Friday, July 27, 2007

A new generation of more efficient solar cells is on the horizon

Today’s solar cells have an efficiency of 17 per cent, where 100 per cent means that all the energy from sunlight is converted to electricity. There are two types of solar cells, known as first- and second-generation cells. The most important difference between the two is the production price. First-generation cells are built of single crystals of silicon, and are expensive to produce,while the production of secondgeneration cells is far less expensive. The drawback of second-generation cells is that they sacrifice efficiency for cost, as compared to firstgeneration cells. However, because the cost is so much lower, the price per produced watt is also reduced.

Now, a new project at NTNU is taking part in the search for third-generation solar cells. Associate Professor Turid Worren is head of a project that will make a test model of the solar cells by the end of the year. The efficiency of the new cells should be beyond anything that has been produced in Norway to date.

“Theoretically, we might reach efficiencies of 60 per cent or higher. In practice we hope for 40 per cent efficiency at the start. Even at that level, the energy efficiency will be 2 to 3 times higher than today’s solar cells”,Worren says.

NTNU is the only institution in Norway where this kind of research is conducted. Worldwide, just a few groups are working on this new type of solar cell; otherwise, interest in the field has been limited.Worren says fossil fuels are to blame.

“I am convinced that a new generation of solar cells would have been available already, if not for cheap fossil energy”, she says.

The new solar cells are based on what are called ‘quantum dots’. All solar cells use semiconductors to absorb sunlight, but today's cells are unable to absorb very much of the infrared heat radiation from the sun. The new solar cells being developed have pyramid-shaped semiconductor dots in addition to conventional semiconductors. These dots absorb a portion of the infrared light that the other parts of the solar cells do not capture.

The project uses new technologies and is partly financed by NTNU’s Nanolab. The longterm goal is to produce solar cells using this new technology.

“Using these kinds of solar cells, we could build solar cell power plants in sunny places in the developing world.At our latitudes, the most realistic use of this technology would be to cover buildings with aesthetic building elements that integrate solar cells", Worren explains. People would accept this approach if the cells were decorative enough,Worren says. “Solar cells can be beautiful, and a good alternative to decorative stone and window glass”, she says.

On a worldwide basis, the installation of new solar cell plants (measured as the amount of energy produced) increased by 63 per cent from 2003 to 2004, with much of the increase due to political involvement. It is estimated that by 2010, the number of solar cell plants will have tripled compared to 2004. In Norway, solar cells are mainly used for mountain cottages and lighthouses, where it can be difficult to connect to the power grid.

“If we could cover 0.3 per cent of Norway’s land area with solar cell plants, we could produce 120 terawatt hours, which corresponds to our entire electricity consumption in 2002”, Worren says.

“That means that it is physically possible to handle Norway’s total energy consumption with power from solar cells, but that is neither necessary nor desirable. One alternative could be to produce just one per cent of Norway's electricity consumption using solar cells. That would correspond to a solar cell area of some 90,000 roofs, each measuring 100 square metres”, she says.

Another factor that makes the production of more efficient solar cells interesting is the lack of raw materials for the current technology. Most solar cells have an active portion made of a thin wafer of silicon. The solar cell industry is currently experiencing a silicon shortage. The search for other ways to produce silicon has begun, but increased efficiency in silicon use will also be an important component of solar cell production.


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Thursday, July 19, 2007

India: cheap, green, food-friendly biofuel produced with sorghum

he first commercial batch of biofuel from the stalks of a new sweet sorghum hybrid has been produced this month (13 June) at a distillery in the state of Andhra Pradesh in India.

Ethanol is produced from the sweet juice in the stalk of the sweet sorghum. The researchers responsible for the hybrid say by using sorghum, resource-poor farmers will still be able to use the sorghum grain and protect food security, while earning an additional income from selling the stalks.

This first batch marks a major success for the research consortium that developed the new hybrid, says Belum V. S. Reddy, principal sorghum breeder at the India-based International Crops Research Institute for Semi-Arid Tropics (ICRISAT).

Sweet sorghum is a cheap biofuel crop to grow, costing about a fifth of that of sugarcane. It also requires half the water needed to grow maize and about an eighth of that required for sugarcane.

It is also carbon neutral, according to the Latin American Thematic Network on Bioenergy — a project promoting the sustainable use of bioenergy. Sweet sorghum takes in the same of amount of carbon dioxide during its growth that it emits during growth and its later conversion to ethanol and the eventual ethanol combustion.

When sweet sorghum biofuel is blended with petrol it also emits less polluting sulphur and nitrous oxide compared to sugarcane biofuel, according to Reddy.

A major problem for ICRISAT was ensuring availability of sweet sorghum stalks throughout the year. "Different plant types produce different amounts of juice at different times of the year and it is important to have genetic stocks that can produce the same amount of juice throughout the year," says Reddy.

ICRISAT solved the problem by developing hybrids that can be planted at any time of the year.

The team intend to plant at least 4000 acres of the new crop during the next rainy season, according to G. Subba Rao, director of Aakrithi Agricultural Associates of India, a partner in the project.

