Sustainablog

This blog will cover some news items related to Sustainability: Corporate Social Responsibility, Stewardship, Environmental management, etc.

24.2.06

Spray-On Solar-Power Cells Are True Breakthrough


Spray-On Solar-Power Cells Are True Breakthrough
Stefan Lovgren
for
National Geographic News
January 14, 2005

Scientists have invented a plastic solar cell that can turn the sun's power into electrical energy, even on a cloudy day.

The plastic material uses nanotechnology and contains the first solar cells able to harness the sun's invisible, infrared rays. The breakthrough has led theorists to predict that plastic solar cells could one day become five times more efficient than current solar cell technology.

Like paint, the composite can be sprayed onto other materials and used as portable electricity. A sweater coated in the material could power a cell phone or other wireless devices. A hydrogen-powered car painted with the film could potentially convert enough energy into electricity to continually recharge the car's battery.

The researchers envision that one day "solar farms" consisting of the plastic material could be rolled across deserts to generate enough clean energy to supply the entire planet's power needs.

"The sun that reaches the Earth's surface delivers 10,000 times more energy than we consume," said Ted Sargent, an electrical and computer engineering professor at the University of Toronto. Sargent is one of the inventors of the new plastic material.

"If we could cover 0.1 percent of the Earth's surface with [very efficient] large-area solar cells," he said, "we could in principle replace all of our energy habits with a source of power which is clean and renewable."

Infrared Power

Plastic solar cells are not new. But existing materials are only able to harness the sun's visible light. While half of the sun's power lies in the visible spectrum, the other half lies in the infrared spectrum.

The new material is the first plastic composite that is able to harness the infrared portion.

"Everything that's warm gives off some heat. Even people and animals give off heat," Sargent said. "So there actually is some power remaining in the infrared [spectrum], even when it appears to us to be dark outside."

The researchers combined specially designed nano particles called quantum dots with a polymer to make the plastic that can detect energy in the infrared.

With further advances, the new plastic "could allow up to 30 percent of the sun's radiant energy to be harnessed, compared to 6 percent in today's best plastic solar cells," said Peter Peumans, a Stanford University electrical engineering professor, who studied the work.
The new material could make technology truly wireless.

"We have this expectation that we don't have to plug into a phone jack anymore to talk on the phone, but we're resigned to the fact that we have to plug into an electrical outlet to recharge the batteries," Sargent said. "That's only communications wireless, not power wireless."

He said the plastic coating could be woven into a shirt or sweater and used to charge an item like a cell phone.

"A sweater is already absorbing all sorts of light both in the infrared and the visible," said Sargent. "Instead of just turning that into heat, as it currently does, imagine if it were to turn that into electricity."

Other possibilities include energy-saving plastic sheeting that could be unfurled onto a rooftop to supply heating needs, or solar cell window coating that could let in enough infrared light to power home appliances.

Cost-Effectiveness

Ultimately, a large amount of the sun's energy could be harnessed through "solar farms" and used to power all our energy needs, the researchers predict.

"This could potentially displace other sources of electrical production that produce greenhouse gases, such as coal," Sargent said.

In Japan, the world's largest solar-power market, the government expects that 50 percent of residential power supply will come from solar power by 2030, up from a fraction of a percent today.

The biggest hurdle facing solar power is cost-effectiveness.

At a current cost of 25 to 50 cents per kilowatt-hour, solar power is significantly more expensive than conventional electrical power for residences. Average U.S. residential power prices are less than ten cents per kilowatt-hour, according to experts.

But that could change with the new material.

"Flexible, roller-processed solar cells have the potential to turn the sun's power into a clean, green, convenient source of energy," said John Wolfe, a nanotechnology venture capital investor at Lux Capital in New York City.

Eco-innovation and biodiversity environmental priorities for 2006 :


Eco-innovation and biodiversity environmental priorities for 2006

EurActiv.com, 17 February 2006 - Commissioner Dimas has presented an optimistic annual environment policy review for 2005 and set out priorities for the coming twelve months. The real figures on environmental deterioration in the same report paint a less rosy picture.

According to the latest annual Environment Policy Review (EPR), the year 2005 was a good year for EU environment policy. The report, which provides the environmental input for the March Spring European Council, claims progress on several fronts:

  • in the fight against climate change, the Kyoto protocol entered into force and the EU's emissions trading scheme made good progress;
  • new thematic strategies on waste, air pollution, marine environment, urban environment, and the use of resources laid the "foundations of the next generation of environment policy";
  • the review of the EU's sustainable development strategy "provided a new framework for addressing long-term economic, social and environmental trends and their synergies"
The annual review also indicates what will be the main priorities for environmental policy in the year 2006. Eco-innovation, biodiversity and continued efforts to deal with climate change will be high on the Commission's agenda in the next twelve months.

The EU's positive environment report, on the other hand, is contradicted by some of the "new evidence" on environmental deterioration mentioned in the same document. Europe's "ecological footprint" (a measure for the environmental pressure) is 4.9 global hectares per person, but the "limit on Earth's resources means that only 1.8 hectares are available for each person," says the Commission's own report.

Stefan Scheuer of the European Environmental Bureau (EEB) evaluates 2005 as a difficult year for EU environment policy. "It was more a year of damage prevention", Mr Scheuer told EurActiv. According to the EEB speaker, Commissioner Dimas was able to rescue the thematic strategies and "avoid a major U-turn" of EU environment policy.

Links

EU official documents

EU Actors positions