Innovations

Researchers Create 68.9%-efficient PV Cell for Laser energy Transmission

At the recently held 48th IEEE Photovoltaic Specialists Conference, researchers from the Fraunhofer Institute for Solar Energy Systems ISE presented their achievement of a record conversion efficiency of 68.9% for a photovoltaic cell under monochromatic laser light.

The scientists at Fraunhofer ISE claimed the success, explaining that it was made possible with a special thin film technology in which the solar cell layers were first grown on a gallium arsenide substrate which was then subsequently removed. A conductive, highly reflective mirror was applied to the back surface of the remaining semiconductor structure, which was only a few micrometers thick. This was their process: Photovoltaic cells convert light into electricity. The incoming light is absorbed in a cell structure, made of gallium arsenide semiconductor material, for example. The absorbed light sets positive and negative charges free, which are in turn conducted to the front and back cell contacts, generating electricity. This “photovoltaic effect” is particularly efficient when the energy of the incident light lies slightly above the so-called bandgap energy inherent to the semiconductor material. Thus, very high efficiencies are theoretically possible when a monochromatic laser as light source is matched with a suitable semiconductor compound material. In this new form of energy transfer, called power by light, the laser energy is delivered either through the air or via an optical fiber to a photovoltaic cell whose properties match the power and the wavelength of the monochromatic laser light. Compared to conventional power transmission via copper wires, power by light systems are especially beneficial for applications which require a galvanically isolated power supply, lightning or explosion protection, electromagnetic compatibility, or completely wireless power transmission, for example.

“This thin film approach has two distinct advantages for the efficiency,” explains the physicist Dr. Henning Helmers, head of the Fraunhofer ISE research team. “First of all, photons are trapped in the cell and the absorption is maximized for photon energies close to the band gap, which simultaneously minimizes thermalization and transmission losses, making the cell more efficient. Secondly, the photons additionally generated internally by radiative recombination become trapped and effectively recycled. This extends the effective carrier lifetime, thus additionally increasing the voltage.”

The research group investigated thin film photovoltaic cells with back-surface reflectors made of gold and an optically optimized combination of ceramic and silver, with the latter showing the best results. An n-GaAs/p-AlGaAs heterostructure was developed as absorber, which shows particularly low charge carrier losses due to recombination.

Ultrasonic Delamination Could Make Battery Recovery Quick & Green

Researchers from the universities of Birmingham and Leicester, working at Faraday Institution on ‘ReLiB’, a battery recycling research project, claim that ultrasonic delamination is a fast, sustainable, and less energyintensive method to recycle batteries.

While old batteries are usually shredded and treated with fire or aqueous solvents to recover precious metals, a process that uses a lot of energy and releases toxic waste, these U.K. scientists have advocated the use of ultrasonic sound waves for battery recovery in their paper “Lithium-ion Battery Recycling Using High-intensity Ultrasonication,” recently published in the journal Green Chemistry.

The paper, which argues that this process could also yield higher-purity materials, was co-authored by Chunhong Lei, Iain Aldous, Jennifer Hartley, Dana Thompson, Sean Scott , Rowan Hanson, Paul Anderson, Emma Kendrick, Rob Sommerville, Karl Ryder, and Andrew Abbott.

According to the scientists, decarbonisation of energy will rely heavily, at least initially, on the use of lithium ion batteries for automotive transportation. The projected volumes of batteries necessitate the development of fast and efficient recycling protocols. Current methods are based on either hydrometallurgical or pyrometallurgical methods. The development of efficient separation techniques of waste lithium ion batteries into processable waste streams is needed to reduce material loss during recycling.

In their paper, they show a rapid and simple method for removing the active material from composite electrodes using high powered ultrasound in a continuous flow process. Cavitation at the electrode interface enables rapid and selective breaking of the adhesive bond, enabling an electrode to be delaminated in a matter of seconds. This enables the amount of material that can be processed in a given time and volume to be increased by a factor of approximately 100. It also produces a material of higher purity and value that can potentially be directly recycled into new electrodes.

The researchers say that the efficiency of the delamination process is strongly affected by the type of polymer binder with water-dispersible binders such as SBR/CMC being more rapidly stripped. Delamination could thus be further optimised using wetting agents and pH modification. Production scrap from the batteries could be rapidly recycled by simply wetting the active material/ binder mixture with an organic solvent.

High rates of material recovery and throughput coupled with the ease of process scale up make high-powered ultrasonic delamination a stepchange in battery recycling, the scientists conclude.

German Partners Launch Hamburg Project to Test H2-powered Aviation

Acollaboration between aircraft services provider Lufthansa Technik, the City of Hamburg and other German partners plans to modify an Airbus A320 to test maintenance and ground-handling procedures for liquid hydrogen-powered aircrafts. Operation of the demonstrator is planned to begin in 2022 in Hamburg, the world’s third-largest aviation center, which is also funding the project.

Liquid hydrogen (LH2) is increasingly being more concretely envisaged in the development departments of large aircraft manufacturers as a sustainably producible fuel for future generations of commercial aircraft. In order to investigate the effects of the use of LH2 on maintenance and ground processes at an early stage, Lufthansa Technik, DLR (German Aerospace Center), ZAL (Center of Applied Aeronautical Research) and Hamburg Airport are now pooling their resources.

“Hamburg is not just one of the three largest aviation clusters in the world, last year the city also developed the clear vision of becoming a major hydrogen metropolis,” explained Michael Westhagemann, Senator for Economics and Innovation of the Free and Hanseatic City of Hamburg.

“The port, the energy sector, industry and the entire mobility sector are involved and are preparing for this groundbreaking technology. With this project, we are now also making an essential contribution to the transformation of aviation into a climate-neutral mobility solution of the future,” he added.

