geography

Grid-Scale Gravity Energy Storage | Earth Wise

September 19, 2023 By EarthWise Leave a Comment

As wind and solar energy play a growing part in our energy system, the need for grid-scale energy storage is growing as well. An historic form of energy storage and still the largest in installed capacity is pumped hydro storage, which makes use of the potential energy contained in having water sitting at a higher elevation where it can be released downward to operate turbine generators. This is an effective system but is limited to places where geography cooperates.

For the past five years, a company called Energy Vault has been developing a system that uses the same principle to generate electricity but instead of pumping water to a higher elevation, it uses mechanical devices to lift heavy objects such as concrete blocks to an appropriate height. Lowering the blocks back to the ground drives generators.

To date, Energy Vault has only built demonstration systems with a fraction of the storage capacity needed for grid-scale operation. Their EV1 Tower in Switzerland was successfully grid interconnected in 2020 and demonstrated round-trip efficiency (the fraction of the energy stored that was produced by the generators) above 75%. Their improved EVx system is expected to do better than 80%.

This year the company, along with partners Atlas Renewable and China TIanying, is now in the first phases of commissioning a grid-scale system located outside of Shanghai, China. The 25-MW system is built adjacent to a wind farm and a national grid interconnection site

This is the first grid-scale gravity energy storage system and is expected to be fully online in the fourth quarter of this year. A second, similar system is now under contract to be built elsewhere in China.

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First grid-scale gravity energy storage system undergoes commencement in China

Photo courtesy of Energy Vault.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change And Species Tipping Points | Earth Wise

June 22, 2023 By EarthWise Leave a Comment

In climate science, tipping points are critical thresholds that, once crossed, lead to large and often irreversible changes in the climate system. For example, surpassing a 1.5 degree C rise in global warming has long been considered a tipping point for the planet.

According to a new study led by researchers from University College London, climate change will abruptly push species over tipping points as their geographic ranges reach unforeseen temperatures.

In the study, which was recently published in the journal Nature Ecology and Evolution, the research team analyzed data from more than 35,000 species of animals and seagrasses from every continent and ocean basin, alongside climate projections up to 2100. The researchers found a consistent trend: for many animals, the thermal exposure threshold will be crossed for much of their geographic range within the same decade.

The thermal exposure threshold is defined as the first five consecutive years where temperatures consistently exceed the most extreme monthly temperature experienced by a species across its geographic range over recent history.

The researchers also found that the extent of global warming will make a big difference for animals. If the planet warms by just 1.5°C, 15% of species studied will be at risk of experiencing unfamiliarly hot temperatures across at least 30% of their current geographic range in a single decade. But this figure will double to 30% of species at 2.5°C of warming.

Since their data provides an early warning system, the researchers hope that their findings will help species conservation efforts.

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Climate change to push species over abrupt tipping points

Photo, posted May 27, 2017, courtesy of Sarah Lemarié via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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.

Climate Change And The Next Pandemic | Earth Wise

May 26, 2022 By EarthWise Leave a Comment

As the planet continues to heat up, animals big and small are moving towards the poles to escape the heat. According to researchers, these animals are likely to come into contact with other animals that they normally wouldn’t, and are likely to relocate to regions with large human populations. These factors create opportunities for pathogens to get into new hosts, which dramatically increases the risk of a viral jump to humans. Climate change could lead to the next pandemic.

An international research team led by scientists at Georgetown University recently made this connection between climate change and viral transmission. In the study, which was recently published in the journal Nature, researchers conducted the first comprehensive assessment of how climate change will restructure the global mammalian virome. Their work focused on geographic range shifts.

As animals eccounter other animals for the first time, the study projects that they will share thousands of viruses. And as animals increasingly move into the same areas as humans, there will be greater opportunities for these viruses to jump to humans. The research team says that the impact on conservation and human health could be alarming as viruses jump between species at unprecedented rates.

In our warming world, much of this process may unfortunately already be underway. And efforts to reduce greenhouse gas emissions may not be enough to stop these events from unfolding.

According to the study, climate change will become the biggest upstream risk factor for disease emergence, eclipsing deforestation, industrial agriculture, and the wildlife trade. Pairing wildlife disease surveillance with real-time studies of environmental change may be part of the solution to predicting and preventing the next pandemic.

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