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Why wind — and soon solar — are already cheaper than fossil fuels

Global levelized cost of energy (LCOE) by various fuel types in $/megawatt-hours (credit: Citigroup)

Citigroup has published an analysis of the costs of various energy sources called “Energy Darwinism II.” It concludes that if all the costs of generation are included (known as the levelized cost of energy), renewables turn out to be cheaper than fossil fuels and a “benefit rather than a cost to society,” RenewEconomy reports.

“Capital costs are often cited by the promoters of fossil fuels as evidence that coal and gas are, and will, remain cheaper than renewable energy sources such as wind and gas. But this focuses on the short-term only — a trap repeated by opponents of climate action and clean energy, who focus on the upfront costs of policies.

Actually, fuel costs can “account for 80 per cent of the cost of gas-fired generation, and more than half the cost of coal,” RenewEconomy says.

Reneweables ahead

The graph above shows that the lowest-cost wind (in the best regions) is already beating coal and gas. Solar in the sunniest regions will do so by 2020, based on conservative estimates. And the cost of solar and wind will continue to fall, with solar eventually beating wind, RenewEconomy projects.

Citigroup estimates a “learning rate” of 19 per cent — meaning that solar costs will fall that much with each doubling in capacity (a variation of Moore’s Law). This translates into cost falls of 2 per cent a year.

“But as real-life experience shows, cost falls are happening faster than that. Last week, one of the big solar module manufacturers, Trina Solar, said costs had fallen 19 per cent in the past year, and would continue to fall by at least 5 per cent to 6 per cent a year in coming years as efficiencies were improved.”

“We should think of installing renewable energy as a benefit rather than a cost to society,” Citigroup writes.

 

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‘Diamonds from the sky’ approach to turn CO2 into valuable carbon nanofibers

Researchers are removing a greenhouse gas from the air while generating carbon nanofibers like these (credit: Stuart Licht, Ph.D)

A research team of chemists at George Washington University has developed a technology that can economically convert atmospheric CO2 directly from the air into highly valued carbon nanofibers for industrial and consumer products — converting an anthropogenic greenhouse gas from a climate change problem to a valuable commodity, they say.

The team presented their research today (Aug. 19) at the 250th National Meeting & Exposition of the American Chemical Society (ACS).

“Such nanofibers are used to make strong carbon composites, such as those used in the Boeing Dreamliner, as well as in high-end sports equipment, wind turbine blades and a host of other products,” said Stuart Licht, Ph.D., team leader.

Previously, the researchers had made fertilizer and cement without emitting CO2, which they reported. Now, the team, which includes postdoctoral fellow Jiawen Ren, Ph.D., and graduate student Jessica Stuart, says their research could shift CO2 from a global-warming problem to a feed stock for the manufacture of in-demand carbon nanofibers.

Licht calls his approach “diamonds from the sky.” That refers to carbon being the material that diamonds are made of, and also hints at the high value of the products, such as carbon nanofibers.

A low-energy, high-efficiency process

The researchers claim this low-energy process can be run efficiently, using only a few volts of electricity, sunlight, and a whole lot of carbon dioxide. The system uses electrolytic syntheses to make the nanofibers. Here’s how:

  1. To power the syntheses, heat and electricity are produced through a hybrid and extremely efficient concentrating solar-energy system. The system focuses the sun’s rays on a photovoltaic solar cell to generate electricity and on a second system to generate heat and thermal energy, which raises the temperature of an electrolytic cell.
  2. CO2 is broken down in a high-temperature electrolytic bath of molten carbonates at 1,380 degrees F (750 degrees C).
  3. Atmospheric air is added to an electrolytic cell.
  4. The CO2 dissolves when subjected to the heat and direct current through electrodes of nickel and steel.
  5. The carbon nanofibers build up on the steel electrode, where they can be removed.

Licht estimates electrical energy costs of this “solar thermal electrochemical process” to be around $1,000 per ton of carbon nanofiber product. That means the cost of running the system is hundreds of times less than the value of product output, he says.

