The technology to capture solar power is becoming much more sophisticated. New Scientist has an article today called “Work light twice as hard to make cheap solar cells,” that mentions how far solar has come:

In 1961, semiconductor pioneers William Shockley and Hans Queisser  showed that [several] factors limited single solar cells to converting no more than 31 per cent of incident solar energy to electrical energy. But around a decade ago Martin Green of the University of New South Wales in Sydney, Australia, challenged that orthodoxy. He suggested the third generation of solar cells could break the 31 per cent barrier.

Stanford engineers published one of those new technologies this week in the Proceedings of the National Academy of Sciences—solar cells thinner than wavelengths of light. From the Stanford Report:

Their research shows that light ricocheting around inside the polymer film of a solar cell behaves differently when the film is ultra thin. A film that’s nanoscale-thin and has been roughed up a bit can absorb more than 10 times the energy predicted by conventional theory.

Another new solar technology published this week—buckyballs. From the press release:

One approach uses a light-absorbing polymer along with a derivative of a sixty-carbon fullerene molecule, commonly known as a buckyball. For maximum efficiency, the two materials must be present in thin layers near opposite electrodes but most analytical methods cannot distinguish between polymer and the buckyball well enough to characterize the plastic solar cell film.

And existing solar cell technology is getting smarter. One of the problems with solar power is that cloud cover can make the intake inconsistent. But new technology will allow solar panels to track cloud movement. Researchers at UC Merced received a grant to make this technology a reality. From the New York Times:

The grant, announced earlier this year, will be used to develop a network of sensors to collect data on solar irradiance and to track cloud cover, water vapor and carbon dioxide in the atmosphere, all of which can affect the amount of sunlight reaching solar cells.

Even small scale wind power made the news this week. A small, ancient town in Italy has four wind turbines—enough to power their village and sell off the surplus to fund community rebuilding projects.

From the small to the huge: a space-based solar sail, that combines wind and solar, from Discovery News:

Using a massive 8,400-kilometer-wide (5,220-mile-wide) solar sail to harvest the power in solar wind, the team hopes their concept could generate 1 billion billion gigawatts of power, far more power than humanity needs — if they can get that power back to Earth.

Wow! The possibilities are endless…

Image by alforesm

August 27^th – Big Mars Day

Despite what you may have heard, or read, Mars will not be bigger than the Moon in the sky tonight. It hasn’t ever been, nor will it ever be. In fact, tonight Mars will be about as far as it can get from Earth—195 million miles away.

It all started on August, 27, 2003 when Mars was very close, about 34 million miles from us, the closest in 60,000 years. But even then, it was still smaller than the Moon. From NASA:

At the height of the display, Mars was about 75 times smaller than the full Moon.

That’s when “the virus” was born.

Someone, somewhere, reasoned as follows: If Mars is 75 times smaller than the Moon, then magnifying it 75 times should make it equal to the Moon… “At a modest 75 times magnification,” the [email] message stated, “Mars will look as big as the full Moon to the naked eye.”

The email was altered and forwarded and continues to surface every August 27^th. Will the hoax ever die? From Universe Today:

I wasn’t going to write an article about the Mars-Moon Hoax this year because I thought it was too passé, but I just looked at some stats and saw that our article on the topic from 2007, “Will Mars Look as Big as the Full Moon On August 27? Nope” has gotten over 50,000 hits the past few days…

Big Solar

Wednesday, the California Energy Commission approved the Beacon Solar Energy Project, which would be “the largest solar power plant in the world” [New York Times]. It will be built on the edge of the Mojave Desert, covering over 2,000 acres, and when it’s operational– hopefully by the end of next year– it should be producing 250 megawatts of energy.

This isn’t your standard solar, according to “80beats” in Discover:

Beacon is solar thermal: Rather than converting sunlight to electricity through photovoltaic cells, solar thermal projects use mirrors to concentrate the heat of the sun, creating steam to turn turbines.

As we wrote Tuesday, Go, Solar!

Caterpillar Munching Trouble and Lizard Live Births

We’re running out of room, but we can’t leave out these two awesome evolution stories!

An article published in Science today describes tobacco plants that have evolved to release chemicals when caterpillars chew on the leaves. The chemicals call out to caterpillar predators. Booby-trapped! Read more in New Scientist.

Also reported in New Scientist: Skinks, a type of lizard, are in the middle of evolving from egg laying to live births. Check it out!

California seems to lead the charge here in the US. Many of the stories are developing right here. KQED Quest has an entire series on renewables called 33×20—named for California’s goal to have 33% of our electricity come from renewables by 2020.

Earlier this week, the program had a great radio story about wind and solar energy development on Indian land. They site two examples in southern California, but there are several more. According to reporter Amy Standen,

Over the last two years, the pot of federal aid for Indian energy development has doubled to about $7 million a year. Tribes are also eligible for stimulus grants.

