Metals Tech

The construction of a 900 MW “water battery,” which cost Switzerland two billion euros and took 14 years to complete, is finally operational. It went online on July 1, 2022. The battery is located in the Swiss Alps, almost 2,000 feet (600 meters) underground, and can store 400,000 electric vehicle batteries’ worth of energy. That’s enough juice to power 900,000 households at once!

Why Does This Water Battery Matter?

Renewable energy sources will become increasingly popular as the world works toward becoming more sustainable. However, these technologies provide intermittent power because they rely on the weather (wind) or time of day (solar). This means we must also find a way to store the electricity it generates for the times it can’t generate enough.

Dense battery packs offer a solution to this issue. Still, they need minerals like cobalt, nickel, and lithium, which must be mined – a practice that is unfavorable to the environment and sustainability efforts. The water battery doesn’t require the consumption of any materials and will never need to be replaced.

Alain Sauthier, the Nant de Drance pumped-storage hydroelectric plant director and engineer, said:

“It is an ecological battery that uses the same water over and over. The output is more than 80%: for every kilowatt hour of electricity used to pump the water upstream, 0.8 is fed into the grid. In less than ten minutes, we can reverse the direction of rotation of the turbines and switch from electricity production to storage.

Such flexibility is key in order to react promptly to the needs of the electricity grid and adapt electricity generation and consumption. Otherwise, you risk a collapse of the grid and blackout, as happened in Texas at the beginning of the year. In the future, it will be increasingly necessary to store large amounts of electricity, as renewable sources gradually replace nuclear and fossil energy.”

The 20 million kWh water battery is expected to help stabilize Switzerland’s and Europe’s energy systems. Moreover, it’s so massive that it can store more energy than Switzerland needs, hence why it can also serve other countries in Europe.

Sauthier continued:

“It can play a role in stabilizing the grid at the European level. We are geographically at the heart of the continent, and energy flows pass through Switzerland. If there is an overproduction of wind power in Germany, we can use the surplus electricity to pump and store water.”

For example, during peak demand, such as a heatwave, the battery can minimize grid overload.

What is a Water Battery?

A water battery, also known as a pumped storage power plant, is a form of hydroelectric energy storage system. The battery is comprised of two enormous pools of water that are spaced at varying heights from one another.

By pumping water up from the lower pool to the higher pool, the battery “charges,” storing extra power generated by renewable energy sources. The flow of water is reversed to “discharge,” or use the stored electricity.

How Does a Water Battery Generate Electricity?

Like other forms of hydroelectric power, electricity is generated by the movement of water via a turbine. In the case of Switzerland’s water battery, there are nine giant turbines between the two pools. As water flows from one pool to the other, it goes through the turbines, and they generate electricity.

Why Did It Take 14 Years to Complete the Water Battery?

The battery was constructed between Valais, Switzerland’s Vieux Emosson and Emosson reservoirs. The plant’s vast 650-foot-long (200 meters) and 100-foot-wide (32 meters) engine room lies 2,000 feet (600 meters) underground. That’s a space big enough to fit the leaning tower of Pisa.

Thus, engineers had to dig tunnels through the Alps to transport building materials. These tunnels are approximately 11 miles long (18 kilometers)! Only after the tunnels were built could building materials and prefabricated structures are carried into the mountain to make the battery.

In addition, the Vieux Emosson dam was raised 65 feet (20 meters) to boost the battery’s energy storage capacity.

The Potential for a Water Battery Revolution

According to Australian National University’s Matthew Stocks, there are 616,000 places throughout the world where closed-circuit hydro-pumping facilities could be developed. Stocks is a researcher who based his judgment only on geographical factors. He says installing just 1% of these would be sufficient to eliminate all difficulties associated with intermittent energy sources.

Pumped-storage hydropower is a well-established technique. Enthusiastic about its potential, Switzerland, together with 11 other nations, is participating in an international event to revive the development of pumped hydro storage in power markets.

The partners of the EU project FlexFunction2Sustain have committed themselves to create a network for innovative solutions for sustainable and smart products powered by nano-functionalized paper and plastic in order to support SMEs, start-ups and industries in the development and market launch of pioneering products. After the first two years, a number of promising results and prototypes have emerged and will be presented at the Conference for Industrial Technologies IndTech 2022 in Grenoble, France, June 27–29, 2022. Among them, a recently finalized highlight: the first working organic photovoltaic cell on recycled plastics.

