quarta-feira, 29 de outubro de 2008
The UNSW ARC Photovoltaic Centre of Excellence already held the world record of 24.7 per cent for silicon solar cell efficiency. Now a revision of the international standard by which solar cells are measured [done by the International Electrochemical Commission in April], has delivered the significant 25 per cent record to the team led by Professors Martin Green and Stuart Wenham (...) The world-record holding cell was fabricated by former Centre researchers, Dr Jianhua Zhao and Dr Aihua Wang, who have since left the Centre to establish China Sunergy.
terça-feira, 28 de outubro de 2008
O Instituto Superior Técnico está a preparar o lançamento de um canal online dedicado ao tema da energia, em Full Screen HD. Este projecto vai ser financiado pelo Programa de Promoção para a Eficácia no Consumo (PPEC), da Entidade Reguladora de Sistemas Energéticos (ERSE). (...) A página, www.tvenergia.tv, vai ser lançada oficialmente no dia 10 de Novembro, com notícias actualizadas “quase diariamente” e, segundo o responsável, três programas actualizados de mês em mês. Estes formatos incluem uma magazine de informação com reportagens e notícias de 25 minutos, chamado Inova Energia, uma plataforma de curta metragens e documentários, de 4 a 5 minutos, com o nome Cinema ao Ar Livre, e, por fim, o Eventos Energia, uma cobertura de convenções sobre a temática.
O acordo oficial entre o Governo português e a aliança Renault-Nissan para a implementação de uma rede de abastecimento para o projecto dos carros eléctricos vai ser assinado a 22 de Novembro. (...) O protótipo que a Nissan está a desenvolver inclui uma bateria de iões de lítio que é instalada sob o chão do veículo e que em 2010 se prevê que tenha uma autonomia de 160km - com o avançar da tecnologia, deverá chegar aos 240km em 2012. A bateria terá uma vida útil de 150 mil km - o que dá uma média de 10 anos, tendo em conta que a quilometragem média de referência nos automóveis é de 15 mil km/ano. (...) "Sem a bateria, o carro deve ser proposto ao cliente final ao mesmo preço que um normal. Será depois este que terá que fazer as contas do que gasta nas duas versões [entre estacionamento, portagens, combustível, mecânica para trocar baterias e o seu valor residual] e optar", avança Diogo Jardim. Calcula-se que o consumo custe, a preços actuais da energia eléctrica, na ordem dos dois a três euros por cada 100km. Hoje, um carro do segmento médio familiar gasta cerca de seis a sete litros de gasolina - ou seja, à volta de oito euros.
[O] cluster industrial eólico em Viana do Castelo (...) antecip[ou] em cerca de um ano o arranque da primeira das suas fábricas (...) [A] Enercon está a construir uma nova unidade de pás não prevista no contrato com o Estado. (...) A primeira unidade de pás, em laboração há um ano, funciona junto ao porto da cidade; a segunda, cuja construção começou em Setembro passado e estará pronta dentro de um ano, fica no parque de Lanheses, a cerca de 15 quilómetros de Viana. São, para já, 55 milhões de euros de investimento e mais 500 postos de trabalho a somar ao projecto inicial. A central dessalinizadora, que vai satisfazer todas as necessidades de água para a laboração da fábrica, é um projecto extracontrato que o consórcio já previa na proposta inicial mas o júri do concurso público não considerou.
segunda-feira, 27 de outubro de 2008
BioSolar announced today that it has filed a patent application to protect the novel inventions and processes behind its proprietary biobased backsheet, a protective covering for the back of photovoltaic solar cells traditionally made from expensive petroleum-based film. (...)
[the] technology made from renewable plant sources [consists] a cellulosic plastic equivalent derived from cotton and castor beans materials.
Expected to cost significantly less ["by allowing manufacturers to lower the cost of their finished product without being impacted by the volatile cost of petroleum.”] than traditional Tedlar based backsheet, the petroleum-based film made by DuPont in use by the majority of silicon-based solar-cell manufacturers today, BioBacksheet meets or exceeds the characteristics of various testing and performance standards for the photovoltaic industry.
sexta-feira, 24 de outubro de 2008
Solterra Renewable Technologies (...) has concluded the worldwide exclusive license with the Rice University for intellectual property which includes the "Synthesis of Uniform Nanoparticle Shapes with High Selectivity." (...) [a] new chemical method for making low cost, four-legged cadmium selenide quantum dots. (...) In addition to photovoltaic applications low cost high quality quantum dots are widely thought to be the enabling factor for a variety of other emerging technologies including high performance QD based lasers, color displays, solid state lighting, bioimaging, quantum computers and solar/hydrogen generation. Solterra is scheduled to begin scale up of this revolutionary technology in early November 2008 with commercial production anticipated to begin in the second half of 2009.
