Solar power is big. It's so big, in fact, that the Department of Energy recently promised up to $7 million in funding to support emerging solar technologies [source: DOE]. Harnessing the sun's energy is smart, but not as simple as it sounds.
It might be easier if we really could "harness" the sun, but that bright spot in the sky is elusive. Sometimes it hides behind clouds and, each night, it disappears altogether for hours at a time. The optimal time to mine the sun's energy is when it is highest in the sky, typically during the summer months when we also enjoy longer days with more average sunshine.
The researchers and engineers who design and build solar panels have to work with and around these factors all while devising new ways to not only collect but reserve free and renewable energy from the sun. For example, using mirrors, they've figured out a way to direct sunlight to solar panels even when the sun moves at an angle that normally would keep it from hitting those very panels.
On the next few pages, discover how innovative people are coming up with ways to use one of our most traditional energy sources more efficiently and effectively. You'll learn more about how solar panels can track the sun, how using different building materials increases efficiency and how solar concentrators channel light waves. Finally, you'll learn how "the sky's no limit" when it comes to collecting the sun's power for use here on Earth [source: SSP].
Is there a way to enhance solar panel efficiency?
A solar panel does not adapt itself to the movement of the sun, and as the day goes on and the sun moves in its regular path, the panel is left without a source of light. Solar trackers offer a solution to the problem of following the sun's passage through the sky; they use mirrors to direct sunlight onto the panels, even when the sun has moved past the point where it would naturally shine on the apparatus.
How did researchers at MIT improve solar concentrators?
Researchers at the Massachusetts Institute of Technology (MIT) improved the efficiency of solar concentrators by using glass sheets instead of plastic ones to house energy-collecting/producing dye cells. In addition, they increased the efficiency of the transfer of energy through the waveguide by adding aluminum molecules, which prevent the dye molecules from reabsorbing energy. The improvements found in MIT's aptly named luminescent solar concentrator (LSC) not only boost efficiency, but do so at a reduced cost.
How do solar concentrators work?
Solar concentrators are stationary devices that channel concentrated light waves through a waveguide toward a specific target. To achieve this, solar concentrators use dye molecules, which are sprayed onto a sheet of plastic and surrounded with solar cells, to collect and distribute solar energy. The dye cells drink in light waves when light shines on the plastic, which causes neutrons in the dye cells to become energized. Unable to maintain this new, energized state, the neutrons eventually release excess energy back into the plastic sheet. The energy bounces around in the plastic sheet until it makes its way to the outer surface. There, solar cells come into play to create electricity.
How can Space Solar Power (SSP) be compared to traditional solar power?
Solar power has become a familiar idea all over the world. Practically everyone understands the basic idea of harnessing the sun to create an alternative power source. The search to overcome solar power obstacles, such as weather conditions, the varying intensity of solar rays and the amount of space needed to farm solar energy, has led to an improved version of solar power. Space Solar Power (SSP) collects solar energy via solar panels connected to a satellite. By collecting solar power in space, weather, seasonal changes in available daylight and other earthly concerns are no longer issues.