Recently, participants from all over the world met at the Stockholm+50 Environment Summit and emphasized the urgency in moving forward quickly with environmental and climate protection measures. The littering of our planet and its oceans is progressing inexorably. A main driver for plastic waste is packaging materials, which are needed to extend the shelf life of food or to protect delicate products and pharmaceuticals from damaging environmental influences. In addition, smart packaging opens up many new and useful possibilities thanks to flexible electronics. In the future, short-life packaging materials for medicines, for example, will be equipped with flexible electronics to monitor medication intake or track sensitive products during their delivery route.

Recycling of plastics and using recycled material for packaging is an important cornerstone on the road to greater environmental protection and reducing plastic waste. To replace such composite and multilayer materials that are not recyclable or degradable, novel polymer compositions (bio-based and/or biodegradable) and adapted product designs are being discussed as a solution approach. In smart packaging, the electronics must also be considered in a more environmentally friendly way and, for example, designed to be recyclable and produced by using recyclates. A number of startups and innovative companies have created concepts for sustainable flexible and smart packaging products.

Gathering 19 partners from research, universities and industry throughout Europe, FlexFunction2Sustain aims at supporting small and medium-sized companies in bringing innovative concepts and ideas for products based on nanofunctionalized plastic and paper surfaces and membranes to market. The FlexFunction2Sustain Network—an Open Innovation Testbed (OITB) for nanofunctionalization technologies—offers comprehensive services to support innovation, e. g. from material and product design, technology and product development, small batch production to the sourcing of development funds.

Two years of FlexFunction2Sustain: What has emerged?

During its first two years, the consortium established an association which purpose is to structure and exploit the OITB member´s service portfolio. Hence, through this association the partnership plans to deliver an easy, fast-track access to the OITB facilities and services to SMEs, start-Ups and industry. To ease the commercialization process, the customer gains access to the OITB through a Single Entry Point (SEP) sales and project management entity. An SEP consults the customer in the selection of appropriate technologies and coordinates all development work and interaction with the OITB members for the customer. FlexFunction2Sustain will establish regional contact points to provide the best possible user experience and to bring the OITB to the whole European single market.

First prototypes of novel, eco-friendly plastic and paper products were prepared and evaluated within different industrial use case scenarios. These included recyclable/compostable food and cosmetic packaging, membranes for water filters and diagnostics, smart plastic surfaces for automotive application, and biodegradable security and anti-counterfeiting labels.

Project coordinator Dr. John Fahlteich sums up: “We are proud to present the first working organic photovoltaic cell (OPV) on a recycled polypropylene substrate along with a whole range of technology demonstrators at IndTech 2022 end of June in Grenoble, France.” Besides the OPV cell, several innovative product concepts will be shown including:—fully recyclable drink pouches,—optical features on biodegradable film,—innovative fresh food packaging made of semi-transparent paper—membrane based syringe filters for diagnostics and water filter applications.

Dr. Fahlteich continues: “At IndTech, FlexFunction2Sustain is embedded in a dedicated section of the exhibition presenting the innovations and services of 13 different Open Innovation Testbeds addressing a variety of technologies and applications ranging from biomaterials to nano-enabled surfaces towards eco-friendly and energy efficient solutions for building envelopes. A broad portfolio of technology solutions awaits SME and industry on site. We are looking forward to exchanging ideas and initiating projects with future partners from SME, Start-Ups and industry.”

World’s first organic photovoltaic cell on recycled polypropylene

The project partners Fraunhofer IVV and IPC Centre Technique Industriel de la Plasturgie et des Composites used recycled polypropylene (rPP)—recovered from a newly designed packaging material for recyclable drink pouches—mixed with virgin polyproypylene (vPP) to produce a substrate film for printed electronics at a recyclate content of 50%.

At Fraunhofer FEP, a transparent electrode—made of indium tin oxide (ITO)—was applied by means of roll-to-roll (R2R) vacuum coating with magnetron sputtering with a specially adapted set of process and winding parameters. The result is impressive, since despite the recyclates used in the substrate, the ITO exhibited almost the same sheet resistance as achieved on pristine film substrates.

Organic Electronics Technologies P.C. (OET) in Greece then performed R2R slot-die coating to produce OPV cells, followed by an encapsulation step over the printing of the organic materials and the finalization of the OPV cells. Here, OET’s researchers performed several trials on the coating parameters and finally succeeded in printing the functional OPV layers on the PP substrate made with 50% rPP recovered from drink pouch packaging material. As a result, the OPV was demonstrated to function as a device with a max efficiency of 1%.