Clusters of villages have been identified for the planting, and seeds distributed to the farmers. A method has also been designed to collect the stalks from the farmers, which will then be crushed at cluster centres and the syrup transported to the main distillery.

Via SciDev.Net

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Friday, July 13, 2007

New Jersey governor signed the toughest U.S. global warming law

Governor Jon Corzine made New Jersey the first state to call for strict greenhouse gas reductions by 2050 in an effort to fight global warming and climate change. Corzine signed the Global Warming Response Act that mandates greenhouse gas emissions in New Jersey to be cut by 16 percent by 2020 and 80 percent by 2050.

The new law also sends a message to the Bush administration, who opposes mandatory emission cuts, preferring voluntary goals instead. But that, Corzine says, is not enough. "We want to send a message to Washington. Wake up, get with the program and start doing something about greenhouse gasses," the Democratic governor told reporters.

Other states have introduced their own measures since the federal government has yet to require mandatory emission regulations. California also passed a greenhouse gas law recently that mandates emission cuts. And while it has a long term goal of cutting emissions by 80 percent in 2050, it is merely a target, and not enforceable like that of the New Jersey law.

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Monday, July 09, 2007

A Chinese company says it has developed a mobile phone that uses solar energy to recharge itself and can provide 40 minutes of talk-time after sitting in the sun for an hour.

Hi-Tech Wealth, a well-known telecommunication products supplier in China, claims its mobile phone is the world's first solar power to recharge its battery. The company says a scale-like solar panel on the top side of the clamshell-designed phone can also be recharged by light from other sources including candles.

Hi-Tech Wealth says it has developed the most advanced solar power technology and owns eight patents and has applied for numerous others. Many companies around the world are working on similar mobile phones but their products are still at the experimental stage, said an official with Hi-Tech Wealth.

Zhang Zhengyu, chairman of Hi-Tech Wealth, said the company began researching the use of light as an energy source in 2000 and has invested hundreds of millions of yuan. "With more than 400 million mobile phones in the country, China would save a great amount of electricity if all its mobile phones were recharged by light," Zhang said, adding that the lifespan of the battery in the new phone is 2.5 times longer that traditional batteries.

In March, Hi-Tech Wealth exhibited its light energy mobile phones at the world's largest electronic, IT and telecommunication products trade show CeBIT in Hanover, Germany. The company plans to put six of its light energy mobile phones on the market this year, and another 30 next year.

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Hitachi to launch Super Eco-factory

On June 25, 2007, Hitachi Group announced its new "Super Eco-factory" standards for environment-conscious plants and the first nine Super Eco-factories. The group aims to reduce CO2 emission by 7% by FY2010 compared with FY1990.

The Hitachi Group has proposed "emission neutral" status, in which the "direct loads" including energy used in production activities such as the acquisition of basic materials and processing and refining of components, greenhouse gases emitted from factories and energy used for transportation, and the reduction of "social loads" referring to the electricity consumed by products and energy used for recycling end-of-life products are balanced out.

Hitachi is striving to implement this status by FY2015. In accordance with this goal, the above-mentioned Super Eco-factory certificate has been formulated since FY2006.

The Hitachi Group defines Super Eco-factories as "environmentally friendly facilities that further promote energy conservation, reduce chemical substance emissions and implement advanced resource recycling measures."

Super Eco-factories are required to be six times more energy efficient than the lowest standard applied by Japan's energy saving laws. The Hitachi Group looks to certify 30 Super Eco-factories out of about 300 factories generating heavy environmental loads by 2010.

The group has already started "Super Eco-product" standards for products that have achieved more than 10 times higher "environmental efficiency," an index that represents "how much product or service value is generated, while lowering environmental loads and resource consumption," compared with relevant products manufactured in around 2000, and authorized 40 Super Eco-products by the end of March 2006.

The group has also authorized 1,012 Eco-products as of the end of fiscal 2006 and aims to increase sales of Super Eco-products to 30% of total Eco-product sales.

In FY2007, the Hitachi Group is moving forward to authorize more Super Eco-factories and about three times more Super Eco-products than 2006 toward the goal of emission neutral status in 2015. Through these measures, the group plans to reduce CO2 emissions by 850,000 t combining direct loads and social loads from the FY2006 level.

via Tech-On

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Sunday, July 08, 2007

Veja Fair Trade eco-sneakers

A company out of France launched in 2005 a good-looking, fair trade shoe with primarily earth-friendly materials.

Veja imports organic cotton from Northeastern Brazil while simultaneously encouraging crop diversity from their suppliers. Additionally, all the rubber used for the soles is natural rubber from Amazon Hevea trees, sourced from rubber tappers with a commitment to forest preservation.

Veja takes an interesting approach to worker recognition by having select worker's profiles on their website including their personal stories. In addition, Veja's employees receive fair wages and their families have access to a traveling teacher who can teach literacy skills to their children. Additionally, according to Veja the fair trade premium paid to the producers aims at financing concrete development projects in health, education or environment fields.

