Floating solar panels could advance US energy goals

by Clarence Oxford

Los Angeles CA (SPX) Jan 15, 2025

Federal reservoirs have the potential to significantly contribute to meeting the country’s solar energy needs, according to a recent study published in Solar Energy.

Geospatial scientists Evan Rosenlieb and Marie Rivers, along with Aaron Levine, a senior legal and regulatory analyst at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), conducted the first comprehensive analysis to quantify the energy potential of floating solar panel projects on federally owned or regulated reservoirs. Their findings reveal that these reservoirs could support floating solar panels capable of generating up to 1,476 terawatt hours of energy annually – enough to power approximately 100 million homes.

“That’s a technical potential,” Rosenlieb explained, clarifying that this figure represents the maximum energy generation possible if every reservoir were fully utilized for floating solar panels. “We know we’re not going to be able to develop all of this. But even if you could develop 10% of what we identified, that would go a long way.”

Although the study does not yet account for the potential impacts of human and wildlife activities on floating solar development, the researchers plan to address these factors in future work. This enhanced data provides critical insights that could streamline project planning and assist in evaluating how floating solar fits into the nation’s energy strategy.

Floating solar panels, or floating PV, offer several advantages. In addition to generating electricity without consuming land resources, they provide cooling and shading to water bodies, reducing evaporation and conserving water supplies. However, large-scale installations remain absent in the U.S., with no single project exceeding 10 megawatts.

Levine noted the challenges and opportunities: “We haven’t seen any large-scale installations, like at a large reservoir. In the United States, we don’t have a single project over 10 megawatts.”

Previous attempts to estimate the energy potential of floating solar panels in the U.S. lacked the detailed analysis of this study, which evaluates the suitability of reservoirs based on factors such as water conditions and infrastructure requirements. For instance, reservoirs with frequent shipping traffic, extreme temperatures, or steeply sloping bottoms may pose challenges for floating solar installations. However, some hydropower reservoirs could serve as excellent sites for hybrid energy systems combining solar and hydropower, enhancing grid reliability and resilience.

The researchers also highlighted the potential of new reservoirs created for pumped storage hydropower projects. These reservoirs, which are often isolated from natural waterways, could serve as ideal locations for floating solar panels, as they do not impact existing ecosystems or human activities.

Future studies will assess additional factors, such as proximity to transmission lines, site-specific development costs, and regulatory considerations. The researchers also plan to expand their analysis to include smaller reservoirs, estuaries, and ocean sites.

Research Report:Floating photovoltaic technical potential: A novel geospatial approach on federally controlled reservoirs in the United States

Related Links

National Renewable Energy Laboratory

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China battery giant CATL’s Hong Kong listing plan gathers steam

by AFP Staff Writers

Hong Kong (AFP) Jan 14, 2025

Chinese electric vehicle battery giant CATL is pushing ahead with plans to list in Hong Kong, with banks reportedly vying for a deal expected to raise at least $5 billion.

CATL, which produces more than a third of the EV batteries sold worldwide, said it plans to “seek a listing on the Main Board of Hong Kong Stock Exchange” in a bid to expand globally and support energy transition.

“This move is primarily aimed at creating an international financing platform to better support our global business development,” the firm told AFP on Tuesday.

“We have sufficient cash and funding for our overall business, and building up an international financing platform will be a strategic arrangement, which is in line with other globalised companies.”

CATL is publicly traded in Shenzhen and its plans for a secondary listing in Hong Kong were announced in an exchange filing last month.

Bank of America, JPMorgan Chase, China International Capital Corporation and CSC Financial Corporation are poised to be the lead arrangers for the deal, Bloomberg News reported this week.

Other banks are likely to be added for a listing that could happen as soon as the first half of this year, which could raise at least $5 billion, according to Bloomberg.

Founded in 2011 in the eastern coastal Chinese city of Ningde, CATL has grown into the world’s largest EV battery maker and supplies firms including Mercedes-Benz, BMW, Volkswagen, Toyota, Honda and Hyundai.

Last week, the US Department of Defense added CATL to a list of companies it says are affiliated with Beijing’s military.

China has denounced the move as “suppression” while CATL said the company is “not engaged in any military related activities”.

CATL’s Shenzhen shares rose 3.8 percent on Tuesday but were still down nearly four percent since the start of the year.

Hong Kong’s stock exchange is eager for the return of big-name Chinese listings in hopes of regaining its crown as the world’s top IPO venue.

The Chinese finance hub has suffered a steady decline in new offerings since a regulatory crackdown by Beijing starting in 2020 led some Chinese mega-companies to put their plans on hold.

A bumper listing by Chinese electronic appliance maker Midea worth $4 billion last year may signal a turnaround, analysts say.

