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This hydrogen fuel machine could be the ultimate guide to self-improvement

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This hydrogen fuel machine could be the ultimate guide to self-improvement

Three years ago, scientists at the University of Michigan discovered an artificial photosynthesis device made of silicon and gallium nitride (Si/GaN) that harnesses sunlight into carbon-free hydrogen for fuel cells with twice the efficiency and stability of some previous technologies.

Now, scientists at the Department of Energy’s (DOE’s) Lawrence Berkeley National Laboratory (Berkeley Lab) – in collaboration with the University of Michigan and Lawrence Livermore National Laboratory (LLNL) – have uncovered a surprising, self-improving property in Si/GaN that contributes to the material’s highly efficient and stable performance in converting light and water into carbon-free hydrogen. Their findings, reported in the journal Nature Materials, could help radically accelerate the commercialization of artificial photosynthesis technologies and hydrogen fuel cells.

“Our discovery is a real game-changer,” said senior author Francesca Toma, a staff scientist in the Chemical Sciences Division at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). Usually, materials in solar fuels systems degrade, become less stable and thus produce hydrogen less efficiently, she said. “But we discovered an unusual property in Si/GaN that somehow enables it to become more efficient and stable. I’ve never seen such stability.”

Previous artificial photosynthesis materials are either excellent light absorbers that lack durability; or they’re durable materials that lack light-absorption efficiency.

But silicon and gallium nitride are abundant and cheap materials that are widely used as semiconductors in everyday electronics such as LEDs (light-emitting diodes) and solar cells, said co-author Zetian Mi, a professor of electrical and computer engineering at the University of Michigan who invented Si/GaN artificial photosynthesis devices a decade ago.

When Mi’s Si/GaN device achieved a record-breaking 3 percent solar-to-hydrogen efficiency, he wondered how such ordinary materials could perform so extraordinarily well in an exotic artificial photosynthesis device – so he turned to Toma for help.

HydroGEN: Taking a Team Science approach to solar fuels

Mi had learned of Toma’s expertise in advanced microscopy techniques for probing the nanoscale (billionths of a meter) properties of artificial photosynthesis materials through HydroGEN, a five-national lab consortium supported by the DOE’s Hydrogen and Fuel Cell Technologies Office, and led by the National Renewable Energy Laboratory to facilitate collaborations between National Labs, academia, and industry for the development of advanced water-splitting materials.

“These interactions of supporting industry and academia on advanced water-splitting materials with the capabilities of the National Labs are precisely why HydroGEN was formed – so that we can move the needle on clean hydrogen production technology,” said Adam Weber, Berkeley Lab’s Hydrogen and Fuel Cell Technologies Lab Program Manager and Co-Deputy Director of HydroGEN.

Toma and lead author Guosong Zeng, a postdoctoral scholar in Berkeley Lab’s Chemical Sciences Division, suspected that GaN might be playing a role in the device’s unusual potential for hydrogen production efficiency and stability.

To find out, Zeng carried out a photoconductive atomic force microscopy experiment at Toma’s lab to test how GaN photocathodes could efficiently convert absorbed photons into electrons, and then recruit those free electrons to split water into hydrogen, before the material started to degrade and become less stable and efficient.

They expected to see a steep decline in the material’s photon absorption efficiency and stability after just a few hours. To their astonishment, they observed a 2-3 orders of magnitude improvement in the material’s photocurrent coming from tiny facets along the “sidewall” of the GaN grain, Zeng said. Even more perplexing was that the material had increased its efficiency over time, even though the overall surface of the material didn’t change that much, Zeng said. “In other words, instead of getting worse, the material got better,” he said.

To gather more clues, the researchers recruited scanning transmission electron microscopy (STEM) at the National Center for Electron Microscopy in Berkeley Lab’s Molecular Foundry, and angle-dependent X-ray photon spectroscopy (XPS).

Those experiments revealed that a 1 nanometer layer mixed with gallium, nitrogen, and oxygen – or gallium oxynitride – had formed along some of the sidewalls. A chemical reaction had taken place, adding “active catalytic sites for hydrogen production reactions,” Toma said.

Density functional theory (DFT) simulations carried out by co-authors Tadashi Ogitsu and Tuan Anh Pham at LLNL confirmed their observations. “”By calculating the change of distribution of chemical species at specific parts of the material’s surface, we successfully found a surface structure that correlates with the development of gallium oxynitride as a hydrogen evolution reaction site,” Ogitsu said. “We hope that our findings and approach – a tightly integrated theory-experiments collaboration enabled by the HydroGEN consortium – will be used to further improve the renewable hydrogen production technologies.”

Mi added: “We’ve been working on this material for over 10 years – we know it’s stable and efficient. But this collaboration helped to identify the fundamental mechanisms behind why it gets more robust and efficient instead of degrading. The findings from this work will help us build more efficient artificial photosynthesis devices at a lower cost.”

Looking ahead, Toma said that she and her team would like to test the Si/GaN photocathode in a water-splitting photoelectrochemical cell, and that Zeng will experiment with similar materials to get a better understanding of how nitrides contribute to stability in artificial photosynthesis devices – which is something they never thought would be possible.

“It was totally surprising,” said Zeng. “It didn’t make sense – but Pham’s DFT calculations gave us the explanation we needed to validate our observations. Our findings will help us design even better artificial photosynthesis devices.”

“This was an unprecedented network of collaboration between National Labs and a research university,” said Toma. “The HydroGEN consortium brought us together – our work demonstrates how the National Labs’ Team Science approach can help solve big problems that affect the entire world.”

