Gregoire's CleanTech Blog

GM announces a new plug-in hybrid vehicle

Last week General Motors (GM) gave a boost to plug-in hybrid vehicles. It announced a new gas-saving technology that could transform transportation and make renewable sources of electricity, such as wind and sun, more feasible.

At the Greater Los Angeles Auto Show, the automaker committed to manufacturing versions of its hybrid Saturn Vue SUV with a much larger battery pack that can be charged via an ordinary household socket. The increased size of the battery pack makes it possible to rely more on electric drive than current hybrid vehicles do, thereby saving much more gasoline. The actual rollout date will depend on the development of suitable battery technology, according to GM chairman and CEO Rick Wagoner.

With the announcement, GM joined other major automakers that are developing plug-in hybrid technology, including Ford, Daimler Chrysler, and Toyota. "We hope to have some products in the near future, but we're not prepared to say yet when that will be," says Bruce Brownlee, the senior executive administrator at Toyota Technical Center, in Gardena, CA. "The potential [of plug-in hybrids] is terrific." (None of these car companies have yet committed to widespread production of such a vehicle.)

The announcement marks a change in strategy for GM, which has previously focused on addressing environmental issues and high fuel prices by modifying existing vehicles to run on ethanol and by developing hydrogen fuel-cell vehicles. Although GM still plans to continue its fuel-cell program, the decision to produce plug-in hybrids represents a move toward a more evolutionary transition from internal combustion vehicles. "It's nice to see General Motors not just putting all their bets on hydrogen," says Jason Mark, vehicles director for the Union of Concerned Scientists, based in Cambridge, MA.

Plug-in hybrids, which use both an electric motor and a gasoline-powered internal combustion engine, have been hailed as a bridge technology that could make it possible to cut gasoline consumption in the short term; meanwhile, researchers will continue to work out the problems with all-electric vehicles, such as the high costs that make long-range battery-powered vehicles unaffordable. The most commonly described version of this technology would allow drivers to commute about 20 miles without using gasoline at all. But in reality, plug-in hybrids will likely use a blended strategy, relying on the gasoline engine to boost power for acceleration or for climbing hills even during the first 20 miles. This blended strategy would still mean that a typical commute would use almost no gasoline. "Having an internal combustion engine for passing or hill climbing is probably a prudent thing to do," says Thomas Keim, a principal research engineer at MIT. "But if you're traveling around town or just cruising on the highway, you can do both of those things from the battery."

Plug-in hybrids have an advantage over all-electric vehicles in that the battery would be the primary source of power only for relatively short distances, allowing for a much smaller and less expensive battery pack. Since short trips represent the majority of driving in the Unites States, the result would be a dramatic decrease in gasoline use. Electricity use would go up, but the price of powering a vehicle with electricity from the grid during off-peak hours would be the equivalent of gas for about 90 cents per gallon, says Terry Penney, a technology manager for advanced vehicle technologies at the National Renewable Energy Laboratory, in Golden, CO.

For longer trips, the vehicle would switch to a standard hybrid mode once the battery has been depleted to a certain point, saving fuel the same way today's hybrids do. This includes using energy recaptured from braking, turning off the engine when the vehicle stops, and allowing the gasoline engine to run at a more constant and efficient speed. Incorporating existing technologies--such as six-speed rather than four-speed automatic transmissions, and turning off fuel to pistons that aren't needed--could further improve fuel efficiency. Indeed, Mark says these technologies alone, even without hybrid technology, could improve average fuel economy by 10 miles per gallon--enough to replace all the oil we import from the Middle East. Using ethanol rather than gasoline could further decrease gasoline consumption.

These fuel savings would only be the beginning, many experts say. As battery technology improves, and if plug-in hybrids are successful, the high-volume production of batteries could lower their price. This would make it affordable to increase battery-pack size in successive generations and rely even less on gasoline. Eventually, the internal combustion engine could be made smaller and be used exclusively to recharge the batteries on long trips in a configuration called a "series" hybrid. "As time goes on, we may look at even more electrification of the vehicle, including solutions that use fuel cells," says Peter Savagian, director of hybrid power-train systems at GM. At some point, the internal combustion engine could be replaced entirely by large electric motors and battery packs, or by hydrogen fuel cells.