Decreasing CO2 to pre-industrial-revolution levels

“We calculate that with a physical area less than 10 percent the size of the Sahara Desert, our process could remove enough CO2 to decrease atmospheric levels to those of the pre-industrial revolution within 10 years,” he says.

At this time, the system is experimental. Licht’s biggest challenge will be to ramp up the process and gain experience to make consistently sized nanofibers. “We are scaling up quickly,” he adds, “and soon should be in range of making tens of grams of nanofibers an hour.”

Licht explains that one advance the group has recently achieved is the ability to synthesize carbon fibers using even less energy than when the process was initially developed. “Carbon nanofiber growth can occur at less than 1 volt at 750 degrees C, which for example is much less than the 3–5 volts used in the 1,000 degree C industrial formation of aluminum,” he says.

No published details on overall energy costs and efficiency are yet available (to be updated).

Abstract of New approach to carbon dioxide utilization: The carbon molten air battery

As the levels of carbon dioxide (CO2) increase in the Earth’s atmosphere, the effects on climate change become increasingly apparent. As the demand to reduce our dependence on fossils fuels and lower our carbon emissions increases, a transition to renewable energy sources is necessary. Cost effective large-scale electrical energy storage must be established for renewable energy to become a sustainable option for the future. We’ve previously shown that carbon dioxide can be captured directly from the air at solar efficiencies as high as 50%, and that carbon dioxide associated with cement formation and the production of other commodities can be electrochemically avoided in the STEP process.1-3

The carbon molten air battery, presented by our group in late 2013, is attractive due to its scalability, location flexibility, and construction from readily available resources, providing a battery that can be useful for large scale applications, such as the storage of renewable electricity.4

Uncommonly, the carbon molten air battery can utilize carbon dioxide directly from the air:
(1) charging: CO2(g) -> C(solid) + O2(g)
(2) discharging: C(solid) + O2(g) -> CO2(g)
More specifically, in a molten carbonate electrolyte containing added oxide, such as lithium carbonate with lithium oxide, the 4 electron charging reaction eq. 1 approaches 100% faradic efficiency and can be described as the following two equations:
(1a) O2-(dissolved) + CO2(g) -> CO32-(molten)
(1b) CO32-(molten) -> C(solid) + O2(g) + O2-(dissolved)
Thus, powered by carbon formed directly from the CO2 in our earth’s atmosphere, the carbon molten air battery is a viable system to provide large-scale energy storage.

1S. Licht, ”Efficient Solar-Driven Synthesis, Carbon Capture, and Desalinization, STEP: Solar Thermal Electrochemical Production of Fuels, Metals, Bleach,” Advanced Materials, 47, 5592 (2011).
2S. Licht, H. Wu, C. Hettige, B. Wang, J. Lau, J. Asercion, J. Stuart “STEP Cement: Solar Thermal Electrochemical Production of CaO without CO2 emission,” Chemical Communications, 48, 6019 (2012).
3S. Licht, B. Cui, B. Wang, F.-F. Li, J. Lau, S. Liu,” Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3,” Science, 345, 637 (2014).
4S. Licht, B. Cui, J. Stuart, B. Wang, J. Lau, “Molten Air Batteries – A new, highest energy class of rechargeable batteries,” Energy & Environmental Science, 6, 3646 (2013).

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‘Information sabotage’ on Wikipedia claimed

 

Research has moved online, with more than 80 percent of U.S. students using Wikipedia for research papers, but controversial science information has egregious errors, claim researchers (credit: Pixabay)

Wikipedia entries on politically controversial scientific topics can be unreliable due to “information sabotage,” according to an open-access paper published today in the journal PLOS One.

The authors (Gene E. Likens* and Adam M. Wilson*) analyzed Wikipedia edit histories for three politically controversial scientific topics (acid rain, evolution, and global warming), and four non-controversial scientific topics (the standard model in physics, heliocentrism, general relativity, and continental drift).

