Sunday, August 15, 2021

NREL's thermoplastic blade research dives deep with verdant power's tidal energy turbines

National Renewable Energy Laboratory (NREL) researchers have been exploring the use of thermoplastic composite materials for wind turbines for several years, but they have only just begun to scrape the surface of how these materials perform underwater. For the first time in history, thermoplastic composite blades, which have the potential to revolutionize the marine energy industry, are being tested on a large-scale tidal power turbine.

Previous laboratory-scale research performed at Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) demonstrated how thermoplastic materials can improve fatigue performance, decreasing the probability for catastrophic blade failures and making tidal turbine blades more sustainable for marine energy applications. The manufacturing process is also faster and more energy efficient. Additionally, thermoplastics, which make up about 75% of worldwide plastic production, can be recycled because the plastic polymer material can be remolded at high temperatures and resolidifies upon cooling.

Thanks to funding from the U.S. Department of Energy's Water Power Technologies Office and a collaboration with Verdant Power, NREL researchers have constructed turbine blades using thermoplastic composite materials and are now testing them on one of Verdant Power's tidal turbines, which are currently deployed in New York City's East River.

Evaluation of the loads and performance of the turbines at the Roosevelt Island Tidal Energy (RITE) project site in New York began in October 2020 with the installation of Verdant Power's TriFrame mount, which holds three tidal turbines. Because of strong tidal currents that change direction multiple times per day, the East River is an ideal location for testing and validating the performance of marine energy turbines. Both the TriFrame and three-bladed turbines were designed to be modular and scalable, allowing researchers to study the 5-meter (m)-diameter turbines and then scale them up to the more economically viable 10- to 15-m-class turbine systems that are more likely to be used in the field.

During their first 6 months in the water, the tidal turbines, whichinitially had epoxy blades, generated almost 200 megawatt-hours of energy—a U.S. record for marine energy production. After a 6-month deployment, in May 2021, the Verdant Power team performed a retrieve-and-replace (R&R) operation, swapping out one of the epoxy-bladed rotors with a new, NREL-manufactured rotor with thermoplastic blades that are identical to the original epoxy blades except for their material.

"Verdant Power provided the NREL team with the blade tooling and geometry details so we could produce thermoplastic blades that are identical to the epoxy blades that they've already manufactured, which allows us to do a side-by-side comparison with traditional materials," Murray said. "We're really interested in using these thermoplastic materials because they could potentially prolong the life of the blades and have improved structural properties for marine applications.

For several months prior to the R&R deployment, NREL Research Engineer Robynne Murray and her team have been tapping into the manufacturing and materials characterization capabilities at NREL's Composites Manufacturing Education and Technology (CoMET) facility. There, they built the 2.5-m blades using a vacuum infusion method with Elium thermoplastic resin. They then worked to confirm that these blades had similar structural performance to the traditional epoxy resin blades prior to deployment, structurally validating the full-scale, thermoplastic, tidal power turbine blades that are now generating power in the East River. After its trial run ends and the blades are retrieved by the end of 2021, the team will measure the blades' structural response to applied loads to quantify the impact of seawater on these materials.

An NREL-built data acquisition system sits inside the tail cone of the newly installed tidal turbine, allowing researchers to measure the strain and angular position of the thermoplastic blades while in action in the East River. The data acquisition system design and validation process, which included submerging the system in water for several days, meets several requirements, including the ability to continuously and reliably acquire, measure, and store all the data generated during the turbine's entire deployment period—estimated to be up to 28 gigabytes.

"This work will demonstrate a potentially game-changing material for marine applications at a meaningful scale," Murray said. "It will also produce strain and acceleration data for full-scale turbines that we can use to validate design tools and derisk future deployments, industrywide. The collaboration with Verdant Power and the ability to join their innovative R&R operation has been key to obtaining these data that will benefit the marine energy industry for years to come."

Since the May 2021 R&R, NREL's tidal turbine has been producing power for New York City's electric grid and even experienced some of the highest loads the blades will see during the deployment. That data will be particularly useful in examining how these turbines perform during the most extreme conditions, adding key information to the growing understanding of operational turbine limits and saturated thermoplastic materials and their promise to resolve tomorrow's marine energy challenges.

This summer, the Pacific Northwest National Laboratory will be performing a survey of the TriFrame's flow speeds at the RITE Project site to obtain flow data for the operational tidal turbines. These data will be used to validate flow velocity models, which will be publicly accessible to the marine energy industry.

