The kudzu vine, also known as “the plant that ate the South,” was brought from eastern Asia in 1876 and can grow more than 6.5 feet a week. Its starchy roots plunge deep into the soil, and just a fragment of the plant remaining in the ground is enough to allow it to come back next season.

“Kudzu is just a large amount of carbohydrate sitting below ground waiting for anyone to come along and dig it up,” Sage said. “The question is, is it worthwhile to dig it up?”
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The roots were by far the largest source of carbohydrate in the plant: up to 68 percent carbohydrate by dry weight, compared to a few percent in leaves and vines.

The researchers estimate that kudzu could produce 2.2 to 5.3 tons of carbohydrate per acre in much of the South, or about 270 gallons per acre of ethanol, which is comparable to the yield for corn of 210 to 320 gallons per acre. They recently published their findings in Biomass and Bioenergy.

Crucial to making the plan work would be figuring out whether kudzu could be economically harvested, especially the roots, which can be thick and grow more than six feet deep. To balance this expense, Sage said, the plant requires zero planting, fertilizer or irrigation costs.

The tech industry is facing an energy crisis. The cost of power consumption by data centers doubled between 2000 and 2006, to $4.5 billion, and could double again by 2011, according to the U.S. government. With energy prices spiking, the challenge of powering and cooling these SUVs of the tech world has become a major issue for corporations and utilities.
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The modern data center is like a vast refrigerator with hundreds or thousands of ovens blazing away inside. Six-foot-tall metal racks stacked with pizza box-size computers, storage devices, and network-routing machines are lined up in rows. Chilled air blows through the equipment from vents in the floors of “cold aisles.” Hot air blows out of the back ends into “hot aisles” and is drawn off and vented out of the building. Inside the centers, there’s a dull roar as large quantities of air shoot through ducts, vents, and computers.

So intense is the competition among tech companies to lower their costs of processing data that some treat information about their energy use like state secrets.
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The $4.5 billion spent in the U.S. in 2006 is the equivalent of the electric bills for 5.8 million U.S. households.

Along a dusty two-lane highway in California’s Mojave Desert, 550,000 mirrors point skyward to make steam for electricity. Google Inc., Chevron Corp. and Goldman Sachs Group Inc. are betting this energy will become cheaper than coal.

The 1,000-acre plant uses concentrated sunlight to generate power for as many as 112,500 homes in Southern California. Rising natural gas prices and emissions limits may make solar thermal the fastest-growing energy source in the next decade, say backers including Vinod Khosla, the founder of computer maker Sun Microsystems Inc. Costs for the technology will fall below coal as soon as 2020, the U.S. government estimates.
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“Solar thermal can provide a substantial amount of our power, more than 50 percent,” says Khosla
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Nine solar thermal plants built in the California desert from 1985 to 1991 still operate, with Juno Beach, Florida-based FPL Group Inc. running seven. They have combined capacity of 354 megawatts, enough to power 230,000 Southern California homes. Development slowed when Congress eliminated tax credits for alternative energy in the early 1990s. Laws put in place in 2005 give solar investors a 30 percent tax credit.

until today, Energy Star didn’t regulate water heaters at all. They’re the most energy-hungry single appliance in the home, and are responsible for about 17% of residential energy use. But because of a lack of consensus on how they should be regulated, and resistance from industry, their efficiency went completely unregulated. Well, that all changed today.
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The water heater first uses a heat pump to bring the water up to the temperature of the ambient air. Then the electric water heater takes over, bringing the water up to 140 degrees F.

This new design is more than 50% more efficient than previous water heaters. If every home in America had one right now, we would need 30 fewer coal-fired power plants! Every home that installs one will see their yearly power bills drop up to $250. Because the new device uses a heat exchanger, it will actually make your furnace work harder during the winter. But in the summer, and in warm climates, it will actually help cool your house!

The Amazon was the chic eco-cause of the 1990s, revered as an incomparable storehouse of biodiversity. It’s been overshadowed lately by global warming, but the Amazon rain forest happens also to be an incomparable storehouse of carbon, the very carbon that heats up the planet when it’s released into the atmosphere. Brazil now ranks fourth in the world in carbon emissions, and most of its emissions come from deforestation.
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Meanwhile, by diverting grain and oilseed crops from dinner plates to fuel tanks, biofuels are jacking up world food prices and endangering the hungry. The grain it takes to fill an SUV tank with ethanol could feed a person for a year. Harvests are being plucked to fuel our cars instead of ourselves. The U.N.’s World Food Program says it needs $500 million in additional funding and supplies, calling the rising costs for food nothing less than a global emergency. Soaring corn prices have sparked tortilla riots in Mexico City, and skyrocketing flour prices have destabilized Pakistan, which wasn’t exactly tranquil when flour was affordable.
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One groundbreaking new study in Science concluded that when this deforestation effect is taken into account, corn ethanol and soy biodiesel produce about twice the emissions of gasoline. Sugarcane ethanol is much cleaner, and biofuels created from waste products that don’t gobble up land have real potential, but even cellulosic ethanol increases overall emissions when its plant source is grown on good cropland. “People don’t want to believe renewable fuels could be bad,” says the lead author, Tim Searchinger, a Princeton scholar and former Environmental Defense attorney. “But when you realize we’re tearing down rain forests that store loads of carbon to grow crops that store much less carbon, it becomes obvious.”

The project will pour $1 billion into utility-scale photovoltaic solar farms that will directly feed power into a country’s electrical grid. The installations will range from fewer than 2 MW to up to 50 MW, while a single farm could cover hundreds and hundreds of acres.

They’ll be installed in Europe. In Asia. And maybe even in America too, one day. Why not now? Because AES wants to sow its solar seeds in only those countries that offer the most “attractive tariffs.” That eliminates the US from the list of potentials, immediately. And it gives countries like Germany, Spain, Italy and South Korea the clear advantage. They all have can’t-beat national incentives for solar developers.

