Gregoire's CleanTech Blog

Silicon-based lighting will compete with incandescent bulbs & LEDs ?

Researchers at a Canadian startup say they've found a way to make low-cost, white-light LEDs that could one day end our addiction to inefficient incandescent bulbs. They claim to have cracked the cost barrier for solid-state lighting by replacing the expensive semiconductors compounds traditionally used in LEDs with low-cost silicon.

"Because it's a silicon-based system, we think [the lighting] will be affordable," says Stephen Naor, chief executive officer of Ottawa-based Group IV Semiconductor (named after silicon's position in the periodic table). "That's critical, because if you don't have affordability, then nobody is going to buy it."

Roughly 60 percent of all lightbulbs in the world are still incandescent--and for good reason: most cost pennies to produce. However, 95 percent of the energy used by these bulbs is wasted as heat. Solid-state lighting is already widely used for specialty applications; LEDs on Christmas tree lights, for example, are based on gallium nitride semiconductors. And experts predict that this technology will be increasingly used for general lighting purposes (see "Turning on LEDs").

But making LEDs using semiconductors based on gallium nitride requires costly manufacturing processes. "The problem is you're using alloys, and there are always impurities. So you have to grow them using very sophisticated gear under ultrahigh vacuum equipment. It's a very costly process," says Sylvain Charbonneau, professor of physics at the University of Ottawa and director of applications technologies at the National Research Council of Canada. Charbonneau is also director of the Canadian Photonics Fabrication Centre, which Group IV will be using to design a prototype of its technology.

Moreover, semiconductors such as gallium nitride are more expensive than silicon, one of the most abundant elements on the planet. Silicon already has a trillion-dollar infrastructure built around it, to support the global electronics industry, and its properties are well researched and thoroughly understood.

"Silicon for electronics is like carbon for organic chemistry," says Moungi Bawendi, professor of chemistry at MIT and an expert on semiconductor nanomaterials. "It's sand--you can't get better than that, so you certainly have a cost advantage if you can base [an LED semiconductor] on silicon."

There's one catch, though: silicon is poor at emitting light. To overcome this, Group IV fabricated a structure in which an electrical current is passed between the top transparent layer of the device and a substrate made of silicon. In-between these two layers is a layer of silicon nanocrystals--quantum dots--that emits the light. When current is applied, the nanocrystal's electrons are energized; once they settle back into their natural state, energy is given off in the form of photons, producing light.

"The final product would definitely compete head-to-head with [conventional] LEDs, but the way of generating the light at the atomic level would be different," explains Ottawa's Charbonneau. "The technology they use is novel."

CEO Naor says Group IV's silicon-based light chips could use up to 90 percent less energy than incandescent bulbs and last up to 50 times longer. He adds that the ultimate goal is to have brighter, higher quality light at far less cost than conventional LEDs, which today can run around $40 for bulbs containing a cluster of 36 LEDs. "You can build an LED lightbulb out of many LEDs," he explains. "But we anticipate one [silicon-based] chip will be bright enough to replace a 100-watt lightbulb, so in that sense we're brighter. And that one chip has huge cost benefits."

But Naor concedes that Group IV's technology is not yet ready to take on conventional LEDs. "We have a lot of work ahead to get brighter, to get it to the efficiency we're targeting, and of course to get the lifetimes that the industry is expecting."

Meanwhile, the traditional LED market isn't standing still. San Jose, CA-based Philips Lumileds Lighting, the world's largest manufacturer of high-powered LEDs, continues to roll out products. The Optoelectronics Industry Development Association estimates that the mass substitution of incandescent lighting with LEDs could happen by 2012, while significant displacement of fluorescent technology would follow several years later.

Whether Group IV can catch up with its competition is not clear; but, after four years of research, the company is ready to move its technology into prototype and product development. "The target is to have a demonstration ability--meaning a real lightbulb--three years from now," says Naor, adding that he'd like to see a product in the marketplace within five years that can be price-competitive with today's compact fluorescents. "It's what people are willing to pay. It's difficult to be precise on where we'll be on price three or four years away, but we're very comfortable we'll be in the ballpark," he says.

Canadian natural gas giant EnCana Corp. and the federal granting agency Sustainable Development Technology Canada together have contributed $4.6 million (Canadian) toward the company's effort. And Vinod Khosla, through his Silicon Valley venture capital firm Khosla Ventures, is also an investor.