Until its deployment ends, the NREL team watches and waits while their thermoplastic blades help generate tidal energy at scale for the first time

NREL advanced manufacturing research moves wind turbine blades toward recyclability

Provided by National Renewable Energy Laboratory

Hydrogen-powered vehicles: A realistic path to clean energy?

by Mark Gillispie and Tom Krisher

Credit: CC0 Public Domain

Each morning at a transit facility in Canton, Ohio, more than a dozen buses pull up to a fueling station before fanning out to their routes in this city south of Cleveland.

The buses—made by El Dorado National and owned by the Stark Area Regional Transit Authority—look like any others. Yet collectively, they reflect the cutting edge of a technology that could play a key role in producing cleaner inter-city transportation. In place of pollution-belching diesel fuel, one-fourth of the agency's buses run on hydrogen. They emit nothing but harmless water vapor.

Hydrogen, the most abundant element in the universe, is increasingly viewed, along with electric vehicles, as one way to slow the environmentally destructive impact of the planet's 1.2 billion vehicles, most of which burn gasoline and diesel fuel. Manufacturers of large trucks and commercial vehicles are beginning to embrace hydrogen fuel cell technologies as a way forward. So are makers of planes, trains and passenger vehicles.

Transportation is the single biggest U.S. contributor to climate change, which is why hydrogen power, in the long run, is seen as a potentially important way to help reduce carbon emissions.

To be sure, hydrogen remains far from a magic solution. For now, the hydrogen that is produced globally each year, mainly for refineries and fertilizer manufacturing, is made using natural gas or coal. That process pollutes the air, warming the planet rather than saving it. Indeed, a new study by researchers from Cornell and Stanford universities found that most hydrogen production emits carbon dioxide, which means that hydrogen-fueled transportation cannot yet be considered clean energy.

Yet proponents of hydrogen-powered transportation say that in the long run, hydrogen production is destined to become more environmentally safe. They envision a growing use of electricity from wind and solar energy, which can separate hydrogen and oxygen in water. As such renewable forms of energy gain broader use, hydrogen production should become a cleaner and less expensive process.

Within three years, General Motors, Navistar and the trucking firm J.B. Hunt plan to build fueling stations and run hydrogen trucks on several U.S. freeways. Toyota, Kenworth and the Port of Los Angeles have begun testing hydrogen trucks to haul goods from ships to warehouses.

In Germany, a hydrogen-powered train began operating in 2018, and more are coming. French-based Airbus, the world's largest manufacturer of airliners, is considering hydrogen as well.Volvo Trucks, Daimler Trucks AG and other manufacturers have announced partnerships, too. The companies hope to commercialize their research, offering zero-emissions trucks that save money and meet stricter pollution regulations.

"This is about the closest I've seen us get so far to that real turning point," said Shawn Litster, a professor of mechanical engineering at Carnegie Mellon University who has studied hydrogen fuel cells for nearly two decades.

Hydrogen has long been a feedstock for the production of fertilizer, steel, petroleum, concrete and chemicals. It's also been running vehicles for years: Around 35,000 forklifts in the United States, about 4% of the nation's total, are powered by hydrogen. Its eventual use on roadways, to haul heavy loads of cargo, could begin to replace diesel-burning polluters.

No one knows when, or even whether, hydrogen will be adopted for widespread use. Craig Scott, Toyota's head of advanced technology in North America, says the company is perhaps two years from having a hydrogen truck ready for sale. Building more fueling stations will be crucial to widespread adoption.

Kirt Conrad, CEO of Canton's transit authority since 2009, says other transit systems have shown so much interest in the technology that SARTA takes its buses around the country for demonstrations. Canton's system, which bought its first three hydrogen buses in 2016, has since added 11. It's also built a fueling station. Two California transit systems, in Oakland and Riverside County, have hydrogen buses in their fleets.

"We've demonstrated that our buses are reliable and cost-efficient, and as a result, we're breaking down barriers that have slowed wider adoption of the technology," Conrad said.

The test at the Port of Los Angeles started in April, when the first of five semis with Toyota hydrogen powertrains began hauling freight to warehouses in Ontario, California, about 60 miles away. The $82.5 million public-private project eventually will have 10 semis.

Hydrogen fuel is included in President Joe Biden's plans to cut emissions in half by 2030. The infrastructure bill the Senate approved passed this week includes $9 billion for research to reduce the cost of making clean hydrogen, and for regional hydrogen manufacturing hubs.

The long-haul trucking industry appears to be the best bet for early adoption of hydrogen. Fuel cells, which convert hydrogen gas into electricity, provide a longer range than battery-electric trucks, fare better in cold weather and can be refueled much faster than electric batteries can be recharged. Proponents say the short refueling time for hydrogen vehicles gives them an edge over electric vehicles for use in taxis or delivery trucks, which are in constant use.

That advantage was important for London-based Green Tomato Cars, which uses 60 hydrogen fuel cell-powered Toyota Mirai cars in its 500-car zero emission fleet to transport corporate customers. Co-founder Jonny Goldstone said his drivers can travel over 300 miles (500 kilometers) on a tank and refuel in three minutes.

Because drivers' earnings depend on fares, Goldstone said, "if they have to spend 40, 50 minutes, an hour, two hours plugging a car in in in the middle of the working day, that for them is just not acceptable."

For now, Green Tomato is among the largest operators of hydrogen vehicles in what is still a tiny market in Europe, with about 2,000 fuel cell cars, garbage trucks and delivery vans on the roads.

About 7,500 hydrogen fuel cell cars are on the road in the U.S., mostly in California. Toyota, Honda and Hyundai produce the cars, which are priced thousands more than gasoline-powered vehicles. California has 45 public fueling stations, with more planned or under construction.

Unlike with buses and heavy trucks, experts say the future of passenger vehicles in the U.S. lies mainly with electric battery power, not hydrogen. Fully electric vehicles can travel farther than most people need to go on a relatively small battery.

And for now, hydrogen production is adding to rather than reducing pollution. The world produces about 75 million tons a year, most of it in a carbon emission-creating processes involving steam reformation of natural gas. China uses higher-polluting coal.

So-called "blue" hydrogen, made from natural gas, requires an additional step. Carbon dioxide emitted in the process is sent below the earth's surface for storage. The Cornell and Stanford study found that manufacturing blue hydrogen emitted 20% more carbon than burning natural gas or coal for heat.

That's why industry researchers are focused on electrolysis, which uses electricity to separate hydrogen and oxygen in water. Hydrogen mixes with oxygen in a vehicle's fuel cell to produce power. The amount of electricity generated by wind and solar is growing worldwide, making electrolysis cleaner and cheaper, said Joe Cargnelli, director of hydrogen technologies for Cummins, which makes electrolyzers and fuel cell power systems.

Currently, it costs more to make a hydrogen truck and produce the fuel than to put a diesel-powered truck on the road. Hydrogen costs about $13 per kilogram in California, and 1 kilogram can deliver slightly more energy than a gallon of diesel fuel. By contrast, diesel fuel is only about $3.25 per gallon in the U.S.

But experts say that disparity will narrow.

"As they scale up the technology for production, the hydrogen should come down," said Carnegie Mellon's Litster.

While a diesel semi can cost around $150,000 depending on how it's equipped, it's unclear how much fuel cell trucks would cost. Nikola, a startup electric and hydrogen fuel cell truck maker, estimated last year that it would receive about $235,000 for each hydrogen semi it sells.

Clean electricity might eventually be used to make and store hydrogen at a rail yard, where it could refuel locomotives and semis, all with zero emissions.

Cummins foresees the widespread use of hydrogen in the U.S. by 2030, sped by stricter diesel emissions regulations and government zero-emissions vehicle requirements. Already, Europe has set ambitious green hydrogen targets designed to accelerate its use.

"That's just going to blow the market open and kind of drive it," Cargnelli said. "Then you'll see other places like North America kind of follow suit."GM, Wabtec to develop hydrogen powered locomotives

© 2021 The Associated Press. All rights reserved.

Touted as clean, 'blue' hydrogen may be worse than gas, coal

by Cornell University

energy grid — Credit: Pixabay/CC0 Public Domain

"Blue" hydrogen—an energy source that involves a process for making hydrogen by using methane in natural gas—is being lauded as a clean, green energy to help reduce global warming. But Cornell and Stanford University researchers believe it may harm the climate more than burning fossil fuel.

The carbon footprint to create blue hydrogen is more than 20% greater than using either natural gas or coal directly for heat, or about 60% greater than using diesel oil for heat, according to new research published in Energy Science & Engineering.

Robert Howarth, professor of ecology and environmental biology at Cornell, together with Mark Z. Jacobson, professor of civil and environmental engineering at Stanford, authored the report.

Blue hydrogen starts with converting methane to hydrogen and carbon dioxide by using heat, steam and pressure, or gray hydrogen, but goes further to capture some of the carbon dioxide. Once the byproduct carbon dioxide and the other impurities are sequestered, it becomes blue hydrogen, according to the U.S. Department of Energy.

The process to make blue hydrogen takes a large amount of energy, according to the researchers, which is generally provided by burning more natural gas.

"In the past, no effort was made to capture the carbon dioxide byproduct of gray hydrogen, and the greenhouse gas emissions have been huge," Howarth said. "Now the industry promotes blue hydrogen as a solution, an approach that still uses the methane from natural gas, while attempting to capture the byproduct carbon dioxide. Unfortunately, emissions remain very large."

