Environment & Energy
Related: About this forumA trick of light: UC Irvine researchers turn silicon into direct bandgap semiconductor
https://news.uci.edu/2024/10/31/a-trick-of-light-uc-irvine-researchers-turn-silicon-into-direct-bandgap-semiconductor/A trick of light: UC Irvine researchers turn silicon into direct bandgap semiconductor
Discovery enables manufacturing of ultrathin solar panels, advanced optoelectronics
Irvine, Calif., Oct. 31, 2024 By creating a new way for light and matter to interact, researchers at the University of California, Irvine have enabled the manufacturing of ultrathin silicon solar cells that could help spread the energy-converting technology to a vast range of applications, including thermoelectric clothing and onboard vehicle and device charging.
Co-author Ara Apkarian, UC Irvine Distinguished Professor emeritus of chemistry, said: This phenomenon fundamentally changes how light interacts with matter. Traditionally, textbooks teach us about so-called vertical optical transitions, where a material absorbs light with the photon changing only the electrons energy state. However, momentum-enhanced photons can change both the energy and momentum states of electrons, unlocking new transition pathways we hadnt considered before. Figuratively speaking, we can tilt the textbook, as these photons enable diagonal transitions. This dramatically impacts a materials ability to absorb or emit light.
According to the researchers, the development creates an opportunity to exploit recent advances in semiconductor fabrication techniques at the sub-1.5-nanometer scale, which has the potential to affect photo-sensing and light-energy conversion technologies.
With the escalating effects of climate change, its more urgent than ever to shift from fossil fuels to renewable energy. Solar energy is key in this transition, yet the commercial solar cells we rely on are falling short, Potma said. Silicons poor ability to absorb light means that these cells require thick layers almost 200 micrometers of pure crystalline material to effectively capture sunlight. This not only drives up production costs but also limits efficiency due to increased charge carrier recombination. The thin-film solar cells that are one step closer to reality due to our research are widely seen as the solution to these challenges.
NNadir
(34,713 posts)...academic press releases.
These announcements are a dime a dozen, as useless as solar energy has been after trillions of dollars squandered on it.
If one enters photon, band, gap, solar, cells in Google Scholar, one gets 619,000 hits, 18,300 in 2024 alone.
Solar fantasies have failed to address the onset of extreme global heating through which we now live.
Making the world safe for natural gas's commercial interests is very different than safety for humanity.
OKIsItJustMe
(20,872 posts)An individual can put solar panels on a roof. They cannot install a fission reactor in their basement.
NNadir
(34,713 posts)...nuclear engineering. The community of nuclear engineers is on the front lines of fighting antinuclear ignorance, I assure anyone who asks that the science is seeing a resurgence, entering an era as dynamic as that described by the nuclear energy pioneer, Alvin Weinberg - the one time director at Oak Ridge National Laboratory - in his wonderful book, The First Nuclear Era. Nuclear engineering creativity is surging.
The data on China's 56 reactors built in this century is here:
China, Reactor Database
(They built one reactor in the 1990's.)
Note that the Chinese have 30 reactors under construction. They're putting them out as fast as the US did in the 1970's. I note that many of those reactors built in the US nearly 50 years ago, developed and engineered by some of the finest minds of their times, still are functioning and saving lives. I also note that those nuclear reactors were designed and built by engineers with slide rules, absent the computational power we now possess.
Apparently the Chinese do not hold the belief put forth by people who don't give a shit as to whether the extreme global heating we are now observing is not "too expensive," the external costs of fossil fuels, measured in millions of deaths each year is not "too expensive," but that nuclear energy is "too expensive."
But then again, in this country, which is competing with Afghanistan and the like to see which of them can be more ruled by ignorance, we have a cult of antinukes who have helped to leave the planetary atmosphere in ruins. In general, they're libertarian types, rugged individuals, Ayn Rand clones, that cooperative efforts involving high intelligence, education are inferior to home installed junk that will be rotting in 20 years, distributed all over the world.
I note that there are many people who would be clueless to be able to understand how to generate the solutions to the Bateman equations that are important in nuclear engineering, while any individual can log on to an antinuke website to get pablum to repeat. This in no way implies that the ability logging on to websites to get ignorant talking points is superior to being able to know how to solve the Bateman equations.
I'm very, very, very proud of my son, who regrettably now lives in a much worse world than the one into which his father was born. I have raised him to fight ignorance and chanting, and I've told him that it is an ethical imperative to put his fine mind to use in service to humanity. It is I believe, an ethical imperative for all people with the skills and intelligence to be engineers 0 not limited of course to nuclear engineers, but also applies to chemical engineers, electrical engineers, mechanical engineers, thermal engineers, and materials science engineers - to apply their skills for the betterment of humanity. (My son's summa cum laude undergraduate degree and his summa cum laude Masters degree are both in the latter, materials science, the perfect and critical topic for nuclear engineering, particularly if we wish to address the need to use nuclear heat to eliminate fossil fuels instead of just producing thermodynamically degraded electricity.)