“Egregious errors and a distortion of consensus science”

Using nearly a decade of data, the authors teased out daily edit rates, the mean size of edits (words added, deleted, or edited), and the mean number of page views per day. Across the board, politically controversial scientific topics were edited more heavily and viewed more often.

“Wikipedia’s global warming entry sees 2–3 edits a day, with more than 100 words altered, while the standard model in physics has around 10 words changed every few weeks,” Wilson notes. “The high rate of change observed in politically controversial scientific topics makes it difficult for experts to monitor their accuracy and contribute time-consuming corrections.”

While the edit rate of the acid rain article was less than the edit rate of the evolution and global warming articles, it was significantly higher than the non-controversial topics. “In the scientific community, acid rain is not a controversial topic,” said professor Likens. “Its mechanics have been well understood for decades. Yet, despite having ‘semi-protected’ status to prevent anonymous changes, Wikipedia’s acid rain entry receives near-daily edits, some of which result in egregious errors and a distortion of consensus science.”

Wikipedia’s limitations

Likens adds, “As society turns to Wikipedia for answers, students, educators, and citizens should understand its limitations for researching scientific topics that are politically charged. On entries subject to edit-wars, like acid rain, evolution, and global change, one can obtain — within seconds — diametrically different information on the same topic.”

However, the authors note that as Wikipedia matures, there is evidence that the breadth of its scientific content is increasingly based on source material from established scientific journals. They also note that Wikipedia employs algorithms to help identify and correct blatantly malicious edits, such as profanity. But in their view, it remains to be seen how Wikipedia will manage the dynamic, changing content that typifies politically charged science topics.

To help readers critically evaluate Wikipedia content, Likens and Wilson suggest identifying entries that are known to have significant controversy or edit wars. They also recommend quantifying the reputation of individual editors. In the meantime, users are urged to cast a critical eye on Wikipedia source material, which is found at the bottom of each entry.

Wikipedia editors not impressed

In the Wikipedia “User_talk:Jimbo_Wales” page, several Wikipedia editors questioned the PLOS One authors’ statistical accuracy and conclusions, and noted that the data is three years out of date. “I don’t think this dataset can make any claim about controversial subjects at all,” one editor said. “It simply looks at too few articles, and there are too many explanations.”

“It has long been a source of bewilderment to me that we allow climate change denialists to run riot on Wikipedia,” said another.

* Dr. Gene E. Likens is President Emeritus of the Cary Institute of Ecosystem Studies and a Distinguished Research Professor at the University of Connecticut, Storrs. Likens co-discovered acid rain in North America, and counts among his accolades a National Medal of Science, a Tyler Prize, and elected membership in the National Academy of Sciences. Dr. Adam M. Wilson is a geographer at the University of Buffalo.

Abstract of Content Volatility of Scientific Topics in Wikipedia: A Cautionary Tale

Wikipedia has quickly become one of the most frequently accessed encyclopedic references, despite the ease with which content can be changed and the potential for ‘edit wars’ surrounding controversial topics. Little is known about how this potential for controversy affects the accuracy and stability of information on scientific topics, especially those with associated political controversy. Here we present an analysis of the Wikipedia edit histories for seven scientific articles and show that topics we consider politically but not scientifically “controversial” (such as evolution and global warming) experience more frequent edits with more words changed per day than pages we consider “noncontroversial” (such as the standard model in physics or heliocentrism). For example, over the period we analyzed, the global warming page was edited on average (geometric mean ±SD) 1.9±2.7 times resulting in 110.9±10.3 words changed per day, while the standard model in physics was only edited 0.2±1.4 times resulting in 9.4±5.0 words changed per day. The high rate of change observed in these pages makes it difficult for experts to monitor accuracy and contribute time-consuming corrections, to the possible detriment of scientific accuracy. As our society turns to Wikipedia as a primary source of scientific information, it is vital we read it critically and with the understanding that the content is dynamic and vulnerable to vandalism and other shenanigans.