Honda's wholly-owned solar cell subsidiary Honda Soltec Co., will begin sales throughout Japan of thin-film solar cells for public and industrial use (...) thin film of copper, indium, gallium and selenium (CIGS).
quinta-feira, 23 de outubro de 2008
Quem quiser uma cópia desta edição, basta pedir-me.Editorial: How to run the world on renewables
THE price of a cup of coffee. That's one estimate of what it will cost each American every day for the next 20 years to break the fossil fuel habit of generations and turn to renewables instead. A daily outlay of a shade under a couple of dollars does add up to trillions over the decades, but is it really that much to ask?
To prevent dangerous climate change, levels of carbon dioxide in the atmosphere need to be cut by 80 per cent by the middle of the century - and that's relative to 1990 levels. It will be a huge undertaking, but both candidates in next month's US presidential election acknowledge that the world's biggest polluter will have to change its tune if others are going to play their part (see "Feeling the Heat").
The UN says the renewable energy that can already be harnessed economically would supply the world's electricity needs 15 times over (see "Electric dreams"). As yet only a tiny proportion of electricity is generated this way, but replace existing coal, gas and oil-fired power stations with renewables and you achieve a colossal environmental win.
There's a bonus, too. Renewable energy breaks nations' dependence on imported sources, and this has brought its traditional, mainly Democratic, supporters in the US some unexpected allies. The Texan oil tycoon and long-time Republican supporter T. Boone Pickens wants to build the world's biggest wind farm in Texas. Former CIA chief James Woolsey is now a vocal advocate of renewables on the grounds of national security. And while many Republicans remain ambivalent, a handful of the party's senators now publicly back the idea.
One long-standing objection to renewables - that wave and sun power can never be relied on for a steady supply, day in day out - is vanishing too as new ways to store energy are rolled out. The nuclear industry can no longer sell itself as the only reliable source of low-carbon baseload electricity.
Shifting the US to a predominantly renewable supply of electricity by 2030 would cost $4.4 trillion and would cut the nation's CO2 emissions by 95 per cent, according to an estimate by internet giant Google. To put this in context, the $700 billion banking bailout attempt approved by Congress last week would already have paid for the first three years. A world run on renewables is no longer a hippy's fuzzy green dream. It's time we stopped arguing about its merits, and got on with making it a reality.
Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.
In a speed-obsessed world, "hypermiler" Jack Martin stands out for going to extremes to squeeze the maximum fuel efficiency from his car. Devin Powell caught up with Martin to find out his top fuel-saving tips - and how hypermiling can change your life
When did your enthusiasm for fuel-efficient driving start?
In the 60s and 70s, school buses in North Carolina were driven by students. I signed up. One day the school asked if I was cutting out part of my route - I was using less gas than the previous driver. I told them, no: my driving instructor said that a good driver is gentle with his vehicle. He doesn't get on the brakes all the time and doesn't floor it.
Something must have triggered this economy bug for you. What was it?
Canoes. When I was young, I used to fish out of these boats and would try to get across the lake using as few paddle strokes as possible. When I taught swimming later in my life I would always say the same thing: see how few strokes you can use to get across the pool, then see if you can improve your strokes and glide to use even fewer.
Being economical is all very well but hypermiling seems a bit extreme. How did you get into it and what do you get out of it?
When I was doing the 2001 World Solar Challenge - a solar-powered car race across Australia - the drivers looked at the route ahead of them and timed their driving so that they didn't use much energy. I took that to heart. I met Hans Tholstrup there, this wild adventurer who had gotten 128 miles per gallon (1.84 litres per 100 kilometres) crossing the outback in a Honda Insight. He didn't call it hypermiling back then, but I started using his techniques.