But MIT's Bawendi says Group IV may have a tough time meeting its schedule. "Three years sounds awfully fast; but I don't know where they're starting from. The challenge for them is one of efficiencies; they must get their efficiencies high and costs way down."

At stake is access to the world's $12-billion lightbulb market. "Clearly solid-state white lighting is something that has many potential opportunities," adds Bawendi. "It's a huge market, so anybody who can get a little piece of it can do well."

Source : Technology Review

Nokia annonce des piles à combustible pour les portables

Nokia vient de faire savoir que la technologie Fuel Cell était prête à être utilisée dans les téléphones portables. Si aucun modèle n’est néanmoins annoncé, c’est que Nokia aurait encore quelques problèmes en termes d’approvisionnement. Nokia affirme que ce serait la seule barrière qui empêcherait la commercialisation de masse de ce genre de produit. Reste que des questions concernant l’autonomie, le poids et la taille de ce type de batteries restent encore en suspends. La firme finlandaise prévoit la sortie de téléphone utilisant la technologie Fuel Cell d’ici deux ans.

Pour rappel, la technologie Fuel Cell est basée sur une réaction inverse à l’électrolyse puisqu’au lieu de dégager de l’hydrogène et de l’oxygène à l’aide de l’électricité, il s’agit d’en produire en combinant ces deux atomes. Pour fournir la batterie en hydrogène, Samsung utilise, comme ses concurrents, du méthanol ; or l’inconvénient est que cela entraîne un rejet de dioxyde de carbone. Canon semble avoir trouvé la parade en fabriquant une batterie recevant directement de l’hydrogène, mais aucune donnée ne circule quant à son autonomie.

Source : Presence-PC

Les étoiles de l'éthanol ne brillent plus à Wall Street

Une bulle d'éthanol aurait-elle explosé à Wall Street? L'appétit des investisseurs pour les producteurs de ce biocarburant auquel le plus grand des avenirs était prédit voilà encore quelques mois semble rassasié. Coté en juin dernier, le titre VeraSun Energy avait bondi de 30% le jour de son entrée en Bourse. Il s'échange actuellement autour de 16 dollars, soit pratiquement la moitié de son prix d'introduction. Aventine, qui est arrivé sur le marché le même mois, connaît un sort similaire. Son action plonge de 48% depuis son sommet annuel touché peu après sa si prometteuse "IPO". Le troisième producteur américain d'éthanol, Hawkeye Holding, devait pour sa part faire une entrée fracassante à Wall Street à la rentrée de septembre. Voilà deux semaines, le groupe a annoncé qu'il préférait reporter son introduction du fait des "conditions de marché".

Quelles sont donc ces conditions si précaires? Tout d'abord, les producteurs semblent avoir anticipé un peu trop vite l'engouement des consommateurs et des industriels pour l'éthanol. Leur production monte en puissance, mais bien plus vite que la demande. Si bien que les cours de l'éthanol s'effondrent. Aux alentours de 2,2 dollars le gallon (3,8 litres), le prix du carburant vert se trouve au plus bas depuis janvier dernier.

Selon la Renewable Fuels Association, lobby basé à Washington qui regroupe les professionnels du secteur, il existe actuellement 103 distilleries d'éthanol aux Etats-Unis. Opérationnelles, celles-ci peuvent produire jusqu'à 4,9 milliards de gallons par an.

Pour les analystes, le fait que les distilleries poussent comme des champignons explique la chute actuelle des cours - de Bourse comme du carburant -, les investisseurs craignant que les producteurs ne se retrouvent avec d'amples stocks sur les bras.

Leurs craintes sont certainement fondées. L'Association indique que 42 nouvelles distilleries sont en cours de construction et que sept font l'objet de travaux d'expansion. Au total, ces nouvelles installations devraient permettre aux producteurs d'augmenter leurs capacités de 2,96 milliards de gallons, soit de 60% par rapport au niveau actuel!

Autre problème pour le secteur, les cours de l'or noir sont en net repli. L'effet est mécanique: plus le prix de l'essence baisse, moins la nécessité de réformer les habitudes énergétiques des Américains semble justifiée. L'administration Bush a une vision à plus long terme pour le pays. La loi sur l'énergie signée l'an dernier par George W. Bush ("Energy Policy Act") prévoit que les raffineurs doublent leur utilisation d'éthanol pour la faire passer à 7,5 milliards de gallons à l'horizon 2012. Si le plan de marche des Hawkeye et consort se déroule comme prévu, les producteurs auront la capacité de répondre à une telle demande avec cinq ans d'avance.

