Nanowires boost efficiency of solar cells

www.compoundsemiconductor.net
19 Apr 2013

ZnO quantum dots could translates fabrication of large-area films making solar panels Solar cells made from quantum dots could be low-cost, flexible, and easy to make. But the efficiency with which they convert light into electricity remains too low for practical use. Capitalising on this, researchers' at the Massachusetts Institute of Technology have combined nanowires with quantum dot solar cells.

The cell's efficiency increases the cells' efficiency by 35%. Quantum dots are semiconductor nanocrystals that absorb different wavelengths of light depending on their size. Solar cells made from different-sized crystals should absorb light over a much wider range of colours than silicon devices.

What's more, because quantum dots are made in solution, they could be easily printed or painted onto flexible surfaces. Scientists have calculated that quantum dots could be used to make thin-film solar cells that could convert light to electricity with 15% efficiency, the same as commercial silicon devices.

The best-performing quantum dot solar cells consist of a lead sulphide quantum dot layer butted up against a zinc oxide or titanium dioxide layer. The quantum dots absorb light, and electrons created in the process travel to the metal oxide layer to reach the electrical circuit.

The problem is that the quantum dot layer has to be thick enough to absorb light efficiently, but thin enough for the electrons to quickly traverse it. The MIT researchers, led by electrical engineering and computer science professor Vladimir Bulovic, overcame that trade off by replacing the flat ZnO layer with an array of vertical zinc oxide nanowires.

Nanowires penetrate the quantum dot layer, providing conductive paths for the electrons to follow out to the electrical circuit, says Joel Jean, a graduate student in Bulovic's group. The researchers published their results in the journal Advanced Materials.

The researchers start with glass substrates that are coated with indium tin oxide transparent electrodes. They deposit a ZnO layer on top and float the entire susbtrate upside down in an aqueous solution of zinc precursors.

An array of aligned nanowires grows downwards from the ZnO layer. After about an hour, the researchers rinse the substrates. Finally, they deposit PbS quantum dots, which fill up the space between the nanowires, and top it off with a gold electrode.

The nanowires boost the output current of the devices by 50% and the efficiency by 35% over planar ZnO devices. The overall light-to-electricity conversion efficiency of the new devices is 4.9%, among the highest reported for ZnO-based quantum dot solar cells, Jean says.

The researchers believe the efficiency could be further enhanced by using thicker light-absorbing layers and longer nanowires, as well as by controlling the spacing between nanowires to better accommodate quantum dots.

The idea of using ZnO nanowires to increase efficiency in quantum dot solar cells is not new, but this is the first significant implementation of the concept, says Matthew Beard, a senior scientist at the National Renewable Energy Laboratory. "The observed efficiency boost is promising and significant", he says. "The efficiencies for these types of solar cells are increasing rapidly and this work demonstrates that the improvements in efficiency will continue".

A key advantage of the nanowire-quantum dot cells, says Jean, is that they could be made on large areas. "One of the main benefits of quantum dots is that they're grown in and deposited from solution", he adds.

"This translates to fabrication of large-area films, which is necessary for making solar panels. Zinc oxide nanowires are also grown in an aqueous solution process. Scalability should be one of the primary practical advantages of this type of solar cell".

Solar cells get silver lining

www.abc.net.au
7 Feb 2013

Light-trapping, silver nano-antennas could dramatically improve the performance of solar panels by catching more light, according to a new study.

A team of physicists, including Professor Constantin Simovski from Finland's Aalto University, has developed theoretical designs that could increase photovoltaic cell efficiency in a commercially viable way. It proposes incorporating chessboard-patterned arrays of tiny silver nano-antennas into solar panels. This would trap more incoming light, allowing it to be preferentially re-radiated through the photovoltaic slab, improving efficiency.

New fabrication techniques for printing a nano-antenna array on thin film means it could be done at low cost. "Pieces of the film with printed nano-antenna arrays can be prepared separately from solar cells so that the price of every piece will be small", report the researchers on the pre-press website ArXiv.org. "We have demonstrated our nano-antenna arrays operate significantly better than the structures based on anti-reflecting coatings".

Existing technology uses coatings to reduce the amount of light reflected off the solar cell, but this fails to prevent up to half of the light passing through the back of the solar cell's thin film and being lost. The best currently available commercial photovoltaic cells convert just 22% of the light they receive into electricity, according to the researchers, who also say that this level can be improved with existing technology, but the cost is prohibitive.

Like minds
Dr Richard Corkish, Head, School of Photovoltaic & Renewable Energy Engineering at the University of New South Wales, says Australian research is following a similar approach. "Our work together with researchers at the Australian National University and Swinburne University, use self-aligning, nano-scale, metal-silver particles that act like nano-antennas redirecting the light", says Corkish. "The difference is our research uses randomly shaped and positioned particles, while this paper discusses very precisely formed and aligned antennas".

While this precise alignment will be more efficient, Corkish thinks it will also be far more expensive. "They're looking for a low-cost approach, while our approach is even more low cost because of the more random nature of the antenna positioning and shapes".

Corkish says his team has managed to get its solar cells performing at 25% efficiency in the lab, however the cost of producing such cells is still prohibitive for industry. "The trick is to get something really cheaply that works and can cover big areas", says Corkish. "They talk about printing big sheets of this material at very low cost and if they can do that, it would be very interesting".

New solar cells hit efficiency record

www.upi.com
21 Jan 2013

DUBENDORF, Switzerland, Jan. 21 (UPI)--Swiss researchers say they've developed thin, flexible solar cells with a record efficiency of 20.4% for converting sunlight into electricity. Scientists at the Swiss Federal Laboratories for Materials Science and Technology say the cells on flexible polymer foils offer a significant improvement over the previous record of 18.7%.

Such lightweight and flexible high-performance solar modules will offer an attractive technology for applications such as solar farms, roofs and facades of buildings, automobiles and portable electronics, the Swiss lab said in a release. They are also closing the efficiency gap with rigid, silicon wafer cells, the researchers said, and can be produced using a continuous roll manufacturing processes that should offer further cost reductions compared with standard silicon technologies.

