The world's largest solar plant is planned for the Mongolian desert of China.
Arizona-based First Solar Inc. and Ordos City in China signed an agreement Tuesday to build what will be a 2-gigawatt solar installation.
The Ordos City project will generate 2,000 megawatts of electricity, enough to power 3 million Chinese homes, with a field of panels stretching for 25 square miles.
It will start as a 30-megawatt demonstration unit with construction beginning in June 2010 and additional phases to come online in 2014 and 2019.
"This major commitment to solar power is a direct result of the progressive energy policies being adopted in China to create a sustainable, long-term market for solar and a low carbon future for China," First Solar chief executive officer Mike Ahearn said in a news release. "It represents an encouraging step forward toward the mass-scale deployment of solar power worldwide to help mitigate climate change concerns."
China announced in July that its renewable energy is expected to represent 10 percent of the country's energy resources by 2010 and 15 percent by 2020.
While financial terms of the deal have not yet been reached, First Solar will operate the plant under China's feed-in tariff, which guarantees prices paid for renewable power.
"This type of forward-looking government policy is necessary to create a strong solar market and facilitate the construction of a project of this size, which in turn continues to drive the cost of solar electricity closer to 'grid parity' -- where it is competitive with traditional energy sources," First Solar said in the release.
Ahearn said that in the United States, a solar plant of this size would cost $5 billion to $6 billion, but it is cheaper to build in China. He did not specify the cost of the Ordos City project.
The project is part of an 11,950-megawatt renewable-energy park planned for Ordos City in Inner Mongolia.
Plans for the park include wind farms to generate 6,950 megawatts, photovoltaic power plants to provide 3,900 megawatts and solar thermal farms to supply 720 megawatts, The New York Times reports.
Noting that China is home to Suntech, the world's third-largest solar module maker, it is "quite significant" that China is "importing a U.S. world leader to the marketplace," said Nathaniel Bullard, a solar analyst at London-based New Energy Finance, the Times reports. "This is going to help ensure technological leadership and not just manufacturing leadership."
China is the world's largest consumer of coal, which accounts for nearly 80 percent of the country's electricity generation.
Statistics from the China Renewable Energy Society suggest that at least two-thirds of China gets more than 2,200 hours of sunshine per year, making China's potential solar energy resources equivalent to 1.7 trillion tons of coal.
Source - Solar Daily
Showing posts with label solar electricity. Show all posts
Showing posts with label solar electricity. Show all posts
Sunday, 13 September 2009
Monday, 31 August 2009
The UK government hates solar panels
Politicians, like the rest of us, are always being urged to “think big”. But, for me, the most interesting issue over the next week or so is going to be rather different: is Ed Miliband big enough to think small?
The question arises because our precocious young Energy and Climate Change Secretary is about to publish plans for a tenfold increase in renewable energy in Britain in little over a decade. The strategy will show whether Mr Miliband has more faith in the British people or in (and I fully realise that this is saying something) possibly the most incompetent and obscurantist collection of civil servants in Whitehall.
Let me explain. For decades, Britain has generated its energy from big installations: whopping great fossil fuel power stations that belch out carbon dioxide to add to global warming; mammoth nuclear power stations with a shocking record of construction delays and cost overruns; oversized wind farms, sometimes plonked down in wholly inappropriate places.
But it’s becoming clear that an excellent way to generate renewable energy is on a small – even household – scale, through rooftop solar panels. Despite the initial cost, the “fuel” is distributed free by nature, without the need for long pipes or power lines, and costs little or nothing to tap once the installation has been paid for. Families gain greater independence, and possibly some income from selling the surplus to the grid.
Last year, a report backed by Lord Mandelson’s Department for Business, Enterprise and Regulatory Reform (as was) concluded that, with proper encouragement, nine million British homes could be using such “microgeneration” by 2020, producing the same amount of electricity as five nuclear power stations. After just another decade, it went on, this could prevent the emission of as much carbon dioxide as taking all of the country’s buses and lorries off the road.
Sounds great? Not to the official ear. Civil servants in successive energy departments have always hated the idea of microgeneration, and done all they could to stifle it.
And why? Because it means someone else – worse, millions of someone elses – make decisions instead of them. And, as every mandarin believes, the man from Whitehall knows best.
