New Solar Cell Could Theoretically Be Pound-For-Pound 1,000 Times More Powerful Than Any Other

The two layers in the MIT team's modeled solar cell. (Credit: Jeffrey Grossman & Marco Bernardi)

The technological momentum in solar cells right now is aimed largely at pursuing greater efficiency. Most solar cells can convert 15 to 20 percent of the light energy that hits them into electricity, with most advanced hitting 30 percent. But researchers at MIT published a paper a few weeks ago exploring advancements in an alternative direction — instead of pursuing better light-to-electricity conversions, they’re looking into ways to create cells using fewer materials. While the process they’ve laid out would construct solar cells with only 1 or 2 percent efficiency, the cells would also be so incredibly thin that they could produce up to 1,000 times more energy per pound than conventional photovoltaic cells.

According to Jeffrey Grossman — the Carl Richard Soderberg Associate Professor of Power Engineering at MIT, who authored the paper along with Marco Bernardi, a postdoc in MIT’s Department of Materials Science, and Maurizia Palummo, a senior researcher visiting MIT from the University of Rome — the process uses nanotechnology to layer together a one-molecule thick sheet of graphene and a one-molecule-thick sheet of molybdenum disulfide. The resulting two-layer solar cell is only one nanometer, or one billionth of a meter, thick. Bernadi also added that stacking multiple sets of the two-layer cell on top of one another could possibly then boost the otherwise-low conversion efficiency.

For comparison, another ultra-thin solar cell in development right now by Alta Devices — which can hit 30 percent efficiency — is 1,000 time thicker at one micrometer (or micron). The Alta Devices cell is also more expensive to manufacture than traditional photovoltaics. By contrast, the MIT process would reduce costs through far less use of raw materials and by not requiring any use of purified silicon. Half the price of most solar panels today also comes from support structures and installation expenses, which would also be cut down by such thin and light cells. “It’s 20 to 50 times thinner than the thinnest solar cell that can be made today,” Grossman added. “You couldn’t make a solar cell any thinner.”

Surprisingly, the cells should be quite physically robust. Most solar cells have to be protected from the open air by heavy glass, but the MIT cells would be “essentially stable in air, under ultraviolet light, and in moisture,” according to Grossman. Between that and the cells’ incredibly light weight, applications in everything from aviation to the space industries and the military seem especially promising. Furthermore, there’s no inherent reason the process has to be limited to the materials MIT used, meaning there’s a wide range of alternatives and alternative combinations the new layering approach opens up for investigation.

The one (big) downside is that all of this so far exist purely in the realm of computer modeling — the MIT team has yet to produce an actual physical demonstration project. There are also no large scale methods for producing molybdenum disulfide and the other materials used in the process, meaning the ability to put together a practical manufacturing process is still a very long way off. It’s “an essential question,” Grossman admits. “But I think it’s a solvable problem.

(HT: Solar Love)

20 Responses to New Solar Cell Could Theoretically Be Pound-For-Pound 1,000 Times More Powerful Than Any Other

  1. catman306 says:

    Now if they can use these cells, or some new cell related in concept, to convert heat directly into electricity, the problem of thermal waste heat will be solved.

    Why can’t photo voltaic cells convert infrared photon radiation into usable electricity, that is, waste heat into usable energy?

  2. catman306 says:

    Ismael Balbuena’s link is about quantum biology where the quantum effects in photosynthesis are being researched.

    From reading Jeff’s article I also was wondering about the efficiency of plants.

    Quoted values sunlight-to-biomass efficiency

    Plants, typical 0.1%[2] 0.2–2%[3]
    Typical crop plants 1–2%[2]
    Sugarcane 7–8% peak[2][4]

  3. Mulga Mumblebrain says:

    I find the prospect of nanotechnology, driven, as ever, by the search for profit, to be a future menace of huge proportions. This would be marvelous news if not for the fear that nano-particles will eventually prove a pollution scourge along the lines of asbestos.

  4. WrenchMonkey says:

    “…the ability to put together a practical manufacturing process is still a very long way off.”

    We don’t have the time to wait for solutions that are “a very long way off”.

  5. Joe Romm says:

    We have solutions now. We need even more in the future!