Methane is a powerful greenhouse gas, Howarth said. It is more than 100 times stronger as an atmospheric warming agent than carbon dioxide when first emitted. The United Nations' Intergovernmental Panel on Climate Change report released on Aug. 9 shows that cumulatively to date over the past century, methane has contributed about two-thirds as much to global warming as carbon dioxide has, he said.

Emissions of blue hydrogen are less than for gray hydrogen, but only by about 9% to 12%.

"Blue hydrogen is hardly emissions free," wrote the researchers. "Blue hydrogen as a strategy only works to the extent it is possible to store carbon dioxide long-term indefinitely into the future without leakage back to the atmosphere."

On Aug. 10, the U.S. Senate passed its version of the $1 trillion Infrastructure Investment and Jobs Act, which includes several billion dollars to develop, subsidize and strengthen hydrogen technology and its industry.

"Political forces may not have caught up with the science yet," Howarth said. "Even progressive politicians may not understand for what they're voting. Blue hydrogen sounds good, sounds modern and sounds like a path to our energy future. It is not."

An ecologically friendly "green" hydrogen does exist, but it remains a small sector and it has not been commercially realized. Green hydrogen is achieved when water goes through electrolysis (with electricity supplied by solar, wind or hydroelectric power) and the water is separated into hydrogen and oxygen.

"The best hydrogen, the green hydrogen derived from electrolysis—if used wisely and efficiently—can be that path to a sustainable future," Howarth said. "Blue hydrogen is totally different."

This research was supported by a grant from the Park Foundation. Howarth is a fellow at the Cornell Atkinson Center for Sustainability.

A clean US hydrogen economy is within reach, but needs a game plan, energy researchers say

More information: Robert W. Howarth et al, How green is blue hydrogen?, Energy Science & Engineering (2021). DOI: 10.1002/ese3.956

Provided by Cornell University

Effectively removing carbon dioxide from the atmosphere

by Sebastian Jutzi, Paul Scherrer Institute

Researchers at the Paul Scherrer Institute PSI and ETH Zurich have investigated the extent to which direct capture of carbon dioxide (CO2) from the ambient air can help to effectively remove greenhouse gasses from the atmosphere. The result: With careful planning, for example with regard to location and provision of the necessary energy, CO2 can be removed in a climate-effective manner. The researchers have now published their analysis in the journal Environmental Science & Technology.

Direct air carbon capture and storage (DACCS) is a comparatively new technology for removal of carbon dioxide from the atmosphere. Since it would allow large amounts of CO2 to be, in effect, trapped, this technology could also reduce the greenhouse effect. Researchers at the Paul Scherrer Institute PSI and ETH Zurich have now investigated how effectively this could be implemented with different system configurations of a certain process. To do this, they analyzed a total of five different configurations for capturing CO2 from the air and their use at eight different locations around the world. One result: Depending on the combination of technology used and the specific location, CO2 can be removed from the air with an effectiveness of up to 97 percent.

To separate CO2 from the atmosphere, air is first passed over a so-called absorbent with the help of fans. This binds CO2 until its capacity to absorb the greenhouse gas is exhausted. Then, in the second, so-called desorption step, the CO2 is released from the absorbent again. Depending on the absorbent, this happens at comparatively high temperatures of up to 900 degrees Celsius or at rather low temperatures of about 100 degrees Celsius. In addition to the energy required for the production and installation of the equipment, the operation of the fans and generation of the required heat produce greenhouse gas emissions. "The use of this technology only makes sense if these emissions are significantly lower than the amounts of CO2 it helps to store," says Tom Terlouw, who conducts research at PSI's Laboratory for Energy Systems Analysis and is first author of the study.

Efficiency of up to 97 percent

In their study, the researchers focused their examination on a system from the Swiss company Climeworks, which works with the low-temperature process. The PSI researchers analyzed the use of the technology at eight locations worldwide: Chile, Greece, Jordan, Mexico, Spain, Iceland, Norway, and Switzerland. For each location, they calculated the overall greenhouse gas emissions over the entire life cycle of a plant. For example, they compared the efficiency of the process when the required electricity is provided by solar energy or comes from the existing electricity grid. As sources for the necessary thermal energy they assumed, for example, solar thermal plants, waste heat from industrial processes, or heat pumps. For the study, they drew up five different system layouts for atmospheric CO2 capture for each of the eight sites. With respect to efficiency, the results show an enormous range, from 9 to 97 percent, in terms of actual greenhouse-gas removal through the use of DACCS.