It was only a couple of years ago that people started holding official hypermiling rallies, at which you're judged on your mileage divided by the US Environmental Protection Agency's fuel-economy rating for your vehicle. That's what I like about hypermiling: someone in a gas-guzzling Hummer could get 18 mpg (15.7l/100km) and this would still be an 80 per cent increase in fuel efficiency. Everyone is competing on a level playing field.
Hypermilers have a reputation for going very slowly to save fuel. Is this accurate?
We're not the slowest people on the road; we're typically the ones going at the speed limit. When a vehicle goes by, you feel it initially suck on you a little bit and then push you. If you're sensitive to that, you can work it, like a porpoise riding the waves created by a boat. You start looking at it as energy around you. And it's nonsensical to try to be too slow because then you're just fighting that wall of air as it goes past you.
What do you think of the more extreme hypermiling techniques, such as draughting in the slipstream of large trucks?
I've seen people draughting, but personally I just don't have the balls for it. It takes a tremendous amount of concentration, and it's cool until you have to go to the hospital to get the tailpipe pulled out of your head.
How does the way you drive differ from how everyone else drives?
I have difficulty multitasking while driving. I can't talk on the phone while driving. It's about awareness and "hyperconsciousness", which takes a lot of practice. You have to look far down the road and be aware of everything going on in front and around you. I first learned that while driving the bus. My eyes were constantly moving to the mirrors, the speed dial, the road, to anticipate conditions and stop in time.
What is one thing this "hyperconsciousness" has shown you that the rest of us miss?
Roads often have little valleys and ridges created by the tyres of many cars. If you ride the ridges, you can get better mileage per gallon, especially if it's been raining and the valleys are filled with puddles.
Would you feel comfortable teaching your children these techniques? Aren't they dangerous?
I have no problem teaching them most techniques - there is a safety gain from the heightened awareness that hypermiling brings. Whether they'll use them is another question. My son's car doesn't get nearly the miles per gallon that I get. But I'm an old man and drive a lot more slowly.
Does hypermiling require changes to your vehicle?
You make sure that your car can breathe - that the air filters are clean - and inflate your tyres to their maximum rated pressure. It's amazing the difference you can feel in the resistance of pumped-up tyres. I once saw a Prius race a slalom course at a competition. The tyres were squealing and bulging on the turns, but then they pumped them up to the maximum rating. The sounds stopped and the time improved.
So what is the best way to improve fuel efficiency?
Buy some kind of feedback system. A scan gauge that costs about $130 will give you instantaneous feedback on how many miles you're getting to the gallon. If you pay attention, it will improve your overall mileage. If you lose focus, if your foot taps just a little too hard, you can see your miles per gallon drop and it's very disheartening.
Most hypermilers also like to drive barefoot to feel the resistance on the accelerator. The connection between that resistance and the numbers on the scan gauge tells you what behaviours improve your mileage. By following my techniques, a friend improved her mpg by 70 per cent.
You make it sound as if hypermiling becomes some kind of life-changing experience for the people who do it.
Hypermiling is a virus which makes you start to change other behaviour. Most hypermilers improve the efficiency of their homes; they'll show you a programmable thermostat that gives them feedback on their energy consumption and cuts the electrical bill by 60 or 70 per cent. One of the things that has always tickled me is how many hypermilers take up bicycling. It starts off as an efficiency thing that grabs their attention, but then they feed off each other and it becomes part of the community.
Which is more important for conserving energy: new technologies or changing behaviour?
I've always thought that the most timely thing we could do is to develop new behaviours that we could use now. We have cut a million barrels of oil out of demand in the US since April because people are not going out as much. If we could just average around 50 miles per gallon (4.7l/100km), we could cut oil usage in half.
You mention concern about exactly who is selling the US its oil. Is there a political side to hypermiling?
When you ask a hypermiler what set them off, you'll find most of them are pretty patriotic. They say, "I don't want to see us going to war, so I'm increasing my fuel efficiency." Some say it's for the environmental benefits or to save money. But not wanting to kill people for oil is probably the most common reason.
Not wanting to kill for oil is the most common reason to hypermile
What's your next big challenge?
There are two things I would love to be able to do. One would be a solar safari around the world, building and giving away solar technology. The other would be to build a solar-powered train and set a transcontinental speed record.