It’s one of the sad facts of Washington’s incoherent clean energy policy these days. How can a country lure in clean energy projects when there are far more appealing offers elsewhere?

The window for applications will be open until mid 2008, when a thorough qualification process will assess safety, cost, features and business plans to ensure that only production-capable, consumer-friendly cars compete. Those that qualify will race their vehicles in rigorous cross-country stage races in 2009 and 2010 that combine speed, distance, urban driving and overall performance. The winners will be the vehicles that exceed 100 MPG, meet strict emissions standards and finish in the fastest time. Host cities involved in the competition route are to be announced shortly.

Wind energy has a considerable impact on avoiding greenhouse gases and combating climate change. The global capacity of 94 GW of wind capacity will save about 122 million tons of CO2 every year, which is equivalent to around 20 large coal fired power stations.

“We’re on track to meeting our target of saving 1.5 billion tons of CO2 per year by 2020”, said Steve Sawyer, “but we need a strong, global signal from governments that they are serious about moving away from fossil fuels and protecting the climate.”

1) 165 F water, pumped three-quarters of a mile from Chena’s 700-ft.-deep production well, enters the evaporator. After circulating through pipes, the water, now 135 F, is reinjected into the reservoir at a well 300 ft. from the power plant.
2) The refrigerant R-134a fills the shell of the evaporator. Heat transferred from the 165-degree water causes the refrigerant to vaporize without the two liquids actually coming into contact.
3) The vapor is expanded supersonically through the turbine nozzle, causing the turbine blades to rotate at 13,500 rpm. This turns a generator at 3600 rpm, producing electricity.
4) 40 F water, siphoned from a shallow well 33 ft. higher in elevation than the plant, enters the con-denser without the aid of a pump. It circulates through pipes before being returned 9 degrees warmer to Monument Creek.
5) Vapor exiting the turbine fills the shell of the condenser, where the 40 F water returns the refrigerant to liquid form.
6) A pump pushes the refrigerant back to the evaporator, generating the pressure that drives the entire cycle so that it may start anew.

You save more fuel switching from a 15 to 18 mpg car than switching from a 50 to 100 mpg car.

I built my first windmill when I was 15. Over the next few years I kept refining the design. I made many modifications to the plans i found in the book. For example, I increased the blades from three to four to provide more power output. The windmill now powers lights for 3 rooms and a light over our porch outside. I also use it to power my family’s two radios. I also can charge mobile phones that the neighbors have.
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Two weeks ago I used a computer for the first time. I learned about Google and searched for “windmill” and “solar energy.” I was amazed to learn how many entries there were for both subjects. My friends showed me how to create an email address and now I am on Gmail. Now I am practicing sending and receiving emails when I have access to a computer.
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On Sunday, my friends from National Solar and I completed the next phase of work on my electrical system. You can see a compete set of (my first) digital photos at my new site on Flickr. I had the following goals:

1. Upgrade the power generation in the windmill
2. Upgrade the battery technology and capacity, to provide more even power for more hours at a time
3. Increase the brightness of the lighting (lumens) to make it easier for my family to accomplish tasks at night, especially to read…

Solar cell technology developed by the University’s Nanomaterials Research Centre will enable New Zealanders to generate electricity from sunlight at a 10th of the cost of current silicon-based photo-electric solar cells.
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Dr Campbell says that unlike the silicon-based solar cells currently on the market, the 10×10cm green demonstration cells generate enough electricity to run a small fan in low-light conditions – making them ideal for cloudy climates. The dyes can also be incorporated into tinted windows that trap to generate electricity.

He says the green solar cells are more environmentally friendly than silicon-based cells as they are made from titanium dioxide – a plentiful, renewable and non-toxic white mineral obtained from New Zealand’s black sand. Titanium dioxide is already used in consumer products such as toothpaste, white paints and cosmetics.

“The refining of pure silicon, although a very abundant mineral, is energy-hungry and very expensive. And whereas silicon cells need direct sunlight to operate efficiently, these cells will work efficiently in low diffuse light conditions,” Dr Campbell says. “The expected cost is one 10th of the price of a silicon-based solar panel, making them more attractive and accessible to home-owners.” The Centre’s new director, Professor Ashton Partridge, says they now have the most efficient porphyrin dye in the world and aim to optimise and improve the cell construction and performance before developing the cells commercially.

When high school science teacher Ray Janke bought a home in Chicopee, Mass., he decided to see how much he could save on his electric bill.

He exchanged incandescent bulbs for compact fluorescents, put switches and surge protectors on his electronic equipment to reduce the “phantom load” - the trickle consumption even when electronic equipment is off - and bought energy-efficient appliances.

Two things happened: He saw a two-thirds reduction in his electric bill, and he found himself under audit by Mass Electric. The company thought he’d tampered with his meter. “They couldn’t believe I was using so little,” he says.
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Cutting back on electricity used for lighting (9 percent of residential usage nationwide) presents the quickest savings-to-effort ratio. The EPA estimates that changing only 25 percent of your home’s bulbs can cut a lighting bill in half. Incandescent bulbs waste 90 percent of their energy as heat, and compact fluorescents, which can be up to five times more efficient, last years longer as well.

The only other countries around the world that have more wind power installed are Germany (19,140 MW as of the end of June), and Spain (10,728 MW).

AWEA expects the U.S. to pass the 15,000 MW mark by the end of 2007 and can have 25,000 MW installed by the end of 2010, with the proper policies in place. At this growth rate, the U.S. could have 100,000 MW installed by 2020, which would provide the nation with approximately 6% of its future power needs, about as much as hydropower provides today.