Middle East Quaking

Discussion in 'Economics' started by ShoeshineBoy, Nov 4, 2008.

  1. It looks like potentially there is a huge break through in solar power at RTI:


    They have come up with a coating that increases absorption through all angles. Between this and thin film solar, do you think the Middle East is starting to "quake in their boots"? Couldn't this change the landscape dramatically in 20 years?

    We don't need another Pakistan and might this not help stop it?

    "Solar Power Game-changer: 'Near Perfect' Absorption Of Sunlight, From All Angles
    ScienceDaily (Nov. 4, 2008) — 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.”

    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.

    This same is true of conventional solar panels, which is why some industrial solar arrays are mechanized to slowly move throughout the day so their panels are perfectly aligned with the sun’s position in the sky. Without this automated movement, the panels would not be optimally positioned and would therefore absorb less sunlight. The tradeoff for this increased efficiency, however, is the energy needed to power the automation system, the cost of upkeeping this system, and the possibility of errors or misalignment.

    Lin’s discovery could antiquate these automated solar arrays, as his antireflective coating absorbs sunlight evenly and equally from all angles. This means that a stationary solar panel treated with the coating would absorb 96.21 percent of sunlight no matter the position of the sun in the sky. So along with significantly better absorption of sunlight, Lin’s discovery could also enable a new generation of stationary, more cost-efficient solar arrays.

    “At the beginning of the project, we asked ‘would it be possible to create a single antireflective structure that can work from all angles?’ Then we attacked the problem from a fundamental perspective, tested and fine-tuned our theory, and created a working device,” Lin said. Rensselaer physics graduate student Mei-Ling Kuo played a key role in the investigations.

    Typical antireflective coatings are engineered to transmit light of one particular wavelength. Lin’s new coating stacks seven of these layers, one on top of the other, in such a way that each layer enhances the antireflective properties of the layer below it. These additional layers also help to “bend” the flow of sunlight to an angle that augments the coating’s antireflective properties. This means that each layer not only transmits sunlight, it also helps to capture any light that may have otherwise been reflected off of the layers below it.

    The seven layers, each with a height of 50 nanometers to 100 nanometers, are made up of silicon dioxide and titanium dioxide nanorods positioned at an oblique angle — each layer looks and functions similar to a dense forest where sunlight is “captured” between the trees. The nanorods were attached to a silicon substrate via chemical vapor disposition, and Lin said the new coating can be affixed to nearly any photovoltaic materials for use in solar cells, including III-V multi-junction and cadmium telluride.

    Along with Lin and Kuo, co-authors of the paper include E. Fred Schubert, Wellfleet Senior Constellation Professor of Future Chips at Rensselaer; Research Assistant Professor Jong Kyu Kim; physics graduate student David Poxson; and electrical engineering graduate student Frank Mont.

    Funding for the project was provided by the U.S. Department of Energy’s Office of Basic Energy Sciences, as well as the U.S. Air Force Office of Scientific Research.


    Journal reference:

    Kuo et al. Realization of a near-perfect antireflection coating for silicon solar energy utilization. Optics Letters, 2008; 33 (21): 2527 DOI: 10.1364/OL.33.002527
  2. Mecro


  3. Technological breakthroughs are important, but actually productizing them is another matter. Any new widget or technique has to be reliably and inexpensively reproducible if it's to be mass marketed.
  4. 1st thing ya gotta do is break the "We've always done it THIS way" mindset.
  5. TGregg


    Not for solar power. The hurdle for solar power is efficient, cheap collectors. Build units that you can put on your roof that will last 20 years, cost only a few grand and cut your `lectric by (say) 50% and you wouldn't be able to make them fast enough.

    How much power is in direct sunlight anyway? You spread your hand out, and it's warm, but not hot - maybe 10 watts a square foot?
  6. Mid-Atlantic US is about 5 kWh/square meter/day. Looks like the UK gets about 3.


    BTW that's the energy actually hitting the earth. Typical solar cells yield a small fraction of that in electrical energy.
  7. Nice improvement but it is not a big jump. Solar is very expensive to install; I looked at putting it on my house but it would cost about $25K to save under $1K a year.

    Also, Solar has a very huge obstacle: Sundown. As of now, there are no economically viable storage systems.

  8. So what's the impact on local climates if the the sun energy is no longer allowed to hit the earth and is immediately turned into electricity?
  9. Mecro


    Depends where you are. Paybacks of 4-5 years are very doable. Think it can get down to 3-4 years nowdays. And this is on an asset where the main component, the panels, are guaranteed for 25 years.

    Whoever tried to sell you the system needs to find a new line of work. It's called grid tied systems. And even off-grid, plenty of storage system available. Are they efficient? Barely. Are they viable? Very, just do a tour of self sufficient homes based on solar.
    For large projects they do have a viable storage system, molten salt solutions.
  10. Mecro


    It's vaporware. Go look up the posts on Nanosolar, then check up on it.

    It's all vaporware till there is a product sample to distribute and commitments can be made. Within the industry, you get one of these breakthroughs every month. So far, in almost 10 years, none of them have materialized.
    #10     Nov 4, 2008