Source : La Tribune

A fascinating paper on the future of the coal industry

When President Bush said “America is addicted to oil”, he could also have said that America is addicted to coal.

Most Americans are not aware of the sheer scale of current coal use in the United States. Over 50% of electricity is generated from coal with 20 pounds of coal per a person being burnt every day to generate electricity.

While questions are increasingly being raised about remaining oil and gas reserves, we are assured that there is plenty of coal left to burn. Indeed in a talk to a meeting of builders and contractors at the Capital Hilton on June 8, 2005 President Bush asked the audience,
"Do you realize we've got 250 million years of coal?"

Hopefully readers will spot this obvious gaffe. The figure quoted by the coal industry is 250 years of reserves, not 250 million years. The energy illiteracy of the average person is worrying enough, but in our political leadership it is a real cause for concern.

There are an estimated one trillion tons of recoverable coal in the world, by far the largest reserve of fossil fuel left on the planet. The United States has over 25% of the world’s recoverable coal reserves. An important point to remember when considering how many years of coal we have left is that these figures are based on current rates of consumption and do no take into account growing demand for electricity. Since 1980 coal use for power generation has increased by over 75%.

A good percentage of the coal that’s left is too dirty to be burned in conventional power plants and much of its buried in inconvenient places. In 1974 the USGS published an estimate of the recoverable reserve base at 243 billion tons. This however failed to take into account real world restrictions on mining: state and national parks, roads, towns, proximity to railroads, coal quality, losses during mining and geologic limitations. When these are factored in less than 50% of the coal estimated as “recoverable” in the 1974 study was available for mining. This fails to taken into account how much is economically recoverable at market prices. In a 1989 study by the U.S. Bureau of Mines in Kentucky, at $30 a ton 22% of coal was economically recoverable. The author Tim Rohrbacher wrote “a strong argument can be made that traditional coal producing regions may soon be experiencing resource depletion problems far greater and much sooner than previously thought”.

Recently there has been a rise in suggestions that America should replace its addiction to oil, with diesel fuel made from American coal. There is currently in place a Coal-to-Liquids Tax Credit of $0.50/gallon in place until 2023. The idea has been around for a long while, in the second world war it was used by the Germans to make Nazi oil from coal when their supply of normal gasoline was cut off. I remember when I first started researching peak oil I realised after awhile if things got bad that coal rich countries might turn to making Nazi oil in desperation when petroleum depletion started to bite. Of course calls to start building Coal to Liquids plants aren’t proof that petroleum depletion is well advanced, but I hardly see it as a source for optimism.

You don’t need to be an expert on coal liquefaction to realise that it’s a bad idea as this article on AutoblogGreen shows. It’s expensive, uses lots of water, produces double the carbon dioxide when compared to regular petroleum use and produces diesel when the vast majority of the U.S. car fleet runs on gasoline. Over at the Ergosphere, the Engineer Poet crunches the numbers and compares coal to liquids versus electric vehicles . He calculates that to replace the United States petroleum consumption at current rates would take 214 four billion dollar coal to liquid plants (that’s not far off a trillion dollars in investment) and the mining of an additional one and a half billion tons of coal a year, in addition to the one billion tons already being mined for electricity generation. It should be noted that the high percentage of electricity currently produced from coal is not an argument against electric vehicles, this is something I have covered in detail elsewhere on this blog. Electric motors are inherently more efficient than the internal combustion engine. It is far easier to control emissions from large power plant, than from the exhausts of thousands of cars. Electric vehicles are not reliant on one source of energy and in the longer term polluting non-renewable sources of electricity can be replaced by clean alternative energy.

The coal industry’s promotion of the idea that America has a vast reserve of coal is slowing the transition to clean renewable sources of energy. In addition to tv spots showing child actors extolling the virtues of coal , the industry has spent heavily to get the ear of the political establishment. According to the Center for Responsive Politics, Peabody Energy, the world’s largest coal company spent over 5% of its revenues on political contributions, for comparison Exxon Mobil and General Motors spent a fraction of one percent.

In seeming return for such generosity, The Energy Policy Act of 2005 included five billion dollars of subsidies for the coal industry.

Virtually every power plant built in America between 1975 and 2002 was fired by natural gas. However between 1970 and 2000, the amount of coal America used to generate electricity tripled.

