Posts Tagged ‘solar cells’
Nanocones for Cheap Solar Cells
This dovetails on the article about the solar-powered airplane. While the efficiency of solar panels is critical to making them worth deploying as an alternative to fossil fuels, that’s only half the issue. The other half, of course, is price. Right now, the cost is a dollar a watt, which is pretty hefty. Fortunately, increasing efficiency and decreasing price go hand-in-hand. In an earlier article, we introduced the idea that adding wrinkles might make the cells more efficient, and therefore cheaper. This time, it’s a different method of increasing surface area: cones.
Credit: Jeong, et al. ©2012 American Chemical Society
Of course, because these are really small cones, they are dubbed “nanocones,” and the Stanford University study was published in “Nano Letters.” There will come a point where we will have to stop using nano- to prefix to everything that’s in the nanometer range, since most technology already incorporates components in that range, and in the near future, all of it will. We’ll need to be a bit more specific. After all, we already have carbon nanocones, which are altogether different in application from these silicon cones. But that’s just a pet-peeve of mine – for now, nano’s captured everyone’s imagination, so I guess we’ll go with it everywhere we can.
The key to the cost-savings of this design is the space between the cones. In a normal polymer cell, you need a full second layer for the polymer, but with this design, it can simply fill the gaps. Having a second layer involves using other materials, so this method renders those unnecessary.
Solar Airplane Upgrading For World Tour
Yesterday, I wrote an article about the energy we could get out of a fusion reactor in development. Today, it’s about the energy we could get from a fusion reactor already in service: the Sun.
Solar power lacks the flair of fusion, and I’m afraid the story of a plane that cruises at 43 mph probably won’t do much to help that along, but there’s a lot to the Solar Impulse that captures the imagination. There’s its magnificent wingspan, for instance:
Solar Impulse (Credit: Matth1 at Wikipedia)
That’s a 208 feet wingspan folks, dwarfing many airliners and bombers. The kicker is that the whole thing weighs in at a max takeoff weight of two tons – 4,400 pounds. It’s empty weight is about the same as your car’s. Think for a moment about the brilliant design and fine construction keeping the weight down must have required. There’s no two ways about it – just the size-to-weight issue makes this a marvel of engineering.
Solar Cell Efficiency Boosted by Wrinkles
While we normally associate wrinkles with aging, nature likes to add wrinkles to surfaces improve efficiency. The wrinkles of the brain increase surface area and therefore processing capability. The friction ridges on our fingertips allow for fine texture perception. Most importantly for the context of this article, nature produces wrinkles in leaves to improve the capture of energy from light.
Taking this cue, researchers from Princeton and the University of Pennsylvania decided to try the same with photovoltaics, which have so far been rather remarkably flat: