Project Sage: Bringing Solar Power to the Masses (w/ Video)

Jul 23, 2009 By Lew Serviss
An organic photovoltaic cell on glass. The goal for UA scientists is to understand and control the interfaces in these devices at nanometer-length scales (less than 1/100,000 the thickness of a human hair) to enable the development of long-lived solar energy conversion devices on tough, flexible and extremely low-cost plastic substrates.

Research at the UA could one day lead to photovoltaic materials thin enough, flexible enough and inexpensive enough to go not only on rooftops but in windows, outdoor awnings and even clothing.

On a 104-degree Friday in July when sunlight bathed The University of Arizona campus, doctoral student Dio Placencia sat before a noisy vacuum chamber in the Chemical Sciences Building trying to advance the renewable energy revolution.

As a member of UA professor Neal R. Armstrong's research group, Placencia conducts research aimed at creating a thin, flexible organic solar cell that could power a tent or keep a car charged between trips to work and back home again.

He's passionate about renewable energy and says it's a waste that so little solar has been incorporated into society. "I have a little flat panel that I walk around with," Placencia said. "I usually put that on my backpack, and I charge my cell phone when I'm walking to school."

The sun is clean and free. "Here it is," he said. "Why not use it?"

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Playing Project Sage: Energy Frontier Research Center Develops New Solar Cells. Video credit: University of Arizona

Across the University, professors, researchers, students and others involved in policy planning and economic analysis are working to make that question moot. In a region noted for abundant sunlight, they are chipping away at problems like how to employ solar at the utility-generating plant level, how to harness it to charge the newly indispensable products of the day - cell phones, MP3 players, laptops - what to do at night and when clouds halt the energy giveaway from the sky.

The research proceeds in labs amid state-of-the-art equipment funded by multimillion-dollar federal grants. It's the product of students' hunches and long careers spent unlocking the mysteries of science. Along the way, students are being immersed in a nascent industry that many hope will be the economic engine of the next decade.

"Looking at renewable energy is a perfect place to emphasize that we don't know where the next breakthrough is going to be," said Leslie P. Tolbert, UA vice president for research, graduate studies and economic development. "Somewhere in a lab someplace, there's somebody figuring out a whole new way to capture sunlight. In fact, there are many people doing that. And even they are depending on knowing that there is, behind them, a cadre of basic science researchers producing new information that will feed their thoughts."

Armstrong, a professor of chemistry and optical sciences at the UA, occasionally teaches freshman chemistry. He decided one day near the end of the semester to try to make the material even more relevant. "I said to myself, well, lithium ion batteries in my cell phone, in my iPod," - his daughter had given him one - "I wonder how much coal we burn to charge those guys up at the end of the day. Because that's one of the big drivers for portable power, to get all this stuff off the grid." After making some very conservative calculations, he arrived at an answer, which he shared with the class: "You burn about a quarter of a pound of coal per charge of your lithium ion battery, and you generate about half a pound of CO2 per charge, per battery, per day .... The room got really quiet."

The next time, he intends to calculate how much coal is burned per Twitter tweet.

"It really is chilling," Armstrong said. "You start doing the math and thinking about the number of consumer electronic devices that you and I have added to our lives in the last decade that I charge up typically once every night - my laptop computer and my cell phone. Then you start thinking about, 'What if I do buy an electric car, and I come home at night and plug that sucker in,' and you do the same thing. We'll shut this grid down in no time."

In April, the U.S. Department of Energy announced it was funding Armstrong's Center for Interface Science as one of 46 Energy Frontier Research Centers. The mission of these centers, which will receive $2 million to $5 million a year for five years, is "to address current fundamental scientific roadblocks to clean energy and energy security," according to the DOE.

Ever since Armstrong was a graduate student during the first Arab oil embargo in 1973, he's experienced a succession of government distress calls over energy. One such emergency led him to discover the work of Heinz Gerischer and Frank Willig in Germany. They had figured out how to adsorb dye molecules to the surface of oxides and split water with light from the sun. "I thought, ‘That's it. That's what I'm going to do my career on.'"

A poster developed by Neal Armstrong's research group on how to make a generation 3 solar cells.

He moved to the UA in 1978, attracted by a program in photo-thermal solar energy conversion. In the 1980s, with gas cheap and plentiful again, solar went back on the back burner.

The next call came about four years ago. "DOE was beginning to sense that the tides were about to shift again, big-time," Armstrong said. "And they were really concerned that they didn't know what to do - how to present this to Congress in a way that would lead to new funding and which would have a rationale associated with it so that by the middle of this century we had someplace to go."