No substitute for reducing emissions

"The technologies for CO2 capture are merely complementary to an overall decarbonisation strategy—that is, for the reduction of CO2 emissions—and cannot replace it," stresses Christian Bauer, a scientist at the Laboratory for Energy Systems Analysis and a co-author of the study. "However, they can be helpful in achieving the goals defined in the Paris Agreement on climate change, because certain emissions, for example from agriculture, cannot be avoided." Thus a net-zero emissions target can only be achieved with the help of suitable negative-emissions technologies.Study says 'blue hydrogen' likely bad for climate

More information: Terlouw, Tom et al, Life Cycle Assessment of Direct Air Carbon Capture and Storage with Low-Carbon Energy Sources ,Environmental Science & Technology (2021) DOI: 10.1021/acs.est.1c0326

Journal information: Environmental Science & Technology

Provided by Paul Scherrer Institute

New study on costs and benefits of new transportation technologies the most comprehensive to date

by Jake Malooley, Argonne National Laboratory

A new Argonne study offers the most complete understanding yet of the costs of owning and operating a vehicle and how those costs vary by powertrain, from the conventional to the cutting-edge.

Advanced vehicle technologies are sometimes more expensive to purchase than conventional technologies but often pay for themselves in reduced operational costs. Now a new study from the U.S. Department of Energy's (DOE) Argonne National Laboratory offers the most complete understanding yet of the costs of owning and operating a vehicle, and how those costs vary by powertrain, from the conventional to the cutting-edge.

Building on its pioneering past work quantifying the costs and benefits of new transportation technologies, Argonne published "Comprehensive total cost of ownership quantification for vehicles with different size classes and powertrains." The study considers vehicle purchase cost, depreciation, financing and fuel costs, in addition to aspects missing from previous technical analysis: costs related to insurance, maintenance and repair, and taxes and fees—all to calculate a holistic total cost of ownership (TCO).

"There has been a lot of past research on the cost of vehicles and the cost of fuel, but these other operating costs haven't been studied in quite the same detail before," said David Gohlke, an energy and environmental analyst at Argonne and co-author of the study. "There were gaps in the data, especially with respect to alternative fuel powertrains—electric vehicles, fuel cell vehicles. They are newer to the road, so it was hard to know, for instance, their historic needs for maintenance over their operational life. Our analysis helped fill those data gaps."

The study, sponsored by the DOE's Office of Energy Efficiency and Renewable Energy's Vehicle Technologies Office, is the result of a collaboration between Argonne and four other DOE national labs: Lawrence Berkeley National Laboratory, National Renewable Energy Laboratory, Oak Ridge National Laboratory, and Sandia National Laboratories.

The report covers light-duty passenger vehicles—compact and midsize sedans, small and large sport utility vehicles, and pickup trucks—as well as medium-/heavy-duty commercial vehicles: semi-tractors; medium-duty vans and pickups; transit buses; box, utility aerial and dump trucks; and garbage trucks. The study looked at several powertrains: internal combustion engine, hybrid electric vehicle, plug-in hybrid electric vehicle, fuel cell electric vehicle and battery electric vehicle.

The study finds, for instance, that battery electric vehicles have maintenance costs 40% lower than ICE vehicles. Overall, hybrid electric vehicles tend to be the lowest-cost powertrain. Hydrogen-powered fuel cell electric vehicles will reach cost parity with conventional vehicles as the price of hydrogen falls. Battery electric vehicles, meanwhile, will reach cost parity as battery prices drop. "There is uncertainty with how quickly these costs will drop," Gohlke noted, "but the technology is trending in the right direction."Key findings include insights into vehicle depreciation, an in-depth examination of insurance premium costs, comprehensive maintenance and repair estimates, an analysis of all relevant taxes and fees, and considerations of specific costs applicable to commercial vehicles.

Other findings of note include that cars depreciate faster than light trucks, and that older electric vehicles have a greater depreciation rate than newer electric vehicles. Light-duty vehicle insurance costs are comparable for different powertrains, and vehicle size and vocation both affect incurred costs for medium/heavy-duty commercial vehicle insurance. Light-duty vehicle taxes and fees are comparable across powertrain types and size classes, though marginally higher registration fees exist for alternative fuel vehicles in many states. Many electric tractor trailers would be affected by additional battery weight, reducing the available payload capacity, and this cost can be substantial. Electric vehicle charging for commercial vehicles can be time-consuming; if this charging is paid at an hourly rate, labor can cause this cost to dominate total cost of ownership.