But plug-in hybrids still face challenges. Their environmental benefits will depend on the source of electricity used to charge the batteries. In areas powered primarily by coal, a plug-in might not be better for the environment than a good hybrid, says Nicholas Twork, a spokesman for Ford. Penney says that plug-ins will typically be better, however, since other areas in the United States rely on cleaner sources of electricity.

What's more, Penney says, "if millions of these things were produced 20 years from now, it would really enable renewable energies like wind to take off." Wind power requires ways of storing energy generated when demand for electricity is low, he says. The cost of the storage makes it hard for wind to compete with other sources of electricity. Millions of plug-in vehicles charging at night would essentially provide free storage.

But right now the biggest challenge to plug-in hybrids is the battery technology. First, batteries are expensive. Several companies sell kits for converting existing hybrids to plug-ins with larger battery packs, and these can add $10,000 to the price of a car (see "Plug-In Hybrids Are on the Way"). The plug-in hybrid application will also be much more demanding on batteries than ordinary hybrids are. In a car such as the Toyota Prius, the battery stays at about a 50 percent state of charge, and this varies only a few percent as it absorbs power from regenerative breaking and delivers it in short bursts to augment the gas engine. With plug-ins, batteries will be charged up to at least 95 percent and then deeply discharged during the first 20 miles of driving before settling into an ordinary hybrid mode. Such deep discharging typically decreases battery life. Automakers want batteries that can last 10 years or so even under these conditions so that consumers won't need to buy new battery packs a few years into owning a vehicle.

Automakers' newfound interest in plug-in hybrids is due in part to promising new battery technologies that could be less expensive and have longer lifetimes, and in part to their being safer than the lithium-ion batteries used in laptops today (see "Safer Lithium-Ion Batteries"). "We're encouraged by the improvements in the technology represented by hybrid batteries today," Savagian says. "And we're encouraged that there are many companies pursuing different formulas for them. But we want to give them cause to continue to press forward."

Source : Technology Review

The Material Research Society (MRS) promises batteries with double-capacity for electric vehicle

Today's battery technology is adequate for electric vehicles with a range of more than 200 miles, but the batteries are still very expensive and require elaborate safety mechanisms. There are also concerns that they won't last long enough to be attractive to most consumers.

But current research will double energy-storage capacity while also increasing the lifetime of batteries, improving safety, and cutting costs more than enough to make electric vehicles and plug-in hybrids practical for the mass market. At least these were the predictions of researchers presenting their latest work at the Materials Research Society (MRS) meeting in Boston this week. And although many significant challenges remain, an experimental type of rechargeable battery that's like a fuel cell could increase battery storage that much more.

Stanley Whittingham, inventor of the first commercial lithium-ion battery and professor of chemistry, materials science, and engineering at the State University of New York, at Binghamton, says current research should make electric vehicles practical--with the following caveat: they'll probably be used for trips of less than 100 miles. Those who want 300-to-400-mile ranges typical of gasoline-powered vehicles will need to turn to plug-in hybrids: vehicles much like today's gas-electric hybrids, but with a much larger battery pack that makes it possible to go longer on electric power, thereby saving gas. These batteries could be partly charged by an onboard gas engine, but also by electricity from a wall socket.

Whittingham says that while he expects battery capacity to double, it's not going to get much better than that. The real advances in batteries, he says, won't be in energy capacity, but in safety, longevity, and cost. If electric vehicles are to be widespread, one of the most important goals of battery research must be to replace the cobalt now used in the lithium-ion batteries found in cell phones and laptops. "There's just not enough [cobalt] in the world," says Whittingham, who is working on mixed-metal electrodes, which require little to no cobalt.

One promising new type of battery, which actually has lower storage capacity than today's lithium-ion batteries, could nevertheless prove a boon to plug-in hybrids. Lithium iron phosphate batteries use iron, a very cheap metal, instead of cobalt, and they have an inherently safe chemistry (see "Safer Lithium-Ion Batteries"). What's more, they operate at a lower voltage that will extend the life of the electrolyte, and therefore the battery.