Now with natural gas prices rising steeply, U.S. power utilities are expected to build the equivalent of 280 500 megawatt coal-fired electricity power plants between 2003 and 2030. China is already constructing the equivalent of one large coal burning power plant a week with two thirds of energy production coming from dirty coal. 16 of the 20 most polluted cities in the world are in China. India is the third largest producer of coal in the world, also getting over two thirds of its energy from coal. If these new coal plants are built, they will add as much carbon dioxide to the atmosphere as has been released by all the coal burned in the last 250 years.

Coal’s sale price may be low, but the true costs of its extraction, processing and consumption are high. Our use of coal leads to ravaged mountains , air pollution from acidic and toxic emissions and fouled water supplies. Coal mining is massively more invasive than oil or gas drilling. Coal burning power plants account for more than two-thirds of sulfur dioxide, 22% of nitrogen oxides, nearly 40% of carbon dioxide and a third of all mercury emissions in the United States. Results of the largest mercury hair sampling project in the U.S. found mercury levels exceeding the EPA’s recommended limit of one microgram of mercury per gram of hair in one in five women of childbearing age tested. Each year coal plants produce about 130 million tons of solid waste, about three times more than all the municipal garbage in the U.S. The American Lung Association calculates that around 24,000 people a year die prematurely from the effects of coal fired power plant pollution.

Techniques for addressing CO2 emissions exist, although the will to quickly implement them lags.

The techniques electric utilities could apply to keep much of the carbon dioxide they produce from entering the atmosphere are known as CO2 capture or geological carbon sequestration. This involves separating the CO2 as it is created and pumping it underground to be stored.

Until recently I wasn’t aware that all the technological components needed for carbon sequestration are commercially ready (according to an article in September’s Scientific American magazine ) as they have already been proven in applications unrelated to avoidance of climate change. However integrated systems have yet to be built on a commercial scale.

Capture technologies have been deployed extensively throughout the world both in the manufacture of chemicals (e.g. fertilizer) and in the purification of natural gas. Industry has gained experience with CO2 storage in operations to purify natural gas, principally in Canada, as well as using carbon dioxide to boost oil production, mainly in the United States.

The Intergovernmental Panel on Climate Change (IPCC ) estimated in 2005 that it is highly likely that geologic locations worldwide are capable of sequestering at least two trillion metric tons of CO2 - more than is likely to be produced by fossil fuel consuming power plants this century.

Carbon sequestration is not without risk. The two main risks are sudden escape and gradual leakage of carbon dioxide. In 1986 at Lake Nyos in Cameroon, Africa carbon dioxide originating from a volcano killed over 1,700 people. However according to IPCC this is unlikely for engineered CO2 storage in carefully selected, deep porous geologic rock formations. In regard to gradual leakage the IPCC estimated in 2005 that in excess of 99% of carbon sequestered is “very likely” to remain in place for at least one hundred years.

Studies indicate that 85%-95% of the carbon in coal could be sequestered using existing power generation technologies.

A key point is that fundamentally different approaches to carbon capture would need to be pursued for power plants using the old pulverised coal technology as opposed to the newer integrated gasification combined cycle (IGCC). IGCC plants use heat and pressure to cook off impurities in coal and convert it into a synthetic gas, this gas is then burnt in a turbine. These plants are 10% more efficient than conventional plants, consume 40% less water, produce 50% less solid waste and burn almost as cleanly as natural gas plants.

Although building IGCC power plants is slightly more expensive (10%-20%), IGCC is likely to be the most effective and cheapest option for carbon capture.

In an IGCC plant designed to capture CO2 the syngas exiting the gasifier, after being cooled and cleaned of particles, would be reacted with steam to make a gas made up mainly of CO2 and hydrogen. The CO2 would then be extracted and pumped to a storage site. The remaining hydrogen would be burned to generate more power. Captured carbon dioxide can by piped up to several hundred miles to a suitable geologic storage site.

A recent study found that for carbon capture in a saline formation one hundred kilometers from a power plant would cost an additional 1.9 cents per kilowatt-hour (over the generation cost of 4.7 cents per kilowatt-hour for a coal IGCC plant that vents carbon dioxide), making a 40% premium. With coal generation costing 6.6 cents for a kilowatt hour, this would make wind power cheaper than coal and with technology advances could also provide a boost to other renewable energy sources (e.g. concentrating solar power).