OET’s project manager Vasileios Kyriazopoulos: “The power conversion efficiency of approx. 1% is already sufficient to supply a wide range of single-use smart packaging productions with sufficient electrical power. Currently, OPV cells on commercially available substrates can achieve efficiencies above 8%, therefore, by improving the entire fabrication process, including film extrusion, layer design, printing and encapsulation, it is achievable to increase the efficiency of OPV cells printed on recyclable material, which is made with 50% rPP, by more than 5%.”

This represents a first major step in the development of more environmentally friendly product designs and flexible electronics. In the future, products such as smart packaging, but also interactive magazines in the field of advertising or consumer electronics can be designed based on these initial developments. Thanks to flexible electronics such as an OPV cell on recycled material, tomorrow’s products will be powered a little more environmentally friendly.

Of course, the initial results only point the way ahead. In the future, the FlexFunction2Sustain consortium will work on improving the extrusion process for the recycled film. In addition, the development of a new layer design for improved surface quality is on the agenda. The OPV process also holds potential for improving drying temperatures and encapsulation strategies. All together leading to the perspective of reaching similar performances of flexible electronics as done on pristine, fossil-based plastic films.

A new study in the Nature Energy Journal exploring the economic and environmental benefits of direct electrification of containerships shows that dramatic improvements in batteries have unlocked the potential to electrify big containerships today on voyages of up to 5,000 km.

The main findings from the report, penned by three scientists from Berkeley in California, suggest that the electrification of container vessels is more economical on voyages of up to 5,000 km and three to five times more efficient than e-fuels such as green hydrogen and ammonia.

Over 40% of global containership traffic could be electrified cost-effectively with current technology, the study claims, also noting that battery-electric container shipping could reduce CO2 emissions by 14% for US-based vessels.

Minimal carrying capacity must be repurposed to house the battery system for most ship size classes along short to medium-length routes, the study claims. For a 7,650 teu containership, the volume required by the battery system is less than the volume currently dedicated to the ICE and fuel tanks for routes under 3,000 km.

A 220MW charger could charge a 7,650 teu containership working regional trades in 24 hours. For longer voyages requiring larger battery capacities, the authors of the study suggest offshore charging infrastructure could be strategically located in global shipping chokepoints such as the Strait of Hormuz, the Panama Canal and the Strait of Malacca, where ships regularly queue for days awaiting passage.

The primary constraint for cost parity of battery-electric ships with ICE ships over longer ranges is the battery cost. Battery prices need to reach $20 kWh for a 10,000 km range battery-electric ship capable of crossing the Atlantic or Pacific Ocean to be cost-effective without recharging. Current commercial lithium battery technologies, and emerging technologies such as solid-state batteries, are not projected to decline to this extent given the cost of the materials used in these batteries. However, battery technologies designed for long duration storage applications from low-cost materials are under development. Iron–air batteries, for example, offer comparable energy density at a fraction of the cost of current lithium-ion batteries and may offer pathways for cost-competitive long-range shipping, the report predicted.

This highly efficient and economical zero-emission solution for container shipping appears to be available today, much earlier than previously thought possible, with pioneers such as US-based Fleetzero gearing up to offer world shipping a battery-powered future.

A fully electric 80 m long containership, the Yara Birkeland, has begun autonomous operations in Norway. Similar battery-electric vessel projects are underway in Japan, China, Sweden and Denmark.

The white boxy structures across the river from the former Great Northern Paper mill in East Millinocket, Maine, don’t look like much from a distance. But a closer look offers a glimpse of Maine’s green energy future — one that’s battery powered.

Half a mile down a dirt road through the woods, you come to a clearing above a dam on the West Branch of the Penobscot River. Nine gleaming white cubes, each the size of a short shipping container, are sitting on cement pads. They generate a faint hum.

The boxes are marked with a red logo: Tesla. They are high-tech lithium ion batteries known as Tesla Megapacks.

“The total of nine megapacks together is 10.3 megawatts. But they can do that for two hours, so the capacity is actually 20.6 megawatt hours,” says Jamey Cole, an electrical engineer with Brookfield Renewable, which owns this battery system. “Each one of these obviously is DC, and they have an inverter which will convert it to AC which is what our grid is. From there it will get stepped up on a transformer, and the battery will go out at AC at 34,500 volts.”

That’s a lot of numbers, but the takeaway is that the Megapacks hold a significant amount of juice, enough to power about 9,000 New England homes for two hours. That’s the reason the batteries have been placed next to an existing substation that’s linked to Brookfield’s East Millinocket dam.

And they don’t just store renewable power when it’s abundant and save it for times when it’s not. Cole says it’s a bit more complicated.