The first Veja model (Veja Trainer) is inspired by Brazilian volley shoes from the 1970s. This summer Veja launches a new collection called Tauá (named after the little village in Northern Brazil where the organic cotton is produced). So walk ethic and fashion this summer...

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Solar power with helium balloons

A new way to produce electricity using helium balloons coated with solar cells has been devised by researchers at the Technion Israel Institute of Technology in Haifa.

Scientists from the Department of Aeronautical Engineering, Architecture and City Construction have already installed two models, one in the city and one in a desert area that lacks power.

Dr. Pini Gurfil, who heads the environmentally friendly project, said that to produce electricity from solar energy, one needs a large area - about 400 dunams - for a power station large enough for commercial use. "Therefore, the balloons should be used at a low altitude in the sky," he explained.

Gurfil and doctoral student Yossi Corrie developed a technique of using helium-filled balloons coated with solar energy cells to provide electricity. The same cable that brings the helium to the balloon will also carry the electricity to the ground.

The Technion researchers estimate that each home or apartment would need only two balloons. If they were mass produced, their cost could be reduced below the estimated $700 per square meter of today's solar cells.

The pair filed a patent application for their invention and hope the technology will compete with existing power producers.

Coated helium balloons could be used, at first, to supply electricity to ships and homes in jungles, deserts and other isolated spots off electricity grids. Beyond that, Gurfil and Corrie hope that homes in cities around the world will get their electricity from such balloons.

via Jerusalem Post

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Friday, July 06, 2007

India: a car that runs on compressed air

The world's first commercial compressed air-powered vehicle is rolling towards the production line. The Air Car, developed by ex-Formula One engineer Guy Nègre, will be built by India's largest automaker, Tata Motors.

After ten years of research and development, MDI is prepared to introduce its clean vehicles onto the market (zero pollution). Unlike electric or hydrogen powered vehicles, MDI vehicles are not expensive and do not have a limited driving range. MDI cars are affordable and have a performance rate that stands up to current standards.

The Air Car uses compressed air to push its engine's pistons. It is anticipated that approximately 6000 Air Cars will be cruising the streets of India by 2008. If the manufacturers have no surprises up their exhaust pipes the car will be practical and reasonably priced. The CityCat model will clock out at 68 mph with a driving range of 125 miles. The cost of a fill up is approximately $2.00.

The perfect vehicle for point-to-point travel in dense urban settings ?

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Wednesday, July 04, 2007

Growing bio-fuel demand underpinning higher agriculture prices

Increased demand for bio-fuels is causing fundamental changes to agricultural markets that could drive up world prices for many farm products, according to a new report published by the OECD and FAO.

The OECD-FAO Agricultural Outlook 2007-2016 says temporary factors such as droughts in wheat-growing regions and low stocks explain in large measure the recent hikes in farm commodity prices.

But when the focus turns to the longer term, structural changes are underway which could well maintain relatively high nominal prices for many agricultural products over the coming decade.

Reduced crop surpluses and a decline in export subsidies are also contributing to these long-term changes in markets. But more important is the growing use of cereals, sugar, oilseed and vegetable oils to produce fossil fuel substitutes, ethanol and bio-diesel. This is underpinning crop prices and, indirectly through higher animal feed costs, also the prices for livestock products.

In the United States, annual maize-based ethanol output is expected to double between 2006 and 2016.

In the European Union the amount of oilseeds (mainly rapeseed) used for bio-fuels is set to grow from just over 10 million tonnes to 21 million tonnes over the same period.

In Brazil, annual ethanol production is projected to reach some 44 billion litres by 2016 from around 21 billion today. Chinese ethanol output is expected to rise to an annual 3.8 billion litres, a 2 billion litres increase from current levels.

The report points out that higher commodity prices are a particular concern for net food importing countries as well as the urban poor. And while higher feedstock prices caused by increased bio-fuel production benefits feedstock producers, it means extra costs and lower incomes for farmers who need the feedstock to provide animal feed.

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Monday, July 02, 2007

Cleaner skies with Easyjet "Ecojet"

British low cost carrier Easyjet has unveiled it’s “Easyjet EcoJet” which they claim can reduce CO2 Emissions by 50% by 2015.

EasyJet said it was in discussions with Boeing and Airbus – the world's largest plane manufacturers – and engine maker Rolls-Royce about producing a next generation of green aircraft.

The easyJet 'ecoJet', crafted by two qualified aeronautical engineers employed by the airline, features "open rotor" engines that will produce 25% less carbon dioxide per passenger kilometre flown than the airline's current Airbus planes.

It will cut fuel burn by a further 15% with wings and fuselage constructed from lighter aluminium composite material. A further 10% will be saved by slower inflight speed and, in a development not linked to the aircraft, changes to air traffic control across Europe.

Boeing and Airbus, whose order books and production lines are full due to a glut of orders, would be able to produce a new plane from scratch within eight years according to Easyjet chief executive.

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