In fact, as Daily Telegraph readers know, the man – and (let’s not be sexist) the woman – from Whitehall usually knows worst. After all, these people who trust you so little are the same bunch of dunderheads who pressed unrelentingly for the building of the mixed-oxide nuclear plant at Sellafield.
This white dinosaur, which has cost the taxpayer £1 billion, was supposed to produce 120 tons of nuclear fuel a year, but managed only a total of 6.3 tonnes between its opening in 2001 and April this year. (But never mind – there are proposals to build another one to make up for it.)
There might conceivably be some excuse for all this arrogance, if ordinary people took irrational, random decisions. But, of course, they don’t.
Other countries have easily devised measures that have ensured a rapid expansion of microgeneration. Germany guarantees generous “feed-in tariffs” for selling home-generated solar electricity to the grid; as a result, in 2007, 130,000 solar roofs were installed, compared with 270 in Britain.
Even in Bangladesh, more than 200,000 poor families have installed solar cells with the help of microcredit loans, bringing power to their villages for the first time and making money by selling it to their neighbours.
British ministers condemned Germany’s successful scheme as “a regulatory nightmare”. Instead, they reluctantly offered families grants to help towards the cost of installation – slashing them back to below incentive levels as soon as they started to be taken up. But now, in a U-turn, Mr Miliband is poised to introduce feed-in tariffs.
Will they be good and generous enough to work? Not, I’ll bet, if the officials can help it: they could well scupper microgeneration again.
A Tory minister would not let them do it: David Cameron understands the importance of this, and the self-reliance and individual initiative it encourages fits in well with his party’s values. But does perhaps the most promising Labour politician of the same generation get it, too? We’ll soon know.
Renewable energy is just the job
Is this an encouraging straw in a chill wind? In the South West, it seems, green firms and jobs are growing “at a dramatic rate”.
A new report – snappily entitled the Economic Contribution of the Renewable Energy and Energy Efficiency Sectors in the South West of England – surveyed 100 firms and found that their turnover had almost doubled over the last, recession-hit year, with the number of staff increasing by 40 per cent.
South Korea this week announced that it planned to create 1.8 million jobs over the next five years by developing solar power, hybrid cars and energy-efficient lighting. Barack Obama has promised to provide work for five million by investing in renewable energy, while David Cameron says: “Decarbonising Britain will help create hundreds of thousands of jobs.”
But will it work? Environmentalists brandish studies, like one from the Massachusetts Institute of Technology that concludes that investing in green technologies employs nearly four times as many people as traditional investment. Sceptics repeatedly refer to a Spanish report that says that 2.2 jobs are lost for every new green one created.
In truth, no one knows. But green measures, like insulating buildings, are often particularly labour-intensive.
Renewable energy seems to provide at least three times as much work per dollar (or pound) as fossil fuels; recycling rubbish employs 10 times as many people as dumping it. So we may soon have a new term: “green-collar jobs”.
Green day? More like dirty brown
Sacré vert! Yesterday, as you may have noticed, was Green Britain Day. Except that it was actually organised by a nationalised French company, which boasts of being “one of the largest participants in the global coal market”.
The day aimed to urge us to “start living low-carbon lives” and to “start making changes” to “be part of a movement to reduce Britain’s carbon footprint”. Yet EDF proudly reports that it “imports around 30 million tons of physical coal a year”.
I don’t know if there is a French word for “greenwash”, but the firm might care to look it up.
Just to add injury to insult, EDF’s logo for the day – a green Union flag – is remarkably similar to one used by a genuinely green energy company, Ecotricity. Dale Vince, its chief executive, says he asked the French company to stop using it.
As a result, he received a phone call from an Andrew Brown, followed the same day by a message from a lawyer saying it would cost £6 million to do so. So he’s now taking the French giant to court.
Andrew Brown? Doesn’t that ring a bell? Yes, it’s the Prime Minister’s brother – the First Sibling, we might call him – who just happens to be EDF’s PR chief.
So here’s an idea for the company. Why doesn’t it “start making changes now” by getting out of coal, the world’s dirtiest fuel?
Otherwise, it could try colouring the flag Brown.