For a simulated small sport utility vehicle in 2025—modeled using Autonomie, Argonne's tool for simulating vehicle energy consumption and performance—the hybrid electric vehicle has the lowest cost, followed by the conventional internal combustion engine vehicle. In the realm of commercial vehicles, the study shows that long-haul battery electric vehicle semi-tractors, which are the most expensive today due to their large batteries, will become the least expensive powertrain in 2035 as battery prices continue to drop. However, for local delivery vehicles such as the Class 4 truck, the battery electric vehicle is the lowest cost option in 2025, the baseline year for the study's modeling.

The study's results will inform future research related to vehicle technology, contribute to Argonne's regular assessments of the potential benefits from the technologies being developed by the DOE and others, and improve Argonne's Alternative Fuel Life-cycle Environmental and Economic Transportation (AFLEET) tool, which assists fleet managers with examining the economic and environmental costs of alternative fuel vehicles. "Fleet owners are particularly sensitive to the bottom line and choose vehicles that can perform the necessary work at the least cost," said Andrew Burnham, an environmental scientist at Argonne, creator of AFLEET, and co-author of the study, "so making this data publicly available and accessible with AFLEET will help them in planning alternative fuel vehicle purchases."

More energy-efficient powertrains for hybrid and electric trucks

Provided by Argonne National Laboratory

Smart energy meter shows energy generation instead of consumption

by University of Twente

An energy meter indicates that hundreds of watts are generated but in reality a small amount of power is consumed. This can happen using the combination of a dimmer and some household equipment, which together only consume about twenty watts. Depending on the actual setting of the dimmer, the energy meter gives the correct read-out, a consumption that is twenty times higher, or even hundreds of watts of generated power. Researchers from the University of Twente will present and explain this effect on the large online conference on electromagnetic compatibility, EMC 2021.

"The meter is running back," we used to say when energy was generated—the dial of the electricity meter turned the other way around, which was a great way of visualizing the power generated by solar panels, for instance. Today's smart meters have a display that can show the energy that is fed back. Earlier UT research, on intelligent electricity meters, indicated that the errors in reading can be huge: they can show substantial under- or overconsumption of hundreds of percentages. As the researchers now found, they can even show a negative amount of energy, as if electronics would generate power instead of using it.

This effect happens when a remotely controlled dimmer is used in combination with some kind of household equipment. When the dimmer is only used for switching on an off, it still appears to dim for a few seconds. For the equipment, this has no direct consequences, but for the measurements the smart meter shows, it can be the difference between a readout that is fully correct, a readout that indicates far too much power and a readout that actually shows energy production. After consumers noticed this in their homes, Frank Leferink's lab tested it using both a simulated main voltage with no further load and a fully operational environment with all types of devices working.

According to the researchers, this has to do with the rapid current pulses formed by the combination of the dimmer and the device. Like many home devices and battery chargers, the dimmer also has a switching power supply—it will work the same for various main voltages (110 V, 230V) by switching rapidly. Thus, it is not linear load anymore, like many loads used to be. The dimmer, in turn, can take action at several moments of the sinusoidal shape of the net voltage. This moment determines the measured outcome: roughly from minus 400 to plus 400 watts.

Switching power supplies, LEDs, and dimmers are far more complex loads. An average electricity meter determines the overall current using a coil. But this too simple and will not accurately measure today's complex net loads. Many of the smart energy meters were upgraded and have the lastest "immunity norm," but even for this article a meter was used that was built in 2019.

The other side of the coin is that the equipment we use should meet the standards as well, as noted in a recent publication of "Netbeheer Nederland' (Netherlands Grid Management). The combination of equipment and a dimmer that is not used for dimming may be a bit out of the ordinay. But imagine you use a remotely controlled device for several purposes: you dim a few lights, and switch on and off another type of device, all in one. So, this situation may not be that extraordinary after all.

The paper "How to earn money with an EMI problem: static energy meters running backwards," by Tom Hartman, Bas ten Have, Niek Moonen and Frank Leferink, will be presented at the IEEE Symposium on Electromagnetic Compatibility, Signal & Power Integrity.Electronic energy meters' false readings almost six times higher than actual energy consumption

Provided by University of Twente

Prominent fact-checker Snopes apologizes for plagiarism

by The Associated Press

The co-founder and CEO of the fact-checking site Snopes.com has acknowledged plagiarizing from dozens of articles done by mainstream news outlets over several years, calling the appropriations "serious lapses in judgment."

From 2015 to 2019—and possibly even earlier—David Mikkelson included material lifted from the Los Angeles Times, The Guardian and others to scoop up web traffic, according to BuzzFeed News, which broke the story Friday.

Mikkelson used his own name, a generic Snopes byline and a pseudonym when he lifted material, including single sentences and whole paragraphs on such subjects as same-sex marriage and the death of David Bowie, without citing the sources, BuzzFeed and Snopes said.

