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Scientists Design Solar Cell That Captures Nearly All Energy of Solar Spectrum
- adamwong246 9y agoI always wondered why we did not just use prisms to separate the different wavelengths, then capturing selections of the spectrum with a variety of simpler, unstacked panels. Perhaps one could even deflect the infrared into a more conventional, presumably more efficient, heat collector while the higher frequencies are directed to true photovoltaics.
- maxerickson 9y agoPeople with excess roof space (and whatever other space) look at cost before they look at efficiency. Half the roof here would provide plenty of power, the problem is that it would be expensive.
- klodolph 9y agoThink of how solar is an investment: you pay money up front, use up a certain chunk of land, and you get energy over the next 25 years. Imagine panel A which costs $100 and has 22% efficiency, versus panel B which costs $500 and has 30% efficiency. No point in buying panel B, since you can buy 5x panel A for the same price.
- jcbrand 9y agoBut then you'd also need to cover 5 times the area, and land also costs money.
- mikepurvis 9y agoI'm doubtful that land area is really a significant cost for most solar installations. Small ones go on rooftops that people already have, and large ones go on marginal land in the middle of nowhere that's cheap. If there's someone with knowledge of the numbers, I'd be interested to be shown otherwise.
- philipkglass 9y agoYou are correct. "Small" utility-scale solar projects of 1-20 MW capacity take 7.6 acres of land per megawatt-peak, for fixed-tilt ground mount systems: http://www.renewableenergyworld.com/articles/2013/08/calculating-solar-energys-land-use-footprint.html http://www.renewableenergyworld.com/articles/2013/08/calcula... Fixed-tilt utility scale systems just recently fell to $0.99 per watt-peak in the US: https://www.greentechmedia.com/articles/read/Sunshot-1-Per-Watt-Solar-Cost-Goal-Mission-Accomplished-Years-Ahead-of-S https://www.greentechmedia.com/articles/read/Sunshot-1-Per-W... You can buy 124 acres of land in California's sunny Imperial County, near existing solar farms, for $95,000: http://www.landwatch.com/Imperial-County-California-Land-for-sale/pid/3446602 http://www.landwatch.com/Imperial-County-California-Land-for... If you turned that land into a solar farm you could fit about 16 megawatts of fixed-tilt solar arrays on it. 16 MWp of installed solar equipment would cost $15.84 million at $0.99/watt and the land is $0.095 million. Land accounts for only 0.6% of the combined costs. (A 16 MWp farm is small by utility-scale project standards and probably would not cost only $0.99/watt because of dis-economies of small scale. I cited $0.99/watt to set a conservative bound on how much cost the land component represents in a utility scale solar project.)
- chriswarbo 9y agoIf the cost is right, land won't be an issue. If solar tech were cheap and rugged enough, it could be added to paint, tarmac, billboards and many other artificial surfaces, even at very low efficiency. I've seen work in this direction with organic molecules (i.e. plastics).
- klodolph 9y agoI'm not optimistic about solar power being added to paint, tarmac, or just wherever you want. See for example the dumpster fire that is Solar Roadways. At this point, there's enough land / rooftops for proper PV installations that easily last decades, so trying to shoehorn fragile PV in places where it has to withstand daily abuse, like tarmac, stinks of bad engineering. Maybe that will change, but it doesn't need to change, because we still have plenty of places to stick solar.
- chriswarbo 9y agoYes, to be clear I didn't mean the sort of rigid, silicon/glass PV panels we have right now; and solar roadways is evidence enough that it would be a bad idea. I meant something more like a polymer, bought by the bucketful and mixed in as an additive.
- tedsanders 9y agoAs usual, cost is the issue. Both the cost of the optics, the cost of tracking, the cost of imperfect tracking, and the cost of the complexity in the design and installation. I know some academic research labs have looked into arrays of microlenses & prisms, which sound interesting, but I haven't heard of any commercial products. Googling for micro prisms and solar cells will show you some projects. Ultimately, I think it's just much easier to install a simple rectangular slab with two wires coming out. And the costs of solar cells are so cheap that they're probably comparable to the cost of the optics you'd want to lay above them. I also imagine that balancing the current-voltage characteristics of the cells could be challenging when light at different times of the day has different spectra (e.g., you wouldn't want diminished performance in reddish sunsets).
- gene-h 9y agoThis approach has been tried before and was used to make a solar cell with record efficiency[0]. This approach might be needed to get up to 50% efficiency. [0]http://www.electronicproducts.com/Sustainable/Solar/Prism_device_helps_scientists_break_solar_efficiency_record.aspx http://www.electronicproducts.com/Sustainable/Solar/Prism_de...