Yet-Ming Chiang, a MIT materials scientist, is developing even better versions of these batteries. Typically when designing batteries engineers have to choose between high-power batteries, such as those needed for power tools and hybrids, which deliver intense bursts of power, and high-energy batteries that pack less of a punch, but can deliver more total energy per charge. According to computer models created by Chiang's lab and presented at the MRS meeting, it may be possible to remove this trade-off by producing nanostructured electrodes made by combining two different types of particles in a specific arrangement in the electrode. This could as much as double energy capacity for high-power applications, without the need to develop new materials, Chiang says.

A researcher at the MRS meeting described another experimental way of creating new electrode structures--a way that could increase energy capacity over existing batteries by four times or more. Peter Bruce, professor of chemistry at the University of St. Andrews, in Scotland, is reviving interest in a type of battery that is something like a fuel cell. This battery has been widely used in the past, but making it rechargeable has proved difficult. Ordinarily, a battery contains all the materials needed to carry out its current-creating chemical reactions. But in this design, one of the reactants, oxygen, can be harvested from the air. As in a fuel cell, in which hydrogen ions combine with oxygen to form water, lithium ions in this battery combine with oxygen to form lithium peroxide. Using oxygen makes it possible to eliminate many of the materials normally included in a battery, drastically cutting its weight. Based on his experiments, Bruce says that such batteries could store as much as 600 to 700 milliamp hours per gram (more than four times that of batteries today) while maintaining the ability to be charged and discharged for many cycles.

So far, Bruce has conducted his experiments using pure oxygen. A working battery would need to be equipped with a membrane, which could be a material similar to Gore-Tex that would seal out both water and carbon dioxide, he says. It might also need a valve to shut off the supply of oxygen to keep reactions from occurring when no current is needed.

Perhaps a bigger problem is the fact that the batteries lose about half of their energy to heat as they are discharged, Whittingham says. This creates a big heat-management issue, and it cuts into the energy-saving motivation for driving hybrids or electric vehicles. "If [Bruce] can be successful, it would be great," he says. But even without such dramatic gains in energy capacity, current research could make batteries much more practical. "I expect the auto companies will be happy with two times [higher capacity] if it will last 10 years," Whittingham says.

Source : Technology Review

UC Berkeley makes thermal rectifier that could be used for energy-efficiency buildings

Scientists have been precisely controlling electric current for decades, building diodes and transistors that shuttle electrons around and make computers and cell phones work. But similarly controlling the flow of heat in solids stayed in the realm of theoretical physics--until now.

Alex Zettl and his colleagues at the University of California, Berkeley (UC Berkeley), have shown that it is possible to make a thermal rectifier, a device that directs the flow of heat, with nanotubes. If made practical, the rectifier, which the researchers described in last week's Science, could be used to manage the overheating of microelectronic devices and to help create energy-efficient buildings, and it could even lead to new ways of computing with heat.

Heat can be thought of as made of tiny packets of vibrations called phonons. A thermal rectifier allows phonons to move only in one direction. But rectifying heat is much harder than rectifying electric current, because most heat transport in materials is by diffusion, which is random, says Arunava Majumdar, a mechanical engineer at UC Berkeley and a coauthor of the Science paper. "The vibrations are not charged, so you can't bias them."

The nanotube thermal rectifier is the first experimental proof that such a device works. "From that point of view, I think it's really interesting," says Michel Peyrard, theoretical physicist at the Ecole Normale Superieure, in Lyon, France. Four years ago, Peyrard and a team of fellow European physicists first proposed a plan for making a thermal rectifier. The basis of the European physicists' scheme was that dissimilar materials conduct heat in various ways at different temperatures. They proposed making a thermal rectifier by combining such materials. But they never ventured into experimental physics to demonstrate their idea.

Other theorists have suggested that if a one-dimensional system has more mass at one end, heat would flow from that end to the low-mass end. Zettl's graduate student Chih-Wei Chang decided to test this theory by making rectifiers with nanotubes, because their extremely narrow width makes them nearly one-dimensional. Plus, they're known to be efficient heat conductors.