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Powering The World in the 21st Century at Energy-Daily.com

Unlocking the potential of lithium-sulfur batteries

by Amber Rose for Argonne News

Lemont IL (SPX) Jan 14, 2025

Lithium-ion (Li-ion) batteries are an integral part of society, from cellphones and laptops to electric vehicles. While Li-ion batteries have been a major success to date, scientists worldwide are racing to design even better ?”beyond Li-ion” batteries in the shift toward a more electrified world. Commercial Li-ion batteries are less energy-dense than alternative batteries and rely on relatively expensive substances, such as cobalt and nickel compounds, which are also heavily dependent on vulnerable supply chains.

One of the more promising alternatives to Li-ion batteries are lithium-sulfur (Li-S) batteries, which have an anode of lithium metal and a cathode of sulfur. This electrode pairing promises two to three times higher energy densities and reduced costs, while also using Earth-abundant resources.

But these batteries do not come without their own challenges, including a short cycle life due to the unwanted migration of polysulfide ions and the uneven distribution and occurrence of chemical reactions within the system.

By developing an innovative additive for the electrolyte, researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are making progress toward addressing these problems that are limiting the widespread adoption of Li-S batteries.

In Li-ion batteries, lithium ions are stored in the spaces between layers of the cathode material and move back and forth between the cathode and anode during charging and discharging.

Li-S batteries, however, rely on a different process. In these cells, lithium ions move between the cathode and anode by a chemical reaction. Elemental sulfur from the cathode is converted into polysulfide compounds – composed of sulfur atom chains – some of which can dissolve in the electrolyte. Because of this solubility, a ?”shuttling” effect occurs, where the polysulfides travel back and forth between the cathode and the anode. This shuttling results in loss of material from the sulfur cathode because it is deposited at the anode, which limits the overall battery cycle life and performance.

Numerous strategies have been proposed to mitigate polysulfide shuttling and other challenges. One such strategy, using an additive in the electrolyte, has long been thought to be incompatible due to chemical reactivity with the sulfur cathode and other battery parts. Argonne chemist Guiliang Xu and his team have created a new class of additive and found that such additives can actually improve battery performance. By controlling the way the additive reacts with sulfur compounds, researchers are better able to create an interface between the cathode and electrolyte that is necessary to facilitate easy transport of lithium ions.

“The additive, called a Lewis acid additive, is a salt that reacts with the polysulfide compounds, forming a film over the entire electrode,” Xu said. ?”The key is to have a minor reaction to form the film, without a continuous reaction that consumes the material and reduces energy density.”

The additive forms a film on both the anode and the cathode, suppressing the shuttle effect, improving the stability of the cell and promoting an ion transport ?”highway” throughout the electrode. This electrolyte design also minimizes sulfur dissolution and enhances reaction homogeneity, enabling the use of additives that were previously considered incompatible.

To validate the concept, the researchers compared their electrolyte with the additive to a conventional electrolyte used in Li-S batteries. They observed a significant reduction in polysulfide formation. The new electrolyte showed very low dissolution of polysulfides, which was confirmed with X-ray techniques. Further, they tracked the reaction behavior during battery charging and discharging. These experiments made use of Argonne’s Advanced Photon Source (APS) and Brookhaven National Laboratory’s National Synchrotron Light Source II, both DOE Office of Science user facilities, which confirmed that the electrolyte design minimized the dissolution and formation of polysulfides.

“Synchrotron techniques provide powerful tools for characterizing battery materials,” said Tianyi Li, a beamline scientist at the APS. ?”By using X-ray diffraction, X-ray absorption spectroscopy and X-ray fluorescence microscopy at the APS, it was confirmed that the new interface design effectively mitigates well-known issues including polysulfide shuttle. More importantly, this interface enhances ion transfer, which helps to reduce reaction heterogeneities.”

Xu added, ?”With further optimization and development of sulfur electrodes, we believe Li-S batteries can achieve higher energy density and better overall performance, contributing to their commercial adoption.”

Another major challenge for Li-S batteries is the stability of the lithium metal – it reacts easily and poses safety concerns. Xu and his team are working on developing better electrolytes to stabilize the lithium metal and reduce the flammability of the electrolyte, ensuring the safety of Li-S batteries.

At the APS, Beamline 20-BM was used for X-ray absorption spectroscopy to probe the solubility of polysulfide. Beamline 17-BM was used for X-ray diffraction imaging to explore the homogeneity or heterogeneity of the entire cell. Beamline 2-ID was used for X-ray fluorescence mapping to confirm solubility of the electrode material and to observe the migration of sulfur in conventional electrolytes.

Other contributors to this work include Chen Zhao, Heonjae Jeong, Inhui Hwang, Yang Wang, Jianming Bai, Luxi Li, Shiyuan Zhou, Chi Cheung Su, Wenqian Xu, Zhenzhen Yang, Manar Almazrouei, Cheng-Jun Sun, Lei Cheng and Khalil Amine.

The results of this research were published in Joule. The study was funded by the Vehicle Technologies Office of DOE’s Office of Energy Efficiency and Renewable Energy.

Research Report:Polysulfide-incompatible additive suppresses spatial reaction heterogeneity of Li-S batteries

Related Links

Argonne National Laboratory

Powering The World in the 21st Century at Energy-Daily.com