The cells are based on CIGS semiconducting material (copper indium gallium (di)selenide.) "The series of record efficiencies for flexible CIGS solar cells developed at [the lab] demonstrates that thin film solar cells can match the excellent performance of polycrystalline silicon cells", lab director Gian-Luca Bona said. "Now it is time for the next step, the scale-up of the technology to cover large areas in a cost-efficient roll-to-roll manufacturing process with an industrial partner".

Nanowires make good solar cells

physicsworld.com
21 Jan 2013

Researchers in Sweden and Germany say they have made an important breakthrough in the development of highly efficient solar cells based on nanowires. They have shown that cells made from tiny wires of the semiconductor indium phosphide (InP) have efficiencies as high as 13.8% while covering only about 12% of the surface of a device. While an efficiency of 13.8% is not as good as the best commercial silicon devices, the team believes that it could be improved significantly by further research.

Nanowires-tiny semiconductor wires with a thickness of just a few hundred nanometres or less-show great potential for making solar cells that are more flexible, lightweight and cheaper than conventional planar devices. Nanostructures such as wires are efficient absorbers of light and can act as "antennas", harvesting much more light than a device with a planar surface. This is thanks to collective oscillations of charge carriers-called plasmons-that interact strongly with light. "One consequence of this strong absorption on nanowires is that we observe high light-absorption efficiencies even though only a small part of the device's surface is covered by the nanomaterials", explains team member Magnus Borgstroem of Lund University.

Millions of wires
The devices made by the team measured about a square millimetre and each contains about four million InP nanowires. The researchers grew their nanowires using an established technique called "vapour solid growth". "Our nanowires needed to be uniform, having a certain diameter and length in a certain pitch. From our first working p-n InP junctions, it has taken us four years to reach this result", Borgstroem explains.

The team, which includes scientists from Solid State Physics in Lund, Fraunhofer ISE in Freiburg, the University of Kassel and the start-up company Solvoltaics, also in Lund, chose InP because it has a direct band gap of 1.34 eV, which means that it can absorb light over a range of solar-spectrum wavelengths.

In this latest work, the team was able to identify the ideal diameter of the nanowires-which turned out to be about 180 nm. "The right size is essential for the nanowires to absorb as many photons as possible. If they are just a few tenths of a nanometre too small, their function is significantly impaired", says Borgstroem.

Proof of principle
The cells made by the team have efficiencies as high as 13.8%-which is promising but still significantly less than the best commercial silicon devices, which operate at 15 22%. "Our findings are the first to show that it really is possible to use nanowires to manufacture solar cells", says Borgstroem. However, the highest efficiency ever reported for a conventional InP solar cell is 22% and the team admits that it still remains to be seen whether that record can be broken using smaller amounts of nanowire material.

The researchers also believe that the way forward for nanowire-based solar cells is the multi-junction approach, which boosts efficiency by using several different structures tuned to different wavelengths of light from the Sun. "We believe that the road ahead for solar cell application involves multi-junction technology with nanowires, for which the record is 44% in thin films", says Borgstroem.

The work is reported in Science.

Novel solar photovoltaic cells achieve record efficiency using nanoscale structures

www.scientificamerican.com
17 Jan 2013

Here's how to make a powerful solar cell from indium and phosphorus: First, arrange microscopic flecks of gold on a semiconductor background. Using the gold as seeds, grow precisely arranged wires roughly 1.5 micrometers tall out of chemically tweaked compounds of indium and phosphorus. Keep the nanowires in line by etching them clean with hydrochloric acid and confining their diameter to 180 nanometers. (A nanometer is one billionth of a meter.) Exposed to the sun, a solar cell employing such nanowires can turn nearly 14% of the incoming light into electricity—a new record that opens up more possibilities for cheap and effective solar power.

According to research published online in Science—and validated at Germany's Fraunhofer Institute for Solar Energy Systems—this novel nanowire configuration delivered nearly as much electricity as more traditional indium phosphide thin-film solar cells even though the nanowires themselves covered only 12% of the device's surface. That suggests such nanowire solar cells could prove cheaper—and more powerful—if the process could be industrialized, argues physicist Magnus Borgström of Lund University in Sweden, who led the effort.

The promise starts with the novel semiconductor—a combination of indium and phosphorus that absorbs much of the light from the sun (a property known as its band gap). "Now we absorb 71% of the light above the band gap and we can certainly increase that," Borgström says.

Read More…

Flexible solar cells can stick to just about any surface

www.technologyreview.com
20 Dec 2012

solar panels are typically heavy, which makes them expensive to install, and rigid, which limits where they can be used. In the current issue of Nature Scientific Reports, researchers describe a novel, potentially cheap way to make solar cells that are both lightweight and flexible.

The technique is meant to work with thin-film solar cells. The active part of thin-film solar cells—the part that gathers sunlight and generates electricity—is thin enough to be flexible, but the cells usually have to be manufactured on rigid materials such as glass to achieve the highest quality.

Researchers led by Xiaolin Zheng, a professor of mechanical engineering at Stanford University, demonstrated a way to transfer the active materials of the solar cell from a rigid substrate onto another surface, such as a sheet of paper or plastic, the roof of a car, or the back of a smartphone. As with other solar cells, wires would then be connected to deliver power, but flexible solar cells could be used on curved surfaces, and, because they're lightweight, they would be easier to install than conventional panels.

Although Zheng has demonstrated that the process can transfer solar cells even to cheap surfaces such as paper, in practical applications, the materials used would be limited by the need to protect the cells from the elements.

These aren't the first flexible solar panels. Several companies already manufacture them. But Zheng says prior approaches to making flexible solar cells have drawbacks. Manufacturers often modify processing steps to accommodate flexible substrate materials that can't tolerate high temperatures or certain chemicals, but this can reduce the performance of the resulting solar cell. And manufacturers have typically used costly flexible substrate materials, such as foils with extremely uniform surfaces, in order to produce high-quality thin films.