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Continued destruction of Earth’s plant life places humankind in jeopardy, say researchers

Earth-space battery. The planet is a positive charge of stored chemical energy (cathode) in the form of fossil and nuclear fuels and biomass. As this energy is dissipated by humans, it eventually radiates as heat toward the chemical equilibrium of deep space (anode). The battery is rapidly discharging without replenishment. (credit: John R. Schramski et al./PNAS)

Unless humans slow the destruction of Earth’s declining supply of plant life, civilization like it is now may become completely unsustainable, according to a paper published recently by University of Georgia researchers in the Proceedings of the National Academy of Sciences.

“You can think of the Earth like a battery that has been charged very slowly over billions of years,” said the study’s lead author, John Schramski, an associate professor in UGA’s College of Engineering. “The sun’s energy is stored in plants and fossil fuels, but humans are draining energy much faster than it can be replenished.”

Number of years of phytomass food potentially available to feed the global human population (credit: John R. Schramski et al./PNAS)

Earth was once a barren landscape devoid of life, he explained, and it was only after billions of years that simple organisms evolved the ability to transform the sun’s light into energy. This eventually led to an explosion of plant and animal life that bathed the planet with lush forests and extraordinarily diverse ecosystems.

The study’s calculations are grounded in the fundamental principles of thermodynamics, a branch of physics concerned with the relationship between heat and mechanical energy. Chemical energy is stored in plants, or biomass, which is used for food and fuel, but which is also destroyed to make room for agriculture and expanding cities.

Scientists estimate that the Earth contained approximately 1,000 billion tons of carbon in living biomass 2,000 years ago. Since that time, humans have reduced that amount by almost half. It is estimated that just over 10 percent of that biomass was destroyed in just the last century.

“If we don’t reverse this trend, we’ll eventually reach a point where the biomass battery discharges to a level at which Earth can no longer sustain us,” Schramski said.

Major causes: deforestation, large-scale farming, population growth

Working with James H. Brown from the University of New Mexico, Schramski and UGA’s David Gattie, an associate professor in the College of Engineering, the research shows that the vast majority of losses come from deforestation, hastened by the advent of large-scale mechanized farming and the need to feed a rapidly growing population. As more biomass is destroyed, the planet has less stored energy, which it needs to maintain Earth’s complex food webs and biogeochemical balances.

NASA Earth Observatory biomass map of the U.S. by Robert Simmon, generated from the National Biomass and Carbon Dataset (NBCD) assembled by scientists at the Woods Hole Research Center

“As the planet becomes less hospitable and more people depend on fewer available energy options, their standard of living and very survival will become increasingly vulnerable to fluctuations, such as droughts, disease epidemics and social unrest,” Schramski said.

If human beings do not go extinct, and biomass drops below sustainable thresholds, the population will decline drastically, and people will be forced to return to life as hunter-gatherers or simple horticulturalists, according to the paper.

“I’m not an ardent environmentalist; my training and my scientific work are rooted in thermodynamics,” Schramski said. “These laws are absolute and incontrovertible; we have a limited amount of biomass energy available on the planet, and once it’s exhausted, there is absolutely nothing to replace it.”

Schramski and his collaborators are hopeful that recognition of the importance of biomass, elimination of its destruction and increased reliance on renewable energy will slow the steady march toward an uncertain future, but the measures required to stop that progression may have to be drastic.

The model does not take into account potential future breakthroughs in more efficient biomass use and alternate energy systems.

Abstract of Human domination of the biosphere: Rapid discharge of the earth-space battery foretells the future of humankind

Earth is a chemical battery where, over evolutionary time with a trickle-charge of photosynthesis using solar energy, billions of tons of living biomass were stored in forests and other ecosystems and in vast reserves of fossil fuels. In just the last few hundred years, humans extracted exploitable energy from these living and fossilized biomass fuels to build the modern industrial-technological-informational economy, to grow our population to more than 7 billion, and to transform the biogeochemical cycles and biodiversity of the earth. This rapid discharge of the earth’s store of organic energy fuels the human domination of the biosphere, including conversion of natural habitats to agricultural fields and the resulting loss of native species, emission of carbon dioxide and the resulting climate and sea level change, and use of supplemental nuclear, hydro, wind, and solar energy sources. The laws of thermodynamics governing the trickle-charge and rapid discharge of the earth’s battery are universal and absolute; the earth is only temporarily poised a quantifiable distance from the thermodynamic equilibrium of outer space. Although this distance from equilibrium is comprised of all energy types, most critical for humans is the store of living biomass. With the rapid depletion of this chemical energy, the earth is shifting back toward the inhospitable equilibrium of outer space with fundamental ramifications for the biosphere and humanity. Because there is no substitute or replacement energy for living biomass, the remaining distance from equilibrium that will be required to support human life is unknown.