However electricity producers are rushing to build conventional coal pulverisation power plants, just as they rushed to build coal plants without sulfur scrubbers prior to legislation coming into force. This is short-sighted as it is more expensive, more energy intensive and less effective to attempt to capture carbon from conventional coal power plants. It is highly likely that having built these plants, that the coal industry would expect the taxpayer to foot the bill for the additional expense. Of the one hundred or so plants being planned or under construction in America only a handful use IGCC technology.

FutureGen , is the Department of Energy financed one billion dollar zero emissions plant intended to turn coal into electricity and hydrogen. Proposed in 2003 and backed by a consortium of coal and electric companies, it is not due to come online until at least 2013. Many in the industry consider this date to be dubious nicknaming the project NeverGen. It is intended to make it look like the coal industry is doing something, while actually doing very little and in the process putting off changing how coal plants are built for a decade or two. Indeed in its Coal Vision report (pdf), the industry does not plan on building “ultra-low emissions” plants on a commerical scale until between 2025 and 2035. According to the report “there is considerable debate about the need to reduce CO2 emissions”. The report also states that “achieving meaningful CO2 reductions would require significant technical advances”.

The report further states “large scale and long term demonstrations of carbon sequestration technologies over a geographically and geologically diverse range of... sites are needed before making any policy decisions concerning carbon management”. The coal industry wants sequestration to be demonstrated not only in the United States but additionally “similar assessments need to be conducted internationally”. In terms of who should pay for these demonstrations the report writes “the government must play a significant role”.

It sounds that if the coal industry has its way, it won’t be using carbon capture for many decades.

Instead of waiting until 2013 or even 2035, the coal industry could be building IGCC power plants with carbon capture now. The rush to build conventional coal pulverisation plants is extremely short sighted as these plants could be operating for the next fifty years or more.

In the first instance I advocate maximising our use of clean renewable energy. At the moment wind power is being used to generate only 0.5% of electricity in the United States. Using existing technology wind power could cost effecively generate a significant portion of many countries electricity supply. Significant sums of money should also be invested in making solar power and wave power more cost effective, as well as investments in energy long shots such as cellulosic ethanol and fusion power. If we are going to continue to use coal as global society as a major source of energy, which seems pretty much inevitable for at least the next few decades in key countries such as the United States, China & India, then we should be building IGCC power plants with carbon capture and retiring existing dirty coal plants now. If there are unforeseen problems with carbon capture, we need to find out now rather than in a few decades time. The coal industry's business as usual attitude is simply not acceptable.

Jeff Goodell in his recent book “Big Coal” concludes, “coal gives us a false sense of security, if we run out of gas and oil, we can just switch over to coal… the most dangerous things about our continued dependence on coal is it preserves the illusion that we don’t have to change our thinking”.

Further Reading:

“Big Coal ” by Jeff Goodell

“What to Do About Coal?” in Scientific American September, 2006

Lively Discussion of Coal to Liquids

Coal Vision by the Coal Based Generation Stakeholders Group

Mountaintop Removal

A Quick Guide to Mountaintop Removal Coal Mining

When Will Coal Production Peak?

Source : Alternative Energy Blog

Comverge files for IPO

Comverge Inc., an East Hanover, N.J.-based provider of hardware and software to utilities, has filed for a $90 million IPO. It plans to trade on the Nasdaq under ticker symbol COMV, with Citigroup serving as lead underwriter. The company has raised nearly $40 million in VC funding from firms like Nth Power, EnerTech Capital Partners, Rockport Capital Partners, Norsk Hydro Ventures, Ridgewood Capital, Easton Hunt, Data Systems & Software Inc., Air Products & Chemicals Inc. and Partners for Growth. www.comverge.com

Source : PE Week

Biomasse : à la recherche des plantes les plus calorifiques

Nom : miscanthus giganteus. Origine : Asie. Particularité : culture énergétique idéale pour la production de chaleur et d’électricité. En France, cette plante vivace vient pour la première fois de passer du stade expérimental à la production commerciale. La société britannique Bical vient de réaliser sa première récolte, en association avec des agriculteurs bretons.

Biomasse combustible, litière pour animaux, panneaux de particule, éthanol, éco-construction… Les débouchés du miscanthus giganteus sont multiples. Cette plante, également appelée "herbe à éléphant", pourrait jouer un rôle majeur dans le développement de la biomasse énergétique. En France, la toute première récolte, destinée au marché industriel, a eu lieu en Bretagne, au printemps dernier. 500 tonnes de ce simili-bambou ont été coupées par une ensileuse, sur une surface de 40 hectares

. Un rendement de 12, 5 t/ ha, qui peut atteindre plus de 20t/ha selon la maturité de la plante et les conditions climatiques.

