube protrusions on the underside. Solar energy absorbed by this causes the nanotubes to emit electrons, picked up by the bottom stainless steel electrode. A wire between electrodes closes the circuit. The prototype energy conversion efficiency is nearly 8% – not particularly high, but proving the concept. For more information contact: University of Tokushima, 2-24 Shinkura-cho, Tokushima 770-850, Japan. Email: [email protected] Or go to: http://www.jgs-g.co.jp
Corrugations The Thin Film Photonics Group, University of Exeter has researched measurement of photoluminescence from corrugate thin films of light-emitting polymers. They found that emission into guided modes, otherwise trapped in the polymer, may Bragg-scatter off corrugations to produce useful, far-field radiation. They compared the efficiency with which radiation is produced by planar and corrugated structures, finding corrugated structures up to a factor of 2.6 more efficient, and indicating how to improve the efficiency of devices based on light emitting thin films. For more information contact: University of Exeter, Northcote House, Queen’s Drive, Exeter EX4QJ, UK. Tel: +44 1392 661000. Email: [email protected]
Down-converter Solar cells could get an efficiency boost of 30%. Martin Green at the University of New South Wales and colleagues say ‘downconverters’ could connect to existing solar cells to double the ‘useful’ photons they capture. A down-converter splits high-energy photons into two lower-energy photons. When a photon reaches the down-converter, it excites an electron into a higher energy level. But the electron returns to its ground state via an intermediate energy level, and emits a lowerenergy photon at each stage. By tuning a downconverter to emit photons with a wavelength corresponding to the energy gap of a solar cell, one high-energy photon could be split into two ‘useful’ photons. This could increase the efficiency of solar cells from the current maximum of about 30% to almost 40%. For more information contact: Martin Green, Centre for Photovoltaic Engineering, University of NSW. Tel:
IN BRIEF Xof1 cross-Canada solar run delayed
The Xof1 solar car team, which was to hit the road in a bid to break distance records by crossing Canada twice, has been thrown off schedule by a technical problem and forced to postpone its trip. ‘The 16,000 km project will now take place during the summer of 2003,’ said team leader Marcelo da Luz ‘The change will allow us more time to properly test the vehicle.’ The problem originated with a tiny sensor embedded in a test model of the high-tech car. When the model was undergoing windtunnel testing a few months ago to fine-tune the car’s aerodynamics, the sensor failed. The delay to replace the sensor and get a new timeslot in the busy wind tunnel in Guelph, Ontario, put the group behind schedule. Xof1 – which stands for ‘power of one’ – is the first solar car project in Canada spearheaded by an individual rather than by formal scientific or research groups. It is is relying on private donations of time and material, and the volunteer group’s goal is to prove that alternative and renewable sources of energy are viable options, and that people who want to take a ‘greener’ approach to life can do so, without government and industry to solve their energy problems for them. The group is cooperating with Osram Sylvania to test a set of extremely bright and energyefficient LEDs to be used as turn signals and brake lights. Xof1 is also working with Shell to fine-tune solar panels to work more efficiently when bonded to the car’s highly curved, aerodynamic body.
Spires solar climbing Spire Corporation, a leading supplier of solar electric systems as well as manufacturing equipment, biomedical products and services, has reported sales of US$4.6m for the second quarter ended June 2002. This is a gain of 53% from the same prior year period. Spire’s Solar Energy revenues were $2.7m, a 50% increase from the same quarter of 2001. Gains were driven by strong growth in Spire Solar Chicago PV systems sales, which recorded $1.8m, an increase of 91% over the same prior year period.
+61 2 9385 4018. Email: [email protected]
Photovoltaics Bulletin
7