Cheaper solar panels on the way

Finally!  I was hoping that government incentives, high fuel prices, and other factors would push down the price of photovoltaic (PV) panels, making solar power a viable alternative to fossil fuels.  It's been a long, slow process, but between economies of scale and technological development, we're getting there.

In addition to lowering the price of panels, increasing their efficiency, learning how to deploy them, and developing panels that use more of the sunlight spectrum to generate electricity, are all helping to make our transition to sustainable energy something I might see in my lifetime.

From Earth Times:

Solar panel image; Credit: © Shutterstock Cheaper solar energy is on the way through more sustainable roof tiles that generate high levels of renewable energy, say American scientists.
As there is enough sun falling on domestic roofs to potentially supply most, if not all of America's electricity, scientists are excited about future prospects.
Tiles that take electricity from the sun, and can be fitted just like traditional roofing, are already commercially available.
Now, solar cells created from "earth-abundant" materials are more productive, affordable and flexible than ever, making it easier to deploy photovoltaics into new areas of buildings, the scientists believe.
The scientists' comments came during a sustainability symposium at the American Chemical Society's (ACS) 244th National Meeting & Exposition. ACS is the world's largest scientific society.
One of those taking part, Harry A. Atwater, Ph.D., says, "Sustainability involves developing technology that can be productive over the long-term, using resources in ways that meet today's needs without jeopardizing the ability of future generations to meet their needs. That's exactly what we are doing with these new solar-energy conversion devices."
The new photovoltaic devices use freely-available cheaper metals such and copper and zinc, described as "earth-abundant materials". They replace indium, gallium and other "rare earth" elements. These often come from foreign countries. For instance, China mines more than 90% of the rare earth elements in batteries for hybrid cars, magnets, electronics and similar high-tech products.
Dr Atwater and James C. Stevens, Ph.D., described how to replace expensive rare earth metals in photovoltaic devices with cheaper and more sustainable materials.
Dr Atwater, a California Institute of Technology physicist, and Dr Stevens, Dow Chemical Company chemist, led collaboration between the two in researching and developing new electronic materials to be used in solar power generation devices.
New devices using zinc phosphide and copper oxide shattered records for the amount of electrical current and voltage generated by thin-film solar energy conversion devices that were made with zinc and copper.
The advance reinforces evidence that zinc phosphide and copper oxide could achieve very high efficiencies and produce electricity at a similar cost to coal-fired energy plants within 20 years.
Dr Stevens assisted in the development of Dow's PowerHouse Solar Shingle at the end of 2011, which generates electricity and can be fitted like traditional roofing. The special shingles make use of copper indium gallium diselenide photovoltaic technology. Dr Stevens and his team are now aiming to incorporate sustainable earth-abundant materials into PowerHouse shingles.
He says, "The United States alone has about 69 billion square feet of appropriate residential rooftops that could be generating electricity from the sun. The sunlight falling on those roofs could generate at least 50 percent of the nation's electricity, and some estimates put that number closer to 100 percent. With earth-abundant technology, that energy could be harvested, at an enormous benefit to consumers and the environment."
The ACS symposium has also heard about:

Moves by mining company Molycorp to increase and update its Mountain Pass, Colorado, facilities to boost production of rare earth elements with more eco-friendly and cheaper technology.

A summary of the challenges of how to maintain a sustainable supply of critical materials from rare earth elements to more abundant metals such as copper.

A new material that can recover rare metals from the 800 billion gallons of wastewater that comes from mining and oil and gas drilling annually. The American Chemical Society is a nonprofit body that has more than 164,000 members. It is a worldwide leader in giving access to chemistry-related studies through its many databases, peer-reviewed journals and scientific conferences. Its main bases are in Washington, D.C., and Columbus, Ohio.

New solar energy system mimics sunflowers

It's no wonder that the future of renewable energy is a hybrid of technology and mimicry of nature.  The sunflower has evolved over many thousands of years to efficiently harvest the energy of the sun.

 

From Hydrogen Fuel News

Researchers engineer solar energy system capable of heliotropism

Researchers from the University of Wisconsin-Madison have taken a lesson from nature in developing a new kind of solar energy system. The system may be capable of harvesting solar radiation more efficiently throughout the day as it would adapt to the changing position of the sun. The system is based on a phenomenon that researchers have observed in sunflowers. Throughout the day, sunflowers will rotate from east to west, with their leaves also changing position in order to harvest as much solar power as they can. This process is called heliotropism.

New system adapts to the position of the sun

Researchers have engineered a solar energy system that is capable of mimicking heliotropism quite accurately. While it is not the first solar energy system that is capable of seeking out the sun and positioning itself for maximum exposure, it does not use the conventional GPS-directed method of these systems. Instead, researchers leveraged the properties they have seen in innovative materials that allow for the passive adaptation of the system to the position of the sun.

LCE’s and carbon nanotubes enable heliotropism

The system is comprised of a combination of liquid crystalline elastomer (LCE) and carbon nanotubes. LCE’s are exhibit change contrast and contraction when exposed to heat. Carbon nanotubes have the ability to absorb a wide range of light waves, making them valuable components to a solar energy system. The solar energy system is equipped with a mirror, which focuses sunlight onto an array composed of LCE’s and carbon nanotubes. When the LCE’s are heated, they contrast, allowing the system to bend toward the source of heat, thereby enabling the system to track the movements of the sun.

Solar energy system made possible through emergence of new materials

Though this is a simplistic approach to the harvest of solar energy, it has only been made possible due to the emergence of new materials in the past few years. These materials have allowed researchers to experiment with new solar energy systems and make these systems more efficient and capable of generating electricity through the collection of sunlight.