La plantation a été réalisée en 2004 par Bical France, filiale de Biomass Industrial Crops Ltd (Bical), qui produit déjà 400 000 t/an au Royaume-Uni. Cette société, fondée par des agriculteurs britanniques en 1998, est le premier fournisseur européen de miscanthus (sur une petite dizaine d’entreprises). Elle a dégagé un chiffre d’affaires de 6 millions d’euros en 2005. Pour s’implanter en France, Bical s’est associée à des agriculteurs locaux, à Bannalec, dans le Finistère, puis à Voves, en Eure-et-Loir. "Nous fonctionnons selon un système coopératif. Tous les exploitants associés possèdent une part du capital de Bical France. Nous souhaitons leur permettre d’obtenir un revenu régulier et décent," explique Emmanuel de Maupeou, directeur général.

Un pouvoir calorifique étonnant

La totalité de la production a été achetée par le groupe Lafarge Ciments, séduit par l’étonnant pouvoir calorifique du miscanthus, plus élevé que la plaquette de bois. Son PCI (pouvoir calorifique inférieur) est en effet d’environ 4700 kWh/t, contre 3300 pour la plaquette, ce qui le rend très rentable, selon Bical.
Créé en Asie à partir des miscanthus sinensis et sacchariflorus, cette graminée hybride peut remplacer jusqu’à 50% du charbon dans une centrale électrique ou une chaudière industrielle, sans modification technique. Il peut aussi se substituer au bois-énergie des chaudières et poêles individuels. Lors de sa combustion, il émet moins de dioxyde de carbone (CO2) qu’il n’a emmagasiné, car une partie de ce dernier est stocké dans ses rhizomes, des tiges souterraines capables d’engendrer de nouvelles pousses. Un bon point pour les industriels qui veulent préserver leur capital de crédits carbone.

Jusqu’à l’arrivée de Bical en France, le miscanthus n’était cultivé que dans le cadre d’expériences scientifiques, alors qu’il a atteint le stade commercial en Grande-Bretagne et dans plusieurs pays européens. L’Institut national de la recherche agronomique (Inra) a procédé à des essais en plein champ, et étudié, avec la société Kalys, à Roubaix, les moyens de réduire le coût de production des pieds de miscanthus. Conclusion : la culture in vitro, le bouturage et la plantation en terre sont compatibles avec les objectifs d’économie agricole.

"Aucune maladie ni ravageurs connus"

La plantation de l’herbe à éléphant nécessite cependant des moyens financiers et humains importants, car elle n’est pas mécanisable. Les plants doivent être mis en terre à la main, dans un sol aéré et creusé de sillons. La première année, l’élimination des adventices (les mauvaises herbes) est nécessaire pour permettre au miscanthus de bien prendre racine et grâce à ses rhizomes produira de nouvelles tiges aériennes au cours des années suivantes. Le désherbage peut être assuré mécaniquement, au moyen d’une herse, ou chimiquement. Bical a choisi cette dernière solution. "Nous utilisons un désherbant homologué uniquement la première année, car à partir de la deuxième année, les feuilles se dessèchent au début de l’hiver et tombent sur le sol, constituant un nutriment naturel et empêchant l’apparition des adventices, précise le directeur général. Nous n’utilisons pas non plus de fongicide ni d’insecticide, puisqu’il n’existe aucune maladie ni ravageurs connus, à part les blaireaux."

L’herbe à éléphant abrite d’ailleurs de nombreux animaux, dont la nidification n’est pas perturbée par la moisson, réalisée en mars, sur un sol sec ou encore gelé, pendant le début du nouveau cycle de pousse. Culture pérenne, le miscanthus repousse naturellement, et peut être exploité sur une période de 5 à 18 ans. Il peut atteindre une hauteur de 4 mètres. Et comme il est stérile, le risque de dissémination est nul.

Reconversion de terrains pollués en Ile-de-France

Plusieurs études ont mis en évidence sa capacité à croître en terrains agricoles ou industriels pollués. Dès 1992, deux chercheurs japonais démontraient sa grande tolérance face à de fortes proportions de métaux lourds dans le sol, et son faible taux d’accumulation de cadmium dans ses feuilles (1,75 mg/kg).
Des résultats confirmés en France par les études de l’Inra, qui participe à la reconversion des anciens champs d’épandage de l’agglomération parisienne vers des filières agricoles. L’opération de 750 000€ implique le conseil régional d’Ile-de-France, et doit durer cinq ans, de 2006 à 2011. Le miscanthus sera testé au même titre que d’autres végétaux (seigle, taillis à rotation rapide…). Objectif : "retrouver, en cinq ans, sur ce secteur pollué, un nouveau système d'activités agricoles durables, axées sur des productions à des fins non alimentaires," indique un rapport de la Région de mai 2006.