Source - Telegraph
The question arises because our precocious young Energy and Climate Change Secretary is about to publish plans for a tenfold increase in renewable energy in Britain in little over a decade. The strategy will show whether Mr Miliband has more faith in the British people or in (and I fully realise that this is saying something) possibly the most incompetent and obscurantist collection of civil servants in Whitehall.
Let me explain. For decades, Britain has generated its energy from big installations: whopping great fossil fuel power stations that belch out carbon dioxide to add to global warming; mammoth nuclear power stations with a shocking record of construction delays and cost overruns; oversized wind farms, sometimes plonked down in wholly inappropriate places.
But it’s becoming clear that an excellent way to generate renewable energy is on a small – even household – scale, through rooftop solar panels. Despite the initial cost, the “fuel” is distributed free by nature, without the need for long pipes or power lines, and costs little or nothing to tap once the installation has been paid for. Families gain greater independence, and possibly some income from selling the surplus to the grid.
Last year, a report backed by Lord Mandelson’s Department for Business, Enterprise and Regulatory Reform (as was) concluded that, with proper encouragement, nine million British homes could be using such “microgeneration” by 2020, producing the same amount of electricity as five nuclear power stations. After just another decade, it went on, this could prevent the emission of as much carbon dioxide as taking all of the country’s buses and lorries off the road.
Sounds great? Not to the official ear. Civil servants in successive energy departments have always hated the idea of microgeneration, and done all they could to stifle it.
And why? Because it means someone else – worse, millions of someone elses – make decisions instead of them. And, as every mandarin believes, the man from Whitehall knows best.
In fact, as Daily Telegraph readers know, the man – and (let’s not be sexist) the woman – from Whitehall usually knows worst. After all, these people who trust you so little are the same bunch of dunderheads who pressed unrelentingly for the building of the mixed-oxide nuclear plant at Sellafield.
This white dinosaur, which has cost the taxpayer £1 billion, was supposed to produce 120 tons of nuclear fuel a year, but managed only a total of 6.3 tonnes between its opening in 2001 and April this year. (But never mind – there are proposals to build another one to make up for it.)
There might conceivably be some excuse for all this arrogance, if ordinary people took irrational, random decisions. But, of course, they don’t.
Other countries have easily devised measures that have ensured a rapid expansion of microgeneration. Germany guarantees generous “feed-in tariffs” for selling home-generated solar electricity to the grid; as a result, in 2007, 130,000 solar roofs were installed, compared with 270 in Britain.
Even in Bangladesh, more than 200,000 poor families have installed solar cells with the help of microcredit loans, bringing power to their villages for the first time and making money by selling it to their neighbours.
British ministers condemned Germany’s successful scheme as “a regulatory nightmare”. Instead, they reluctantly offered families grants to help towards the cost of installation – slashing them back to below incentive levels as soon as they started to be taken up. But now, in a U-turn, Mr Miliband is poised to introduce feed-in tariffs.
Will they be good and generous enough to work? Not, I’ll bet, if the officials can help it: they could well scupper microgeneration again.
A Tory minister would not let them do it: David Cameron understands the importance of this, and the self-reliance and individual initiative it encourages fits in well with his party’s values. But does perhaps the most promising Labour politician of the same generation get it, too? We’ll soon know.
Renewable energy is just the job
Is this an encouraging straw in a chill wind? In the South West, it seems, green firms and jobs are growing “at a dramatic rate”.
A new report – snappily entitled the Economic Contribution of the Renewable Energy and Energy Efficiency Sectors in the South West of England – surveyed 100 firms and found that their turnover had almost doubled over the last, recession-hit year, with the number of staff increasing by 40 per cent.
South Korea this week announced that it planned to create 1.8 million jobs over the next five years by developing solar power, hybrid cars and energy-efficient lighting. Barack Obama has promised to provide work for five million by investing in renewable energy, while David Cameron says: “Decarbonising Britain will help create hundreds of thousands of jobs.”
But will it work? Environmentalists brandish studies, like one from the Massachusetts Institute of Technology that concludes that investing in green technologies employs nearly four times as many people as traditional investment. Sceptics repeatedly refer to a Spanish report that says that 2.2 jobs are lost for every new green one created.
In truth, no one knows. But green measures, like insulating buildings, are often particularly labour-intensive.
