Sustainable Design Update

LED lights on display from the Appropriate Technology Collaborative

At SDU we love LEDs.  Experts have predicted that they will inevitably beat CFLs as the most energy efficient and cost effective form of lighting.  Currently though, the cost of LEDs keeps them from winning the lighting wars.  New Scientist is reporting on a promising new method for manufacturing gallium nitride LEDs that has to potential for greatly reducing the cost of production.  From the article:

The cost of production has kept the LEDs far from homes and offices, however. Gallium nitride cannot be grown on silicon like other solid-state electronic components because it shrinks at twice the rate of silicon as it cools. Crystals of GaN must be grown at 1000°C, so by the time a new LED made on silicon has cooled, it has already cracked, rendering the devices unusable.

One solution is to grow the LEDs on sapphire, which shrinks and cools at much the same rate as GaN. But the expense is too great to be commercially competitive.

Now Colin Humphreys‘s team at the University of Cambridge has discovered a simple solution to the shrinkage problem.

They included layers of aluminium gallium nitride in their LED design. These layers shrink at a much slower rate during cooling and help to counteract the fast-shrinkage of pure gallium nitride. These LEDs can be grown on silicon as so many other electronics components are. “They still work well as LEDs even with those extra layers inside,” says Humphreys.

Bringing us one step closer to a world lit entirely by LEDs.

-Ben Connor Barrie

41.1% Efficient Solar Cell

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have achieved a record efficiency of 41.1% for the conversion of sunlight into electricity. Using concentrated sunlight focused onto a small 5 mm² multi-junction solar cell made out of GaInP/GaInAs/ Ge (gallium indium phosphide, gallium indium arsenide on a germanium substrate (whew!)).

“We are elated by this breakthrough,” says Frank Dimroth, head of the group at Fraunhofer ISE. “At all times the entire team believed in our concept of the metamorphic triple-junction solar cells and our success today is made possible only through their committed work over the past years.”

Since 1999, Fraunhofer ISE has been developing highly advanced solar cells. The cells are made from their exotic alphabet soup crystals only by applying a trick called metamorphic growth. In contrast to conventional solar cells, the semiconductors in these cells do not have the same lattice constant (distance between the atoms in a crystalline structure). This makes it difficult to grow the semiconductor layers with a high crystal quality.  I imagine it is like trying to stack an even layer of ping-pong balls on a layer of tennis balls using atoms instead of balls.

While Mr. Dimroth is justifiably elated by this work, the breakthrough is more in the area of manufacturing, not in solar efficiency.  The 41.1% conversion efficiency is just slightly better than the previous world champion cell which has a conversion ratio of 40.7 percent efficiency previously demonstrated by Spectrolab.

More at Fraunhofer

Photo: Fraunhofer ISE

Namba Parks, Osaka Japan

What I like about the Namba Parks multi use building is how well nature is integrated into the fabric of the building.  The data I could find on Namba Parks doesn’t include green features like energy efficiency, indoor air quality etc. but the zeitgeist of this building – the bold integration of inside and out, the natural and man made, are easily integrated into LEED certified buildings. 

Architects have long sought ways of integrating outside and in.  Frank Lloyd Wright imagined buildings where the transition from inside to out was imperceptible. 

Moshe Safdie managed to make pre-fab housing an integrated experience with his Habitat building in Montreal. 

Habitat, Montreal – 1966

From the Habitat Website:

Expo 67, one of the world’s largest universal expositions was held in Montreal. Within the movement of liberalization and opening to the world characterizing this period, the exposition was entitled “Man and his World” as the title of Antoine de Saint-Exupéry’s masterpeace. Housing was one of the main themes of Expo 67.

Saint-Exupéry wrote: “We have to make lively this new house that doesn’t have a face yet. The truth for one was to build; it is, for the other, to occupy it.”