The trick to peeling thin-film silicon away from a solid substrate of silicon dioxide involves depositing a layer of nickel on top of an underlying wafer. After the cell is finished, it's immersed in room-temperature water. The water interacts with the nickel and silicon dioxide, causing the solar cell to come loose. It can then be peeled away and deposited onto another material. The researchers demonstrated that the efficiency of the solar cell wasn't affected by the transfer process.

The current paper shows that the process works for dislodging a solar cell from a silicon and silicon dioxide wafer. Zheng says the group has also demonstrated the process with solar cells made on a glass surface, but this work has not yet been published. This could make it possible to use the technique with copper indium gallium selenide solar cells, which are nearly twice as efficient as amorphous ones.

Emissions sink as consumers turn off coal

www.smh.com.au
20 Dec 2012

Weak demand for electricity across eastern mainland states has sparked a "dramatic fall" in greenhouse gas emissions from Australia's power stations, the latest review of data by consultants Pitt and Sherry has found. While demand for base-load electricity from black coal-fired power stations has been in retreat for about three years, the decline has extended in recent months to two of Victoria's emissions-intensive brown coal-fired plants, Hazelwood and Yallourn.

Changes in demand of electricity on this scale are unprecedented in the entire 120 year history of the electricity supply industry in Australia Hazelwood, one of the country's oldest and dirtiest power plants, was operating at only 67% capacity in November, down from the mid-80% range in May and June, Hugh Saddler, principal consultant in the climate change business unit of Pitt and Sherry, said.

The data, analysed from half-hourly reports to the Australian Energy Market Operator, also show Yallourn was operating at just 56% last month even after it announced it was mothballing one of its four units. That ratio is down from 90% capacity use in December last year, Dr Saddler said.

In NSW, power stations were operating in the 60-70% capacity range, with Eraring down to 44% and Bayswater 64% last month. The slide in coal-fired power generation means "it should really be quite easy" for the government to meet its goal of cutting Australia's greenhouse gas emissions by 5% by 2020 from 2000 levels, he said.

Total emissions from energy use for the year ended September 30 were 2 million tonnes of CO₂ lower than in the year ended July 2012. In November alone, CO₂ emissions from energy dropped another 600,000 tonnes based on a rolling 12 month data series.

Pitt and Sherry analysis shows demand for electricity fell 2.5% in year to November, compared with a year earlier, led by a decline of more than 5% for NSW. South Australia and Tasmania posted falls of about 3%, with Queensland and Victoria registering small retreats in demand. Higher electricity prices appear to be an important prompt to the demand drop.

"The price is a signal to consumers to use less electricity", Dr Saddler said. "There's also been a dramatic increase in residential use of small-scale reverse cycle air-conditioners, which have become very much more efficient in recent years".

Using electricity demand in 2008-09 as the base, annual demand to the end of November 2012 has seen an 11% fall in Victoria, 8% in NSW, with smaller drops in other states. "Changes in demand of electricity on this scale are unprecedented in the entire 120 year history of the electricity supply industry in Australia", the Pitt and Sherry report said.

The rapid spread of solar photovoltaic panels is also beginning to erode demand, although the full impact may not be felt until more companies rather than homes install the technology, he said. Commercial power demand typically matches solar PV output more closely than residential use.

Solar boost Meanwhile, one of Australia's biggest PV installers, Mark Group, has begun offering additional solar payments to foster demand even as state governments roll back feed-in tariffs.

Earlier this year, Victoria cut its feed-in tariff from 25¢ per kW-hour to 8¢. Mark Group, along with retailer Diamond Energy, has lifted that rate to 33¢, with plans to roll out similar programs in NSW, Queensland and South Australia next year.

A surge in Chinese PV production has seen the cost of panels drop from $1.80 to 65¢ per kW capacity in the past two years. "We're not that far from operating without subsidies", Rob Grant, chief executive of Mark Group's Australian operations, said. "The biggest uptake is going to commercial".

Australia takes a shine to solar energy research

www.smh.com.au
13 Dec 2012

The Gillard government will step up its investment in joint solar power research with the US, using additional funds from its new $2.2 billion renewable energy agency.

Martin Ferguson, Minister for Resources and Energy, will today announce more than $83 million for research as part of the United States-Australia Solar Energy Collaboration (USASEC) launched in 2010. The funding taps into money not yet spent from the $50 million Australian contribution to USASEC, managed by Newcastle-based Australian Solar Institute (ASI).

In addition, the new Australian Renewable Energy Agency will contribute about $38 million in funds to the research. The agency will absorb the ASI at the start of 2013. "These projects will leverage an investment of $140 million from industry, resulting in more than $220 million for solar research and involving over 40 organisations across Australia and the US", Mr Ferguson said in a statement. Most of the combined funding will be spent on two research endeavours.

About $33 million will go to the US-Australia Institute for Advanced Photovoltaics to develop the next generation of PV technologies and spur increases in performance and lower costs. The University of New South Wales will lead the research, supported by other universities in Australia and the US, and commercial partners including Blue-Scope Steel and Suntech Power R&D Australia.

The other major research focus, the Australian Solar Thermal Research Initiative (ASTRI), will receive $35 million aimed at making Australia a global leader in so-called Concentrating Solar Power technologies. The effort will be led by the CSIRO and mostly involve Australian and US universities, and Sandia National Laboratories Corp. An additional $15.5 million will be allocated to collaborative research projects under the Open Funding Round of the USASEC, the statement said.

Projects range from developing an Australian Solar Energy Forecasting System-a venture the CSIRO had sought funding for-that will improve the integration of solar power generation, to a solar device that simplifies incorporation of solar power into hybrid fossil fuel applications.

Read More…

Carnegie wins EPA green light

au.news.yahoo.com
11 Dec 2012

Fremantle-based Carnegie Corporation Energy has won the race for Australia's first environmental approval of a wave energy project, but yesterday's green light from WA's watchdog has swung the spotlight on streamlined approvals for the renewable energy sector.