Renewable energy seems to provide at least three times as much work per dollar (or pound) as fossil fuels; recycling rubbish employs 10 times as many people as dumping it. So we may soon have a new term: “green-collar jobs”.
Green day? More like dirty brown
Sacré vert! Yesterday, as you may have noticed, was Green Britain Day. Except that it was actually organised by a nationalised French company, which boasts of being “one of the largest participants in the global coal market”.
The day aimed to urge us to “start living low-carbon lives” and to “start making changes” to “be part of a movement to reduce Britain’s carbon footprint”. Yet EDF proudly reports that it “imports around 30 million tons of physical coal a year”.
I don’t know if there is a French word for “greenwash”, but the firm might care to look it up.
Just to add injury to insult, EDF’s logo for the day – a green Union flag – is remarkably similar to one used by a genuinely green energy company, Ecotricity. Dale Vince, its chief executive, says he asked the French company to stop using it.
As a result, he received a phone call from an Andrew Brown, followed the same day by a message from a lawyer saying it would cost £6 million to do so. So he’s now taking the French giant to court.
Andrew Brown? Doesn’t that ring a bell? Yes, it’s the Prime Minister’s brother – the First Sibling, we might call him – who just happens to be EDF’s PR chief.
So here’s an idea for the company. Why doesn’t it “start making changes now” by getting out of coal, the world’s dirtiest fuel?
Otherwise, it could try colouring the flag Brown.
Source - Telegraph
Saturday, 20 June 2009
Solar Electricity Goes Mainstream
David Egles, one of Canada's leading authorities on the solar industry, applauds the Green Energy Act passed in Ontario.
"This could be the beginning of solar electricity going mainstream," says Egles, founder and President of Canada's foremost provider of home solar systems, Home Energy Solutions
"Solar electricity has the potential to provide significant amounts of clean energy to power Ontario homes, simply by using existing roofs," says Egles.
"The Green Energy Act will promote the growth of the solar industry, resulting in lower costs and cheaper energy in the long run."
Through the Green Energy Act's solar feed-in tariffs, homeowners installing up to 10-kilowatt solar systems are eligible to receive $0.80 for each kilowatt of excess energy their systems deliver for the next 20 years. A complete 10-kilowatt system costs approximately $100,000; on a south-facing roof, it would generate approximately $9,600 each year in income.
"An investment in solar has a strong financial yield while being a green, ethical investment," says Egles. "Over two decades, homeowners can recoup twice their initial cost - and then continue to reap all the benefits of an environment-friendly energy system."
Source - Solar Daily
"This could be the beginning of solar electricity going mainstream," says Egles, founder and President of Canada's foremost provider of home solar systems, Home Energy Solutions
"Solar electricity has the potential to provide significant amounts of clean energy to power Ontario homes, simply by using existing roofs," says Egles.
"The Green Energy Act will promote the growth of the solar industry, resulting in lower costs and cheaper energy in the long run."
Through the Green Energy Act's solar feed-in tariffs, homeowners installing up to 10-kilowatt solar systems are eligible to receive $0.80 for each kilowatt of excess energy their systems deliver for the next 20 years. A complete 10-kilowatt system costs approximately $100,000; on a south-facing roof, it would generate approximately $9,600 each year in income.
"An investment in solar has a strong financial yield while being a green, ethical investment," says Egles. "Over two decades, homeowners can recoup twice their initial cost - and then continue to reap all the benefits of an environment-friendly energy system."
Source - Solar Daily
Sunday, 7 June 2009
Lasers Are Making Solar Cells Competitive
Solar electricity has a future: It is renewable and available in unlimited quantities, and it does not produce any gases detrimental to the climate. Its only drawback right now is the price: the electric power currently being produced by solar cells in northern Europe must be subsidized if it is to compete against the household electricity generated by traditional power plants.
At "Laser 2009" in Munich, June 15 to 18, Fraunhofer researchers will be demonstrating how laser technology can contribute to optimizing the manufacturing costs and efficiency of solar cells.
Cell phones, computers, MP3 players, kitchen stoves, and irons all have one thing in common: They need electricity. And in the future, more and more cars will also be fuelled by electric power. If the latest forecast from the World Energy Council WEC can be believed, global electricity requirements will double in the next 40 years. At the same time, prices for the dwindling resources of petroleum and natural gas are climbing.