He has been suspended from editorial production pending the conclusion of an internal review but remains CEO and a 50% shareholder in the company, according to a statement from Snopes' senior leadership.

"Let us be clear: Plagiarism undermines our mission and values, full stop. It has no place in any context within this organization," the statement said.

In a separate statement, eight current Snopes writers also condemned Mikkelson's actions, while former staffers indicated to BuzzFeed that he routinely encouraged the practice as a way to make Snopes appear faster than it was.

Mikkelson did not immediately return an Associated Press email seeking comment Saturday. He told BuzzFeed his behavior was due to a lack of formal journalism experience.

"I didn't come from a journalism background," he said. "I wasn't used to doing news aggregation. A number of times I crossed the line to where it was copyright infringement. I own that."

Created in 1994 under a different name by Mikkelson and his then-wife, Barbara Hamel, Snopes has earned two Webby Awards and served as one of Facebook's fact-checking partners between December 2016 and February 2019, BuzzFeed News said. In recent years, the site has been the focus of a contentious ownership battle between Mikkelson and the company that bought Hamel's shares.

BuzzFeed News flagged stories from a range of outlets that also include The New York Times, CNN, NBC News and the BBC. Six were originally published under the Mikkelson pseudonym Jeff Zarronandia, three under Mikkelson's name and the rest as "Snopes staff." Snopes said it has identified 140 stories with possible problems, including the 54 found to include appropriated material.

Snopes also cited AP material that wasn't properly attributed. It did not specify which stories.

Senior management said in the statement that Snopes was removing unattributed content while leaving up individual pages. An editor's note will be used to outline the issues and link to original sources.

"We are in the process of archiving and retracting all of the offending stories, along with disabling any monetization features on those posts," the statement said. "We will attempt to contact each news outlet whose reporting we appropriated to issue an apology."

Snopes meets $500K crowdfunding goal amid legal battle

China's youth react to gaming curbs with anguish and cunning

by Danni Zhu, Beiyi Seow

Online gaming appears to be the latest target for China's regulators.

It is Zhang Yuchen's last summer break before high school, but events have taken an unwelcome turn—the 14-year-old's game time has been decimated as China's tech firms try to dispel accusations that they are selling "spiritual opium" to the country's youth.

An edict by gaming giant Tencent means players under 12 can no longer make in-game purchases in multiplayer battle smash-hit "Honor of Kings", while under-18s are locked out after two hours during holidays and one hour on school nights.

"I wanted to cry," an anguished Zhang said as the news ricocheted across the world's largest gaming market, which soaked up $20 billion in the first half of this year alone.

"Limiting game time over the holidays means I can't play (Honor of Kings) to my heart's content," he told AFP.

The changes—incontestable and imposed far too quickly for the liking of Zhang and his peer group—have come as a censorious state scours the tech scene for signs of any firm growing too big, owning too much data or having too great a hold over China's people.

Gaming appears to be the latest target for regulators who have already strafed mega-apps providing ride-hailing, personal finance and online learning, as the Communist Party refines the type of capitalism it wants for society.

State media reports have singled out gaming, with one article calling it "spiritual opium" and another advocating an end to tax breaks for the sector.

'I have nothing to do'

Investors rushed to sell shares in Tencent and rivals NetEase, XD Inc and Bilibili, despite China's place as the world's biggest gaming market.

In reaction, Tencent this month dropped the bombshell curbs on play time, an early sign of broader industry changes to come.

Minors complain that the measures are too sweeping, affecting even teens who have finished their university entrance exams and just want to relax.

Tech giant Tencent has imposed curbs on its games, locking out under-18s from its hit game 'Honor of Kings' after two hours of p — Tech giant Tencent has imposed curbs on its games, locking out under-18s from

"I'm on vacation now and have nothing to do, but I can only play for a short while," said a 17-year-old student surnamed Li.

"It's quite upsetting," she added, noting that older teens have more self-control and should not be forcibly stopped from playing.

She gets automatically locked out after hitting the two-hour holiday limit.

But there are loopholes even with broader curbs, Li added, as playing an hour on different games could still lead to teens gaming for the same hours as before.

Others have circumvented the policy altogether, by borrowing an adult's account or using their parents' mobile phones.

"By borrowing an account now, I can play two to three hours a day and of course, game after 10 pm," said another 17-year-old student on condition of anonymity.

Some analysts say the reaction to state media reports about gaming may be excessive.

"Investors made it a big story by overreacting," Ether Yin, partner at consultancy Trivium China, told AFP.