“Ideally we would keep them about 50% charged, that way if they needed, the grid needed power we can put it out, or if the grid needed us to take power, we could put it in,” he says.

Cole says Brookfield can use the batteries to respond to the needs of ISO New England, which manages the regional electrical grid.

“It all depends on how we operate day to day. It may sit there and it may follow what ISO wants us to do; it might charge one minute and discharge the next. Or if the demand is there and we have the power, they may be asked to output power for the next two hours. It kind of goes day to day, depending on the grid needs,” he says.

In the best scenario, Brookfield could be paid to pull energy off the grid, when it is “negatively priced,” then sell it back when it has a higher value.

The corporation has another similar facility just up the road at the former mill in Millinocket. And it’s planning two more near its dams on the Androscoggin and Saco rivers.

Another company, NextEra, has a battery on Cousins Island in Yarmouth. These are some of the first sparks in a coming charge of battery power.

Chris Rauscher works from Maine for Sunrun, a national company specializing in solar and battery systems for residences. He is not involved in these large Maine battery projects, but he says, in general, batteries are sort of like bacon.

“Everything is a little better with bacon on it. And that’s true for the grid, everything is better with a battery attached. That’s whether we’re talking about homes or businesses that need backup power from a battery if the grid goes down, or renewable installations like solar and wind, the batteries can provide firming up, can provide energy at night when the sun isn’t shining on or when the wind isn’t blowing, or to provide all sorts of other services on the grid,” he says.

Battery storage is one part of a massive electrification project that will be increasingly critical as the nation weans itself from the fossil fuels that are the biggest drivers of climate change. The grid will be carrying more juice as more renewable power projects come online, and electricity replaces internal combustion engines in cars and other uses.

A bill signed by Maine Gov. Janet Mills in 2021 established a state goal of developing 300 megawatts of battery storage by 2025 and 400 megawatts by 2030.

State Rep. Mo Terry of Gorham sponsored a bill this year creating sales tax exemptions for battery storage developers, and directing the Governor’s Energy Office to explore other tax incentives for the industry.

Terry says a battery storage facility planned for her hometown is on an entirely different scale than those now operating in Maine.

“The storage facilities that we have right now are on the smaller size, 10-15 megawatts per facility, where the one that’s coming to Gorham is hopefully going to be up to about 150 megawatts of storage,” she says.

That proposed facility, Plus Power’s Cross Town Project, would be about 17 times the size of the Tesla system near East Millinocket. That’s about enough to power 150,000 Maine homes for two hours.

Back at the Tesla battery plant near the East Millinocket dam, Cole says not only are batteries like these becoming more abundant, the technology is evolving quickly.

“The size of the batteries now, the technology seems to be a lot better. Probably 10-15 years ago, they would have been three times the size of what it is now. They’re always developing the technology, and I would say there probably is coming something that will be a lot smaller in the future, that’s for sure,” he says.

But for now, these batteries sitting on a bank above the river in the North Woods, quietly breathing energy in and out, are state of the art, offering a small glimpse of the electrified future.

Passive day cooling is a promising technology for the sustainable reduction of energy consumption. It avoids the heating up of buildings by solar radiation and dissipates accumulated heat without external energy consumption. Researchers at the University of Bayreuth have now created a test system with which the materials used for passive cooling can be reliably characterized and compared—regardless of weather conditions and environmental conditions. The measurement setup presented in Cell Reports Physical Science is the first step towards a standardized, globally applicable test system for comparing high-performance cooling materials.

“Increasing fossil energy consumption worldwide is still contributing to global warming and is a major cause of the heating up of our cities. Cooling buildings during the day using passive cooling materials has great potential to establish itself as an effective tool for energy conservation. Many technologically interesting materials and classes of material have consequently been developed for the dissipation of heat, but it is still a challenge to precisely determine and compare their performance. The laboratory set-up we have designed helps to overcome this difficulty. It is a test system that makes important contributions to the characterization of previously existing cooling materials and the design of new ones, regardless of the weather,” says Prof. Dr. Markus Retsch, project leader of the study and Chair of Physical Chemistry I at the University of Bayreuth.

The laboratory-based test system mimics the most important factors that influence passive cooling performance. Essential components are therefore a simulator of sunlight, an aluminum dome cooled with liquid nitrogen that absorbs thermal radiation, a changeable filter that only allows light rays of certain wavelengths to pass through, and a heatable gas flow that can be used to set a specific ambient temperature. This allows the intensity of solar radiation, the temperatures acting on the cooling materials, and other environmental influences to be simulated on a miniature scale.

