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Thread: How Graphene Can Better Harness The Sun's Energy

  1. #1 How Graphene Can Better Harness The Sun's Energy 
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    Combining wonder material graphene with other stunning one-atom thick materials could create the next generation of solar cells and optoelectronic devices, scientists have revealed

    University of Manchester
    and National University of Singapore researchers have shown how building multi-layered heterostructures in a three-dimensional stack can produce an exciting physical phenomenon exploring new electronic devices.

    The breakthrough, published in Science, could lead to electric energy that runs entire buildings generated by sunlight absorbed by its exposed walls; the energy can be used at will to change the transparency and reflectivity of fixtures and windows depending on environmental conditions, such as temperature and brightness.

    The isolation of graphene, by University of Manchester Nobel Laureates Professor Andre Geim and Professor Kostya Novoselov in 2004, led to the discovery of the whole new family of one-atom-thick materials.

    Graphene is the world’s thinnest, strongest and most conductive material, and has the potential to revolutionise a huge number of diverse applications; from smartphones and ultrafast broadband to drug delivery and computer chips.

    Collectively, such 2D crystals demonstrate a vast range of superlative properties: from conductive to insulating, from opaque to transparent. Every new layer in these stacks adds exciting new functions, so the heterostructures are ideal for creating novel, multifunctional devices.

    One plus one is greater than two – the combinations of 2D crystals allow researchers to achieve functionality not available from any of the individual materials.

    The Manchester and Singapore researchers expanded the functionality of these heterostructures to optoelectronics and photonics. By combining graphene with monolayers of transition metal dichalcogenides (TMDC), the researchers were able to created extremely sensitive and efficient photovoltaic devices. Such devices could potentially be used as ultrasensitive photodetectors or very efficient solar cells.

    In these devices, layers of TMDC were sandwiched between two layers of graphene, combining the exciting properties of both 2D crystals. TMDC layers act as very efficient light absorbers and graphene as a transparent conductive layer. This allows for further integration of such photovoltaic devices into more complex, more multifunctional heterostructures.

    Professor Novoselov said: “We are excited about the new physics and new opportunities which are brought to us by heterostructures based on 2D atomic crystals. The library of available 2D crystals is already quite rich, covering a large parameter space.

    “Such photoactive heterostructures add yet new possibilities, and pave the road for new types of experiments. As we create more and more complex heterostructures, so the functionalities of the devices will become richer, entering the realm of multifunctional devices.”

    University of Manchester researcher and lead author Dr Liam Britnell added: “It was impressive how quickly we passed from the idea of such photosensitive heterostructures to the working device. It worked practically from the very beginning and even the most unoptimised structures showed very respectable characteristics”

    Professor Antonio Castro Neto, Director of the Graphene Research Centre at the National University of Singapore added: “We were able to identify the ideal combination of materials: very photosensitive TMDC and optically transparent and conductive graphene, which collectively create a very efficient photovoltaic device.

    “We are sure that as we research more into the area of 2D atomic crystals we will be able to identify more of such complimentary materials and create more complex heterostructures with multiple functionalities. This is really an open field and we will explore it.”

    Dr Cinzia Casiraghi, from The University of Manchester, added: “Photosensitive heterostructures would open a way for other heterostructures with new functionalities. Also, in future we plan for cheaper and more efficient heterostructure for photovoltaic applications.”


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    I am genuinely surprised that no-one else has responded yet. The potential breadth of possibilities is jaw-dropping. Super-efficient solar panels and opto-electronic devices. For goodness sake, surely we are, as a human collective, crying out for renewable energy resources.

    However, what has not been mentioned yet is the portability and cost of graphene solar energy devices and the ease with which these devices can be adapted for domestic needs. I suppose location on the Earth is also an important factor. Any clues on cost?


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    I can't wait to see if these get applied to the recently developed solar plane designs.
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    Personally, I'm more interested in using grapene to construct supercapacitors that can store .16 megajoules per volt/gram (current design limit is 400 farad per gram). They can also discharge 1000 or so times faster than L-ion batteries.
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    I think it's interesting that graphene solar cells seem to be able to absorb photons in near infrared - although less energetic and producing less energy, if I understand correctly it should offer some potential for a heat to electricity conversion - which would have potential for making use of low grade heat, from atmospheric and ground radiation (night time) or for thermal energy storage. Graphene already shows potential for improving energy storage devices, including Li-ion.

