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Pumped Hydro Storage In Switzerland | Earth Wise

September 15, 2022 By EarthWise Leave a Comment

Pumped hydro energy storage is still by far the largest form of energy storage in the world, representing more than 90% of storage capacity worldwide. The theory behind it is simple. Water is pumped into an upper reservoir (that is, one at a higher elevation), and when electricity is needed, the water is allowed to flow downhill to power turbines and then is collected in a lower reservoir. When there is excess electricity, it is used to pump water back uphill for use later.

Pumped hydro installations can’t be built just anywhere. Geography and hydrology have to be suitable, which means high voltage transmission lines need to be constructed to link electricity sources like wind and solar farms with the storage location. But in those situations where pumped hydro makes sense, it is a great solution to the energy storage problem.

Switzerland has just completed one of the largest pumped hydro facilities in the world. The Nant de Drance installation makes use of the Emosson reservoir, which is an artificial lake built high in the Alps near the French border. Over the past 14 years, 10 miles of tunnels have been dug into the mountains to connect the Emosson reservoir to the Vieux Emosson reservoir to the south.

In between the two reservoirs is a giant underground cavern where six of the largest water-driven turbines in the world are spun from the water rushing down from above. The turbines have a capacity of 900 megawatts, making Nant de Drance one of the most powerful generating plants in Europe. In terms of storage capacity, the installation has a maximum capacity of 20 gigawatt-hours, and can store that energy indefinitely, which is challenging for other storage technologies.

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14 Years In The Making, 20 GWh Pumped Hydro Storage Facility Comes To Switzerland (With Video)

Photo, posted September 7, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solid State Batteries For Cars | Earth Wise

January 7, 2022 By EarthWise Leave a Comment

Today’s electric cars run on lithium-ion batteries, the same sort that power our phones, computers, and many other consumer electronic devices. These batteries are far superior to the batteries of the past, offering long-life, high-energy density, and recyclable components.

Lithium-ion batteries do have their drawbacks. They may be lighter than older battery technologies, but because the electrolytes in the batteries are liquid, they are still fairly heavy. The huge number of them in an electric car adds up to a considerable amount of weight. In addition, the flammability of the electrolytes can lead to explosions or fires if the batteries are damaged or exposed to extreme temperatures.

Solid-state batteries are an alternative technology that contain a solid electrolyte. Such batteries are lighter, have higher energy density, offer more range, and recharge much more quickly than lithium-ion batteries. They have been used for years in some small devices like cardiac pacemakers, RFIDs, and some wearable devices.

For all these benefits, scaling up production to the level needed to be used in cars is an expensive and challenging endeavor. The hope is that with sufficient effort, the result will be smaller, lighter battery packs for cars that can be charged in minutes and provide extended range.

Nissan Motor Company has recently announced that it is investing $17.6 billion over the next five years towards developing solid-state batteries for cars. No doubt other companies will also be working on the technology.

Lithium-ion batteries have proven to be quite practical for powering vehicles. But if solid-state batteries can meet the challenges of scaled up production, the lithium-ion era might end up being a relatively brief one.

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Nissan to Spend $18 Billion Developing a Cheaper, More Powerful EV Battery

Photo, posted November 13, 2018, courtesy of FirstEnergy Corp via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Roads And Chimpanzees | Earth Wise

November 8, 2021 By EarthWise Leave a Comment

The chimpanzee is a species of great ape native to tropical regions of Central and West Africa. Chimpanzees are highly social animals and can live to be over 50 years old. In fact, chimpanzees are our closest cousins. We share about 98% of our genes with chimpanzees.

According to the African Wildlife Federation, it’s estimated that at most only 300,000 chimpanzees remain in the wild today. They face a myriad of challenges, including habitat degradation and hunting.

According to new research from the University of Exeter in the U.K., roads have a negative impact on chimpanzee populations that can extend for several miles. In the study, which was recently published in the journal Conservation Letters, the researchers analyzed the impact of major and minor roads on wild western chimpanzee numbers in the eight African countries in which they live. They found that negative impacts extended an average of 10.7 miles from major roads, and 3.4 miles from minor roads. The researchers found that the density of chimpanzee populations dropped steadily from the edges of these areas to the lowest value alongside the roads. Only 4.3% of the chimpanzees’ range remains unaffected by roads.

While the study did not investigate why roads affect chimpanzee numbers, the research team did offer some clues. In addition to noise and roadkill, roads provide access to unexploited areas for industries that often reduce or remove chimpanzee habitats. Roads can also restrict chimpanzee movements, and provide easier access for hunters.

The researchers hope their findings will bring about more effective guidelines to mitigate the impact of roads on wildlife.

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Roads have far-reaching impact on chimpanzees

Photo, posted August 12, 2014, courtesy of Rod Waddington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tracking Ocean Plastics | Earth Wise

July 30, 2021 By EarthWise Leave a Comment

Plastic pollution in the oceans is a major problem. An estimated 8 million tons of plastic trash enters the ocean every year. Most of it is broken up by sun and waves into microplastics, which are tiny bits that ride currents for hundreds or thousands of miles. All of this debris is harmful to marine ecosystems, and it is both challenging to track and very difficult to clean up.

University of Michigan researchers have developed a new technique for spotting and tracking ocean microplastics across the globe. The approach relies on the Cyclone Global Navigation Satellite System, or CYGNSS, which is a constellation of eight microsatellites launched in 2016 to monitor weather near large storm systems. It turns out that the radar systems on CYGNSS that measure surface roughness to calculate the wind speed near the eyes of hurricanes can also be used to detect the presence of microplastics.

With the satellite measurements, the researchers have found that global microplastic concentrations tend to vary by season, peaking during the summer months. For example, June and July are the peak months for the Great Pacific Garbage Patch. The data also showed spikes in microplastic concentration at the mouth of China’s Yangtze River, long suspected to be a chief source of plastic pollution. The researchers produced visualizations that show microplastic concentrations around the world.

The information provided by the new technique could help organizations that clean up microplastics to deploy ships and other resources more efficiently. Data of single-point release of plastics, such as from rivers, may also be useful to UNESCO, which has sponsored a task force to find new ways to track the release of microplastics into the world’s waters.

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Ocean microplastics: First global view shows seasonal changes and sources

Photo, posted April 3, 2018, courtesy of Rey Perezoso via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.