- meri_dian 9y ago>"This particular solar cell is very expensive, however researchers believe it was important to show the upper limit of what is possible in terms of efficiency. Despite the current costs of the materials involved, the technique used to create the cells shows much promise. Eventually a similar product may be brought to market, enabled by cost reductions from very high solar concentration levels and technology to recycle the expensive growth substrates." We will end our reliance on fossil fuels not by forcing masses of people to change their lifestyles and inconveniencing them, but by developing green energy tech that is simply more efficient and cost effective than fossil fuels. Once this happens the transition away from carbon based energy sources will be swift. Given the rate of progress, I believe we'll see widespread adoption of renewable energy far before climactic conditions on earth become dire for humanity.
- vkou 9y agoWhen do you think we will reach 1/10th of our current GHG emissions? 2020? 2030? 2040? 2050? 2100? Plus or minus five years? Will we have a linear decline to that level? When do you think that decline will start? Is there a particular model you're thinking of? What degree of GHG concentrations/temperature increase will be the limit of what you consider to be 'not dire for humanity'? Is it compatible with your expected model of GHG emissions? Are the billion people living in the Indian subcontinent included in your definition of humanity, or are we talking about North Americans and Europeans? If yes, will we be willing to shelter environmental refugees from impacted areas? I'd really love to believe that everything will turn out fine - but while I've ran into many optimists, I've yet to run into one that is willing to quantify the reasons for their optimism.
- guimarin 9y ago10% -> 2025; 20% -> 2030; 50% -> 2040; 95% -> 2050. India/Africa are included there. I think 95% of potential GHG emmissions (not just indexed to today but to 'present time') will be crossed in like 2060 or so. Renewables are going extremely quickly. we are in the steep part of the s-curve and there is no reason to believe we wont' get a few doublings due to battery cost decreases and deployed solar cost efficiencies. The transition will be a lot faster than ppl believe.
- afeezaziz 9y agoIf the process to make this kind of solar cell can be lowered enough through scale then they should communicate this process to Chinese solar companies. I am sorry for my poor understanding of chemical process; if the materials of the solar cell are roughly the same then it would be quite easy for the existing manufacturers to actually switch to this solar cell production. I cannot wait for the era of super cheap electricity!
- rini17 9y agoSwitching manufacturing from silicon would not be easy, likely this needs whole new process from scratch. Also, as the article notes, they won't be available in large sheets but only small milimeter chips - which require light concentration and thus sun-tracking mechanism.
- wavefunction 9y agoWhy should research funded by American taxpayers be transferred to Chinese solar cell producers, and by whom? I hope an American firm implements the underlying science into a manufacturing process, and any Chinese firms that want to use the process pay a fair and equitable license for the technology.
- zAy0LfpBZLC8mAC 9y ago> Why should research funded by American taxpayers be transferred to Chinese solar cell producers, and by whom? Because Americans live in the atmosphere that Chinese CO2 emissions go to? Not saying they should, but that would obviously be the reason?
- wavefunction 9y agoWell, I'm in favor of technological spread across the world, especially when it's beneficial to the environment or society at large. However, Chinese solar cell firms have been dumping cheap and sub-standard solar panels on America for years in an attempt to destroy the American industry, so I am less excited about specifically Chinese solar panel firms gaining access to this technology. I suppose it marks me as a bit of a chauvinist in this case but I would prefer if those who conduct themselves as adversaries do not also enjoy the benefits accorded a friend.
- Gys 9y ago'The new design converts direct sunlight to electricity with 44.5 percent efficiency, giving it the potential to become the most efficient solar cell in the world.'
- sbierwagen 9y agoNote careful use of "potential" there. Fraunhofer hit 46% two years ago with a four-junction cell: https://www.nrel.gov/pv/assets/images/efficiency-chart.png https://www.nrel.gov/pv/assets/images/efficiency-chart.png
- londons_explore 9y agoit's sad that nothing more has been published on that architecture for 2+ years... One would imagine most of the research dollars being into how to make multi-junction cells cheaply, rather than into other much lower efficiency cells.
- sbierwagen 9y ago"The only figure of merit in a PV system is cost per kilowatt-hour installed". Multijunction cells require concentrating panels and two-axis tracking. In order for them to make economic sense, both the panels and the tracking have to have lower lifetime costs than standard untracked panels. So far, they don't. Plus, concentrating panels don't work under cloudy skies, so...
