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Green Revolution: Solar Power

6 minutes

(Describer) In an animation, different colored icons include a car, a house, a model for hydrogen, and an arrow that looks like lightning. In another one, a woman connects cables. As she laughs and smiles, title: Green Revolution, with Lisa Van Pay PhD (Scientist).

(Describer) Other icons: light bulb plus grids times a leaf equals question mark.

(Describer) Title: Solar Power.

(Lisa Van Pay) Here's the sun. It's about 93 million miles from the Earth. It's big and contains tremendous energy. Light is how energy moves through space. But when light hits the Earth, the energy is spread out. We must discover how to collect and concentrate it to use it. To get lots of power, we use solar farms. On some farms, thousands of mirrors focus sunlight to heat pipes filled with fluid. Elsewhere, rotating mirrors aim the sun's rays at a liquid-filled tank at the top of a tower. Both convert heat energy to electricity using a generator. Then there are huge farms of solar cells, collecting the sun's energy and turning it directly into electricity. Solar cells can work on a smaller scale too, powering everything from streetlights to houses to stores, even airports. What about flexible cells that travel with you? You could charge your phone en route to meet friends. Arizona State University researchers are looking to the solar experts, plants, to make solar cells that work better with your life.

(Describer) Lisa meets Brad Brennan, ASU Graduate Student.

(Describer) She puts on safety glasses like the ones he wears.

Brad, can you tell me about the research you're doing in your lab? Our group focuses on the first steps of photosynthesis, where plants take light and start converting it into energy.

(Van Pay) In a plant, chlorophyll molecules absorb sunlight, using that energy to move around electrons. Solar cells based on photosynthesis can be smaller, cheaper, and more flexible than current ones.

(Describer) Title: How does it work? A diagram has a rectangle with three layers and a handle connecting the first and third.

Most solar cells used now are made from silicon layers, engineered to be positive or negative. When the layers are sandwiched together,

(Describer) The connected layers.

the space in between acts like a magnet. Light energy excites electrons, making them jump into the in-between space. Its magnetic properties push them to the other side. Once electrons build up, the negative charge makes them push each other through the circuit,

(Describer) The handle.

creating a useful electrical current. Brad makes colored dyes that help the solar cell absorb more light energy, like chlorophyll does in plants.

(Brennan) We make increasingly complex molecules for us to eventually try and mimic what the plant does.

(Describer) Title: So what happens next? Brad holds up a clear disk with slides taped on it.

What are we looking at here? We're looking at different pieces of a dye-sensitized solar cell, showing the different parts to form our solar cell. We have a very thin film on that. We cover that film with a dye we make that absorbs light very well. If we clipped two wires to those pieces of glass and put it in the sunlight, we'd be getting electricity out of that. It's a stepwise process in research. You never know what works and what doesn't. Here, you might need to collaborate with others that could give you ideas how? Many people have different specialties, and they might be on the other side of the Earth at a different university, but they'll solve your problem.

(Describer) Title: Far away? Close enough. Lisa sits at a laptop.

(Van Pay) Collaboration is important in solving problems.

(Describer) She opens video chat.

Remember that thin film Brad was talking about? That's something researchers are improving. Brittany, can you tell me about the work you're doing in the lab right now?

(Describer) Brittany Lynn:

The lab's goal right now is to make organic solar cells more efficient. The work I was doing to help this along was to take certain layers on a solar cell and make it so they were bumpy. What being bumpy does is it helps the interface between two surfaces have more surface area. There's more surface area, but the surfaces have to be close enough for the electrons to jump. Yes, they're limited in the distance they move by the material we're using. We must make really thin solar cells. When it's thin, you can see through it easier. If it's transparent, that means the light's not absorbed by the material. We want to have it thicker to increase absorption in sunlight, and you get more power. I wanted to work over the summer, gaining experience in a chemistry lab, so I could touch machines I'd learned about in class, and work with solar cells. That's a big field in optics and science.

(Van Pay) Earth receives huge amounts of the sun's energy daily. Daily, we're getting better at harnessing it. New ideas are shared every summer, as students worldwide participate in the Solar Decathlon, a competition to see who makes the best solar-powered house. Soon, photovoltaic shingles for your house and light-flexible cells that can charge your stuff on the move will be everywhere. Someday, we might have solar power beamed down from satellites. The National Science Foundation supports researchers who study things we already know about, like plants and solar cells, and think about them in new ways. New ideas that could lead to a brighter tomorrow.

(Describer) Lisa rests in a hammock in one of the solar houses. Icons: light bulb plus grids times a leaf equals the sun.

(Describer) Titles: Produced by Bobby Mixon, Lisa Van Pay.

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Arizona gets plenty of sunlight, and researchers there are working hard to turn that energy into electricity. At Arizona State University, graduate student Brad Brennan makes and tests new materials that will allow industry to build smaller, cheaper, flexible photovoltaic solar cells that can go almost anywhere.

Media Details

Runtime: 6 minutes

Green Revolution
Episode 1
7 minutes
Grade Level: 7 - 12
Green Revolution
Episode 2
6 minutes
Grade Level: 7 - 12
Green Revolution
Episode 3
6 minutes
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Green Revolution
Episode 4
6 minutes
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Green Revolution
Episode 5
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Green Revolution
Episode 6
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Green Revolution
Episode 7
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Green Revolution
Episode 8
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Green Revolution
Episode 9
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