In the first phase of the project, by the end of 2021, the partners aim to identify the most urgent fields of development for closer scientific examination and, on this basis, to elaborate the concept for subsequent practical testing. The practical implementation of the concept will start at the beginning of 2022 and will involve the modification of a decommissioned Airbus A320 aircraft. It will be equipped with an liquid hydrogen infrastructure to be used as a fully functional field laboratory at Lufthansa Technik’s base in Hamburg.

In parallel, a virtual environment is being created at DLR that will be used to achieve digital and highly accurate mapping of the defined development fields. The new development platform is to provide inspiration for the design process of the next generation of aircraft by means of parameterized and highly accurate virtual models. Against this background, Lufthansa Technik will primarily contribute its operational expertise in the maintenance and modification of commercial aircraft, and can also incorporate the customer perspective through its close contact with airlines around the world. DLR will add its long-standing and cross-sector experience with hydrogen, and focus on the development of the virtual environment.

Mondragon Assembly Launches New Solar Module Equipment

Mondragon Assembly has launched new interconnection equipment for solar modules. The device has been designed for the production of different kinds of technologies, including half-cut products, glass-glass and glass-backsheet panels, as well as mono or bifacial PERC, PERL and PERT modules.

The Spanish PV production equipment provider claims that the new machine is also suitable for the production of modules that incorporate BIPV technologies and modules with high-efficiency cell technology, such as heterojunction (HJT) or TOPCon.

With regard to the sizes of the cells, this new machine is compatible with any cell size on the market, including M10 (182 mm) and M12 (210 mm) cells. The company states that this new machine is capable of interconnecting an unlimited number of ribbons or threads, with a cycle of 120 modules per hour, a non-stop autonomy of more than eight hours and an overall ‘uptime’ of 99%.

Other features are precise welding and zero breakage rate, no manual operations, and easy integration with the Manufacturing Execution System (MES), which is an information system that connects, monitors and controls complex manufacturing systems and data flows on the factory floor.

In describing its new product, the company said, “Versatility, autonomy, quality and, above all, performance, are the characteristics that give it a uniqueness and distinction on the market,” and added that it offers its clients “comprehensive support throughout the life of their business, providing specialized advice on new and future technologies.”

This year, in March, signed an agreement with Romaniabased Karpat Solar to supply a production line for photovoltaic solar modules with a capacity of 100 MW per year. The 100 MW in modules was announced to be the first phase of a large-scale project with aims to initially secure the production for the local market and to eventually expand in the European Union.

“In addition to the standard modules, we will see companies launching modules for HJT, BIPV and other niche products suited to European demand, where Mondragon Assembly has the solution for all those new technologies,” Igor Herrarte, international sales manager at Mondragon Assembly, had said at the time.

Form Energy Reveals Chemistry of its Long Duration Iron-air Battery

US technology firm Form Energy has announced the battery chemistry of its first commercial product and a $200 million Series D financing round led by ArcelorMittal’s XCarb™ innovation fund. The four-year-old startup claims that through the use of iron, one of the most common elements on Earth, it has built an inexpensive battery that can discharge power for days on end.

The company is currently working on developing a new class of cost-effective, multi-day energy storage systems to fight climate change.

Solar and wind resources are the lowest marginal cost sources of electricity in most of the world. The electric grid now faces a challenge: how to manage the multi-day variability of renewable energy, even in periods of multi-day weather events, without sacrificing energy reliability or affordability. Form Energy’s first commercial product is a rechargeable ironair battery capable of delivering electricity for 100 hours at system costs competitive with conventional power plants and at less than 1/10th the cost of lithium-ion. Made from iron, one of the safest, cheapest, and most abundant minerals on Earth, this front-of-the-meter battery can be used continuously over a multi-day period and will enable a reliable, secure, and fully renewable electric grid year-round, said the company in a press statement.

How Does it Work? Form Energy battery is composed of cells filled with thousands of small iron pellets that rust when exposed to air. When oxygen is removed, the rust reverts to iron. By controlling the process, the battery is charged and discharged. The firm’s plan is to mount small cells into larger modules, then assemble modules into batteries that can be scaled to power electric grids. The firm’s first battery, a 300Mwh, full-scale pilot project, using 500 modules, is under construction at the Great River Energy power plant in Minnesota in 2023. Form Energy intends to source the iron domestically and manufacture the battery systems close to the final site. The Minnesota project is right near the American Iron Range.

Mateo Jaramillo, CEO and Co-founder of Form Energy, said, “We conducted a broad review of available technologies and have reinvented the iron-air battery to optimize it for multi-day energy storage for the electric grid. With this technology, we are tackling the biggest barrier to deep decarbonization: making renewable energy available when and where it’s needed, even during multiple days of extreme weather or grid outages.”

The ArcelorMittal Connection Form Energy and ArcelorMittal are working jointly on the development of iron materials which ArcelorMittal would non-exclusively supply for Form’s battery systems. Greg Ludkovsky, Global Head of Research and Development at ArcelorMittal, said, “Form Energy is at the leading edge of developments in the long-duration, grid-scale battery storage space. The multi-day energy storage technology they have developed holds exciting potential to overcome the issue of intermittent supply of renewable energy. They are exactly the kind of ambitious and innovative company we are seeking to invest in through our XCarb™ innovation fund.” Jaramillo added, “This is an extremely exciting time at Form Energy and we are pleased to welcome ArcelorMittal as a business partner and investor. ArcelorMittal is a world-leading steel and mining company and this investment demonstrates their commitment to innovation and deep decarbonization. We appreciate their confidence in our team and in our technology as we work to reshape the global electric system to enable a clean energy future.”