Armstrong realized it was time to come back to the problem that he wanted to work on 30 years before. "This time, we were really well-equipped," he said. "We've learned how to image molecules at the molecular level, we've learned how to measure energies of incredibly thin films, we've learned how to make devices, we've collaborated with physicists and material sciences and that sort of thing, we've done a lot of interesting other stuff and I suddenly realized I could bring it all back together here."

In his office, he displays a sample of his work: a 1-inch square of glass on which is deposited a thin film of indium tin oxide, a conducting transparent oxide commonly found in display technologies like computer screens. On top of that is a thin film of organic dyes. The last layer is an aluminum electrode.

"You'd have a roll of plastic with these cells laid out on it," he explained. "The idea is for you to go to Target or something like that and buy this roll of plastic and roll it out. It's got two wires connected to it, and you plug in your battery or your laptop and charge it up."

"The grand total in terms of the thickness is about 400 nanometers, which is one ten-thousandth the thickness of a human hair. And yet, shine a light on it and you get electricity out of it. Now we'd like it to be a bit thicker. We have to keep them thin in order to get all of the electrical charge out of the device. But if you think about this as a sandwich structure, we've made this incredibly thin sandwich and then each of the layers in contact with each other have to be just right in terms of the chemical composition, the orientation of the molecules, how well they adhere to each of the underlying surfaces. And if I go in and change just one molecule layer, the composition - that's at the level of 1 nanometer in thickness - I can take a good device and turn it into a bad device; I can take a bad device and turn it into a good device. That's the kind of level of control that we need. And we don't fully understand it."

But the equipment available now - optical microscopes capable of imaging individual molecules and revealing their electrical properties and spatial orientation - are helping his team understand. His goal is to figure out how to have the molecules arrange themselves - every time - in a way to produce lots of electricity. "They have to all line up like little soldiers," he said.

"We have to give you a technology that is going to look like an ink, like a blue ink, that you can spray down on one of these surfaces and the molecules at the nanometer level are going to say, ‘OK, we're going to get organized this way,' and in doing so, when I put that top electrode on and shine a light, I'll get lots and lots of electricity out of there," Armstrong said.

A high vacuum photoelectron spectrometer allows them to build each molecular layer, moving it within the vacuum to study it, and then continue with another molecular layer. Other tools, like a silicon microtip, which looks like a tiny phonograph needle, can be positioned to +/- 0.01 nanometers. "Well inside the diameter of a molecule," he said. Bouncing a laser off the back of the tip yields an image. Passing current through the tip, they can map the electrical properties of molecules. All this can help them build a template to create the ideal array of the molecule assemblies.

Erin Ratcliff joined the team as a postdoctoral electrochemist with a doctorate from Iowa State. "My background wasn't in at all," she said. "I had to come here and had to learn everything, where grad students get it from Day One at the UA."

She spoke of the business school curve, resembling a hockey stick, when progress begins to accelerate rapidly. "We're right at the magic moment when the hockey stick starts to take off, when you go from flat to hockey stick. We're right there. It's exciting to read the literature and hope that, yes, we will take off. It will be exciting to look back and say ‘I was there for that.'"

Provided by University of Arizona (news : web)

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User comments : 23

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otto1923
5 / 5 (1) Jul 23, 2009
How hard could it be, to develop thermoelectric materials which can use heat from the environment? I've heard some of the theories but I can imagine the potential disruption to strategic economies and research this could cause, which might mean it's being suppressed. We need grids and membranes under parking lots and roads, in building skin materials, under desert sand rather than above; anywhere that heat is.
Bob_Kob
3 / 5 (1) Jul 23, 2009
Cost to energy ratio is not great enough.
Lord_jag
not rated yet Jul 24, 2009
Not yet... The materials are cheap and the methods seem easy. When you can make a car covering for less than paint, it'll look like a great idea.
Soylent
4.7 / 5 (3) Jul 24, 2009
How hard could it be, to develop thermoelectric materials which can use heat from the environment?


Exceedingly so and any heat engine would need a cold sink as well in order to operate so you can't get rid of the plumbing.

It wouldn't be particularly disruptive even if you could do it, since you can't be guaranteed that you can have the energy when and where you want it and there's very little hope of storing it. What you end up with is mostly just burning a lot of natural gas.
RayCherry
not rated yet Jul 24, 2009
Solar; Wind; Water; Geothermic ... spread the research budgets around, but do not hold back money.
earls
5 / 5 (1) Jul 24, 2009
Yah, that's great, solar panels everywhere, coming out my rear, but guess what? Still no way to safely, cheaply, and weightlessly, store high density energy.