"Rising energy prices are making alternative energy sources increasingly cost-effective. Sometime in the coming years, renewable energy sources, such as solar energy, will be competitive, even without subsidization," explains Dr. Arnold Gillner, head of the microtechnology department at the Fraunhofer Institute for Laser Technology in Aachen, Germany.
"Experts predict that grid parity will be achieved in a few years. This means that the costs and opportunities in the grid will be equal for solar electricity and conventionally generated household electricity." Together with his team at the Fraunhofer Institute for Laser Technology ILT in Aachen, this researcher is developing technologies now that will allow faster, better, and cheaper production of solar cells in the future.
"Lasers work quickly, precisely, and without contact. In other words, they are an ideal tool for manufacturing fragile solar cells. In fact, lasers are already being used in production today, but there is still considerable room for process optimization."
In addition to gradually improving the manufacturing technology, the physicists and engineers in Aachen are working with solar cell developers - for example, at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg - on new engineering and design alternatives.
New production technologies allow new design alternatives
At "Laser 2009" in Munich, the researchers will be demonstrating how lasers can drill holes into silicon cells at breathtaking speed: The ILT laser system drills more than 3,000 holes within one second. Because it is not possible to move the laser source at this speed, the experts have developed optimized manufacturing systems which guide and focuses the light beam at the required points.
"We are currently experimenting with various laser sources and optical systems," Gillner explains. "Our goal is to increase the performance to 10,000 holes a second. This is the speed that must be reached in order to drill 10,000 to 20,000 holes into a wafer within the cycle time of the production machines."
The tiny holes in the wafer - their diameter is only 50 micrometers - open up undreamt-of possibilities for the solar cell developers.
"Previously, the electrical contacts were arranged on the top of the cells. The holes make it possible to move the contacts to the back, with the advantage that the electrodes, which currently act as a dark grid to absorb light, disappear. And so the energy yield increases. The goal is a degree of efficiency of 20 percent% in industrially-produced emitter wrap-through (EWT) cells, with a yield of one-third more than classic silicon cells," Gillner explains.
The design principle itself remains unchanged: In the semi-conductor layer, light particles, or photons, produce negative electrons and positive holes, each of which then wanders to the oppositely poled electrodes.
The contacts for anodes and cathodes in the EWT cells are all on the back, there is no shading caused by the electrodes, and the degree of efficiency increases. With this technique, it may one day be possible to use unpurified "dirty" silicon to manufacture solar cells that have poorer electrical properties, but that are cheaper.
Drilling holes into silicon cells is only one of many laser applications in solar cell manufacturing. In the EU project Solasys - Next Generation Solar Cell and Module Laser Processing Systems - an international research team is currently developing new technologies that will allow production to be optimized in the future. ILT in Aachen is coordinating the six million euro project.
"We are working on new methods that make the doping of semiconductors, the drilling and the surface structuring of silicon, the edge isolation of the cells, and the soldering of the modules more economical," project coordinator Gillner explains. For example, "selective laser soldering" makes it possible to improve the rejection rates and quality of the contacting, and so reduce manufacturing costs.
Until now, the electrodes were mechanically pressed onto the cells, and then heated in an oven. "But silicon cells often break during this process," Gillner knows. "Breakage is a primary cost factor in production." On the other hand, however, with "selective laser soldering" the contacts are pressed on to the cells with compressed air and then soldered with the laser.
The mechanical stress approaches zero and the temperature can be precisely regulated. The result: Optimal contacts and almost no rejects.
Laser technology means more efficient thin film cells
Laser technology is also helping to optimize the manufacture of thin film solar cells. The extremely thin film packages made of semiconducting oxide, amorphous silicon, and metal that are deposited onto the glass panels still have a market share of only ten percent.
But as Gillner knows, "This could be higher, because thin film solar cells can be used anywhere that non-transparent glass panels can be mounted, for example, on house facades or sound-insulating walls. But the degrees of efficiency are comparable low at five to eight percent, and the production costs are comparatively high."
The laser researchers are working to improve these costs. Until now, the manufacturers have used mechanical methods or solid-state lasers in the nanosecond range in order to structure the active layers on the glass panels. In order to produce electric connections between the semiconductor and the metal, grooves only a few micrometers wide must be created.