Cars and Motoring - Learn more about the latest technologies in our comprehensive special report.
Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.
quarta-feira, 22 de outubro de 2008
Evergreen Solar, a manufacturer of STRING RIBBON™ solar power panels (...) announced it has filed suit in the United States Bankruptcy Court for the Southern District Court of New York against Barclays PLC, Lehman Brothers Holdings Inc. and certain of their affiliated entities declaring that Lehman Brothers did not have title to shares of Evergreen Solar’s common stock previously loaned by the company to Lehman Brothers in July 2008 and seeking their return. (...) The 30.9 million shares in question were loaned to Lehman Brothers in connection with a $375 million financing Evergreen Solar completed in July 2008.
The efficiency and operation of organic solar cells strongly depends on the nanomorphology of the active layer, i.e. on a stable mix of organic compounds that can trap the light’s energy and transport it to an electric contact. IMEC already reported such cells based on P3HT:PCBM with efficiencies near 5%. But to date, the lifetime of these cells is far too short for commercial applications, for which 5 years is seen as a minimum. (...) [IMEC has now] introduced a new method and new conjugated polymers to stabilize the nanomorphology of the active layer making it far more robust to phase segregation under prolonged operation. Experiments on bulk heterojunction organic solar cells based on this new material showed no degradation of the efficiency after more than 100 hours whereas reference cells degraded already after a few hours. This means that a lifetime improvement of at least a factor 10 can be obtained.
LG Electronics (LG), a global leader and technology innovator in consumer electronics, decided at its board of directors meeting held on October 20 to convert its A1 plasma panel-manufacturing line in Gumi, Korea, into solar cell production lines. LG plans to invest KRW 220 billion by 2010 to establish two production lines. The company expects that the first line will be able to begin mass production from the first quarter of 2010, with the second line beginning full operations in the first quarter of 2011. Both lines will manufacture crystalline silicon solar cells and modules with a capacity of 120MW each.
quarta-feira, 15 de outubro de 2008
[Frondel et al, Energy Policy, Nov 2008; also available from here] This article demonstrates that the large feed-in tariffs currently guaranteed for solar electricity in Germany constitute a subsidization regime that threatens to reach a level comparable to that of German hard coal production, a notoriously outstanding example of misguided political intervention (...) For the first scenario [if it had ended in 2007], we have estimated real net cost of approximately 26.5 Bn€, while an abolition in 2010 [after the next federal election] comes at similarly large additional net cost of about 27 Bn€ (in prices of 2007) (...) We argue that in the early stages of development of noncompetitive technologies, it appears to be more cost-effective to invest in research and development (R&D) to achieve competitiveness, rather than to promote their large-scale production.
sexta-feira, 10 de outubro de 2008
Solyndra's technology is a copper-indium-gallium-diselenide (CIGS)-based thin-film PV system. The company said that its system invloves rolling CIGS thin-films into a cylindrical shape and then placing 40 of the cylinders into a 1-meter-by-2-meter panel. (...) The panels' cylindrical modules could be capable of capturing sunlight across a 360° photovoltaic surface and are capable of converting direct, diffuse and reflected sunlight into electricity.
quinta-feira, 9 de outubro de 2008
[Nature Materials, Rodgers at al, Illinois] The authors carve their microcell arrays from a rectangular block of silicon. They begin by etching the outlines of the microcells (the tops and sides) onto the upper surface of the silicon block. They then make electronic junctions and electrical contacts by doping the silicon, adding boron and phosphorus, and using an inert mask to define the regions to be doped. A further round of etching exposes the final three-dimensional shape of the microcells, retaining a thin sliver of silicon to anchor the cells to the block. Finally, the base of the wafer is doped with boron, to yield functioning solar microcells. To make bendable, large-scale solar cells, Rogers and colleagues use a printing technique. They press a flat stamp onto the arrays of microcells on the silicon block, breaking the anchors that tether them to the silicon. The microcells stick to the soft surface of the stamp, and are transferred to a flexible substrate simply by pressing the stamp onto the substrate. The authors then construct electrodes to connect the microcells to each other, using one of various established methods. [more details on Semprius]
quarta-feira, 8 de outubro de 2008
Está a decorrer esta semana em Lisboa a Eurosun 2008, organizada pela ISES e a SPES. O tema da conferência é "Solar heating, cooling and buildings" com um cheirinho de fotovoltaico. A conferência serve ainda de pretexto para uma outra iniciativa da Faculdade de Ciências da Universidade de Lisboa, em colaboração com a Universidade de Kassel, na Alemanha: a organização de um curso de uma semana sobre energia solar para estudantes de mestrado de todo o mundo que participem na Eurosun.
