Tuesday, July 29, 2008

Richest 10% create bigger ecological footprint

The richest 10 percent of Canadians create a bigger ecological footprint – a whopping 66 percent higher – than the average Canadian household, says a new study by the Canadian Centre for Policy Alternatives (CCPA).

The study, Size Matters: Canada’s Ecological Footprint, By Income, is the first Canadian study to link national income and consumption patterns with global warming.

“When we look at where the environmental impact of human activity comes from, we see that size really does matter,” says Hugh Mackenzie, CCPA research associate. “Higher-income Canadians create a much bigger footprint than poorer Canadians.”

Among the study’s findings:

The richest 10% of Canadian households create an ecological footprint of 12.4 hectares per capita – nearly two-and-a-half times that of the poorest 10%.
While the size of an individual’s ecological footprint increases as household income increases, the real jump is at that top 10% level. When it comes to environmental impact, it really is a case of the rich and the rest of us.

The bottom 60% of Canadian households’ ecological footprint is below the national average but even the lowest-income Canadians create an ecological footprint that is several times the average for those in poorer nations.

“All Canadians share responsibility for global warming,” says co-author Rick Smith, executive director of Environmental Defence. “But wealthier Canadians are leaving behind a disproportionately larger footprint – and should be expected to make a disproportionate contribution to its reduction.”

Mackenzie says the study contains lessons for policy makers: “Clearly ecological impact is stongly related to income. Greenhouse gas emissions policies should reflect that reality or risk being less effective and unfair to low- and middle-class Canadians.”

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Monday, July 28, 2008

Hybrid SolarWall PV/T System in Olympic Village

The Beijing Olympic Village is now home to cutting-edge solar technology, one of the world's first SolarWall photovoltaic/thermal (PV/T) hybrid systems.

Mounted on the roof of one of the central buildings, which will be a service centre for athletes during the Olympics, the SolarWall® PV/T technology is unique in that it is one of the first commercially viable hybrid solar systems. The technology produces both electricity and heat energy from the same surface area, generating 200-300 per cent more energy than a conventional PV system. It combines SolarWall® air heating technology with photovoltaics to create a total energy solution in which the payback period is reduced and the CO2 displacement is maximized.

As an added benefit the SolarWall® panels act as a racking system to the PV; removing the heat from the back of the modules and channeling it into the facility’s traditional heating system.

The building is also home to a conventional SolarWall® air heating system, which was integrated into the architecturally unique front façade.

The project was done through the Canadian SolarWall office, with Conserval Engineering working in partnership with Natural Resources Canada and the Olympic Village developer to incorporate these innovative solar technologies into the site.

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Sunday, July 20, 2008

Bamboo rechargeable battery

Specialists of the Institute of Chemistry of the V.V. Kuibyshev Far-Eastern State Polytechnic University (Far-Eastern Branch, Russian Academy of Sciences) have designed an experimental facility for producing anodic matrices for rechargeable lithium-ion cells. The rechargeable cells are made of renewable vegetable stuff – bamboo sprouts and cane-sugar.

Dynamic evolution of portable electronics is impossible without rechargeable lithium-ion cells. They take a leading place in the area of self-contained power supply. Irrespective of the rechargeable cells shape and dimensions, anode, cathode and electrolyte make part of the cells. To produce them, researchers are trying to select the less-expensive and nonpolluting materials, keeping in mind, however, the quality of the article. The Far-Eastern researchers suggest that the cells should be produced from bamboo sprouts and cane-sugar of Chinese manufacturing. To produce anodic material, the raw stuff is cleaned and then heated up several times at high temperatures (from 800°Ñ to 1100°Ñ), cool off and reduce to fine particles. In the course of manufacturing, the material is processed by soda, calcium, sodium and potassium chlorides, and sodium hydroxide. As a result, carbon dust is obtained, its particle size making about 14 microns.

The obtained anodic materials fit for both lithium-ion and lithium-polymer rechargeable cells. As the investigations have proved, the obtained carbonic modifications contain oval-shaped particles of a layer structure resembling graphite layer structure. The obtained carbonic structures are practically similar to the structure of commercial anodic materials (graphite modifications), i.e., they have a crystal structure. They possess very good operating qualities and even exceed some commercial materials. Nevertheless, to enable carbon modifications (obtained from cane-sugar and bamboo sprouts) serve as the anode material for lithium-ion (polymer) rechargeable cells, their processing characteristics should be refined.

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Monday, July 14, 2008

See-Through Solar Hack Could Double Panel Efficiency

If there's one thing most people know about solar cells, it's that they are too expensive.
Now, MIT researchers think they may have found a way to double the performance of solar arrays with cheap dyed glass and some tricks borrowed from fiber optics.

Their so-called solar concentrator could be placed on top of existing solar arrays. It could capture some wavelengths of visible light and guide them to high-voltage solar cells on the edges of the array, while still allowing the infrared light that largely powers current solar systems to pass through.

"If you stick one of these on top of existing solar panels, we think we could nearly double the performance of these systems with minimal added cost," said Marc Baldo, the lead researcher on the work.

The new research, published tomorrow in the journal Science, is another major advance in solar energy, a field that's received renewed interest due to concerns about climate change and rising fossil fuel prices. The new MIT technology marries the science behind two of the most promising ways of harnessing solar energy: light concentrators and thin-film solar cells.
Companies like SolFocus, which has raised $95 million, are using mirrors to concentrate sunlight on small amounts of photovoltaic cells. They can generate a lot of power, but rely on expensive sun-tracking mirrors. Another hot research area of solar research is thin-film solar, which uses dyes to print solar cells on cheap plastic. Putting the two technologies together could be a new way of making solar power cheaper. Current PV generation costs about 20 cents per kilowatt hour, several times more expensive than coal, wind and natural gas power generation.

If Baldo's technology scales up and can get past the inevitable engineering hurdles, it could help drive that kilowatt hour price closer to the market price for electricity, which would undoubtedly drive uptake.

"If they can solve the engineering issues, then this would very much help with the efficiency and cost of solar cells," said Marc Bünger, research director at Lux Research.

Baldo's concentrators consist of a simple piece of glass coated with dye. The glass concentrates the sun's rays by directing light almost like a fiber optic cable does. Sunlight enters the glass and is absorbed by the dyed molecules in the glass. When the dye molecules reemit the energy, it enters waveguides that send the waves to the edges of the glass.

Fundamentally, Baldo said that his organic concentrators, so named because their dyes contain carbon, help solve a fundamental problem that solar arrays have had: They have two very different functions that require different types of materials.

"Solar cells have got to absorb light and generate electricity and what we tried to do was separate those functions," Baldo said. "It doesn't make sense to use a really beautiful electronic material like silicon in huge fields to absorb light. Lots of things can absorb light, like paint."
Using a cheaper material to do the light absorbing allows the most efficient energy generating materials to be used in much smaller quantities.

Beyond driving costs down, the see-through nature of his technology means that it could integrated into buildings or products. That gets designers and architects excited but Baldo's not so sure that's the most effective way of deploying the concentrators.

"You could put them on plastic and roll it up. You can tune the color to what you'd like. Architects get really excited about this stuff," Baldo said. "But as an engineer, I'm not sure how cost effective it is to to do solar windows."

Because the technology is simple and inexpensive, Baldo thinks it will be easy to manufacture and could be deployed in the field within three years. Towards that end, colleagues of his at MIT have spun out a new company, Covalent Solar, to commercialize the technology.

via Wired

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