At the Fraunhofer-Gesellschaft booth at "Laser 2009" the ILT researchers will be demonstrating a 400-watt ultrashort pulse laser that processes thin-film solar modules ten times faster than conventional diode-pumped solid-state lasers.
"The ultrashort pulse laser is an ideal tool for ablating thin layers: It works very precisely, does not heat the material and, working with a pulse frequency of 80 MHz, can process a 2-by-3 meter glass panel in under two minutes," Gillner reports. "The technology is still very new, and high-performance scanning systems and optical systems adapted to the process must be developed first. In the medium term, however, this technology will be able to reduce production costs."
The rise of laser technology in solar technology is just taking off, and it still has a long way to go. "Lasers simplify and optimize the manufacture of classic silicon and thin-film cells, and they allow the development of new design alternatives," Gillner continues. "And so laser technology is making an important contribution towards allowing renewable energy sources to penetrate further into the energy market."
Source - Solardaily
At "Laser 2009" in Munich, June 15 to 18, Fraunhofer researchers will be demonstrating how laser technology can contribute to optimizing the manufacturing costs and efficiency of solar cells.
Cell phones, computers, MP3 players, kitchen stoves, and irons all have one thing in common: They need electricity. And in the future, more and more cars will also be fuelled by electric power. If the latest forecast from the World Energy Council WEC can be believed, global electricity requirements will double in the next 40 years. At the same time, prices for the dwindling resources of petroleum and natural gas are climbing.
"Rising energy prices are making alternative energy sources increasingly cost-effective. Sometime in the coming years, renewable energy sources, such as solar energy, will be competitive, even without subsidization," explains Dr. Arnold Gillner, head of the microtechnology department at the Fraunhofer Institute for Laser Technology in Aachen, Germany.
"Experts predict that grid parity will be achieved in a few years. This means that the costs and opportunities in the grid will be equal for solar electricity and conventionally generated household electricity." Together with his team at the Fraunhofer Institute for Laser Technology ILT in Aachen, this researcher is developing technologies now that will allow faster, better, and cheaper production of solar cells in the future.
"Lasers work quickly, precisely, and without contact. In other words, they are an ideal tool for manufacturing fragile solar cells. In fact, lasers are already being used in production today, but there is still considerable room for process optimization."
In addition to gradually improving the manufacturing technology, the physicists and engineers in Aachen are working with solar cell developers - for example, at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg - on new engineering and design alternatives.
New production technologies allow new design alternatives
At "Laser 2009" in Munich, the researchers will be demonstrating how lasers can drill holes into silicon cells at breathtaking speed: The ILT laser system drills more than 3,000 holes within one second. Because it is not possible to move the laser source at this speed, the experts have developed optimized manufacturing systems which guide and focuses the light beam at the required points.
"We are currently experimenting with various laser sources and optical systems," Gillner explains. "Our goal is to increase the performance to 10,000 holes a second. This is the speed that must be reached in order to drill 10,000 to 20,000 holes into a wafer within the cycle time of the production machines."
The tiny holes in the wafer - their diameter is only 50 micrometers - open up undreamt-of possibilities for the solar cell developers.
"Previously, the electrical contacts were arranged on the top of the cells. The holes make it possible to move the contacts to the back, with the advantage that the electrodes, which currently act as a dark grid to absorb light, disappear. And so the energy yield increases. The goal is a degree of efficiency of 20 percent% in industrially-produced emitter wrap-through (EWT) cells, with a yield of one-third more than classic silicon cells," Gillner explains.
The design principle itself remains unchanged: In the semi-conductor layer, light particles, or photons, produce negative electrons and positive holes, each of which then wanders to the oppositely poled electrodes.
The contacts for anodes and cathodes in the EWT cells are all on the back, there is no shading caused by the electrodes, and the degree of efficiency increases. With this technique, it may one day be possible to use unpurified "dirty" silicon to manufacture solar cells that have poorer electrical properties, but that are cheaper.
Drilling holes into silicon cells is only one of many laser applications in solar cell manufacturing. In the EU project Solasys - Next Generation Solar Cell and Module Laser Processing Systems - an international research team is currently developing new technologies that will allow production to be optimized in the future. ILT in Aachen is coordinating the six million euro project.