  6. In an amplification to that statement, Joe, I would like to quote from Nassim Taleb’s Antifragility. “Post-event adaptation, no matter how fast, would always be a bit late.” Applied here, that means we need to start adapting now, if only the Republicans would allow us to pay for it.

    We can’t wait either for future needs to drive the development of new solutions. It will always be a bit too late.

  7. David Britt says:

    “The one (big) downside is that all of this so far exist purely in the realm of computer modeling”

    Are you kidding me?!? Talk about burying the lede. If every theory paper I ever read came true we would be living on hovercraft made out of phytoplankton powered by cold fusion. Honestly, I’m disappointed. I expect a lot from this blog, granted, but this is completely inappropriate.

    As someone who knows more than your average Joe about nanoscale fabrication, what this paper proposes is downright laughable from a synthesis perspective. Complete science fiction. Please ask them to model what kind of efficiency you get when you have overlapping, somewhat edge-oxidized layers of graphene with MoS2 layers of variable thickness and shunts everywhere. I don’t even want to think about how you would contact these layers electrically. I don’t know who Grossman talked to in order to decide that these problems are “solvable,” but whoever it was hasn’t done a lot of (any?) nanofab.

  8. Superman1 says:

    “We don’t have the time to wait for solutions that are “a very long way off”.” Absolutely correct! The lowest hanging fruit is demand; physically, it can be reduced overnight.

  9. Superman1 says:

    There are steps we can take today; eliminate all non-essential uses of fossil fuel as a starter.

  10. catman306 says:

    If you or I were King of the World, global climate disruption would have been solved decades ago with the world’s climates returning to what they were in the 70s. But we are not, and therein lies the problem. Nobody’s listening.

  11. Joan Savage says:

    Take at least a wiki look at what else might change if people embraced this new technology.

    I’m curious about the environmental consequences of thin film manufacturing, involving two lubricants, and the fate of the product and by-products over time.

  12. Gord says:

    I find the technology interesting from an R&D POV but I don’t see the advantage of developing a diffuse collector for a diffuse energy source.

    Interesting yes, practical, not really … we have lots of diffuse harvesting technologies already on line and working.

    What we need is a new source of concentrated energy production to take the place of carbon / uranium nuclear fueled generation.

    Think new power supplies for the cities to be built on the shores of the Arctic Ocean in support of the resource based “gold rush” over the next 100 years. No diffuse sources are available and with today’s technology, carbon based fuels would have to be shipped in. No pipelines are possible over 2000 km of melting permafrost.

    Think new power supplies for our existing cities being swapped out with clean ones.

    So bottom line … concentrated clean energy sources are required going forward.

    IMO using the weak force (fission based energy production) is the only way forward to achieve the required energy generation concentration. Uranium based anything is obsolete, dangerously complex, a proliferation nightmare, inefficient, and costly. Thorium based nukes? Who knows? We’ll see what China does in the next 15 years.

  13. Superman1 says:

    “using the weak force (fission based energy production)”. What specifically did you have in mind?

  14. rollin says:

    Pie in the sky with too little efficiency to be practical if it ever works. There are much better practical alternatives out there now.

  15. Gord says:

    Thorium LFTR technology is certainly one candidate. Some variation of Alvin Weinberg’s design from the 60’s maybe? China is investing heavily in developing this technology atm.

  16. fj says:

    Extreme light-weighting will likely be one of major methods for large scale reductions of our environmental footprint greatly facilitated by material science advances and commercialization after mid-century.

    For transportation, solutions exist now simply by designing vehicles small and light enough to be easily powered by human power.

  17. fj says:

    After 2050 it may be possible to fold these vehicles into a back pocket.

  18. ozajh says:

    I see the opportunity for a two-stage process in PV, similar to what happened in the 19th century with rail in the U.S. (but NOT in the U.K., where many of the early lines were overbuilt and hence over-capitalised).

    In the first stage, get something built and the infrastructure in place. Use the cheapest cells that give an acceptable ROI.

    In the second stage, retrofit more efficient cells into the existing infrastructure. In the very long term you’re going to want to have the highest efficiency economically possible to maximise the ultimate limiting resource (sunlight).

  19. Mulga Mumblebrain says:

    Sunlight ‘limiting’. Not really. Pretty nearly infinite, for our future purposes.