Sadly, we are observing that ignorance often wins, as we are seeing now politically. I wish i could say that only right wingers are extremely ignorant, but my experience with antinukes on our end of the political spectrum, unhappily precludes me from doing so. We've seen in the long antinuclear era, a celebration and orgy of ignorance that has left the planet in flames, and regrettably, some came from the left, not the right. That is no reason to surrender to ignorance. We can change. We should change. For nuclear engineers on the front lines, the task is to get up, dust off, and fight again, to rebuild the intellectual skills and infrastructure destroyed by the antinuke cults. It's what my son and his colleagues are doing. They are printing reactor cores, something that would have been impossible in the 1970s. Their work is about saving what is left to save, and to restore that which might be restored. The breadth of the latter is shrinking, not growing, because, again, ignorance has won.
Thanks for sharing and give me the opportunity to counter the claim which I reject by appeal to numbers.
Have a nice evening.
OKIsItJustMe
(20,872 posts)By technology reporter James Purtill
Mon 15 Jul
In short:
China is installing record amounts of solar and wind, while scaling back once-ambitious plans for nuclear.
While Australia is falling behind its renewables installation targets, China may meet its end-of-2030 target by the end of this month, according to a report.
What's next?
Energy experts are looking to China, the world's largest emitter and once a climate villain, for lessons on how to rapidly decarbonise.
It's installing at least 10 gigawatts of wind and solar generation capacity every fortnight.
NNadir
(34,713 posts)The unit of energy is the Joule, not the Watt. Yet, most claims about how fast solar and wind junk is spread across industrial parks carved out of wilderness, deliberately treat unreliable solar and wind as the equivalent of nuclear power plants, the most reliable energy producing devices on the planet.
Personally I oppose short lived crap that spews microplastics into the atmosphere, but that's just me.
This may come as a surprise, but the capacity utilization of wind and solar is seldom more than 30%. It's widely reported and generally accepted that sunlight is available for only a part of the 24 hour day, and the wind doesn't blow continuously. For the other 70% of the time, advocates for solar and wind have no problem with burning fossil fuels. They just couldn't give a shit about fossil fuels, because, in fact, the use of solar and wind depends on them.
Evidence:
Nuclear powered France:
Coal burning antinuke hell, Germany:
These are annualized figures (2023) available at Electricity Map
The current graphic, as of this writing, 11/07/2024 9 pm EST (US) is particularly illustrative:
In "percent talk" it appears that the climate gas intensity of Germany is 1106% higher than that of France, not that I expect the fossil fuel coddling apologists for the trillion dollar solar and wind hype to give a rat's ass about that fact.
As for China building 500% more transitory solar and wind junk, I'm sure that I assumed to be gullible and stupid enough to not understand the difference between a peak Watt and a Joule, but I'm no longer offended by this dishonest slight of hand, although I am disturbed to see what this dishonest rhetoric has done to the planet, leaving it in flames. For the record, in my scientific environmental reading, a prodigiously observed habit I've embraced for decades, I fully understand that in every LCA (Life Cycle Analysis) paper, the lifetime of infrastructure is included. This shows, again and again, that the climate intensity of solar and wind energy, not to mention the mass and land intensity, do not, and never will, match nuclear energy for cleanliness and sustainability. In my opinion, solar and wind, lipstick on the fossil fuel pig. They are not, and never were, about preventing the extreme global heating now burning the planet.
As for lifetime, again, always included in LCA calculations:
China's nuclear reactors will be serving humanity a the dawn of the 22nd century approaches, if not well into it with refurbishing, well over half a century after every wind turbine blade and every solar cell on this planet will have been landfill, some of it quite toxic, for half a century.
Thanks for taking my mind off the political tragedy, by the way. I'm pleased with myself for adjusting my ignore list here to point, once again, to the difference between a Watt and a Joule. I feel slightly, but not entirely, better. On some level its disturbing that this distinction, between the Watt and the Joule, which should be covered in high school, still gets by, but offering a correction is a distraction from a dire reality, the worst being the collapse of the planetary atmosphere, followed by the disgusting practices of the American electorate.
Nevertheless, it's tiresome now, so I'll quit it; this late in the game there's no point to trying to address dogma.
Have a nice evening.
