Published on March 24th, 2011 | by Glenn Meyers


Chicago Skyscraper to Generate Solar Electricity

Willis Tower in Chicago — formerly Sears Tower

Skyscrapers, notorious huge energy consumers, may soon become solar energy producers.

In an experimental program, Chicago’s tallest building, Willis Tower (previously the Sears Tower) will soon feature high power density photovoltaic glass units (PVGUs) on the south side of the 56th floor, replacing the existing windows with a new type of photovoltaic glass developed by Pythagoras Solar. The new window units will preserve daylighting and views while reducing heat gain and producing the same energy as a conventional solar panel.

According to Inhabitat, the project could grow to 2 MW in size — which is comparable to a 10-acre field of solar panels — turning North America’s tallest building into a huge urban vertical solar farm. This will depend on what the return on investment is for this experimental technology.

The project is collaboration between the tower’s owner and Pythagoras Solar, with offices in California, Israel and Taiwan. The new PVGUs use a hybrid technology that lays typical monocrystalline silicon solar cell horizontally between two layers of glass to form an individual tile. An internal plastic reflective prism directs angled sunlight onto the solar cells but allows diffuse daylight and horizontal light through, providing natural light inside.

“We are excited to launch this pilot with Pythagoras Solar’s leading-edge solar window solutions as a test for not only the energy savings that can be achieved, but the potential they represent to actually generate power through the sun,” said John Huston, Executive Vice President of American Landmark Properties, one of the ownership partners of Willis Tower.

Source: Pythagoras Solar

Pythagoras Solar claims that the vertically integrated solar cells will produce the same amount of energy as normal rooftop-mounted solar panels. This is great news for cities that have precious little rooftop space and towering walls of glass. The product is also a potential breakthrough in energy efficiency in glass towers, where solar heat gain is difficult for those inside the building.

On its website, the PVGU manufacturer highlights a section titled, Toward Net-Zero Buildings. There it discusses Building Integrated Photovoltaics, stating, “Building Integrated Photovoltaics, by replacing common materials in the building envelope, provides the most promising solution for harnessing the sun at the point of use–the buildings where we live and work.”

This You Tube Video animation from Pythagoras Solar provides a good perspective for the potential for PVGU buildings.

According to the Pythagoras Solar website, the company was conceived at Precede Technologies, an Israeli incubator, which teams up scientists, inventors, and entrepreneurs. “Dr. Itay Baruchi, an award-winning physicist, and Gonen Fink, a leader in taking Check Point Software from start-up to a multibillion dollar company, saw a business opportunity at the intersection of rising demand for Green Buildings and declining cost of Photovoltaic (PV) solar power.”

Pythagoras Solar’s PVGU uses patent-pending optical technology, high-efficiency silicon, and advanced materials to provide the industry’s first highest-transparency and highest-density PV power generation in a standard double-pane window form factor.

General Mills experiments with Groupon; The company says an unusual offer aims to drive more traffic to grocery retailers for its products.(BUSINESS)

Star Tribune (Minneapolis, MN) April 22, 2011 Byline: MIKE HUGHLETT; STAFF WRITER General Mills Inc. is trying a new approach to get its products in front of customers.

The Golden Valley-based company on Thursday posted its first deal offer on Groupon, the online deep-discount coupon site usually used by restaurants and other retailers.

General Mills’ $20 offer in the Twin Cities included 4,500 variety samplers of its products along with a coupon book — a combined value of around $40, including shipping. The company offered 500 of the same packages Thursday in San Francisco. The sampler packages are to be delivered directly to Groupon customers’ homes. go to web site groupon chicago

Chicago-based Groupon, which entered the Twin Cities market in late 2009, offers daily discounts of around 50 percent on all sorts of services. For instance, on Thursday its Twin Cities website was offering half-off deals on a dinner train ride in Spooner, Wis., and bowling, bocce ball or bistro eats at Pinstripes in Edina. groupon chicago

Groupon usually takes a 50 percent cut on the deals. The idea is that the Groupon coupon will help drive traffic to an establishment — though some have said it’s a losing proposition if it fails to do that.

For General Mills, Groupon “is not an e-commerce platform for us,” said Karl Schmidt, the company’s director of promotional marketing. “We are not looking to make money on this.” Rather, by mailing out samples, the company is trying to direct more traffic to grocery retailers for its products, Schmidt said.

General Mills said it was pleased with the response to the Groupon offer. Posted on the Internet at midnight in the Twin Cities, it sold out at 10:42 a.m.

A key gauge to the offer’s overall success will lie in the redemption rate of the coupons offered with the sampler package. The higher the better, General Mills marketing executives say.

If General Mills deems the project a success, it will look to expand Groupon offerings, Schmidt said.

Thursday’s sampler featured a dozen products, including a box each of Reese’s Puffs, Kix and Cinnamon Toast Crunch cereal; a package of Hamburger Helper; Fiber One chewy bars; and a Wanchai Ferry dinner kit.

Mike Hughlett – 612-673-7003

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About the Author

Writer, documentary producer, and director. Meyers is a contributor to CleanTechnica, and founder of Green Streets MediaTrain, a communications connection and eLearning hub. As an independent producer, he's been involved in the development, production and distribution of television and distance learning programs for both the education industry and corporate sector. He also is an avid gardener and loves sustainable innovation.

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