Outdoors, these factors change quickly and cannot be controlled, but in the new measurement setup from Bayreuth, they can be set with great specificity. As a result, the test results are reproducible at any time, regardless of time, place, or weather. This is the only way to characterize the properties and behavior of cooling materials with high precision and to compare them under identical conditions. The measurement setup is robust, cost-effective, and also has the advantage of being replicable without great technical effort.

The Bayreuth scientists have demonstrated the high performance and reliability of the test system on three different materials: a silver mirror (Ag), a film of polydimethylsiloxane (PDMS) applied to silver, and a graphite-coated silicon wafer. In doing so, they not only tested the heating and cooling of the materials, but also determined their cooling performance.

“Our measurement setup is the first step towards standardized performance comparisons between cooling materials that have been developed around the world under very different climatic and weather conditions. Such a test system is an important prerequisite for passive cooling to become a globally applied technology for significantly reducing energy consumption,” says Dr. Qimeng Song, first author of the study and postdoc at the research group led by Prof. Dr. Markus Retsch.

Safe from harsh environmental conditions, electrically and thermally conductive, and with great lithographic resolution: Embedding thin metal microstructures in glass promises exceptional properties for a range of applications. The technology could be used to create sensor components that are corrosion-proof, dimensionally stable, and reliably functional even in extremely rugged environments. A technique developed at Fraunhofer IZM offers a new way of integrating electrically conductive elements in glass, with the metal microstructures not deposited on the surface, but embedded and encased in the glass itself.

Glass is winning more and more favor as a substrate for electrical circuits. This is due to its special material properties: It maintains its dimensions over a vast range of temperatures, it is available even in large formats (e.g. full-format 24×18 inch panels), and it offers high electrical resistance, a smooth surface, and a high dielectric constant (e.g. 5.0 at 77 GHz). These properties have motivated developers for some time already to construct electrical structures like conductors as thin metal layers on and through glass substrates. Contacts can be created not just on a single layer, but also through several layers of the finished design by way of Through-Glass Vias (TGV).

Researchers at Fraunhofer IZM have developed a novel means for integrating metal conductors in glass. The highlight: The technique keeps the smooth surface of the glass intact, and it avoids any issues with the bond between the glass and the metal layer, which is fully embedded in the glass itself. No additional bonding agent—typically another metal—is needed.

The researchers managed to develop a process for controlling the formation of metal structures in thin glass. In their effort to create homogeneous electrical conductors near to the glass surface, they tested a range of materials and processing techniques to find the best possible approach. The key to their success lies in both the choice of material and the new processing technique: The metal layer can be extremely thin, down to several hundred nanometers, or visible to the naked eye at micrometer thickness due to the strong reflection creating a mirrorlike effect on the glass surface. The technique can create metal layers with lengths ranging from several millimeters up to ten centimeters, and it is versatile enough to integrate very specific metal structures and create electrical conductors within the glass itself.

“Electrical signals can now be routed through the conductors without worrying about environmental factors like aggressive liquids, gases, chemical reactions like corrosion, or simple mechanical wear and tear. The structures are completely enclosed by the glass and not simply placed on top of it,” says Philipp Wachholz, research assistant in the EOCB team (electrooptical circuit boards).

The new ability to embed electrical conductors inside and not on glass opens the doors for many novel applications. It would be possible to fit glass micro vacuum chambers with electrical contacts, without compromising their hermetic seal. Glass-integrated conductors could also be used in adverse conditions that surface-mounted conductors would not withstand, e.g. for rugged sensors. Tiny microelectrodes could be used for electrochemical biosensors to record biochemical processes like enzyme reactions or antigen antibody interactions. With the glass-integrated structures easily coping with temperatures up to 200°C, the possibilities for extremely robust sensors seem limitless.

And the researchers at Fraunhofer IZM are ready to test these limits: After successful feasibility studies, they want to team up with partners from science and industry to bring the new technology to active use. For this purpose, they are currently looking for and waiting to hear from interested industry partners to share in their glass expertise.

Benefits of glass-integrated electrical metal structures over surface vapor deposition:

• No bonding issues on the glass surface
• Electrically conductive microstructures embedded in glass: electrical vias
• Integration of other electrical structures possible (resistance, capacitors etc.)
• Metal structures safe from environmental forces: Corrosion-proof, Protected against wear and tear, Glass surfaces easily cleaned
• Glass conducts heat away from the metal microstructures
• Reduced CTE difference between metal and glass structures