- ZenoArrow 9y ago> "In order for them to make economic sense, both the panels and the tracking have to have lower lifetime costs than standard untracked panels." Is this the problem that Insolight have a potential solution for? https://insolight.ch/ https://insolight.ch/
- sbierwagen 9y agoWe'll know as soon as they put product pricing on their site.
- sbierwagen 9y agoAs usual with press releases, this pretends there is no prior art. Of course, stacking solar cells to increase efficiency has been a thing for five decades: https://en.wikipedia.org/wiki/Multi-junction_solar_cell https://en.wikipedia.org/wiki/Multi-junction_solar_cell
- ndonnellan 9y agoYep, see 40% cells used 4 years ago in http://www.businesswire.com/news/home/20130426005162/en/Amonix-Achieves-World-Record-PV-Module-Efficiency http://www.businesswire.com/news/home/20130426005162/en/Amon... (36% eff in practical application due to system losses)
- k__ 9y agoNice. What's the maximum? What's the current standard?
- hwillis 9y agoMax so far is 46%[1], max theoretical is 86.8%[2] Most solar panels are 15% or better. The best residential cells are 22.2%[3], the commercial cells are 25.3%. The theoretical maximum efficiency of single-layer silicon PV cells is ~32%. [1]: https://www.nrel.gov/pv/assets/images/efficiency-chart.png https://www.nrel.gov/pv/assets/images/efficiency-chart.png [2]: https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limit https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limi... [3]: https://us.sunpower.com/sites/sunpower/files/media-library/data-sheets/ds-x22-series-360-residential-solar-panels.pdf https://us.sunpower.com/sites/sunpower/files/media-library/d...
- schoen 9y agoThat's awesome. I remember always hearing 10% when I was a kid, which looks about right on that first chart, assuming it takes a few years before things are commercialized. It's terrific to see the march of improvements in efficiency.
- 9y ago
- philipkglass 9y agoThe abstract is more informative than the press coverage: http://onlinelibrary.wiley.com/doi/10.1002/aenm.201700345/abstract http://onlinelibrary.wiley.com/doi/10.1002/aenm.201700345/ab... The cell is assembled in a mini-module with a geometric concentration ratio of 744 suns on a two-axis tracking system and demonstrated a combined module efficiency of 41.2%, measured outdoors in Durham, NC. Taking into account the measured transmission of the optics gives an implied cell efficiency of 44.5%. Since this is a concentrating cell, compare to the concentrator cell records tracked on NREL's PV efficiency records chart: https://www.nrel.gov/pv/assets/images/efficiency-chart.png https://www.nrel.gov/pv/assets/images/efficiency-chart.png The current record for 4-junction-or-more concentrator cells is 46.0%. This isn't a record-setting cell even if the implied efficiency holds up under standardized test conditions. This cell like all high-concentration cells is unlikely to see mass market acceptance on Earth. The module needs precise two-axis sun tracking to work effectively even under perfect clear-sky conditions. That's significantly more expensive than fixed arrays or single-axis sun tracking as used by conventional large scale PV. And there's a vicious feedback loop: since two-axis tracking is significantly more expensive, it doesn't get developed/scaled, so the cost gap gets even wider over time WRT its competitors. But that's not actually the worst problem of high-concentration PV for terrestrial use. The worst problem is that HCPV can use only direct normal irradiance. Ordinary non-concentrating PV cells produce very nearly 25% of its rated output if it receives 25% of test-condition illumination under non-ideal conditions (due to some combination of clouds, air pollution haze, dusty glass, etc.) Concentrating cells will produce close to 0% of rated output under the same non-ideal conditions. Few regions have clear enough skies to work with HCPV, but those same regions tend to be dusty, which the concentrating optics cannot tolerate. Mechanical and optical complications make HCPV higher-maintenance than ordinary flat PV and more expensive to install initially. That's why there were a dozen+ companies working on concentrating PV in 2008 and all of them are now bankrupt or have exited HCPV manufacturing. Eking out another cell-level improvement wouldn't have rescued the value proposition of their complete systems. The refined polysilicon price spike that made exotic technologies look briefly promising only lasted a few years and then it became clear again that crystalline silicon is very hard to beat.
- mark-r 9y agoI wonder if it wouldn't have more luck in outer space applications? Perhaps not if the optics add much weight for the amount of power produced.