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A 99% biodegradable computer chip

A cellulose nanofibril (CNF) computer chip shown on a leaf (credit: Yei Hwan Jung, Wisconsin Nano Engineering Device Laboratory)

University of Wisconsin-Madison and U.S. Department of Agriculture Forest Products Laboratory (FPL) researchers have jointly developed a wood chip in an effort to alleviate the environmental burden* of electronic devices.

Well, actually, a wood-substrate-based semiconductor chip. They replaced the silicon substrate portion in a conventional chip with environment-friendly cellulose nanofibril (CNF). CNF is a flexible, biodegradable material made from wood, as the researchers note in an open-access paper published May 26 in the journal Nature Communications.

“[More than 99%] of the material in a chip is support,” said Zhiyong Cai, project leader of an engineering composite science research group at FPL. With the new substrate, the chips are “so safe you can put them in the forest and fungus will degrade it. They become as safe as fertilizer.”

The new material is especially important for microwave chips (such as those used in mobile phones) made with gallium arsenide, which is especially difficult to fabricate on foreign substrates. That’s because of the small feature sizes and high temperature processes required for high performance.

Cai’s group addressed two key barriers to using wood-derived materials in an electronics setting: surface roughness and thermal expansion. “You don’t want it to expand or shrink too much. Wood is a natural hydroscopic [water-absorbing] material and could attract moisture from the air and expand,” Cai says. “With an epoxy coating on the surface of the CNF, we solved both [problems].”

* In 2007, it was estimated that over 426,000 cell phones (most of them were still functional) and 112,000 computers were discarded every day in the US, totalling 3.2 million tons of electronic waste generated per year, the researcher note in the paper.

Abstract of High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

Today’s consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials.

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Light-emitting, transparent flexible paper developed in China

Left: optical images of normal filter paper (bottom layer), nanocellulose-quantum dot paper (middle layer), and with acrylic resin coating added (top layer). Right: photo of luminescent nanocellulose-quantum dot paper in operation. (credit: Juan Xue et al./ACS Applied Materials & Interfaces)

The first light-emitting, transparent, flexible paper made from environmentally friendly materialshas been developed by scientists at Sichuan University in China, the scientists report in the journal ACS Applied Materials & Interfaces.

Most current flexible electronics paper designs rely on petroleum-based plastics and toxic materials.

The researchers developed a thin, clear nanocellulose paper made from wood flour and infused it with biocompatible quantum dots — tiny semiconducting crystals — made out of zinc and selenium. The paper glowed at room temperature and could be rolled and unrolled without cracking.

The researchers are currently developing papers that emit other colors than blue.

The authors acknowledge funding from the Research Fund for the Doctoral Program of Higher Education of China and the National Natural Science Foundation of China.

Abstract of Let It Shine: A Transparent and Photoluminescent Foldable Nanocellulose/Quantum Dot Paper

Exploration of environmentally friendly light-emitting devices with extremely low weight has been a trend in recent decades for modern digital technology. Herein, we describe a simple suction filtration method to develop a transparent and photoluminescent nanocellulose (NC) paper, which contains ZnSe quantum dot (QD) with high quantum yield as a functional filler. ZnSe QD can be dispersed uniformly in NC, and a quite low coefficient of thermal expansion is determined for the resultant composite paper, suggesting its good dimensional stability. These results indicate that the meeting of NC with ZnSe QD can bring a brilliant future during the information age.