    Unknowable - do you have a link for the use of graphene for supercapacitors?
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    https://www.youtube.com/watch?v=NPResi9p5uU
    A basic overview, though the sound is a bit distorted.

    Graphene supercapacitors are 20 times as powerful, can be made with a DVD burner | ExtremeTech
    about how they can be made and how good they are.

    Can't remember where I heard that they were 400 farad per gram (theoretical limit something like 550 farad/gram).

    We might even be able to use them in L-ion batteries to make them better, but I don't know of a page for that.

    Also, scientists have already built an infrared PV cell:
    http://phys.org/news188637189.html
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    Thanks for the links - interesting.

    It seems there is still lots of room yet for discovery and innovation when it comes to energy storage as well as for better, cheaper PV; a bit of a worry that energy storage is held up as the biggest impediment to renewable energy yet it remains a low R&D priority. If it get's a fraction of the funding that unlikely to ever be cost competitive technologies like Carbon Capture and Sequestration or fusion power I'd be surprised.

    Here's a link to another new material for improved supercapacitors - little detail unfortunately.

    I don't know if there's been much recent progress - the public are rarely kept informed of ongoing efforts - but I think nantennas have enormous potential, including for the use of lower grade heat via IR being converted to electricity. I don't think the value of being able to harvest IR should be underestimated for both reducing energy waste as well as for thermal energy storage systems.
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    Quote Originally Posted by jimmythesaint View Post
    I am genuinely surprised that no-one else has responded yet. The potential breadth of possibilities is jaw-dropping. Super-efficient solar panels and opto-electronic devices. For goodness sake, surely we are, as a human collective, crying out for renewable energy resources.
    I'd say mass storage is a lot more important...even if we had cheap 90%+ efficient broad spectrum solar panels--they'd still have rather limited utility because we lack effective means to store the power, nor the electrical infrastructure to shunt power around across the nations depending on availability of that renewable source.
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    Disappointing that large scale energy storage, even now, is not a high R&D priority - but I don't think it's a matter of can't be done or even can't be done at reasonable cost, but that, even now, the need hasn't become that pressing. Certainly the energy companies that currently put more effort into ensuring their business model is maintained, irrespective of the climate costs have little desire to invest in efforts to develop and deploy large scale energy storage when there is still so much room to skew the political system to keep the regulatory regime favoring BAU.

    But I don't think large scale storage is rocket surgery or requires technologies that don't exist or can't be adapted; like Isentropic's pumped heat energy storage system, that is currently claiming lower costs than pumped hydro without the climatic and geographic constraints.

    It's transport that most needs the technological innovation and, by the look of the continuing advances and discoveries - graphene tripling LiIon capacity here, 10x there, dramatically better supercapacitor dielectric materials somewhere else, etc - leaves me thinking that none of these problems are beyond solutions. The biggest problems remain the incumbent advantages of existing fossil fuel plants and the free ride they continue to get with respect to defraying the accumulating external health, environmental and climate costs onto future consumers.
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    Quote Originally Posted by Ken Fabos View Post
    Disappointing that large scale energy storage, even now, is not a high R&D priority - but I don't think it's a matter of can't be done or even The biggest problems remain the incumbent advantages of existing fossil fuel plants and the free ride they continue to get with respect to defraying the accumulating external health, environmental and climate costs onto future consumers.
    When cleaner sources of power are competitive price-wise, they will take over simply because they ARE cleaner. I'm guessing the IR PV cells will help with it. They will make nuclear, geothermal, and CPV far more efficient. Fossil fuels will become more efficient too, making them produce more energy with less fuel use.
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    Wind and Solar are already competitive price wise, just not 24/7 yet. That "not 24/7 yet" should be reason for enormous optimism because the electricity industry line was that they would never be competitive, not ever. Those players, unfortunately and irresponsibly, want that "not 24/7 yet" to be reason for such pessimism about adapting to distributed and intermittent energy that they are exempted from doing anything more profound than making electricity with fossil fuels a bit more efficiently. Yet it's not unreasonable (in a place like Australia and much of the world at least) to foresee that storage and distribution of cheap PV solar that's on every roof will be as much the core business of future energy companies as energy production by whatever means.