The people of the Campo Kumeyaay Nation have found a great way to use land that’s otherwise unusable:

This project… is an enormous source of pride for the Campo people, in part because it makes use of a resource that until recently, didn’t seem to offer a lot of options.

MONIQUE LACHAPPA: Look where we’re located. We’re out here in the middle of nowhere. It makes it difficult for anybody who wants to be able to do more for their family, or send their kids to college.

The New York Times tackles unusable California land—salty or dry earth previously used for agriculture—in their recent article “Recycling Land for Green Energy Ideas”. In the San Joaquin Valley, a large project is underway to bring solar to 30,000 acres of land too salty from years of irrigation to support agriculture any longer. And it’s a win-win situation: landowners and regulators are on board as well as environmentalists:

Unlike some renewable energy projects blocked by objections that they would despoil the landscape, this one has the support of environmentalists.

The project helps ease ever-present drought conditions for farmers, as well:

For Westlands farmers, the promise of the solar project is not clean electricity, but the additional water allocations they will get if some land is no longer used for farming.

With water deliveries slashed because of drought and environmental disputes, he [Mark Shannon] could plant only 20 percent of his property with irrigated crops this year.

“Come hell or high water, there just is not enough water to farm this whole district,” Mr. Shannon, 41, said. “If I lease my land for solar, we can farm elsewhere.”

Finally, in another article, The New York Times looks at Portugal’s aggressive development of clean energy. This year, that country will get 45% of their electricity from renewables—solar, wind and more (Science In Action’s “Wave Power” story included many images from operations in Portugal). By 2011, there will be a national network in place for charging electric cars.

There’s a reason for this forward thinking:

Portugal’s venture was driven by necessity. With a rising standard of living and no fossil fuel of its own, the cost of energy imports — principally oil and gas — doubled in the last decade, accounting for 50 percent of the country’s trade deficit, and was highly volatile.

We can learn a lot of lessons from what they’ve done in such a short time, the article states. The country has developed new skills for new technologies, and they grab power from even the smallest producers—residential solar roof panels, for example. But there are drawbacks, too.

While Portugal’s experience shows that rapid progress is achievable, it also highlights the price of such a transition. Portuguese households have long paid about twice what Americans pay for electricity, and prices have risen 15 percent in the last five years, probably partly because of the renewable energy program, the International Energy Agency says.

Although a 2009 report by the agency called Portugal’s renewable energy transition a “remarkable success,” it added, “It is not fully clear that their costs, both financial and economic, as well as their impact on final consumer energy prices, are well understood and appreciated.”

Only time will tell how it all plays out on our soil. Let’s just hope the process of converting to cleaner energy continues to move swiftly forward.

Creative Commons image by Ceinturion

Scientists from two southern US universities have recently announced low-tech plant-based solutions to modern problems, hoping they’ll translate to the developing world.

Water Purification by Cactus

According to an abstract published in Environmental Science and Technology earlier this month, “Although nearly all newly derived water purification methods have improved the water quality in developing countries, few have been accepted and maintained for long-term use.” That’s because, according to one of the authors, Norma Alcantar, PhD, the residents don’t know how to actually use or maintain the technology.

She and other scientists from the University of South Florida in Tampa have taken the prickly pear cactus and the thick, gooey mucilage within it and created a type of water purifier.

According to New Scientist, “Alcantar found that the mucilage acted as a flocculant, causing the sediment particles to join together and settle to the bottom of the water samples. The gum also caused the bacteria to combine and settle, allowing 98 per cent of bacteria to be filtered from the water.”

It’s already been helping residents of a rural Mexico town clean their drinking water and Alcantar only sees it going further. “The World Health Organization recognizes a need for developing low-cost ways of cleaning water for household use,” she said, and the cactus, also known as Opuntia ficus-indica, is widely available.

According to the abstract, “This natural material not only displays water purification abilities, but it is also affordable, renewable and readily available.”

Pokeberry Solar Power

Civil War soldiers used the red dye of pokeberries as ink by to write letters home. And now scientists from Wake Forest University are hoping that the dye will help improve the efficiency of solar cells.

Wake Forest’s Center for Nanotechnology and Molecular Materials has already developed a fiber-based solar cell that’s both less expensive and more efficient that standard solar cells. And now the pokeberry dye will make it even more so. The dye acts as an absorber, helping the cell’s tiny fibers trap more sunlight to convert into power.

Pokeberries proliferate even during drought and in rocky, infertile soil. That means residents of rural Africa, for instance, could raise the plants for pennies.

“We could provide the substrate,” David Carroll, Ph.D., the center’s director said. “If Africa grows the pokeberries, they could take it home. It’s a low-cost solar cell that can be made to work with local, low-cost agricultural crops like pokeberries and with a means of production that emerging economies can afford.”

Creative Commons image by Mary Emily Eaton and Daniel Schweich