Habitat 67 then became a thematic pavilion invaded by thousands of admiring visitors that came from all around the world, on top of being the temporary residence of many dignitaries passing by Montreal. (more…)

A model of the prefabricated paper house

Designers at Bauhaus University have developed a low cost paper house that could be used to provide housing for slum dwellers. From the article in Spiegel:

Niemöller is a co-founder of the Swiss company The Wall AG, which holds the patent for material used in the construction of the mini-homes. But, he says, he envisions the houses — called the “Universal World House” — ultimately being produced in the countries where they are needed. And, he says, the sticker price for the 36 square meter (387.5 square foot) structures won’t be more than $5,000 each.

The material used in the construction of the houses mimics the honeycomb pattern used in the manufacture of airplanes and other products for which both weight and strength are important factors. But instead of using aluminium or other alloys, Niemöller used resin-soaked paper processed to form thin, light — yet strong — panels. The material is also an excellent insulator, and is flexible, making it appropriate in areas at risk of earthquakes.

At a price of $5,000 the house is out of range for some of the poorest of the poor.  None the less, Nigeria has already put in an order for 2,400 houses.

-Ben Connor Barrie

Photo via: Spiegel

The Sail at Marina Bay – Certified Gold

Singapore has committed to building only certified Green Buildings using their local standard – a standard which based on a short presentation I saw last fall sounds a lot like the US. Green Building Council LEED Standard for new construction.

The Sail Building will be a stunning mixed us building on Marina Bay.  One feature it has that many of the green buildings going up in planned green cities are missing is a really cool urban context.  Singapore is a wonderful urban experience with walkable streets, interesting shops and even religious structures mixed into the urban fabric. 

From World Architecture News:

The Sail will be the first project to introduce residential units to the area, helping create a sustainable environment via the reduction of traffic, congestion and smog. It will also offer an environment that directly engages with water and the surrounding green space, and encouraging residents to engage their urban environment 24/7. The project will achieve Singapore’s Gold standard of sustainability, adding to the city’s “green city” image and creating a healthier environment for its residents.

 

 

Singapore Sail – Floor Plan

Singapore is a tiny country that doesn’t have a lot of natural resources other than location.  Singapore is on major shipping routes between Aisa and the United States.  It has one of the busiest harbors in the world and a very diverse population.  Their commitment to green building is understandable when one considers the cost of energy, most of which has to be imported. 

Via: Inhabitat

The following is from the Huffington Post, or actually from several Eco-Themed Blogs:

Austin, Texas, Dec. 20, 2000: “Natural gas is hemispheric. I like to call it hemispheric in nature because it is a product that we can find in our neighborhoods.” (Source: Treehugger)

Washington, D.C. March 13, 2001: “There are some monuments where the land is so widespread, they just encompass as much as possible. And the integral part of the–the precious part, so to speak–I guess all land is precious, but the part that the people uniformly would not want to spoil, will not be despoiled. But there are parts of the monument lands where we can explore without affecting the overall environment.” (Source: Slate)

Washington, D.C., January 6, 2009: “The new steps I’ve announced today are the capstone of an eight-year commitment to strong environmental protection and conservation.” Check out this interesting graphic from the Natural Resources Defense Council illustrating the last eight years in environmental policy…

New Delhi, India, Mar. 2, 2006 “Obviously, nu-que-lar power is, uh, a renewable source of energy, and the less demand there is for non-renewable sources of energy, like fossil fuels, the better it off it is for the American people.” Well, he got the second part right, but nuclear energy produced from uranium is, uh, not renewable as far as we know… (Source: Treehugger)

Washington, D.C., June 8, 2005: “We’re spending money on clean coal technology. Do you realize we’ve got 250 million years of coal?” (Source: Slate)

Michigan, September 2000, explaining his energy policies: “I know the human being and fish can coexist peacefully.” (Source: AP)

A Freudian slip made while addressing Australian Prime Minister John Howard at the APEC Summit, Sept. 7, 2007: “Mr. Prime Minister, thank you for your introduction. Thank you for being such a fine host for the OPEC summit.”

And a bonus: “[It's] time for the human race to enter the solar system.”

While not an eco-themed quote the following is possibly the best “W” quote of the last 8 years: Check the GAP

I think you can guess the author of these quotes…  Two days and counting. 

jsbarrie