Archive for the ‘Solar Power’ Category

‘Glitter-sized’ solar cells you could wear

Saturday, December 26th, 2009

By David L. Brown

Microscopic solar cells with the potential to bring solar power to places where no solar cell has gone before are being developed at the Sandia National Laboratories, Albuquerque, NM. The tiny cells are one-tenth the thickness of traditional solar cells and can potentially pv_microbe attached to flexible backings that could be mounted onto any odd-shaped object such as buildings, clothing, or even camping tents, thus bringing solar power to anyplace where the Sun shines.

The tiny cells, described as “glitter-sized,” are made from crystalline silicon and are expected to eventually be cheaper to make and more efficient than present photovoltaic collectors, according to a news release. They can be made in present manufacturing facilities, using far less silicon than traditional solar cells and with less waste. The cells, pictured above, measure from 0.25 to 1 mm in size (1/100 to 1/25 inch).

According to Sandia field engineer Vipin Gupta larger installations on the roofs of houses and warehouses “could have intelligent controls, inverters and even storage built in at the chip level.”

Thinner than the thickness of a human hair, the chips perform as well as conventional cells that are ten times thicker. They use 100 times less silicon to generate the same amount of electricity, the researchers say. Because the cells are so small they are less sensitive to overhead obstructions that can cause conventional panels to turn off entirely when part of the surface is blocked from the Sun.

According to lead investigator Greg Nielson, the “glitter-sized” cells could allow campers, hunters and military personnel in the field to recharge cell phones, cameras and other electronic gear just by walking around in the Sun while wearing special clothing. Other potential uses are in satellites and remote sensing installations.

Solar concentrators, arrays of microscopic lenses to focus the sunlight, can be placed over the tiny cells to increase the efficiency by increasing the number of photons striking the cells. The concentrators should be cheaper to make and more efficient, again because of the small size of the cells.

Because of the large number of cells in an array, high-voltage output can be generated directly, reducing costs and taking advantage of lower losses due to electrical resistance in wiring at higher voltages.

Sandia Laboratories is operated by Lockheed-Martin Company for the Department of Energy’s National Nuclear Security Administration.

Below are pictured three of the Sandia research team members holding micro solar arrays; from left: Murat Okandan, Greg Nielson, Jose Luis Cruz-Campa.

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Bumps Along the Way to Clean Energy

Friday, May 15th, 2009

By David L. Brown

According to a story today on the Detroit News website, a $900,000 demonstration house built by the city of Troy, MI with support from the local power company is closed until further notice. The house was designed without electrical and gas connections, relying entirely on solar energy. The house was dedicated with a ribbon cutting ceremony late last year.

The people in charge must have taken the global warming threat a bit too literally, because they failed to reckon on the fact that it still gets pretty cold in Michigan during the winter. Maybe they forgot that global warming means climate change, not overall warming, which resulted in an unusually cold winter this past season in many areas.

Anyway, to cut to the chase, the batteries ran down, the pipes froze and burst, and a flood of water caused thousands of dollars of damage to the house.

Well, that was a demonstration all right—a demonstration that we have a lot of learning to do before we can sail into a new world of energy independence. In fact, let’s cue Homer Simpson for what is truly a Doh! moment.

I have to wonder whether the power company, DTE, might have expected something like that to happen. If so, they might be doing Mr. Burns impressions about now, rubbing their hands together and muttering “Ex-cell-ent!” Like them, Mr. Burns is a seller of energy, but at least he uses only clean nuclear generation. DTE does do nuclear, but it also seems to be heavily invested in coal and gas.

Here is a picture of the demonstration house, which has 800 square feet and was supposed to be able to provide a living environment year-around plus enough electricity to support a home-based business and an electric car. All from solar power. In Michigan. In the winter. Double Doh!

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Well, for $900K, I have to say this doesn’t look too impressive. Not the kind of place over which Freddie Mac and Fanny Mae would be fighting each other for the chance to guarantee a jumbo loan. In fact, I’ve seen people in Mexico living in old boxcars that had more eye appeal than this thing, thanks to some bright paint and a few flower pots.

Does this represent the grim future for humanity?

Well, not necessarily. As I have written before, the concept of living above ground needs to be reconsidered for a number of reasons. It’s just too subject to the ambient temperature. Down below the frost line things don’t freeze in the winter. That’s why the water pipes to your house are buried below the ground.

In my opinion, only by going underground can a truly practical solar house become a reality. Such a house would remain naturally cool in summer and warm in winter with very little power needed for ventilation and supplemental heating. The entire above-ground lot would be available for gardens, a small orchard, chicken and rabbit coops, a greenhouse, and of course solar panels and possibly even a windmill. Such a dwelling could be almost entirely self-sufficient in food as well as energy, and could even sell energy back to the grid. We need to think outside of the box (i.e., the boxy houses we are accustomed to living in).