The Environmental Protection Authority announced that it had approved Carnegie Corporation's $31 million, 2 MW wave energy development for the Royal Australian Navy off Garden Island, without a full public review (PER). Carnegie Corporation is backed by prominent Perth investors, including John Poynton, Tim Roberts, Dale Alcock and Tim Holmes.

EPA chairman Paul Vogel told WestBusiness any perceptions that renewable energy projects were given favourable approval treatment was misplaced, and Carnegie Corporation's plan could be managed within existing maritime planning regulations. He also said the wave-power pioneer had done a mountain of work to reassure the EPA that there would be no damage to the environment.

"Each project is assessed on a case-by-case basis on their merits", he said. "Their environmental plan needed a bit of tweaking (such as how marine trenching might be rehabilitated),,, but they did a good job of front-end loading the process and addressing all of the issues".

However, Dr Vogel said the EPA was aware of growing angst in the community about wind farm developments, as in Victoria, and it would be issuing a bulletin next year to clarify its thinking on the issue. Dr Vogel said that while it had approved wind farms in the past without full PER's, as for other renewable energy projects, they still had to meet rigorous standards.*

Sustainable Energy Association adviser Ray Wills said renewable projects should have the same, not more, rigour applied to them as other projects and said industrial developments on the Kwinana strip were not assessed for low frequency sound impacts, as for wind proposals.

Carnegie Corporation chief executive Michael Ottaviano said the company's submerged power buoys had no visual impact, an environmental footprint no different to other buoys and its project had attracted marine life to the area. Its shares closed unchanged at $0.042

*In fact there is no "growing angst" regarding windfarm developments in Victoria, there is a small group of people attempting to portray that sentiment however and it is being exploited by the Victorian government.

Nanosolar Completes 10.63 MW Solar Installation in Valencia Region of Spain

www.renewablesbiz.com
14 Nov 2012

Nanosolar Inc, today announced its largest solar photovoltaic (PV) installation to date, a 10.63 MW project in the town of Alfarrasi, which is located in the Valencia region of Spain. Developed by Smartenergy Invest AG and Advanta Capital Ltd., the new solar field is now the region's largest PV power plant to date. The plant was energized earlier this month and is expected to produce energy to power 4,000 households per year.

"Our installation supports Spain's national renewable energy action plan, which calls for renewable sources to account for at least 20% of the final energy consumption by 2020", said Stephan Hansen, executive vice president of Global Sales for Nanosolar. "The natural conditions in the Valencia region are excellent for photovoltaic and we expect Spain to be among the first countries to provide competitive solar electricity in Europe".

The Alfarrasi installation will be capable of producing 16,500 MWh per year. The total amount of electricity produced by this Nanosolar project represents a savings of more than 5,528 tons of CO₂ emissions each year, and is equivalent to planting approximately 142,000 trees.

"Nanosolar's innovative Utility Panel design made installation of our Alfarrasi system quick and simple", said Jose-Fidel Roig Agut, CEO of VALFORTEC, S.L., the Castellon, Spain-based EPC. "We were able to achieve a very cost-effective installation because of the unique design of Nanosolar's panels, and the ease with which they can be interconnected".

Bringing Clean Energy to Alfarrasi
The town of Alfarrasi is an ideal location for this solar installation, which encompasses over 50,000 panels across 65 acres of former agricultural land. The region features a semi-arid climate with very mild winters and long warm to hot summers. Solar irradiance is above-average with a typical annual temperature of 22.3° C (72.1° F) during the day and an annual irradiation of approximately 1,650 kW/m2.

"As businesses and consumers look for ways to be more reliant on clean, sustainable energy sources, multi-MW solar installations, such as the one in Alfarrasi, become even more important", said Horst Mahmoudi, senior partner at Smartenergy AG. "Nanosolar has been a great technology partner to work with on this project, providing cutting-edge utility panels with superior energy yields that will enable us to deliver the benefits of abundant solar across the Valencia region".

About Nanosolar Nanosolar designs, engineers, and manufactures innovative thin-film solar cells and panels based on printing CIGS (Copper, Indium, Gallium, Selenium) proprietary inks on low-cost aluminum foil. The company's current product, the Nanosolar Utility Panel, enables competitively priced peak power and installed system economics at utility-scale. Nanosolar operates the industry's first roll-to-roll solar cell printing factory at its headquarters in San Jose, Calif., and a panel-assembly factory in Luckenwalde, Germany. For more information, please visit www.nanosolar.com.

Solar funding round leaves Mildura in the dark

www.theage.com.au
12 Nov 2012

A huge solar power farm intended for the north-western Victorian town of Mildura is in doubt after the EnergyAustralia-backed project again missed out on federal government funding. The Australian Renewable Energy Agency (ARENA) today unveiled its investment plan for 2012 15 and its general funding strategy aimed at promoting the development of renewable energy, particularly in regional Australia.

ARENA, which was launched in July, increased the funding available for investment, including for the Solar Flagships Program it inherited, from $1.7 billion to $2.2 billion. Even so, the agency had to make "tough decisions" on its allocation, Greg Bourne, chair of ARENA, said in a statement. ARENA decided not to commit funds to EnergyAustralia's proposed Mallee Solar Park, costing as much as $700 million to develop, because of its "broad similarity" to a thin-film solar photovoltaic project being built by AGL Energy and FirstSolar.

"We are obviously disappointed with the decision", a spokeswoman for EnergyAustralia, formerly TRUEnergy, said. "We believe we submitted a strong and competitive proposal that would have provided economic and environmental benefits to the State, however we understand we were up against some other good projects", she said. "We will continue to assess what funding options are available".

The federal government has already committed $129.7 million and the NSW government $64.9 million to the AGL Energy-FirstSolar's sites in Nyngan, west of Dubbo, and Broken Hill. "We are also continuing discussions with Moree Solar Farm and Infigen Energy-Suntech Power on potential projects based on their short-listed Solar Flagships Program applications", Mr Bourne said. the Mallee Solar Park had missed out on a previous flagship grant. The Baillieu government had pledged funding for the project if it succeeded in securing federal funds after the Brumby government had promised to tip in as much as $100 million.

The 600 hectare solar park would reportedly have been 180 MWs in size and created as many as 200 jobs. John Forrest, the Federal MP for Mallee, described the $700 million project as potentially "be one of the largest solar power stations globally" that would be "a project of both State and national significance", according to a report on his website.

Also ruled out for ARENA funding was the 250 MW Solar Dawn Project solar thermal project proposed to be built near Chinchilla in south-western Queensland. That venture aims to construct a solar field of mirrors, steam boiler tubes and a "power block" over 450 hectares.

ARENA plans
ARENA has $3.2 billion funding locked in until 2020 to help renewable energy technologies move from research, development and demonstration to commercialisation, although some of the funds are already earmarked for projects support by the Australian Solar Institute and other government bodies that will be rolled into the agency.

Among its list of priorities released today, ARENA said the majority of its funds over the next three years will be directed to energy generation projects "that are closest to commercial viability and where investment will accelerate this outcome".

"We have around about $2 billion yet to be allocated", Mr Bourne told Fairfax Media. Solar, which along with geothermal technologies, received much of the assigned funding, is likely to be remain a priority. "On a world stage we do actually have pretty much world leadership still in the solar photovoltaic area", he said. "That's very, very hard to say about any other technology in the pie-charts that are around".

Beyond the identification of technologies where Australia has an edge or the prospect of grabbing one, the agency will also work on removing obstacles to their take-up. "Is it possible to set up conditions (enabling) a cascade of change to occur?", Mr Bourne said".It may be that we can make a small in investment in the removal of some of those roadblocks".

Among the agency's activities will be efforts to explore the opportunities of off-grid and near-grid energy generation. The funding may also extend to identifying potential for renewable transport fuels. The Energy White Paper released by the government last week, forecast the share of Australia's power generation will double to 20% by 2020 and double again to 40% by 2035 and reach a half share by 2050. The latter target may require as much as $200 billion in investment to achieve, the report said.

Thin-Film photovoltaics market aims to convert on huge potential

news.thomasnet.com
5 Jun 2012

Ultimately, the world will run out of fossil fuels. Meanwhile, as the world fights over fossil fuels, our planet hangs in space a mere 93 million miles from a giant fusion reactor that's 1.4 million km wide. The sun gives us about 1.37 kilowatts per m² of energy. If it were somehow possible to convert 100% of the sun's energy into usable power, we would need only one hour of it to power the Earth for an entire year.

Using the sun for energy is hardly a new concept. Nor are photovoltaics (PV), which convert sunlight into electricity; the technology has been under commercial development since the 1970s, though up until recently, it remained difficult to achieve economies in manufacturing to make PV affordable. To date, solar panels large enough to fulfill significant energy needs have been neither very cheap nor very portable.

While the military has developed folding, semi-portable solar panels for installations in remote locations, few organizations or individuals have the kinds of budgets of the Department of Defense. Not to mention that most solar panels to date have been opaque, rigid and hard to use in places that could use a little supplemental energy from PV: atop a car or a building's windows.

The future practicality of PV--lower price point and putting PV cells onto less rigid surfaces so they can be "wrapped" or molded around buildings, cars and even people, in the form of PV-cell clothing--seems to lie in making PV cells flexible. Enter the plastics industry and the development of thin-film solar cells (TFSC), also called thin-film photovoltaic (TFPV) cells. TFSCs are made by depositing one or more thin layers, i.e., films, of photovoltaic material onto a substrate. The thickness of the layers is small, ranging from a few nanometers to a few tens of micrometers. Existing thin-film processes generally use semiconductor materials such as copper, indium, gallium, cadmium and selenium to create the PV cells.

Read More…

Dhursar solar project commissioned

www.power-eng.com
28 Apr 2012

FirstSolar, Inc, has announced the commissioning by Reliance Power Ltd, a Reliance ADAGroup company, of a 40 MW ground mounted solar photovoltaic power plant in Rajasthan that will provide clean energy to Mumbai. The project was built in just five months. Comprising some 500,000 FirstSolar thin-film modules, the power plant is spread over 350 acres near Dhursar village in Jaisalmer district.The plant is expected to generate more than 60 million units (kW) of clean solar power a year,making it one of the country's largest photovoltaic power plant in terms of electricity generation.

Covering 350 acres, it is 23 times the size of Calcutta's famous EdenGardens cricket grounds and is expected to satisfy the annual electricity needs of more than 70,000 average Indian households. It will displace more than 60,000 tonnes of CO₂ emissions per year,the equivalent of taking more than25,000 cars off the road. The Dhursar project is the first of several that Reliance plans to build with FirstSolar modules as part of a 100 MW module order placed last year.

Suntech to add 1GW Shanghai capacity as demand jumps

www.reuters.com
Jun 6, 2010

SunTech Power Holdings Co Ltd, China's largest solar panel marker, plans to invest 2.68 billion yuan ($393 million) to build 1GW in additional production capacity in Shanghai over the next three years as it rushes to meet surging demand, Chairman Zhengrong Shi said.

Despite an expected cut in German solar power subsidies in July that analysts warn will dampen third-quarter demand, Shi told a briefing for reporters on Saturday that returns for power producers in that market would still be attractive, while other markets such as the United States were growing rapidly. "We're all sold out for this year. We're short of capacity and can't meet our clients' needs," he said. "We have a backlog in the second quarter. We have a backlog in the third quarter. We haven't seen any impact from the reduction in German subsidies."

He predicted that Germany, the biggest market for solar cells, would see 70 to 80% full-year growth this year, while the U.S, market would double in size in the second half of the year from the first half, reaching 1GW for the full year. The first phase of the company's new Shanghai plant, with 180MWs of production capacity, would be completed at the end of June, he said, putting it easily on course to reach its total production capacity target for this year of 1.4GW, after reaching 1.2GW at the end of the first quarter.