- matt_wulfeck 9y agoI just had my panels turned on. I love solar. It's still difficult to justify it short-term on a cost-basis, but I'm saving about a dollar a day after all things are said and done. That being said, I'm generating my own electricity and my panels will run for a very long time. The best is cranking the AC and still watching the meter run in reverse during really scorching days.
- fred_is_fred 9y agoWhat the NPV and pay-off time of your system? I've been unable to get one bid here that's less than 10 years because electricity is fairly cheap here.
- matt_wulfeck 9y agoYes it's 10 years for me as well. Most of that is because we have a 30% efficiency hit because we didn't want to cut down a tree in our backyard that shades it for 2 hours a day during about 6 months of the year. Our system is also larger than our current usage, because we plan to use more (electric car, more kids, etc). Another benefit to think about is you've effectively locked in your electricity rate. With some companies that might not be a big thing, but here in CA PG&E has been relentless with their rising kwh costs.
- fred_is_fred 9y agoI pay on average about 10.3 cents per kwh and have a newer home that's very efficient at holding cool air (and live in a state where we heat more than we cool). For those reaons it's a tough sell for me. If rates continue to rise and solar continues to fall, we'll have a cross over that works for me probably in a few years.
- matt_wulfeck 9y agoIt's not cost competitive for you at 10 cents. Why bother? I'd kill for that kind of price in electricity. Our total cost with solar is around 13c per kwh over 20 years.
- marcgcombi 9y agoThis is great news! Hope they can get it to market ASAP! kudos to those whom worked on the project!
- vectorjohn 9y agoWhat is it that makes solar panels cost what they do, ultimately? Not materials, right? Those are all basically sand and other not so special things. Labor? Isn't it mostly automated? Upkeep of the factories? Input energy? Maybe it's just all those things together. But it sure seems like if we wanted to it wouldn't be that hard to ramp up production and drive costs down a couple fold. Not that I know how.
- MengerSponge 9y agoMy understanding is that the cost is dominated by panel interconnects and power inverters and whatnot, not by the silicon itself.
- cpsempek 9y agoNot that I know either, but the quality control process is possibly a source of much cost of production. Every part must pass a series of tests during and after production before deemed ready for sale. Every failure of a test costs time and money. These yield rates are either low with low cost manufacturing, or, high with high manufacturing costs. This could be part of it.
- cpsempek 9y agoNot that I know either, but the quality control process is possibly a source of much cost of production. Every part must pass a series of tests during and after production before deemed ready for sale. Every failure of a test costs time and money. These yield rates are either low with low cost manufacturing, or, high with high manufacturing costs. This could be part of it.
- philipkglass 9y agosand : solar farm :: iron ore : lawnmower That said, if you increase production scale you can expect module costs to fall significantly. That's what Chinese manufacturers have actually done: http://pubs.rsc.org/en/Content/ArticleLanding/2013/EE/c3ee40701b#!divAbstract http://pubs.rsc.org/en/Content/ArticleLanding/2013/EE/c3ee40... A lot of talk about solar trade has highlighted "unfair" competition from cheap, low-quality Chinese modules. But China also has companies making high-quality modules (LONGi, Jinko Solar, Yingli, and Trina Solar were identified as top performers in DNV GL's 2017 PV Module Reliability Scorecard, along with longer-established Japanese, Korean, European, and American manufacturers) and still making them cheaper than European/American/Japanese producers. The greatest difference is scale. Recently-bankrupt American solar manufacturer Suniva is trying to get the US International Trade Commission to impose a minimum $0.78/watt price on imported solar modules: https://www.eenews.net/stories/1060057180 https://www.eenews.net/stories/1060057180 https://www.pv-tech.org/news/breaking-suniva-asks-trump-for-78-cents-price-floor-on-imported-modules https://www.pv-tech.org/news/breaking-suniva-asks-trump-for-... Suniva made good modules. But it was manufacturing only 200 megawatts of modules per year. And its modules were not more efficient or durable than good imports. The large, high-quality South Korean manufacturer Hanwha Q CELLS is guiding 5500-5700 megawatts of shipments this year. The large, high-quality Chinese manufacturer Jinko Solar is guiding 8500-9000 megawatts this year. American solar manufacturers can't turn a profit so they don't scale up. And they don't scale up so they can't turn a profit. Jinko Solar and Hanwha can stay in the black at price levels that will bankrupt small producers lacking the same economies of scale.
- grandalf 9y agoWould these panels capture energy from the signal being radiated by my mobile phone? What about gamma rays? In other words, is a solar cell something that captures energy from photons and converts it into usable electricity? Or from some subset of photons?