Chang made carbon nanotubes and boron-nitride nanotubes between 10 and 40 nanometers wide. He placed individual nanotubes in a test chamber, with each end of the tube bonded to silicon and platinum-based electrodes that act as either heaters or sensors. Then he deposited a platinum compound unevenly along the length of the nanotube so that the tube had more mass at one end than at the other. Finally, he sent a known amount of power through the heater end and measured the change in temperature at both electrodes to see how much heat was passing through the nanotube. As it turned out, as many as 7 percent more phonons were traveling from the high-mass end to the low-mass end than in the opposite direction.

This small efficiency is not enough for practical applications. But what's more important at this stage is the solid proof that the thermal-rectifying effect exists, says Giulio Casati, a professor of physics at the University of Insubria, at Como, Italy, who, along with Peyrar, originally proposed the idea of a thermal rectifier. "It's the first step," he says. "When [engineers] built the first electrical diode, the efficiency was very low. So it'll take time."

Majumdar says the next step is to explore various nanotube geometries as well as the platinum compound loaded on the nanotubes. "Could we change that material or could we change the geometry and thereby increase rectification?" he asks. "That's still up for grabs right now."

Source : Technology Review

Milodiou, moi les renouvelables j'y crois !

Norbert a une mobilette neuve
Vidéo envoyée par katane

Hi hi...

Pareil que Norbert !

Les dernières mesures françaises en faveur du climat et des biocarburants

Le Gouvernement poursuit la réforme de la fiscalité afin d'inciter encore davantage à la protection de l’environnement.

Au terme du comité interministériel pour le développement durable visant à actualiser le plan climat, Dominique de Villepin a proposé ce lundi, d'autres mesures incitatives qui seront présentées au Conseil des ministres le 15 novembre.

Nous vous présentons ci-dessous, celles qui sont destinées tout particulièrement à réduire la consommation d’énergie :

• Instauration d’une taxe sur la consommation de charbon. Le charbon est le seul combustible jusqu’à présent exempt de toute taxation spécifique, alors qu’il est l’un des plus polluants, tant par ses émissions de CO2 que par les autres polluants atmosphériques. La taxe a été fixée au taux de 1,19 euro /MWh.

• Possibilité offerte aux collectivités locales d’exonérer de taxe foncière sur les propriétés bâties, totalement ou à hauteur de 50 %, les constructions obéissant à certains critères de performance énergétique.

Cette mesure vise à créer une incitation, additionnelle à celle du crédit d’impôt habitat existant, à la réalisation de travaux de rénovation permettant d’accroître l’efficacité énergétique des logements anciens. Elle comporte aussi un volet sur les constructions neuves.

• Instauration d’un “livret de développement durable”, à partir du Codevi, élargi au financement de travaux de rénovation améliorant la performance énergétique des logements anciens. Les intérêts des sommes portées sur ce livret sont exonérés d’impôt sur le revenu et de prélèvements sociaux.

• Soutien fiscal aux différentes composantes de la filière flex-fuel (véhicules, installations de distribution), en sus de la défiscalisation du carburant superéthanol déjà introduite dans le projet de loi de finances.

BP Solar finance les travaux de recherche de l'Université de Lisbonne pour mettre au point un procédé de production de wafers fins - EZ-Ribon

BP Solar, un de plus gros fabriquant de cellules et panneaux solaires, va financer un travail de recherche de l'Université de Lisbonne visant à réduire les coûts de production de l'énergie solaire.

Le Portugal est un des pays d'Europe qui dispose de la plus importante quantité de radiations solaires. A titre comparatif, il dispose de 2200 h à 3000 h par an contre 1200 h à 1700 h en Allemagne. Il présente cependant un retard très important dans ce domaine par rapport aux autres pays européens. L'Allemagne, deux fois moins ensoleillée que le Portugal, possède 18 fois plus de panneaux solaires et en installe actuellement 200 fois plus par an.

BP Solar est un des premiers industriels à s'intéresser au potentiel important du Portugal en terme d'énergie solaire. Depuis 3 ans, BP Solar finance les recherches de la Faculté des Sciences de l'Université de Lisbonne (FCUL) qui visent à développer une nouvelle technique de production de panneaux photovoltaïques. Ce soutien a été formalisé le 14 Juillet dernier par la signature d'un protocole de développement de ce nouveau produit.