I guess the plan is that the energy will be constantly generated so that it doesn't need to be stored. Oh right, until the sun stops shining.

Someone needs to throw me a bone here, because I fail to realize how our "storage crisis" receives little to absolutely no consideration for the role it plays in our energy challenges.

Thermoelectrics hold great promise, unfortunately, their efficiency is even worse than solar panels right now, plus the additional challenges Soylent mentioned.
Icester
2.3 / 5 (3) Jul 24, 2009
earls> Shhhhh. You're going to let everyone in on the secret! Must not think about storage, only "being green." Storage is just a pesky little problem anyways, right?

I want someone to release a study that shows the environmental harm causes by the production of hybrid cars vs clean diesels vs economy gas cars. Also a study showing the environmental impact of payoff-time of these puny solar cells and other "green" solutions that people use.
eachus
not rated yet Jul 24, 2009
Storage is just a pesky little problem anyways, right?

Storage is a pesky little solved problem. I remember when the valves for the Bear Swamp pumped power plant were trucked through Williamstown MA, they had to reinforce several bridges along the route.

Any hydroelectric dam can also operate as a pumped power facility. Most though are just operated as peak power (as opposed to base power) plants. They save the water coming into the lake behind the dam to use for power when needed, rather than drawing the water level down constantly.

There is no risk of solar power catching up to the hydro-electric storage capacity anytime soon, especially as solar tends to provide power during peak demand for electricity anyway.
defunctdiety
not rated yet Jul 24, 2009
We need grids and membranes under parking lots and roads, in building skin materials, under desert sand rather than above; anywhere that heat is.


The problem is that this energy is so diffuse. The problem is concentrating that diffuse energy so that it is usable by our current grid. Storing (concentrating) it, as people above have indicated, is a problem, though it seems (and keep in mind I'm no electrical engineer when I say this) like it should be a fairly simple feat to develop mega-super-duper capacitors, or whatever... but apparently it's a big problem.

I fail to realize how our "storage crisis" receives little to absolutely no consideration for the role it plays in our energy challenges.


You're absolutely right, I hope it's not receiving little to no consideration, I hope we just don't hear about it because it's economically (capitalistically) very valuable research and so it's just not being bantered about so freely so as not to compromise a market share.

I want someone to release a study that shows the environmental harm causes by the production of hybrid cars vs clean diesels vs economy gas cars.


Icester, you missed earls' point entirely... The studies you want to see are completely moot points, especially in this conversation, which is about the viability of various sustainable energy "collection" methods due to the technological barriers in concentrating these diffuse energy sources and making them reliable.
earls
5 / 5 (2) Jul 24, 2009
"because it's economically (capitalistically) very valuable"

That's just it... In the long run it's not. When a car and/or home can sustain itself from "free" energy produced by natural means and stored in high capacity, the power and gasoline industries will tank.
defunctdiety
not rated yet Jul 24, 2009
That's just it... In the long run it's not. When a car and/or home can sustain itself from "free" energy produced by natural means and stored in high capacity, the power and gasoline industries will tank.


There's still plenty of capital in selling the "storage units" and maintaining them, and in charging cars which is a large source of continuous income, and not to mention if we could develop municipal sized ones where people would pay for energy use from it on a grid, just like a modern base-load or peaking plant.

Plus the gasoline industry will eventually tank anyway, and they know it's coming (better than we do), and when there's no more gasoline, it stands to reason that they would want to be the ones who provide the "next-gen" fuel.
earls
not rated yet Jul 24, 2009
You're a little to optimistic.

Superconducting rings will require little to no maintenance (assuming we won't have to cool them).

Cars will charge from the sun/wind/whatever just like the homes will. There will be no need to purchase energy to run your vehicle. "Free" energy generation is trivial.

Yes, the fuel industry is facing its demise very soon, but that doesn't mean they will not try to artificially sustain themselves beyond their natural life expectancy like the RIAA/MPAA via litigation or be "bailed out" by the Government like the auto and banking industries.

"Power to the people" is not something a capitalistic society wishes to embrace.
defunctdiety
not rated yet Jul 24, 2009
You're a little to optimistic.

Superconducting rings will require little to no maintenance (assuming we won't have to cool them).


