Produce Scraps —-> Gas?!?!?!

2/15/12: This morning posted a very interesting article about a european pilot program, focused on turning scraps of produce into bio-gas. Take a few minutes to read the full article, posted below:

Fuel Gets Fruity: Converting Produce Scraps into Gas


The compost pile and worm bin are no longer the only appropriate resting places for peach pits, banana peels, and apple cores. The Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Europe’s largest applied research center, announced last week that it will begin turning old produce into bio-gas at a pilot site in Stuttgart, Germany. Conveniently located next to the city’s wholesale vegetable market, the facility will use microorganisms to transform food scraps into methane gas, which can power a car once compressed and emits less carbon dioxide during combustion than gasoline.

According to the research lab, the conversion process from fruit to fuel will only take a few days. But the challenge lies in dealing with the inconsistency of the raw materials—the acidity of a mound of food scraps can vary wildly. (Oranges are acidic. Lettuce, not so much.) The facility’s managers have to adjust the pH balance of the system accordingly to keep the microorganisms that do the converting work healthy and happy.

While other researches are working on converting fruit peels into fuel and plastics elsewhere, one exciting aspect of Fraunhofer’s project is the versatility of all the components it generates, not just the bio-gas. Making methane releases carbon dioxide and waste liquid, both of which are captured and used to nourish the 21st century’s hippest organismalgae, another feedstock for biofuel. And the only waste product, a “sludgy fermentation residue,” is shipped to another lab in Switzerland where it’s made into even more methane.

Via Gas 2.0; Photo courtesy of Fraunhofer

Startup Making Big Moves In The Solar Energy Field

Below is a fantastic article about one company’s solar panels that are able to concentrate sunlight, making it the world’s most efficient solar panel:



Concentrated Solar Startup Sets a New Efficiency Record

Semprius makes solar modules using tiny cells that need less cooling.

  • Friday, February 3, 2012
  • By Kevin Bullis

Semprius, a startup that makes miniscule solar cells capable of capturing concentrated sunlight without costly cooling systems, announced this week that it had made the world’s most efficient solar panel.

The company’s solar panels use tiny solar cells made of gallium arsenide—the record-breaking solar module contains hundreds of such solar cells, each about the width of a line drawn by a ball-point pen, arranged under lenses that concentrate sunlight 1,100 times.

Gallium arsenide is far better at absorbing sunlight than silicon, the material used in most solar cells, but it’s also more expensive. Furthermore, although concentrated solar modules use less semiconducting material, they usually require expensive optics, cooling systems, and tracking systems to keep them aimed at the sun. Semprius’s microscaled solar cells are inherently much better at dissipating heat, making them cheaper.

Semprius’s modules have another advantage: whereas a silicon solar cell only efficiently absorbs a narrow band of sunlight, the solar cells in this module are made of three layers of gallium arsenide, each modified to convert a different part of the solar spectrum into electricity.


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Tests by a third-party certified the efficiency of Semprius’s solar panel at 33.9 percent, marking the first time any solar module has been able to convert more than one-third of the sunlight that falls on it into electricity. Conventional silicon solar panels typically convert less than 15 percent of light into electricity, and the record for a silicon solar panel is 22.9 percent. The previous record for any solar panel was 32 percent, Semprius says.

One-off, experimental modules have achieved higher efficiencies, but Semprius’s record-setting module is designed for commercial use. It was made with the same type of equipment that the company is installing in a small factory in Henderson, North Carolina, that it will open this summer. “It’s a good indication of the efficiencies our customers can expect,” says Joe Carr, Semprius’s CEO.

Semprius’s process forms tens of thousands of tiny solar cells on a single wafer of gallium arsenide, and uses chemical etching and a robotic system to transfer each layer to an inexpensive substrate. The same gallium-arsenide wafer can be reused many times, reducing costs. The approach is based on a method for transferring small electronics from a wafer to other substrates that was developed by John Rogers, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign.