Thursday, September 17, 2009

Tree Power!


Trees Produce Electricity

I saw this in Technology Review recently, this is a post from Green Design Briefs:

Last year, MIT researchers found that plants generate a voltage of up to 200 millivolts when one electrode is placed in a plant and the other in the surrounding soil. A University of Washington team followed up on this research, and has run a custom circuit entirely off tree power.

By hooking nails to trees and connecting a voltmeter, Carlton Himes, a UW undergraduate student, found that bigleaf maples generate a steady voltage of up to a few hundred millivolts.

The UW researchers next built a device that could run on this available power. Brian Otis, assistant professor of Electrical Engineering, led the development of a boost converter - a device that takes a low incoming voltage and stores it to produce a greater output.

The team’s custom boost converter works for input voltages of as little as 20 millivolts, an input voltage lower than any existing such device. It produces an output voltage of 1.1 volts, which is enough to run low-power sensors.

The UW circuit is built from parts measuring 130 nanometers and it consumes on average just 10 nanowatts of power during operation.

Photo: Dustin Schroeder/University of Washington

Monday, November 10, 2008

New Solar Technology

New Anti Reflective Coating Increases Solar Power

A new anti-reflective coating is being hailed as a "Game Changer" for photovoltaic energy. The nano structured coatings help panels absorb nearly all the light that falls on them, including light at angles that normally bounces off.

This technology could increase solar output by 20 - 30%.

From Rensselaer Polytechnic:

Researchers at Rensselaer Polytechnic Institute have discovered and demonstrated a new method for overcoming two major hurdles facing solar energy. By developing a new antireflective coating that boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire solar spectrum from nearly any angle, the research team has moved academia and industry closer to realizing high-efficiency, cost-effective solar power.

"To get maximum efficiency when converting solar power into electricity, you want a solar panel that can absorb nearly every single photon of light, regardless of the sun's position in the sky," said Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university's Future Chips Constellation, who led the research project. "Our new antireflective coating makes this possible."

Results of the year-long project are explained in the paper "Realization of a Near Perfect Antireflection Coating for Silicon Solar Energy," published this week by the journal Optics Letters.

An untreated silicon solar cell only absorbs 67.4 percent of sunlight shone upon it - meaning that nearly one-third of that sunlight is reflected away and thus unharvestable. From an economic and efficiency perspective, this unharvested light is wasted potential and a major barrier hampering the proliferation and widespread adoption of solar power.

After a silicon surface was treated with Lin's new nanoengineered reflective coating, however, the material absorbed 96.21 percent of sunlight shone upon it - meaning that only 3.79 percent of the sunlight was reflected and unharvested. This huge gain in absorption was consistent across the entire spectrum of sunlight, from UV to visible light and infrared, and moves solar power a significant step forward toward economic viability.

Lin's new coating also successfully tackles the tricky challenge of angles.

Most surfaces and coatings are designed to absorb light - i.e., be antireflective - and transmit light - i.e., allow the light to pass through it - from a specific range of angles. Eyeglass lenses, for example, will absorb and transmit quite a bit of light from a light source directly in front of them, but those same lenses would absorb and transmit considerably less light if the light source were off to the side or on the wearer's periphery.

More at: Rensselaer Polytechnic,

Sustainable Design Update

Friday, October 03, 2008

New Blog

It is definitely worth checking out the new blog: (GAP)

The blog is fresh, intelligent, informative and fun.

GAP will cover politics, the environment, robotics and more. The writers are unusually intelligent with a real sense of humor.

Check it out and add it to your bookmarks!



Wednesday, September 24, 2008

New Solar Cell Process Saves $$$

Univ. of Utah Students Cut Germanium for Solar Cells

University of Utah engineers devised a new way to slice thin wafers of the element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by using less raw material and reducing waste.

Germanium solar cells, the most efficient solar cells, now are used mainly on spacecraft, but with the improved wafer-slicing method, "the idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor," particularly for solar power on Earth, says Eberhard "Ebbe" Bamberg, assistant professor of mechanical engineering.

Dinesh Rakwal, a doctoral student in mechanical engineering, adds: "We're coming up with a more efficient way of making germanium wafers for solar cells - to reduce the cost and weight of these solar cells and make them defect-free."

Bamberg and Rakwal are publishing their findings in the Journal of Materials Processing Technology. Their study has been accepted, and a final version will be published online late this month or in early October, and in print in 2009.

Their novel process uses a brass-coated, steel-wire to slice round wafers of germanium from cylindrical ingots. The brittle germanium cracks easily, requiring a saw with a soft touch. The width of the saw creates waste. In the past a significant amount of germanium is lost during the cutting process. The new U of U sawing method improves efficiency by about 10%.

The new method for slicing solar cell wafers - known as wire electrical discharge machining (WEDM) - wastes less germanium and produces more wafers by cutting thinner wafers with less waste and cracking. The method uses an extremely thin molybdenum wire with an electrical current running through it.

More Info at: U of Utah

Check Out: Sustainable Design Update

Saturday, September 06, 2008

New HP Laptop - 97% Package Free!

HP - Laptop Without Box

I saw this over at Gizmodo and thought it deserved to be a Friday post.

From Gizmodo:

We've seem our share of good packaging ideas and bad packaging ideas, but this new method from HP is a great packaging idea. Their Pavilion dv692 systems available at Wal-Mart and Sam's Club will sit on the shelf in their own recycled material messenger bags, stabilized and protected with internal air bubbles. This alternative to huge boxes shoved full of styrofoam has reduced HP's individual consumer packaging by an outrageous 97%.

Via: Gizmodo

Tuesday, August 26, 2008

Megabus - MegaEfficient Transportation


Last weekend I had a chance to catch the Megabus from Chicago to Ann Arbor. The Megabus is a new intercity express bus line that provides fast, safe and inexpensive travel between select cities in the Midwest and the Northeast.

Mass transit options are increasing to keep pace with the price of fuel. The bus I rode is a double decker that holds 79 passengers in comfort. It gets about 6 - 7 miles per gallon so that works out to 474 - 553 passenger miles per gallon. You would have to pack 10 passengers Clown-Car style in your Prius before you reached passenger fuel economy equivalent to the Megabus.

Costs are low and Megabus overhead is kept to a minimum by ticketing only online. There are no Megabus Stations. For my trip I caught the bus near the Chicago Union (train) Station. The pick up is a public bus stop with no shelter. At Union Station there is a sign on the door stating:

You have chosen a carrier that has not provided an indoor passenger waiting area for you. Amtrak and Chicago Union Station have no business relationship with 'Megabus' and cannot provide assistance unless patronizing Chicago Union Station establishments. Please wait outdoors for your bus.

More at: Sustainable Design Update

Monday, August 25, 2008

Living Like Ed

Ed Begley Jr.

I met Ed Begley Jr. this weekend at the Great Lakes Green Conference. Ed was speaking on how to make your home energy efficient and incorporate renewable energy without going broke. He also has a new book, "Living Like Ed". I got a chance to review a copy and it is the ideal place to begin if you want to make your house more energy efficient.

We had a chance to talk a bit after his presentation. Ed comes across as a down to earth, no nonsense kind of guy. His sincere nature and desire to save the earth makes a great contrast with his wife Rachelle, who goes along with many of Ed's ideas on how to live sustainably, but has her own ideas of what living comfortably is. The Begleys are filming their third season of "Living With Ed".

If you get a chance you should ask Ed about his rather cut-throat competition with Bill Nye - The Science Guy.

Ed has been a committed environmentalist ever since the first Earth Day He has always tried to “live simply so others may simply live.” Now, as more and more of us are looking for ways to reduce our impact on the planet and live a better, greener life, Ed shares his experiences on what works, what doesn't–and what will save you money!

From Random House:

These are tips for environmentally friendly living that anyone–whether you own or rent, live in a private home or a condo–can try to make a positive change for the environment. From quick fixes to bigger commitments and long-term strategies, Ed will help you make changes in every part of your life.

And if you think living green has to mean compromising on aesthetics or comfort, fear not; Ed's wife, Rachelle, insists on style–with a conscience. In Living Like Ed, his environmentalism and her design savvy combine to create a guide to going green that keeps the chic in eco-chic.

From recycling more materials than you ever thought possible to composting without raising a stink to buying an electric car, Living Like Ed is packed with ideas–from obvious to ingenious–that will help you live green, live responsibly, live well. Like Ed.

Check Out:
Living Like Ed: A Guide to the Eco-Friendly Life