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Solar Cells Crystallized Out of Molten Silicon
Hot Toddy sends in a link to a story up on Digital World Tokyo about a more efficient process for manufacturing solar cells. It involves dropping molten silicon from a height of 14 m; surface tension causes tiny spheres 1 mm in diameter to form; the silicon crystallizes in the 1.5 seconds of free-fall. The spheres can be mounted on surfaces of any shape. They capture light from many directions, increasing their solar efficiency. Kyosemi is the company behind the Sphelar technology. Some of the pages on this site date to 2003 and the status of most listed Sphelar products is either "under development" or "engineering sample is available."
It's trivial to create a zero-G manufacturing environment here on Earth. The only limitation is that it's only zero-G for a couple of seconds (as it falls down a tower). That is apparently enough for many types of processes such as this one. In space there's no limit on the duration, so growing protein crystals etc might be easier, but the costs of doing anything in space are so enormous that those protein crystals had better be worth thousands of dollars a pound to make them worth doing in space.
Missing from the story are important and obvious details.
1. Electrical output efficiency compared to a correctly aimed flat solar panel.
2. How are tiny silicon balls connected to produce electricity?
Any other questions, please chip in.
Thanks, Jim
This discussion bring back to me an ancient memory of myself reading, I believe a "Popular Science" magazine blurb in the school library when I was a little kid. This memory is really old, like Madonna wearing 10 crucifixes at a time old.
The article was about a system that used little silicon spheres set onto dish shaped depressions pressed into a piece of tinfoil. The individual cells looked like an orange in a shallow cereal bowl. (but, you know, lots and lots smaller.) The dish acted as a solar reflector thereby making the effective efficiency higher for a given amount of pure silica. It produced less electricity per square inch than equivalent conventional cells, but it's total cost was supposed to be lower.
IIRC The material proved be a dud for many reasons. It was overly delicate, they had a serious problem with reliably attaching the spheres to the aluminum, an when they finally got it going the actual efficiency numbers were far lower than they were predicting.
I mark this as one of those ideas that crop up every now and again when it's been long enough for people to forget that it was stupid the last time.
Peak oil is an environmental problem, not an economic problem. There are lots of fuel alternatives, they are just expensive or environmentally damaging. As oil prices rise, alternative methods of energy storage become viable. As alternative energy sources become profitable, the price of oil drops. The result is that no matter how hard you try, you can't force oil prices up rapidly over a long period of time. The worst that will happen will be a steady long term climb as oil is phased out and new energy sources are phased in.
The real danger in peak oil is the environmental impact. As oil becomes more expensive, alternative methods of fueling vehicles will be needed. Now, there are lots of viable alternatives to get buy one little to no oil. The problem is that all the alternatives require spending energy... energy that will likely come from the grid. You could switch to a hydrogen fueled car or plug in hybrids for instance in a few years. The problem is that making hydrogen (or any alternative fuel) or to recharge off the grid is going to demand you spend energy from the grid. This is good in that your automotive industry becomes as clean as your gird... so if you have a clean grid, you have a clean automotive industry. The downside is that as you pull more power from the grid, energy prices go up. The only way to keep them down and keep from killing the grid is to put more power online. Coal is the cheapest and most efficient way to dump more power into the grid, but coal has the downside of being less than friendly to the environment or good for CO2 emissions.
My point is that the world will move on smoothly from peak oil (should it exist). The market will happily even out the price and the transition will be smooth. The real danger is an environmental danger as we scramble to get energy from alternative sources.
At the moment, we pretty much drill a hole in the ground and start sucking. The energy put in is tiny relative to the energy we get out. As we have to put more energy in to find our energy we have less energy to expend elsewhere. Even nuclear energy has a lower energy return than oil does. When the ratio of energy input to energy output falls to 1:1, the entire economy is employed finding and exploiting new sources of energy. So as we move from oil, the energy sector takes up larger and larger proportions of our spending and investment.
While I don't doubt that market forces will make us move to different fuels, those same market forces may also require us to abandon our cars and skyscrapers. There is nothing magical about the market, it's simply individuals making choices. The reason I asked "is there going to be enough time" is that alternative infrastructures take time, perhaps 10-20 years to build.
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