Même si les qualités du miscanthus sont reconnues, le coût de sa mise en œuvre, la concurrence des autres énergies renouvelables et la difficulté de convaincre les agriculteurs sont autant de freins à son développement. Mais pour Emmanuel de Maupeou, la principale barrière est "psychologique". "Un certain nombre d’environnementalistes réprouvent l’arrivée d’une plante non-indigène, mais ils oublient que c’est aussi le cas du maïs ou de la pomme de terre."

Acciona : The largest PV solar plant in Europe : 60MW

ACCIONA has been selected to build and operate as owner a 62 MW photovoltaic solar plant near the town of Moura, in southern Portugal. The plant will be the largest in the world, with 6 times as much installed power as the next largest one.

With an investment in excess of 200 million euros, its construction will be carried out in two stages: the first, with 40-45 MW, will be concluded in 2008 and the other, with the remaining power, will be completed by 2010. With a production capacity of 91 million kWh per year, the plant will make ACCIONA the world's leading owner of photovoltaic assets.

The company will build a photovoltaic panel manufacturing plant in the municipality of Moura with a minimum annual production capacity of 24 MW and will contribute €3,500,000 to a social fund for the development of infrastructures to be owned by the municipality.

To materialise the operation, ACCIONA will acquire 100% of the shares of Amper Solar —owner of the rights to the solar plant, authorized by the Portuguese Ministry of Economy— from its current shareholders —Moura Town Council (88%), Comoiprel (2%) and the consultant Renatura Networks.Com (10%). The Town Council may retain, if it so wishes, up to 20% of the company's capital. ACCIONA Solar will be in charge of the turn-key construction of the plant.

This agreement is ACCIONA's first international venture into photovoltaic solar energy, a sector that is experiencing a worldwide annual growth of 30-40%. In Europe, this energy industry grew by 50% in 2005, reaching a figure of 1,793 MW thanks to its strong implementation in Germany, with 1,537 MW in operation (about 85.7%). In Spain, Europe's second country in its implementation, growth figures also exceeded 50% last year. 

New example of PV solar plant project in the US

Xcel Energy on Friday selected Baltimore's SunEdison to build the largest solar electric farm in Colorado.

The 8-megawatt solar farm, capable of powering more than 2,600 homes along the Front Range and other parts of Colorado, would be built in the San Luis Valley near Alamosa.

Xcel has said the project could cost an estimated $60 million and go online before the end of 2007.

The utility, which serves 1.3 million electric ratepayers in Colorado, chose SunEdison after spending months reviewing bids from several other companies since announcing the project in March.

"The (decision) was pretty quick for an RFP process," said Xcel spokesman Tom Henley, referring to the request-for-proposal, or bidding, process.

Henley said the project would use two types of solar technologies, making it the largest of its kind in the United States.

SunEdison last month became the nation's largest commercial photovoltaic contractor after it acquired Team Solar Inc., a PV installer from Northern California, according to its news release.

A call to Jigar Shah, SunEdison's chief executive, was not returned.

"There haven't been that many utility-scale photovoltaic projects in the country, so this is pioneering in many respects," said Gary Schmitz, a spokesman for the National Renewable Energy Laboratory in Golden.

Schmitz said solar power from photovoltaic panels, on average, costs about 22 cents to 25 cents per kilowatt/hour. That compares with 4 cents to 6 cents per kwh for wind power. But NREL expects the "cost to come down substantially in the next 10 years," Schmitz said.

Pat Vincent, president and chief executive of Public Service Company of Colorado, an Xcel subsidiary that is the largest electric and gas utility in the state, will formally announce the project Monday.

Xcel must install about 18 megawatts of solar power through 2010 to comply with renewable energy standards outlined in Amendment 37.

Approved by voters in November 2004, the mandate requires Xcel to acquire 10 percent of its electricity sales from renewable sources such as wind, sun, or plant and animal waste through 2015. At least 4 percent of that must come from solar energy.