Shi added that expansion of thin-film manufacturing capacity in Shanghai, now at 200MWs, may be delayed due to low competitiveness of thin-film modules and a need for further research and development to boost conversion rates. He also reiterated that the fall in the euro was taking a heavy toll on the company's bottom line. SunTech announced first-quarter results on Thursday in line with Wall Street expectations, although it took a larger than expected hit from the weak euro. Europe accounted for 68% of SunTech's product sales in the first quarter, down from 74% for all of 2009.

Thin Film Solar Panels Take A Giant Leap Toward Affordable Renewable Energy

solar.coolerplanet.com
April 01, 2010

Two drawbacks to solar power were cost and the bulk of the panels, but newer panels, called thin-film solar panels are lowering the cost of solar and allowing new types of solar panels to be made. Some are flexible and can either be rolled up or formed into roof tiles, so it's hardly noticeable that you're powering your home with the sun!

Over the past decade continual breakthroughs have made the manufacture of thin-film solar panels less expensive while improving their efficiency in producing electricity. Some are even capable of rivaling the power produced by their heavy silicone counterparts. Abound Solar, a Colorado based company, has claimed they can produce thin-film photovoltaics at $1 per watt. That makes it cost-competitive with fossil fuels. By comparison, crystalline silicone panels cost roughly $4 per watt to make.

Most home installed systems convert 10% or 11% sun's energy into electricity. But it ranges between 8% and 20%, according to the National Renewable Energy Lab (NREL), which researches and tests new photovoltaic technologies. Traditional crystalline silicone photovoltaic panels (the ones on most homes) are more costly, partly because the silicone used in making them can comprise 40% to 50% of the total cost of the panel. Still, these silicone panels are the most efficient panels and can convert up to 20.3% of the sun's rays. Some thin-film photovoltaics are now reaching that level.

The lab set a world record in 2008 when it made a thin-film solar panel that was 20% efficient using a Copper Indium Gallium diSelenide (CIGS) semiconductor. The other promising technology is cadmium-telluride (CdTe), which has converted solar power at up to 16.8% efficiency. NREL scientist Ingrid Repins foresees that using the 20% efficient formula as the base, companies will be able to roll out kilometer-long sheets of solar cells that achieve 16% efficiency, while using the cheapest materials and emphasizing speed. Repins explains that the cost-savings achieved when the panels reach an average 16% efficiency is huge. The more efficient cells won't need to be as large and use less material. Both of which lower manufacturing and materials cost. And the smaller size also lowers installation costs, she says.

Since it takes less energy to make thin-film photovoltaics they should be able to make less-expensive solar panels for utility and residential uses, according to NREL. These new photovoltaics will be on the market soon. But thin-film solar is already available. Companies like Uni-Solar and SRS Energy are making thin-film solar panels in the form of roof shingles and tiles. And those backpacks and portable solar panels you buy to power your mobile devices while on the go are also thin-film photovoltaics.

Big companies are lining up to start producing thin-film photovoltaics. General Electric recently stopped making hard silicone panels and will begin producing cadmium telluride panels, based on PrimeStar Solar Inc.'s technology, a company GE owns most of.

The company plans to introduce the new panels in 2011. And it plans to be a high-volume producer of the new panels. "After having completed an exhaustive survey of the PV landscape, we determined that thin films were the optimum path for GE," said Danielle Merfeld, GE's solar research and development leader. The company thinks the cadmium telluride technology will allow it to produce low-cost, high efficiency solar cells.

A new wire twist on silicon solar cells

www.reuters.com
Feb 14, 2010

CHICAGO, Feb 14 (Reuters) - U.S, researchers have devised a way to make flexible solar cells with silicon wires that use just 1% of the material needed to make conventional solar cells. The eventual hope is to make thin, light solar cells that could be incorporated into clothing, for instance but the immediate benefit is cheaper and easier-to-install solar panels, the researchers said.

The new material, reported on Sunday in Nature Materials, uses conventional silicon configured into micron-sized wires (a micron is one-millionth of a meter) instead of brittle wafers and encases them in a flexible polymer that can be rolled or bent. "The idea is it would be lower cost and easier to work with by being more flexible than conventional silicon solar cells," Michael Kelzenberg of the California Institute of Technology in Pasadena, who worked on the study, said in a telephone interview. solar cells, which convert solar energy into electricity, are in high demand because of higher oil prices and concerns over climate change.

Many companies, including Japanese consumer electronics maker Sharp Corp and Germany's Q-Cells SE, are making thin-film solar cells using organic materials such as polymers, but they typically are less efficient at converting solar energy into electricity than conventional cells using silicon. The study is among the latest to combine the flexibility of the new organic or carbon-containing films with the high efficiency of silicon, which is heavy and stiff.

Kelzenberg said the material uses about 1/100th as much silicon per cell area as a silicon wafer. "It is potentially a route to bypass many of the costs associated with producing solar cells," he said. He said a big problem with working with silicon wafers is they are fragile. More testing is needed but Kelzenberg said the material would be about 15% to 20% efficient, about the same level as solar cells used on roofs to heat homes.

A similar effort is under way in the lab of John Rogers, a professor of materials science at the University of Illinois-Urbana-Campaign, who is working on ways to make inorganic materials more flexible. While many companies are investing in organic solar cells - - basically materials like plastic that contain carbon - - Rogers said these materials have relatively low performance, less long-term reliability and an unproven cost structure. "We like the inorganics - - trying to adapt them and use them in non-standard ways," Rogers said in a telephone interview.

Last year, his team reported on a new manufacturing process that creates thin arrays of solar cells that are flexible enough to be rolled around a pencil and transparent enough to be used to tint windows on buildings or cars. "We can make them stretch like a rubber band or bendable like a sheet of plastic," he said. He is founder of a start-up semiconductor company called Semprius Inc in Durham, North Carolina, that last month announced a joint effort with Siemens AG (SIEGn.DE) to develop large systems for utility-scale power generation. "The same technology they are using to make these rigid utility-scale modules could be used for flexible devices as well," he said. Rogers said that the company has funding from the U.S. Department of Defense and the CIA.