"Keeping kids from getting addicted to games has been the policy of the land since 2018."

'Why do they have to do this?'

To get ahead of public criticism, however, Yin believes other gaming companies will likely roll out their own plans to restrict minors from playing and spending money inside games.

Chinese regulators have moved against tech giants in recent months over issues such as data security — Chinese regulators have moved against tech giants in recent months over issues

The impact on Tencent for now will be "minimal", given that children under 16 contribute around three percent of gross billings, said Michael Norris, research and strategy manager at consulting firm AgencyChina.

But with the gaming sector already highly scrutinised, Norris called it "unusual" to single out online gaming, which is regulated, if the concern was addiction.

For now, Tencent's gaming curbs have claimed unlikely victims—with some parents who game with their children also locked out.

Programmer Peng Jianfei said his 12-year-old son was using his account to play "Honor of Kings" while on summer break when an authentication prompt appeared and the boy entered his own ID number, triggering a block.

"I think such measures can, to an extent, reduce minors' gaming time," the 45-year-old said.

"But for now... if I can't play Tencent's games, I could always go to NetEase, don't you think?"

But other parents welcomed the restrictions.

"If children spend too much time on games, it's bad for their eyesight," said a 34-year-old mother in Beijing surnamed Wang.

Tugging on her arm was her 10-year-old son, an "Honor of Kings" fan who was less enthusiastic about the changes.

"Mum, say it's a bad decision!" he said. "Why do they have to do this?"

China gaming shares dive after 'spiritual opium' warning

Disease ecologists document person-to-person spread of antimicrobial-resistant plague

by Northern Arizona University

Although the world is focused on the COVID-19 pandemic, there are many other dangerous pathogens still out there, like Yersinia pestis, which causes plague—the deadly disease that killed tens of millions of people during the infamous Black Death in the 14th century. Although plague has been largely eradicated in the developed world, it still affects hundreds of people globally each year.

When a human is infected with bubonic plague from a flea bite and it goes untreated, the infection can progress and spread to the lungs, resulting in pneumonic plague. The most feared clinical form of plague, pneumonic plague is typically lethal if not quickly treated, and infected patients can transmit the disease to others via respiratory droplets. A team of scientists from Northern Arizona University's Pathogen and Microbiome Institute, led by professor Dave Wagner, recently published their findings from a remarkable study involving antimicrobial resistant (AMR) plague.

Although pneumonic plague outbreaks are now extremely rare, scientists consider plague to be a reemerging and neglected disease, particularly in the East African island country of Madagascar, which reports the majority of annual global cases. With no vaccine against it, preventing mortality from plague requires rapid diagnosis followed by treatment with antibiotics. An AMR strain of Y. pestis—resistant to the antibiotic streptomycin, usually the first-line treatment for plague in Madagascar—was isolated from a pneumonic plague outbreak that occurred there in 2013, involving 22 cases, including three fatalities.

Wagner's team, including PMI senior research scientists Dawn Birdsell and Nawarat Somprasong, PMI assistant director Amy Vogler, professor Herbert Schweizer, associate professor Jason Sahl and senior research coordinator Carina Hall, conducted a study of this outbreak, together with long-term research partners at the Institut Pasteur de Madagascar and scientists at the Institute Pasteur Paris and the Madagascar Ministry of Public Health. The results of the study, "Transmission of antimicrobial resistant Yersinia pestis during a pneumonic plague outbreak," were recently published in the journal Clinical Infectious Diseases.

"By characterizing the outbreak using epidemiology, clinical diagnostics and DNA-fingerprinting approaches," Wagner said, "we determined—for the first time—that AMR strains of Y. pestis can be transmitted person-to-person. The AMR strain from this outbreak is resistant to streptomycin due to a spontaneous point mutation, but is still susceptible to many other antibiotics, including co-trimoxazole. Luckily, the 19 cases that were treated all received co-trimoxazole in addition to streptomycin, and all of them survived.

"The point mutation, which also is the source of streptomycin resistance in other bacterial species, has occurred independently in Y. pestis at least three times and appears to have no negative effect on the AMR strain, suggesting that it could potentially persist in nature via the natural rodent-flea transmission cycle. However, AMR Y. pestis strains are exceedingly rare and the mutation has not been observed again in Madagascar since this outbreak."Why health officials are concerned about the Madagascar plague outbreak

More information: Voahangy Andrianaivoarimanana et al, Transmission of Antimicrobial Resistant Yersinia pestis During a Pneumonic Plague Outbreak, Clinical Infectious Diseases (2021). DOI: 10.1093/cid/ciab606

Journal information: Clinical Infectious Diseases

Provided by Northern Arizona University

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