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Natural solutions for coastal defense

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Protecting coastal cities and towns from the dangers of tsunamis, storm surges, and sea-level rise has become an ever-increasing challenge.  There are so-called hard coastal defenses as well as nature-based solutions.  A new study by the University of Tokyo has found that combining the two types of defenses may be the most effective way to protect, support, and enrich coastal communities.

Sea walls, dikes, dams, and breakwaters are the traditional hard measures.  They are popular and have proven track records but are facing challenges to keep pace with increasing climate risks.  They are expensive to build and require continuous upgrades and repairs.  While they do provide protection from many disaster risks, they also can cause significant disruption to coastal ecosystems as well as to coastal communities.

Nature-based coastal defenses include such things as mangroves and coral reefs.  So-called soft measures involve restoring, rehabilitating, reforesting, and nourishing natural ecosystems that protect coastal areas.

The Tokyo researchers analyzed the defense strategies in terms of risk reduction, climate change mitigation, and cost-effectiveness over a 20-year period. The results of the study were that among all coastal defense options in lower-risk areas, hybrid measures provide the highest risk reduction and can harness the advantages of both hard and soft measures. 

The findings provide strong evidence for integrating nature-based components into coastal defenses, but these approaches have not yet been adequately tested in circumstances of extreme events and high-risk urgency.  Research in this area has important implications for policy makers, coastal planners, and communities looking to make evidence-based decisions.

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A natural touch for coastal defense

Photo, posted October 22, 2021, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Falling Lithium Prices | Earth Wise

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Lithium, the key element in the batteries that power electric cars, as well as smartphones, tablets, and laptop computers, is sometimes called white gold.  Over time, the price of the metal has gone up and up.  But recently, and surprisingly, the price of lithium has actually gone down, helping to make electric vehicles more affordable.

Over the first couple of months of this year, the price of lithium has dropped by nearly 20%.  The price of cobalt, another important component of vehicle batteries, has fallen by more than half.  Even copper, another battery material, has seen its price drop by 18%.

Many analysts predicted that prices of these commodities would stay high or even climb higher.  The reason for the decline, as well as whether it is likely to persist, is the subject of much debate.

Some experts believe that the price drops are a result of demand not being as high as expected, perhaps related to slowing sales growth of EVs in Europe and China after certain subsidies expired.  Other industry experts said that the drop was a result of new mines and processing plants providing additional supply sooner than was thought possible.

Despite the price drops, mining and processing lithium remains an extraordinarily profitable business.  It costs from $5,000 to $8,000 to produce a ton of lithium that sells for ten times that amount.  With such fat profit margins, there is no shortage of banks and investors eager to finance lithium mining and processing projects.  Such profit margins are probably not sustainable and that will likely result in more reasonable prices over time.

There is plenty of lithium in the world.  The huge demand for it is a recent phenomenon and the world is still working out how to meet that demand.

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Falling Lithium Prices Are Making Electric Cars More Affordable

Photo, posted January 9, 2023, courtesy of Phillip Pessar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Stretchy And Washable Batteries | Earth Wise

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Wearable electronic devices are a big market but there are limitations created by the properties of the batteries that operate them.  The ideal battery for wearable electronics would be soft and comfortable, stretchable, and washable.  Researchers at the University of British Columbia have recently developed just such a battery.  The work has been described in a new paper published in Advanced Energy Materials.

The battery encompasses a number of engineering advances.  Traditional batteries are made from hard materials encased in a rigid external shell.  The UBC battery is stretchable because its key components are ground into small pieces and then embedded in a rubbery polymer.  Ultra-thin layers of these materials are then encased in the same polymer.  This construction creates an airtight, waterproof seal.

The batteries survived 39 cycles in washing machines using both home and commercial-grade appliances.  The batteries came out intact and functional.

The batteries use zinc and manganese dioxide chemistry which is safer than lithium-ion batteries in case they break while being worn.

The materials used are low-cost, so if the technology is commercialized, it will be cheap.  When it is ready for consumers, it is likely to cost no more than existing batteries.  Work is underway to increase the power output of the batteries and their cycle life.  There is already commercial interest in the technology.

There are many potential applications for such batteries.  Apart from watches and medical monitors, they might also be integrated with clothing that can actively change color or temperature.  If the batteries are commercialized, they will make wearable power comfortable, convenient, and resilient.

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Stretchy, washable battery brings wearable devices closer to reality

Photo, posted April 15, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Stretchable Batteries | Earth Wise

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Wearable technology is an ever-increasing part of our world.  Fitness trackers have become commonplace for people of all ages.  Smart watches perform a growing range of functions.   There are wearable health monitoring systems of many types for assisted living, elderly patients, and people with specific health problems.  Virtual reality headsets are increasingly popular and there is now even smart technology footwear that is integrated with smartphones and mapping software.

The adoption of wearable electronics has so far been limited by their need to derive power from relatively bulky, rigid batteries that reduce comfort and even may present safety hazards related to chemical leakage or combustion.  To date, there has not been a power source that can stretch and bend the way our bodies do, which would enable electronic designs that people can comfortably wear.

Researchers at Stanford have recently announced the development of a soft and stretchable battery that relies on a special type of plastic to store power more safely than the flammable formulations used in conventional batteries today.

The lithium ion batteries in our phones, computers, cameras and electric cars already make use of plastic electrolytes.  These polymer electrolytes are in the form of flowable gels.  The Stanford researchers developed a new polymer that is solid and stretchable rather than gooey and potentially leaky.  But it still carries an electric charge and maintains a constant power output even when squeezed, folded or stretched to nearly twice its original length.

The prototype battery is thumbnail-sized and stores only about half as much energy for its size as a conventional battery.  But the researchers are working to increase both the size and the energy density of the battery. 

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A new stretchable battery can power wearable electronics

Photo, posted November 28, 2016, courtesy of Timo Newton-Syms via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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