- [David] Imagine if all of the windows of all of the buildings in downtown Seattle were generating electricity at the same time that they were letting some light into the occupants of the office.

And so now, all of your rooftops are generating power.

All of your windows are generating power.

All of the guardrails along the highway are generating power.

If you add up all that land area in the U.S., we've already covered more than enough land area to supply all of our electricity needs with solar.

- [Katie] So what is the Clean Energy Institute?

- We're a state-funded institution at the University of Washington.

Our focus spans energy generation from renewable sources, primarily solar.

There are a lot of problems with our current energy use.

It's not sustainable.

It emits a lot of carbon.

We need to provide a new, more sustainable energy sources.

- Okay, so when I think of solar energy, I think of the panels that people put on their homes.

What are you doing that's different on that?

- So, the panels that people put on their home are made of material called silicon, which is basically sand that's been purified.

That's great, sand is everywhere!

Why do we want something different?

Well, it takes a lot of energy to refine that sand into silicon.

Silicon solar cell would be made of little pieces.

The reason it's so thin is because it takes so much energy to produce that you wanna use as small amount of material as possible.

In fact, sawing these into thinner and thinner pieces, and you just discovered one of the other disadvantages of crystalline silicon solar cells is they're incredibly fragile.

- Yeah, I'd say so, barely even touched it.

- And so something this thin and this fragile has to be packaged to protect it.

We wanna make solar cells light, thin, cheap, and flexible, something that can absorb light and generate electricity.

And you can print that just like you could print a newspaper.

- [Katie] So that's the ink?

- [Man In White Shirt] That's the ink.

- So walk me through the process.

How do you make this magic ink?

(joyful music) - Gloves on glove.

- [David] You literally take powders of the precursors, methylammonium iodide, lead iodide, dissolve them in different solvents, just like you would dissolve salt in a soup, and then you get an ink that looks just like this.

And then we squirt it out on a little piece of glass and spin it around and then it dries.

And you'll see it turn from yellow to black as it leaves solution, as it becomes a solid in film.

And then we bake it for a very short time.

- Cold winter day, you come here and heat up your face.

- So when you have flexible solar cells, you can imagine doing all sorts of new things that you couldn't do with a rigid solar cells as well.

You can imagine putting solar into your backpack, into your tent, right, into a canvas and a tarp, there are early prototypes for things like emergency shelters, where you roll out the big emergency shelter tent to house refugees, but also have solar panels integrated into the canvas.

- And would this work anywhere in the world or do you have to be someplace that it's actually sunny all the time?

- Obviously you have to have sunlight for solar power to work.

But we make these jokes about, oh, why would study solar power in Seattle?

It's not that Seattle gets no sunlight, it just gets less sunlight than other areas.

- If these got too efficient, would they suck all the light from the sun?

- I think we're eons away from having that be a significant problem.

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