Le principal obstacle au développement de l'énergie solaire au Portugal est dû aux coûts très élevés de production de la matière première des cellules solaires, les cristaux de silicium. La méthode traditionnelle engendre une perte de plus de la moitié de la matière car les cristaux de silicium sont produits en grand lingots puis découpés en lamelles de 0,2 mm entraînant une perte très importante de matière première.

Les chercheurs de la FCUL, dirigés par António Vallêra, ont mis au point une technique de production qui permet une baisse significative des coûts de production. Cette technique, appelée EZ-Ribbon, fait l'objet d'un dépôt de brevet international dans lequel BP Solar a souhaité investir.

Le principe de cette méthode est de fabriquer le silicium directement sous forme de lamelle éliminant ainsi l'étape de découpe et par conséquence les pertes de matières occasionnées par la méthodes traditionnelle.

Ce brevet prévoit d'attribuer la propriété intellectuelle de ce projet aux chercheurs de FCUL grâce à la couverture des frais par la Fondation des Sciences et de la Technologie.

Source : BE Portugal

Ceram Hyd invente le stockage d'hydrogène sécurisé

Ceram Hyd est une jeune société spécialisée dans le développement de solutions nouvelles dans le domaine des énergies renouvelables. Elle s’intéresse en particulier aux technologies liées à la production d’hydrogène. Ces technologies sont actuellement limitées par la distribution et la gestion de l’hydrogène.
La start-up propose une solution innovante, le stockage par absorption ionique, qui permet de résoudre ces problèmes en stockant l’hydrogène lors de sa production chez l’utilisateur de manière sécurisée. L’innovation majeure de son procédé est liée à son mode de stockage rechargeable. Il permet d’effectuer le rechargement d’hydrogène à température ambiante et pression atmosphérique.
La technologie de Ceram Hyd combinée à une solution de pile à combustible permettra de proposer des piles à hydrogène de nouvelle génération. L’entreprise développe une batterie instantanément rechargeable par simple échange de son réservoir-cartouche. Un système portatif permettra d’assurer la recharge de ces réservoirs-cartouches par un simple branchement électrique domestique.
Avec sa technologie, la start-up se positionne sur le créneau de la production et du stockage d’hydrogène pour les batteries portables de moins de 100 W. D’ici 2009-2011, Ceram Hyd compte être un acteur majeur dans le domaine des piles à combustible pour ordinateurs portables.

Date de création : septembre 2005
Fondateurs : Arthur Mofakhami, Tarek Nassar et Eric Levet
Lieu : Buthiers (77)
Tel : 08 71 25 30 83
Renseignements : [email protected]

Source : Industries & Technologie

Pôle de compétitivité brésilien sur les biocarburants

Les APL (Systèmes Productifs Locaux) sont des clusters mis en place au niveau gouvernemental pour favoriser l'expansion de pôles locaux de compétitivité. Ils rassemblent sur un même territoire des institutions publiques et de recherche avec des entreprises ayant des spécialisations communes ou complémentaires. Mis en place en 2004, le pôle national pour l' alcool coordonne les actions et définit des stratégies dans le domaine de l'utilisation des différentes sources d'énergies propres, comme l'éthanol, le biodiesel ou la biomasse.
L'"APL Alcool", situé à Piracicaba dans l'Etat de São Paulo, vise à renforcer la filière éthanol par la diminution des coûts, la hausse de la productivité et de la qualité finale des produits. Cet APL regroupe des acteurs de l'industrie énergétique et de la recherche : le groupe Cosan (17 usines de production de sucre-alcool), Copersucar (5 usines sur les 29 du groupe), le Syndicat local des Industries chimiques et celui des Industries métallurgiques, le Centre de Technologie de la Canne à Sucre et l'ESALQ (Ecole Supérieure d'Agriculture Luiz de Queiroz). Outre la présence des institutionnels locaux, cet APL dispose d'une interface entre les entreprises et les centres de recherche : le Pôle National des Combustibles.
L'expérience de l'APL Alcool n'est pas isolée au Brésil, puisqu'il existe dans l'Etat du Rio Grande do Sul un APL Bioénergie, qui se positionne en première ligne dans le biodiesel. Au titre des entreprises participantes, l'APL intègre Petrobras, le groupe Ipiranga, la CGTEE (Compagnie de Production Thermique d'Energie Electrique), la Compagnie Sulgás et la CEEE (Compagnie d'Energie Electrique de l'Etat du Rio Grande do Sul). Conjointement aux autorités gouvernementales locales, 19 Universités et centres de recherche, dont l'Embrapa, sont parties prenantes de l'APL Bioénergie.
Contacts :
- http://www.missioneco.org/bresil/documents_new.asp?V=3_PDF_122437
- email : [email protected]

Source : Bulletin Electronique

Nanosolar veut constuire la plus grande usine de cellules solaires (430 MW)

La compagnie Nanosolar a annoncé son intention de construire la plus grande usine de production de cellules solaires au monde en Californie près de San Jose. L'objectif est de produire 200 millions de cellules solaires par an soit une puissance cumulée de 430 mégawatts qui pourrait alimenter 300.000 habitations.
Bien que les cellules silicium dominent actuellement la quasi-totalité du marché photovoltaïque, Nanosolar a choisi la technologie Cuivre Indium Sélénium (CIS) pour ses cellules solaires. Cette technologie présente plusieurs avantages par rapport aux cellules classiques en silicium. Premièrement, elle permet de s'affranchir de la pénurie de silicium qui affecte actuellement l'industrie photovoltaïque. Deuxièmement c'est une technologie couche mince qui ne nécessite que quelques µm de couches actives contre plusieurs centaines pour une cellule silicium cristallin. Enfin la cellule peut être construite sur un substrat flexible. Ceci ouvre la porte à la fabrication de panneaux de forme adaptée à leur utilisation.
Les progrès réalisés ces dernières années permettent aux cellules CIS d'approcher les rendements atteints par les cellules silicium polycristallin (autour de 12% de rendement). Nanosolar prétend avoir développé un procédé de fabrication qui réduit considérablement les coûts de production des cellules CIS, facteur qui a jusqu'ici freiné le développement commercial de ces cellules. Derrière l'entreprise on retrouve Larry Page et Sergey Brin, les fondateurs de Google. Sentant que le solaire a maintenant le vent en poupe, ils ont décidé d'investir massivement pour le développement de Nanosolar. Distancés par le Japon et l'Allemagne dans la course à la production de panneaux solaires et de plus en plus préoccupés par leur situation énergétique, les Etats-Unis semblent en passe de réagir et ce projet en est un exemple tout comme le récent programme d'incitation pour le solaire en Californie. C'est aussi l'opportunité de renforcer sa position dans un marché des énergies renouvelables à la croissance exponentielle dont la valeur est déjà de 40 milliards de dollars et pourrait atteindre 170 milliards en 2015.

Source : Bulletin Electronique

Aerowatt lève 17m€ auprès de ses investisseurs historiques et sur le marché libre

Producteur indépendant d'électricité éolienne en France métropolitaine et en Outre-mer, Aérowatt annonce l'admission de ses titres sur le Marché Libre d'Euronext Paris, par cotation directe.

Sous l'égide d'Arkeon Finance, Aérowatt a réalisé un placement privé auprès d'investisseurs institutionnels français et étrangers, sous forme d'une augmentation de capital ayant permis de lever de 17 millions €. A cette occasion, 591 510 actions nouvelles ont été créées au prix de 28,74 € par action. Parmi les actionnaires déjà présents dans le capital d'Aérowatt, Viveris, Demeter Partners, Crédit Agricole Private Equity et CIC ont souscrit à l'augmentation de capital.

Conformément à la stratégie de développement, cette levée de fonds va permettre de financer de nouvelles centrales éoliennes en France Métropolitaine et en Outre-mer et conforter ainsi la place de leader d'Aérowatt sur un marché à très forte croissance.

« Je tiens à remercier nos actionnaires historiques pour leur soutien et nos nouveaux actionnaires pour leur confiance. Grâce à eux, nous allons franchir une nouvelle étape, développer de nouveaux sites et construire les centrales qui sont en portefeuille. Cette reconnaissance du marché est une raison supplémentaire pour notre équipe d'être encore plus efficace et performante », déclare Jérôme Billerey, Président du Directoire d'Aérowatt.