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2 solar projects to supply power for 5 military installations

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2 solar projects to supply power for 5 military installations


2 solar projects to supply power for 5 military installations

by Mike Heuer

Washington DC (UPI) Jun 18, 2024






The Department of Defense is partnering with Duke Energy to provide solar power for five military bases in North and South Carolina.

The DOD announced the power partnership with Duke Energy in which all power produced by two new Duke Energy solar energy facilities in South Carolina will power the five military bases.

The military bases are the Army’s Fort Liberty, the Marine Corps’ Camp Lejeune and Cherry Point Air Station bases, and the Seymour Johnson Air Force Base in North Carolina.

The Shaw Air Force Base in South Carolina also will obtain power from the two Duke Energy solar power plants that are under construction and expected to be operational by September 2026.

“By supporting the construction of new clean, renewable energy, we are enhancing our resilience in support of the warfighter and DOD’s mission,” Brendan Owens, the DOD’s chief sustainability officer, said in a news release Tuesday.

Owens said the two Duke Energy solar arrays will “deliver power exclusively to [the] DOD over the agreement’s 15-year term and contribute to a more reliable and resilient commercial electric grid.”

The DOD agreed to pay $248 million over 15 years to obtain an estimated 4.8 million megawatt hours of carbon-free solar energy from Duke Energy.

The federal government is the nation’s largest user of energy, and President Joe Biden in 2021 ordered federal agencies to achieve 100% carbon-free electricity usage by 2030.

Biden’s executive order requires government officials to ” support the growth of America’s clean energy industry … in ways that are good for taxpayers and communities,” said Andrew Mayock, chief sustainability officer at the White House Council on Environmental Quality.

Duke Energy recently undertook its Green Source Advantage program to provide renewable energy for the five military bases.

“As our large business customers plan for the future, they also have increasingly specific goals around decarbonization,” Duke Energy Vice-President Meghan Dewey said.

Dewey said those goal “require access to renewable energy sources that can support those needs.”

DOD officials agree.

“This project is a great opportunity to assist our military departments and our warfighters in their decarbonization goals,” Air Force Col. Jennifer Neris said.

The Army’s Assistant Secretary for Installation, Energy and Environment Rachel Jacobson said the Duke Energy partnership is “essential for delivering energy resilience for the Army.”

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Argentina starts removing solar panels from Chilean border

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Argentina starts removing solar panels from Chilean border


Argentina starts removing solar panels from Chilean border

by AFP Staff Writers

Santiago (AFP) June 17, 2024






Argentina on Monday began removing solar panels that were installed by accident on the wrong side of its shared border with Chile, after a complaint from Chilean President Gabriel Boric.

In late April, the Argentine Navy inaugurated a maritime surveillance post on the border with Chile, in the Patagonia region of South America.

But the solar panels, which provide energy to that military unit, were set up on the Chilean side of the frontier.

In a statement, the Argentine Navy acknowledged the mistake and said it had “transferred personnel and means to begin the removal of a solar panel installed in the territory of the sister republic of Chile, north of the Island of Tierra del Fuego.”

Earlier in the day, Boric demanded that the panels be removed or Chile itself would do it.

“Borders are not something that can be ambiguous. It is a basic principle of respect between countries and therefore they must remove those solar panels as soon as possible or we are going to do it,” Boric told reporters during a visit to Paris.

Chile and Argentina share a border of about 5,000 kilometers (more than 3,000 miles).

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Chinese Premier Li targets clean energy in Australia visit

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Chinese Premier Li targets clean energy in Australia visit


Chinese Premier Li targets clean energy in Australia visit

by AFP Staff Writers

Sydney (AFP) June 18, 2024






Premier Li Qiang toured a Chinese-controlled lithium refiner in Perth on Tuesday, a sign of his country’s vast appetite for Australian “critical minerals” required for clean energy technologies.

Li ended his four-day visit to Australia with a tour of the low-carbon energy industry in resource-rich Western Australia.

His first stop was Tianqi Lithium Energy Australia, a 51-percent Chinese-owned venture comprising a mine for hard rock lithium ore, and a lithium refinery.

Along with at least a dozen other officials, China’s second most powerful man donned a white helmet during a rainy visit to the facility south of Perth.

The Chinese premier will also view a private research facility for clean energy-produced “green hydrogen” — touted as a fuel of the future to power heavy-duty items such as trucks and blast furnaces.

Australia extracts 52 percent of the world’s lithium, the vast majority of it exported as an ore to China for eventual refining and use in batteries, notably in China’s world-dominant electric vehicle industry.

But despite being a huge Australian customer, China’s involvement in the country’s critical mineral industry is sensitive because of its dominance of global supply chains.

Australia has only recently begun refining lithium rather than exporting the ore.

And the government has announced a strategic plan to develop new supply chains with friendly countries for critical minerals such as lithium, nickel and so-called rare earths.

Earlier this year, the government ordered five China-linked shareholders to sell off a combined 10 percent stake in Northern Minerals, a producer of the rare earth dysprosium.

Such foreign ownership was against Australia’s “national interests”, Treasurer Jim Chalmers said.

About 99 percent of the world’s dysprosium — used in high-performance magnets — is currently produced in China.

China has invested in critical minerals in Latin America, Africa and Australia over the past 10-20 years, said Marina Zhang, associate professor at the University of Technology Sydney’s Australia-China Relations Institute.

Developing supply chains independent of China is “fine and dandy” but unlikely to be achieved even in the short to medium term, she said.

“We are facing a very time-pressing issue that is fighting against climate change — so that issue should be at the centre of the discourse,” Zhang said.

“But unfortunately the Western allies are taking the approach that China’s dominance across the supply chains of critical minerals is imposing national security threats,” she said.

China’s narrative, however, was that it was investing and making a contribution to sustainability and environmental protection, the analyst said.

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