Silicon Valley makes big push into solar and smart-grid technologies

www.mercurynews.com
01/31/2010

Cleantech's vast ecosystem includes a dizzying array of emerging technologies, from green building materials to electric vehicles, lighting and wind energy. But as Silicon Valley reinvents itself as a global center of clean technology, two sectors - solar energy and "smart" upgrades to the electric grid - already are reshaping the valley and changing the way energy is produced and used.

The Bay Area is believed to have the nation's largest concentration of cleantech jobs, and much of that job growth has been in solar and smart grid, technologies that leverage the valley's formidable strengths. Next 10, a nonpartisan think tank, estimates that the Bay Area now has about 7,000 jobs in renewable energy alone.

"The skills that have been put to such good use in the valley with chips - engineering the processes to be more efficient, bringing costs down - are now being applied to solar," said San Jose Mayor Chuck Reed, who wants to create 25,000 new cleantech jobs and cut the city's per capita energy use in half by 2022. "And in order to make a smart grid smart, you've got to collect an enormous amount of information and manage it and network it. It's a huge market opportunity for what companies here are already doing."

Solar technology is an extension of the semiconductor industry - a solar cell is basically a simple, large and inexpensive chip, and some manufacturing processes are similar in both industries. Smart grid, meanwhile, builds on the telecommunications and software industries to improve the electric grid by making it more reliable, secure and efficient all the way from the power plant to the home and office.

Nationwide, demand for electricity is expected to grow 30% by 2030, according to the Department of Energy, and the nation's aging grid is struggling to keep up. There's currently no way to store electricity, so utility companies often crank up capacity to meet peak demand during the evening hours, when consumers come home from work and turn on their appliances. If consumers were given incentives and the means to reduce energy use at critical times, that could offset the need to build additional power plants.

There's an environmental opportunity as well: A mere 5% improvement in the grid's efficiency would be equal to eliminating the fuel and greenhouse gas emissions from 53 million cars, according to the Department of Energy.

Smart grid market
Morgan Stanley predicts that the smart grid market will grow from $20 billion in revenue this year to $100 billion - roughly three times Apple's current revenues - by 2030. Networking giant Cisco, which is positioning itself to be a major player, believes the communications infrastructure alone for the smart grid could be worth $20 billion a year within the next five years. A smart grid would also allow utilities to more nimbly manage renewable sources of power like wind and solar, which can be unpredictable and intermittent on cloudy days. And consumers would get real-time information about energy usage, so they could identify the electricity hogs among their appliances and adjust their behavior to reduce energy consumption and bills.

Creation of a smart grid is a top priority of the Department of Energy, which has funneled $4.5 billion in stimulus dollars to the effort, including $303 million to California utilities. Spurred on by federal dollars, utility companies across the country are rolling out smart meters to better monitor energy consumption at homes and businesses. More than 250 million of them will be installed worldwide by 2015, up from 46 million in 2008, according to Pike Research. In Northern California, PG&E is installing more than 12,000 smart meters every day toward a goal of having 10 million in place by 2012. Currently, they merely allow PG&E to collect data without meter readers but later will add useful energy-monitoring features.

The nationwide push for smart meters has been a boon to Silver Spring Networks, a Redwood City startup that makes software for several utilities, including Florida Power & Light, PG&E and the Sacramento Municipal Utility District. Silver Spring's software allows devices like meters, load management controllers and electric vehicle charging stations to communicate with each other and the utility. "Anything we can do to make energy usage and distribution more efficient so we don't need to build more power plants is a pretty big benefit for all of us," said Eric Dresselhuys, Silver Spring's executive vice president. "

A lot of people are talking about electric vehicles and rooftop solar. If we're going to adopt those technologies on a massive scale, we need a network in place to communicate with all of these devices." At least 40 to 50 companies in Silicon Valley, including startups and tech giants, are focused on smart grid development, said Mayor Reed. Experts in the utility industry stress this is just the beginning.

'Huge opportunity'
"There's a huge opportunity," said Don Von Dollen, director of the IntelliGrid program at EPRI, the Electric Power Research Institute in Palo Alto. "Everyone is trying to figure out how to mine the data that comes out of the smart meters and turn it into usable information that can help consumers save energy and reduce their bills. There are going to be lots of opportunities to develop apps, and that's Silicon Valley's sweet spot. Someone is going to come up with the iPod for in-home energy management."

Cisco veteran Laura Ipsen, who was chosen last fall to lead a new Smart Grid Business Unit of more than 100 people, says Cisco's utility customers were "clamoring for us to explore this area." Cisco wants to provide the communications infrastructure to connect all points on the grid, from power plants to homes, as well as tools to manage energy use. "If we can connect it," she added, "it can be more green."

Cisco has already rolled out its Building Mediator, a product that can automatically and remotely control a building's heating and air conditioning, lighting, security and other electricity use. NetApp, a maker of network storage equipment, uses Cisco's Building Mediator at its Sunnyvale headquarters and reduced energy costs for its 1.2 million square feet of office space by 25% - and $2 million - over an 18-month period. Another valley company pioneering smart grid technologies is San Mateo's eMeter, which is piloting a product to alert consumers by text message that they are about to blow their preset electricity budget unless they modify their behavior.

Redwood City startup EcoFactor, meanwhile, creates software that can continuously tweak the settings of a home thermostat - including adjusting heating or air conditioning based on variations in outside temperatures and local weather. The company, which recently announced $2.4 million in first-round financing, has a contract with the Texas utility Oncor.

Even Google has gotten into the act. The search giant has introduced PowerMeter, which allows consumers with smart meters to monitor their energy consumption from their iGoogle home page. "We can begin to see what a clean energy future will look like," President Obama said in an October speech announcing smart grid grants. "We can imagine the day when you'll be able to charge the battery on your plug-in hybrid car at night, because your smart meter reminded you that nighttime electricity is cheapest."

