Tag: peel and stick solar panels

Powered by the Sun: Microbead Solar Cells

solar3Despite how far solar cells have come in recent years, issues like production and installation costs have remained an ongoing obstacle to their full scale adoption. But as they say, obstacles are meant to be overcome, and can often produce very interesting solutions. For example, peel and stick solar panels that can be manufactured by a 3D printer are one option. Another is the recent creation of a solar cell as thin as a strand of hair. And as it happens, a third has just been unveiled.

This latest one comes to us from the University of Oslo, where researchers have come up with a way to produce silicon solar cells that are twenty times thinner than commercial solar cells. Typically, solar cells are fashioned out of 200-micrometer-thick (0.2mm) wafers of silicon, which given their average rate of power generation works out to about five grams of silicon per watt of solar power. Combined with all the silicon wasted in the production process, this makes for a very inefficient process.

Solar-Wafer-Solar-CellsOne way around this is to reduce the thickness of solar wafers, but this presents its own problems. As the wafer gets thinner, more light passes straight through the silicon, dramatically reducing the amount of electricity produced by the photovoltaic effect. Blue light, which has a short wavelength, can be absorbed by a very thin solar cell; but red light, which has longer wavelengths, can only be captured by thicker wafers.

Enter into this the breakthrough created by the Oslo researchers. Using a revolutionary technique involving microbeads – tiny plastic spheres that create an almost perfect periodic pattern on the silicon. Apparently, these beads force the sunlight to “move sideways,” ensuring a more uniform and powerful rate of absorption. Another trick is to dot the backs of each cell with asymmetric microindentations,which can trap even more solar energy.

solar_beadsUsing these techniques, silicon wafers can be created that measure a mere 10 micrometers in thickness but can do the job of a 200 micrometer cell. By using 95% less silicon, the cost of production drops considerably, which will reduce the cost of solar power installations and – more importantly – increase profits. With current production methods and costs, the profit margin associated with solar power is pretty negligible.

This latter aspect is especially important as far as commercial production comes into play. If we are to expect industries to adopt solar power for their energy needs, it has to be worth their while. At the moment, the Oslo researchers are in talks with industrial partners to investigate whether these methods can be scaled up to industrial production. But given the nature of their work, they seem quite confident that their technology could come to the market within five to seven years.

Stay tuned for more installments in the PBTS series!

Source: Extreme.tech

Powered by the Sun: The Future of Solar Energy

Magnificent CME Erupts on the Sun - August 31Researchers continue to work steadily to make the dream of abundant solar energy a reality. And in recent years, a number of ideas and projects have begun to bear fruit. Earlier this year, their was the announcement of a new kind of “peel and stick” solar panel which was quite impressive. Little did I know, this was just the tip of the iceberg.

Since that time, I have come across four very interesting stories that talk about the future of solar power, and I feel the need to share them all! But, not wanting to fill your page with a massive post, I’ve decided to break them down and do a week long segment dedicated to emerging solar technology and its wicked-cool applications. So welcome to the first installment of Powered By The Sun!

spaceX_solararrayThe first story comes to us by way of SpaceX, Deep Space Industries, and other commercial space agencies that are looking to make space-based solar power (SBSP) a reality. For those not familiar with the concept, this involves placing a solar farm in orbit that would then harvest energy from the sun and then beam the resulting electricity back to Earth using microwave- or laser-based wireless power transmission.

Originally described by Isaac Asimov in his short story “Reason”, the concept of an actual space-based solar array was first adopted by NASA in 1974. Since that time, they have been investigating the concept alongside the US Department of Energy as a solution to the problem of meeting Earth’s energy demands, and the cost of establishing a reliable network of arrays here on Earth.

Constructing large arrays on the surface is a prohibitively expensive and inefficient way of gathering power, due largely to weather patterns, seasons, and the day-night cycle which would interfere with reliable solar collection. What’s more, the sunniest parts of the world are quite far from the major centers of demand – i.e. Western Europe, North America, India and East Asia – and at the present time, transmitting energy over that long a distance is virtually impossible.

NASA "Suntower" concept
NASA “Suntower” concept

Compared to that, an orbiting installation like the SBSP would have numerous advantages. Orbiting outside of the Earth’s atmosphere, it would be able to receive about 30% more power from the Sun, would be operational for almost 24 hours per day, and if placed directly above the equator, it wouldn’t be affected by the seasons either. But the biggest benefit of all would be the ability to beam the power directly to whoever needed it.

But of course, cost remains an issue, which is the only reason why NASA hasn’t undertaken to do this already. Over the years, many concepts have been considered over at NASA and other space agencies. But due to the high cost of putting anything in orbit, moving up all the materials required to build a large scale installation was simply not cost effective.

spacex-dragon-capsule-grabbed-by-iss-canadarm-640x424However, that is all set to change. Companies like SpaceX, who have already taken part in commercial space flight (such as the first commercial resupply to the ISS in May of 2012, picture above) are working on finding ways to lower the cost of putting materials and supplies into orbit. Currently, it costs about $20,000 to place a kilogram (2.2lbs) into geostationary orbit (GSO), and about half that for low-Earth orbit (LEO). But SpaceX’s CEO, Elon Musk, has said that he wants to bring the price down to $500 per pound, at which point, things become much more feasible.

And when that happens, there will be no shortage of clients looking to put an SBSP array into orbit. In the wake of the Fukushima accident, the Japanese government announced plans to launch a two-kilometer-wide 1-gigawatt SBSP plant into space. The Russian Space Agency already has a a working 100-kilowatt SBSP prototype, but has not yet announced a launch date. And China, the Earth’s fastest-growing consumer of electricity, plans to put a 100kW SBSP into Low-Earth Orbit by 2025.

space-based-solarpowerMost notably, however, is John Mankins, the CTO of Deep Space Industries and a 25-year NASA vet, who has produced an updated report on the viability of SBSP. His conclusion, in short, is that it should be possible to build a small-scale, pilot solar farm dubbed SPS-ALPHA for $5 billion and a large-scale, multi-kilometer wide power plant for $20 billion. NASA’s funding for SPS-ALPHA dried up last year, but presumably Mankins’ work continues at Deep Space Industries.

Cost and the long-term hazards of having an array in space remain, but considering its long-term importance and the shot in the arm space exploration has received in recent years – i.e. the Curiosity Rover, the proposed L2 Moon outpost, manned missions to Mars by 2030 – we could be looking at the full-scale construction of orbital power plants sometime early in the next decade.

And it won’t be a moment too soon! Considering Earth’s growing population, its escalating impact on the surface, the limits of many proposed alternative fuels, and the fact that we are nowhere near to resolving the problem of Climate Change, space-based solar power may be just what the doctor ordered!

Thanks for reading and stay tuned for the next installment in the Powered By The Sun series!

Source: Extremetech.com