Every reader of this blog knows that I favor a move toward energy self-sufficiency and clean, renewable power. Please do not interpret my playful scoffing as criticism of the basic idea behind this demonstration. In fact, demonstration phases of any new technology are needed exactly so that things can go all pear-shaped. Only by making mistakes, then failing to repeat them, can progress be made. And, who knows? perhaps the house will eventually be modified to be able to survive a Michigan winter. Let’s hope so.

Meanwhile, I’ve been dreaming about the concept of underground construction since I was a teenager in the 1950s, and it’s an idea whose time has come. Let’s hope someone notices. I’m not holding my breath.

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New Technologies Emerging for Solar Energy

Sunday, July 13th, 2008

By David L. Brown

There is an old saying about people who live in glass houses, but perhaps that is a model for the future. As it begins to sink in that cheap oil is a thing of the past, it is encouraging that some real progress appears to be taking place in the field of solar energy. For example, a story titled “High-Efficiency Organic Solar Concentrators for Photovoltaics” that appeared in the current issue of Science magazine describes a cheaper and effective method of creating electricity from the Sun’s rays.

The new approach relies on thin film dye coatings on regular glass, channeling the light into receptors at the edges of the glass. The panels do not have to rotate to face the sun, and the researchers at MIT predict the organic concentrator panels could be ready for the market in as little as three years, provide greater efficiency, and at lower cost than current solar collectors.

Here is a diagram from the ScienceDaily web site that reports on the new technology in this article:

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As the diagram shows, the dye particles that coat the glass transfers the light to the edges, where the solar cells convert it into electricity. By stacking two layers of collectors, both high voltage and low voltage power can be produced, enhancing the efficiency.

Because the panels can be mounted flat on roofs or other plane surfaces, they could easily be installed in many places. It could make it possible for owners of houses and commercial property to cut or even eliminate their electric costs, thus helping reduce the need for power produced with fossil fuels.

The new work from MIT isn’t the only news from the solar front. According to this article, also posted on the ScienceDaily site just a few days ago, an Australian researcher at Queensland University of Technology’s Institute of Sustainable Resources (ISR) has developed transparent windows that could reduce heating and cooling costs while producing electricity from the Sun. Here is an excerpt from the story:

Professor John Bell said QUT had worked with a Canberra-based company Dyesol, which is developing transparent solar cells that act as both windows and energy generators in houses or commercial buildings.

He said the solar cell glass would make a significant difference to home and building owners’ energy costs and could, in fact, generate excess energy that could be stored or onsold.

Professor Bell said the glass was one of a number of practical technologies that would help combat global warming which was a focus of research at the ISR.

“The transparent solar cells have a faint reddish hue but are completely see-through,” Professor Bell said.

“The solar cells contain titanium dioxide coated in a dye that increases light absorption.

“The glass captures solar energy which can be used to power the house but can also reduce overheating of the house, reducing the need for cooling.”

Professor Bell said it would be possible to build houses made entirely of the transparent solar cells.

“As long as a house is designed throughout for energy efficiency, with low-energy appliances it is conceivable it could be self-sustaining in its power requirements using the solar-cell glass,” he said.

Imagine living in a house made entirely of glass and requiring nothing but the Sun to provide electricity, heating and cooling. Such a house would be the ultimate in green efficiency, although privacy issues would need to be addressed.

These are only two of the interesting new solar power possibilities that are coming over the horizon. As the cost of conventional energy continues to rise, there will be plenty of incentive for development and marketing of new alternatives such as these. One real bright feature of these new alternatives is that they do not rely on large quantities of silicon, which is expensive and in short supply.

What is needed now is government incentives to match, such as tax deductions, credits or grants for individuals or businesses that install environmentally friendly solar collectors. I know I would respond to such a program if it could be made affordable.

A couple of decades ago the government offered credits for the purchase of solar water heating systems, and the devices sold like hot cakes — until the subsidies were stopped. You don’t hear much about solar water heaters today, and that is too bad because hundreds of thousands of them could have been installed over the past couple of decades, helping to alleviate the current energy crisis. Congress and the administration could move the shift away from fossil fuels ahead by a giant step by instituting financial incentives to help people like me to take the move to solar.

Posted in Default File, Energy Technology, Solar Power | 1 Comment »

Let the Sun Shine In

Friday, April 28th, 2006

The Sun bathes the Earth with an enormous amount of energy every day. Our star is the source of nearly all energy on Earth … and yet, we largely ignore those powerful solar rays in favor of burning fossil fuels, damming up rivers, splitting atoms, and engaging in other activities that harm the planet and provide no renewable sources of energy.

Solar power is the ultimate resource, because for all practical purposes it is infinite. Except for wind, geothermal and wave power, no other eneregy sources meet this criterion. In Star Phoenix Base we will regularly seek out and report developments in photo-voltaics and other technologies to harness the power of our Sun.

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