Henley said Xcel will be in compliance with the standards on wind energy through 2018, after it installs 775 megawatts of new wind projects by the end of 2007. Xcel already has 282 megawatts of wind power in its system.

The mandate also requires half the solar power to come from customers. Xcel would get the rest from the San Luis farm.

Because solar and wind power are intermittent in nature, Xcel estimates 1 megawatt serves roughly 330 customers.

More than 90 Xcel customers have installed solar systems at homes and businesses for a total of more than 350 kilowatts - less than 5 percent of the requirement. Xcel has paid more than $1 million in rebates to solar customers since the program debuted in March and is reviewing an additional 210 rebate applications.

The utility has earmarked a total of $20 million this year for the rebate program, as well as a portion of the cost of the solar farm.

Xcel collects six-tenths of 1 percent of the electric portion of a monthly bill from ratepayers, an average of 36 cents a month. The money pays for the solar and wind energy programs.

Xcel's solar electric farm 

Contractor: Baltimore-based SunEdison LLC

Where: San Luis Valley

Cost: Estimated at $60 million

Capacity: 8 megawatts, enough to power more than 2,600 homes

Schedule: Online by the end of 2007

Couplage ENR (solaire) & désalinisation - projet espagnol

Tabernas, province d'Almeria, Espagne. Une plate-forme solaire déchire l'horizon. Autour de ces capteurs solaires s'ébroue une usine pilote de dessalement unique au monde. Sa particularité : Elle utilise l'énergie solaire et une pompe à chaleur pour générer de l'énergie. Ce projet qui répond au nom d'Aquasol exploite une technologie hybride de dessalement avancée, basée sur des capteurs solaires statiques. Elle met en œuvre la distillation thermique multi-effets, un procédé précis et robuste qui produit une eau très pure et présente un bon rendement énergétique grâce notamment à l'utilisation d'énergies renouvelables.

Intérêt du concept : les résidus saumurés issus du dessalement sont pour la première fois transformés en sel commercialisable. Cela évite la pollution marine et transforme un déchet en matière première. Actuellement, le coût de 1 m³ d'eau est de 6 euros environ, mais il pourra être réduit à 0,47 euro pour une production de trois millions de m³ par an (environ 12 000 m3/j), rendant la technologie compétitive. Cette production devrait permettre de réduire les émissions de CO2 de 14 000 tonnes par an. Quatre pays ont collaboré à ce projet financé par la Commission européenne : l'Espagne, la Grèce, le Portugal et la France.

Source : Plein Soleil

New investment by REC to extend its capacity

Renewable Energy Corporation (REC) has decided to more than quadruple its solar cell production and double its solar module production within 2008. REC's production of cells and modules will be increased from today's 45MW level, up to a total of 225MW in cells and 100MW in modules.

Both plants will continue to utilize multicrystalline wafers from REC Wafer.

"We are now taking another important step to further implement our integrated business model strategy. Growing our cell and module business will leverage our strong position in polysilicon and wafers, and thus capture more of the value generated in these businesses", says Erik Thorsen, President and CEO of REC ASA.

Both expansion projects will be initiated immediately through extensions of the existing cell plant in Narvik, Norway, and the module plant in Glava, Sweden.

The cell expansion will be undertaken in two equal steps. Ramp-up of the first step will start in Q4 2007, and the second step will start in Q2 2008. Total investment related to cell expansion will amount to approximately NOK 700 million and includes a number of important technology steps. The ramp-up of the module capacity which is expected to start Q4 2007, also includes a significant increase in automation of the existing production. Total investment related to the solar module expansion is approximately NOK 100 million.

The expansions will create approximately 175 new jobs in Narvik and 20 new jobs in Glava over the next 18 months.

"REC Solar has already today the competencies and resources necessary for continued strong growth. Through further optimizing the size of our existing cell and module plants we are also ensuring that these plants have the necessary scale and competitive edge to strengthen REC's market position going forward", says Thor Christian Tuv, Executive Vice President Solar of REC ASA.

The expansion projects also create room for REC to subsequently introduce its own proprietary technology in both the cell and module manufacturing. With a potential to increase cell efficiency by between 1 - 2 percentage points on multicrystalline wafers, this new technology will contribute to achieve a targeted cost reduction in cells and module manufacturing.

"We are very exited about the prospects of taking the next technology step and thereby moving further down the cost-per-watt curve. The expansions will also allow us to retrofit parts of this new technology into our existing production lines", Erik Thorsen adds.

Source : SolarBuzz