OKIsItJustMe
(20,872 posts)Thats simply wishful thinking on your part. I get it, you think the world should be powered by nuclear fission. Let go. The world doesnt agree.
https://www.iea.org/reports/renewables-2024/executive-summary
2030 forecast has two main drivers: solar PV and China
China is set to cement its position as the global renewables leader, accounting for 60% of the expansion in global capacity to 2030. The country is forecast to be home to every other megawatt of all renewable energy capacity installed worldwide in 2030, after surpassing its end-of-the-decade 1 200 GW target for solar PV and wind six years early. Since ending feed-in tariffs in 2020, China's cumulative solar PV capacity has almost quadrupled and wind capacity has doubled, driven by cost-competitiveness and supportive policies. China's success stems from comprehensive support for both large-scale and distributed renewables across all renewable technologies.
OKIsItJustMe
(20,872 posts)Chinas growing energy needs are increasingly met by renewables, natural gas and electricity. The scale of Chinas future electricity demand and the challenge of decarbonising the power supply help explain why global investment in electricity overtook that of oil and gas for the first time in 2016, and why electricity security is moving firmly up the policy agenda. That said, cost reductions for renewables are not sufficient on their own to secure efficient decarbonisation or reliable supply.
Between 2019 and 2024, China will account for 40% of global renewable capacity expansion, driven by improved system integration, lower curtailment rates and enhanced competitiveness of both solar PV and onshore wind. During the same period, China is forecast to account for almost half of global distributed PV growth, overtaking the EU to become the world leader in installed capacity by 2021. China is also set to lead global growth in biofuel production, given the rollout of ethanol blending in a growing number of provinces and increasing investments in production capacity.
However, Chinas coal demand and production capacity remain high. Currently, one of every four tons of coal used globally, is burned to produce electricity in China. The government is pushing for emissions reductions and improved air quality by switching to gas in industrial and residential sectors, but Chinas coal fleet is young, highly efficient and still ten times larger than its gas-fired fleet. At the prevailing gas prices, new onshore wind and solar photovoltaic (PV) are much cheaper ways to generate electricity than new combined-cycle gas turbines (CCGTs). Under these circumstances, the major contribution of gas-fired generation to displacing coal is likely to be an indirect one, by aiding the integration of renewables.
The policy challenge is to ensure sufficient investment in electricity networks and in a mix of generation technologies that are the best fit for power system needs. The latter can provide the flexibility that is increasingly vital as the contribution of wind and solar PV increases (reinforcing the links between electricity and gas security).
OKIsItJustMe
(20,872 posts)OKIsItJustMe
(20,872 posts)Why is solar PV important?
Solar photovoltaics (PV) is a very modular technology that can be manufactured in large plants, which creates economies of scale, but can also be deployed in very small quantities at a time. This allows for a wide range of applications, from small residential roof-top systems up to utility-scale power generation installations.
What is the role of solar PV in clean energy transitions?
Despite increases in investment costs due to rising commodity prices, utility-scale solar PV is the least costly option for new electricity generation in a significant majority of countries worldwide. Distributed solar PV, such as rooftop solar on buildings, is also set for faster growth because of higher retail electricity prices and growing policy support.
Where do we need to go?
The exceptional growth in PV deployment in recent years will need to continue and scale up to follow the Net Zero Emissions by 2050 Scenario, requiring continued policy ambition.
In 2023, solar PV alone accounted for three-quarters of renewable capacity additions worldwide
Renewable power capacity additions will continue to increase in the next five years, with solar PV and wind accounting for a record 96% of it because their generation costs are lower than for both fossil and non-fossil alternatives in most countries and policies continue to support them.
Solar PV and wind additions are forecast to more than double by 2028 compared with 2022, continuously breaking records over the forecast period to reach almost 710 GW.
2028 Hmmm how many nuclear plants can be deployed by then?
NNadir
(34,713 posts)I have in my electronic files almost every issue of the World Energy Outlook, and each year I use the data tables (which also contain soothsaying) for the most current issue in my posts. Here's this year's:
World Energy Outlook 2024
Table A.1a: World energy supply Page 296, showing the primary energy available as of 2023 compared to 2022.
I can and do reproduce this table as often as required to confront ignorance.
I would not be surprised to hear someone claim that 8 + 8 is greater than 30. The first 8 is the amount of energy produced at a trillion dollar cost for solar energy, the second 8 for wind, (which grew by zero percent between 2022 and 2023), and the thirty is what nuclear energy has been producing in an atmosphere of mindless vituperation for roughly three decades, saving lives and about two years worth of annual dumping dumping of the dangerous fossil fuel waste carbon dioxide.
Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power (Pushker A. Kharecha* and James E. Hansen Environ. Sci. Technol., 2013, 47 (9), pp 48894895)
The WEO "scenarios" if one looks back over the decades are both disturbing and amusing.
I agree that antinuke ignorance has prevented nuclear from doing what it might have done, but whatever humanity does going forward, albeit clearly too little, too late, can at least slow the growth of dependence of fossil fuels.
OKIsItJustMe
(20,872 posts)The IEA is tracking with present-day reality.