Many of those hybrid owners may be recharging their cars with solar energy, another cleantech sector with enormous potential and deep roots in Silicon Valley. The solar market - including modules, system components and installation - will grow from a $30 billion global industry in 2008 to $81 billion by 2018, according to Clean Edge, a cleantech research firm. Currently, the dominant solar company in Silicon Valley is San Jose-based SunPower, which assembles its panels at the historic Ford assembly plant in the East Bay city of Richmond, where tanks were built for World War II.

Powered by SunPower
Its recent projects include a solar energy system at Agilent's Santa Clara headquarters capable of generating one MW of electricity, about enough to power 750 to 1,000 homes. SunPower also completed a 1-MW system at the University of California-Merced campus expected to produce two-thirds of the campus' electricity on summer afternoons. SunPower's panels, like most others, use sunlight to excite electrons in silicon to generate electricity. But several companies have created a lot of buzz by replacing silicon with other compounds to make so-called thin-film panels to drive down costs and improve efficiency.

The industry leader in thin film is FirstSolar, an Arizona company that makes cadmium telluride solar cells and has a deal with the Chinese government to build a 2-GW solar plant in Mongolia, enough to power about 3 million Chinese households. But Silicon Valley has a cadre of thin film startups that manufacture solar panels using a compound known as CIGS - shorthand for copper indium gallium selenide- that they say will represent a great leap in solar technology.

Fremont-based Solyndra, a CIGS company founded by veterans of Applied Materials, has filed for a $300 million initial public offering. Several other local companies, including SoloPower, Nanosolar, and MiaSolé, are also racing to bring thin-film CIGS into volume production. Santa Clara-based MiaSolé got a big boost last month when it received $101.7 million in federal cleantech manufacturing tax credits. The company doubled its workforce to 300 last year and is ramping up production at its Santa Clara factory. "The first CIGS company to deliver will be an enormous hit," said Stephen O'Rourke, a solar industry analyst with Deutsche Bank. "A lot of people bought tickets, and now it's time to deliver."

NY air base to get solar energy farm

www.wcax.com
January 25, 2010

NEWBURGH, N.Y. (AP) - Rep. Maurice Hinchey (D-NY) says a new solar energy farm at Stewart Air National Guard Base will serve as a model for other military installations and demonstrate that solar panels are a cost-effective energy source. The project, to be built this year, is funded by a $4 million federal investment under the 2010 Defense Appropriations bill.

Congress and the Pentagon have set new requirements that each branch of the military must purchase or generate at least 25% of the energy they consume from renewable sources by 2025. The Stewart Air National Guard base solar farm will be constructed by The Solar Energy Consortium using Applied Materials thin-film solar photovoltaics technology. It's expected to generate the amount of electricity used by 100 homes.

Satcon Selected for Largest Urban Solar Power Plant in the U.S.

www.businesswire.com
November 10, 2009

Partners with SunPower to Deliver 10 Megawatts of Solar PV for Exelon City Solar in Chicago

BOSTON--(BUSINESS WIRE)--Satcon Technology Corporation (NASDAQ CM: SATC), a leading provider of utility scale power solutions for the renewable energy market, today announced that it has been selected for the 10-MW Exelon City Solar photovoltaic (PV) power plant, the nation's largest urban solar energy plant, which will be built at a former industrial site in the West Pullman neighbourhood on Chicago's South Side. The site, owned and operated by Exelon Generation, was designed and is being constructed by SunPower Corp., a manufacturer of high-efficiency solar cells, solar panels and solar systems.

The 41-acre solar facility will utilise Satcon Prism™, a fully customisable one MW medium voltage package complete with factory integrated step-up transformers, switchgear, and electronics. The Prism solutions will connect nearly 32,300 SunPower solar panels to the local utility and efficiently convert the sun's rays into enough clean, reliable electricity to meet the annual energy requirements of up to 1,500 homes per year.

"The Exelon City Solar project demonstrates solar energy's integration as a stable and viable core contributor into one of the country's largest energy markets," said Howard Wenger, president, global business unit at SunPower. "This project is a clear example of the unique demands of large scale solar energy generation, and required that we design a system that is composed of the industry's highest performing and most reliable components. Satcon Technology's experience and expertise in large scale solar made them the natural choice for us."

The Exelon City Solar plant will combine Satcon Technology's Prism solution, designed to deliver the highest levels of energy harvesting, efficiency and system uptime, with SunPower panels, which generate up to 50% more power than conventional solar panels and two to four times as much power as thin-film solar technology. The site will also use SunPower® Trackers, solar tracking systems that tilt toward the sun as it moves across the sky, increasing daily energy production by up to 25%.

Satcon Technology Prism is built on the foundation of the industry standard setting PowerGate(R) Plus 500kW solar PV inverter platform, the most advanced and field proven large scale inverter solution, with over 400 MWs delivered since 2005. The solution is delivered complete in an all-climate outdoor enclosure and ready to connect to the PV array and utility grid, enabling rapid installation through a modular prepackaged design.

"We are honored to be chosen as a key partner by SunPower to deliver our Prism solutions to Exelon City Solar," said Steve Rhoades, Satcon Technology's President and Chief Executive Officer. "Satcon's solutions have been used on some of the largest renewable energy sites in the world with hundreds of millions of grid connect kW hours delivered to date. Exelon City Solar showcases today's best in class total system solutions, optimally designed to deliver the highest levels of reliable large scale solar energy production."

China Solar Power Buys ThinSilicon

www.solarindustrymag.com
10 November 2009

China Solar Power Holdings Ltd. (CSP), a manufacturer of thin-film amorphous silicon photovoltaic modules, has purchased ThinSilicon Inc., a Mountain View, Calif.-based developer of thin-film manufacturing process technology. No financial terms were disclosed. ThinSilicon was founded three years ago and has since developed a unique device and process technology that significantly boosts both panel efficiency and manufacturing throughput, according to CSP.