    I think the difficulty and cost of large scale storage is exaggerated and won't impoverish anyone - but failure to develop it and invest in it ahead of the predictable crunch can ensure that an exaggerated problem ends up as bad as they say. I don't think they should be rewarded for that failure by being given an ongoing license to dump more CO2 into the atmosphere than the climate system can bear.
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    According to wikipedia (Cost of electricity by source - Wikipedia, the free encyclopedia) only geothermal, wind and hydro can compete in terms of cost per mwh. Solar is more expensive than even coal with Carbon capture systems, which greatly increases cost. Maybe with Graphene and new manufacturing techniques, though, they can produce more energy and will be cheaper. Though most of that cost seems to be because of the low capacity factor.
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    TheUnknowable - I actually had in mind the varying spot prices for electricity, where PV is replacing peak wholesale priced electricity from other sources - and that used to be a bit of high value profitable icing on the cake for generators able to ramp up and down quickly enough to take advantage of it. The electricity market, developed for the advantage of existing generators actually helps make PV more commercially viable in the daytime supply market. In Australia rooftop solar, subsidised by government schemes as well as by home owner spending choices, is already affecting daytime demand for coal and gas power. Where both wind and solar have a lot of penetration - South Australia - they are forcing coal plants to close and forcing wholesale electricity prices down.


    I think we will see that window for solar grow from shaving the peak off daytime peak demand. As penetration begins to really require storage we will see it start being an element of energy network infrastructure investment. Batteries at the domestic level seem inevitable - like these systems developed in Europe to hold daytime excess solar though the evening peak and smooth the daily supply/demand cycle. In Europe this is for the benefit of the whole network. In Australia we would use this with grid tied systems to prevent gouging of grid tied PV suppliers by unfair pricing arrangements. Too expensive at this point but they will get cheaper.

    Utility scale storage requires the major incumbent energy companies to lead the way - here it appears they are betting all their money and our futures on a political system being unwilling to make them do so. But having an electricity sector that actually wants a low emissions future and works to facilitate it would deliver more and quicker than any specific technological advancements.
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    Thank you for the good writeup. It in fact was a amusement account it. Look advanced to far added agreeable from you! By the way, how could we communicate?
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    Quote Originally Posted by kittyshen2013 View Post
    Thank you for the good writeup. It in fact was a amusement account it. Look advanced to far added agreeable from you! By the way, how could we communicate?
    I'm thinking probably not English...
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    Quote Originally Posted by Ken Fabos View Post
    TheUnknowable - I actually had in mind the varying spot prices for electricity, where PV is replacing peak wholesale priced electricity from other sources - and that used to be a bit of high value profitable icing on the cake for generators able to ramp up and down quickly enough to take advantage of it. The electricity market, developed for the advantage of existing generators actually helps make PV more commercially viable in the daytime supply market. In Australia rooftop solar, subsidised by government schemes as well as by home owner spending choices, is already affecting daytime demand for coal and gas power. Where both wind and solar have a lot of penetration - South Australia - they are forcing coal plants to close and forcing wholesale electricity prices down.


    I think we will see that window for solar grow from shaving the peak off daytime peak demand. As penetration begins to really require storage we will see it start being an element of energy network infrastructure investment. Batteries at the domestic level seem inevitable - like these systems developed in Europe to hold daytime excess solar though the evening peak and smooth the daily supply/demand cycle. In Europe this is for the benefit of the whole network. In Australia we would use this with grid tied systems to prevent gouging of grid tied PV suppliers by unfair pricing arrangements. Too expensive at this point but they will get cheaper.

    Utility scale storage requires the major incumbent energy companies to lead the way - here it appears they are betting all their money and our futures on a political system being unwilling to make them do so. But having an electricity sector that actually wants a low emissions future and works to facilitate it would deliver more and quicker than any specific technological advancements.
    1) Is the price still decreasing when you count the overall effect the policies have on the economy, such as loss of coal jobs, increased taxes, etc.?
    2) BP Alternative Energy - Solar power BP is making solar, wind, and other, alternative forms of power.
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