terça-feira, 7 de outubro de 2008
[N]o âmbito das medidas de eficiência energética anunciadas em Janeiro que irão permitir a redução em 40 por cento da factura energética do edifício (...) os painéis solares vão permitir fornecer uma "potência de génese solar fotovoltaica de cerca de 20kW". Com uma capacidade de produção estimada em 30.152KWp anuais [talvez kWh!?], o sistema fotovoltaico instalado cobre cerca de 15 por cento dos consumos eléctricos da Presidência da República.
segunda-feira, 6 de outubro de 2008
The U.S. Department of Energy today announced up to $17.6 million, subject to annual appropriations, for six early stage photovoltaic module incubator projects that focus on the initial manufacturing of advanced solar PV technologies.(...) Upon negotiation of their subcontracts through DOE’s National Renewable Energy Laboratory (NREL), the following six companies will begin their 18-month projects:
- 1366 Technologies - new cell architecture [for] low-cost multi-crystalline silicon cells
- Innovalight- very high-efficiency, low-cost solar cells and modules by ink-jet printing their proprietary “silicon ink” onto thin-crystalline silicon wafers
- Skyline Solar - integrated lightweight, single-axis tracked system (...) 10X onto silicon cells
- Solasta - novel cell design based on an amorphous-silicon “nanocoax” structure
- Solexel - high efficiency mono-crystalline silicon cell technology
- Spire Semiconductor - three-junction tandem solar cells by growing differentiated bi-facial cells on a Gallium Arsenide substrate
sábado, 4 de outubro de 2008
Solar companies proposing large power plants in the Mojave Desert are facing opposition from conservationists. They say a rush to build solar here threatens to tear up large tracts of desert habitat and open space. (...) Conservationists worry that a plan for the Mojave desert will upset species’ habitats (...) Desert’s defenders argue that solar panels should be located on city rooftops rather than pristine lands.
Solar power for toxic waste sites?
Why not set up utility-scale, renewable energy in polluted zones instead?
That's what the Environmental Protection Agency is proposing. (...) 850,000 acres it has cleaned up, among 15 million contaminated acres total, are exceptional destinations for clean-power companies, in part due to the low cost and existing infrastructure there. Plus, brownfields, former mines, etc are unattractive for most commercial and residential development, especially in rural areas.
quarta-feira, 1 de outubro de 2008
No âmbito do concurso BII da Faculdade de Ciências da Universidade de Lisboa o Centro de Sistemas de Energias Sustentáveis da UL propõe quatro projectos para estudantes do 1º Ciclo com interesse em "aprender a investigar" energia solar. O período para candidaturas termina dia 15 de Outubro.
[Nanomaterials, N. Hoth, Konarka] The technological attraction in organic solar cells is their compatibility to printing processes. However, up to today, nearly no literature on “printed” organic solar cells have been published and the major body of the research work was done by spin coating or blading techniques. Transferring the spin-coating or doctor blading process currently used for the fabrication of bulk heterojunction solar cell to a printing process holds morphological challenges that have not been observed or reported up to today. We highlight these challenges and we show that inkjet printing of organic bulk heterojunction solar cells requires completely novel approaches and skill sets compared to the current state of the art (...) report a new record power conversion efficiency of 3.5% for inkjet printed poly(3-hexylthiophene):fullerene based solar cells.
[Advanced Materials, Mitzi et al, IBM] In an effort to significantly reduce fabrication costs relative to vacuum-based approaches (e.g., no vacuum requirements, less energy intensive deposition, better materials utilization efficiency), as well as known solution-based approaches (e.g., fewer processing steps, no high-temperature selenization treatment, more facile Ga incorporation), we are pursuing a simple molecular-based approach for solution-depositing CIGS layers. (...) yielding a short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor, and total area power conversion efficiency of 25.7 mA cm2, 605 mV, 0.66, and 10.3%, respectively.