"We are working on new methods that make the doping of semiconductors, the drilling and the surface structuring of silicon, the edge isolation of the cells, and the soldering of the modules more economical," project coordinator Gillner explains. For example, "selective laser soldering" makes it possible to improve the rejection rates and quality of the contacting, and so reduce manufacturing costs.
Until now, the electrodes were mechanically pressed onto the cells, and then heated in an oven. "But silicon cells often break during this process," Gillner knows. "Breakage is a primary cost factor in production." On the other hand, however, with "selective laser soldering" the contacts are pressed on to the cells with compressed air and then soldered with the laser.
The mechanical stress approaches zero and the temperature can be precisely regulated. The result: Optimal contacts and almost no rejects.
Laser technology means more efficient thin film cells
Laser technology is also helping to optimize the manufacture of thin film solar cells. The extremely thin film packages made of semiconducting oxide, amorphous silicon, and metal that are deposited onto the glass panels still have a market share of only ten percent.
But as Gillner knows, "This could be higher, because thin film solar cells can be used anywhere that non-transparent glass panels can be mounted, for example, on house facades or sound-insulating walls. But the degrees of efficiency are comparable low at five to eight percent, and the production costs are comparatively high."
The laser researchers are working to improve these costs. Until now, the manufacturers have used mechanical methods or solid-state lasers in the nanosecond range in order to structure the active layers on the glass panels. In order to produce electric connections between the semiconductor and the metal, grooves only a few micrometers wide must be created.
At the Fraunhofer-Gesellschaft booth at "Laser 2009" the ILT researchers will be demonstrating a 400-watt ultrashort pulse laser that processes thin-film solar modules ten times faster than conventional diode-pumped solid-state lasers.
"The ultrashort pulse laser is an ideal tool for ablating thin layers: It works very precisely, does not heat the material and, working with a pulse frequency of 80 MHz, can process a 2-by-3 meter glass panel in under two minutes," Gillner reports. "The technology is still very new, and high-performance scanning systems and optical systems adapted to the process must be developed first. In the medium term, however, this technology will be able to reduce production costs."
The rise of laser technology in solar technology is just taking off, and it still has a long way to go. "Lasers simplify and optimize the manufacture of classic silicon and thin-film cells, and they allow the development of new design alternatives," Gillner continues. "And so laser technology is making an important contribution towards allowing renewable energy sources to penetrate further into the energy market."
Source - Solardaily
Sunday, 12 April 2009
Developer plans all-solar city
A Florida developer says he wants to build a 19,500-home city powered entirely by solar energy.
Babcock Ranch will be developed by Kitson & Partners on 17,000 acres northeast of Fort Myers, Fla. The developer said it will be the "first city on Earth powered by zero-emission solar energy," The Miami Herald reported Saturday.
The city will include the world's largest photovoltaic power plant, to be operated by Florida Power & Light. The facility will cost about $300 million.
"We're out to prove that it works economically," developer Syd Kitson was quoted as saying. "And it's the right thing to do for the long-term solutions in this country."
The newspaper said researchers are working to develop storage capability for sunlight-generated power since solar electricity is available only during daytime hours.
Solar panels to power the city will sit on 350 acres within the development. The newspaper said more than half of the city's 17,000 acres will be permanently protected as greenways and open space, and will adjoin the 73,000-acre Babcock Ranch Preserve, which has been purchased by the state.
Source - Solar Daily
Babcock Ranch will be developed by Kitson & Partners on 17,000 acres northeast of Fort Myers, Fla. The developer said it will be the "first city on Earth powered by zero-emission solar energy," The Miami Herald reported Saturday.
The city will include the world's largest photovoltaic power plant, to be operated by Florida Power & Light. The facility will cost about $300 million.
"We're out to prove that it works economically," developer Syd Kitson was quoted as saying. "And it's the right thing to do for the long-term solutions in this country."
The newspaper said researchers are working to develop storage capability for sunlight-generated power since solar electricity is available only during daytime hours.
Solar panels to power the city will sit on 350 acres within the development. The newspaper said more than half of the city's 17,000 acres will be permanently protected as greenways and open space, and will adjoin the 73,000-acre Babcock Ranch Preserve, which has been purchased by the state.
Source - Solar Daily
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