I try to be optimistic, I've personally found pessimism seldom produces positive results. But I think your statements are reasonable as well, and I agree that our government/economy would try to prevent "free" energy.

However my only thought, is that whatever method of storage emerges (when combined with the energy gathering/generation) will certainly, at least initially, not be economical for every household to have it's own, self-contained system. It will most logically (in my mind) have a centralized entity behind it that provides initial capital and then charges others for it's continual use. As the technology is refined it may become available to individuals, but the powers-that-be would probably move to stop it from becoming widely available, somehow.
Riverbill
not rated yet Jul 24, 2009
If you look to government or money intersts to push something that will cause them to lose their grip, it's not going to happen. Energy systems need storage, just as nature does. Remember government and money are man made and will fail. Money seems to be OU but it is not. Power to the people.
otto1923
not rated yet Jul 24, 2009
@earls

Thermoelectrics hold great promise, unfortunately, their efficiency is even worse than solar panels right now, plus the additional challenges Soylent mentioned.
-Imagine a mesh rolled out under a roadbed for miles, like the wire mesh they use for reinforcement now. Direct heat-to-electric conversion, maybe charge or power car systems directly. Imagine square miles of mesh under desert sand, unseen, soaking up heat. Efficiency could be VERY low and still be practical. Latent heat is everywhere. This would be an extremely disruptive potential.
earls
not rated yet Jul 24, 2009
Brother, I'm a thermoelectric cheerleading whore. In fact, I don't really see a difference between thermoelectrics and solar panels myself. Both convert photons into electricity... Though I'm sure some expert physicist will be happy to slap the taste out of my mouth.

If your coldsink is near absolute zero, you could operate the thermo-solar-electric-cells even at night. The secret is to make sure that the cells are 100% efficent and the incoming photons don't warm your cold sink. Physically impossible? Probably. But as long as the incoming energy is greater than the energy it requires to cool the cells, you have winnar!
otto1923
not rated yet Jul 24, 2009
I remember the first time I read about superconductivity was in a Larry Niven 'Ringworld' novel. His cable things could conduct heat as well as electricity from one end to the other at lightspeed, no loss. I never understood if this was part of the general scientific understanding of superconductivity or what. Niven usually extrapolated from hard science. Anybody?
nkalanaga
5 / 5 (1) Jul 24, 2009
Yes, "old fashioned" superconductors conduct heat as well as electricity. Whether all of the new "high-temperature" varieties do I don't know. The only problem with using traditional superconductors for heat transfer is that they quit working if they warm up!
otto1923
4 / 5 (1) Jul 24, 2009
There was a scene in one of Niven's 'Ringworld' books where the main character put one end of this cable in a lake and sent the other end aloft. Heat drawn from the water caused clouds to form at the other end (my 30yo recollection) His super-thermo-conductor transferred photons with no resistance, as well as electrons. Was this a manifestation of an ideal room-temperature superconductor, or a combination of materials theories? Is there such a thing as a thermal superconductor? A 'heat pipe'? A 'fiberthermic'? One could envision a dendritic array or matrix to absorb IR photons to a converter-
otto1923
not rated yet Jul 24, 2009
-or actually, he used the lake as a heatsink and cooled the air around the other end to form condensation, is probably it-
nkalanaga
5 / 5 (1) Jul 24, 2009
He was using the lake as a heatsink, to absorb concentrated sunlight being used as a weapon. If you had a high-temperature superconductor, that could withstand the input temperature, yes, this would work. And, yes, it could be used as a "heat pipe", although for infrared it would probably be easier to convert it to electricity at the source, unless you needed the heat somewhere else. It would work better in hot solids or liquids, where there it's easier to get the energy to the fiber. An IR sensitive photovoltaic cell would would be easier to make for near infrared.
otto1923
not rated yet Jul 25, 2009
Right... those sunflower things. I was thinking nanofiber-coated 'fuzzy roots' or mesh. It was just an aside thought to the idea of direct heat-to-electric conversion materials. Removing heat from large areas, as in roofs or pavement, would tend to offset heatgain and the 'urban island' effect. Many LEED points for that, cool roofs, energy production, etc. An advantage to thermoelectrics is they would not need to be exposed to the elements, uv, vandals, environmentalists, etc.
otto1923
not rated yet Jul 25, 2009
You might even prefer black, low emissivity materials. I've wondered what all that re-irradiated sunlight might do to the atmosphere above. Better to find technologies which absorb and use, like green roofs. But then you gots tons of dirt on a roof you have to mow. Messy. Crude. Inelegant.