capturing

Harvesting Fresh Water From Ocean Air | Earth Wise

January 19, 2023 By EarthWise Leave a Comment

Roughly three-quarters of the world population has access to a safely managed water source. That means that one-in-four people do not have access to safe drinking water. Even in the wealthy United States, persistent drought in the west is creating problems in places like Phoenix, Arizona.

Water is plentiful on Earth but more than 99% of it is unusable by humans and many other living things because it is saline, frozen, or inaccessible. Only about 0.3% of our fresh water is found in the surface water of lakes, rivers, and swamps.

There is an almost limitless supply of fresh water in the form of water vapor above the oceans, but this source is untapped. Researchers at the University of Illinois have been evaluating the feasibility of a hypothetical structure capable of capturing water vapor from above the ocean and condensing it into fresh water.

Existing ways to obtain fresh water like wastewater recycling, cloud seeding, and desalination have met only limited success and present various problems with regard to cost, environmental impact, and scalability.

The researchers have proposed hypothetical large offshore structures measuring 700 feet by 300 feet to capture water vapor that is continually evaporating from the ocean in subtropical regions. Their modeling concluded that such structures could provide fresh water for large population centers in the subtropics. Furthermore, climate projections show that the amount of water vapor over the oceans will only increase over time, providing even more fresh water supply.

This is only a theoretical study at this point, but the researchers believe it opens the door for novel infrastructure investments that could address global water scarcity.

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Researchers propose new structures to harvest untapped source of fresh water

Photo, posted June 28, 2009, courtesy of Nicolas Raymond via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Capture: Solution Or Band-Aid? | Earth Wise

July 13, 2022 By EarthWise Leave a Comment

The idea of capturing the CO2 emissions from industry and locking them up is nothing new. It’s been going on for decades in some places. Norway’s state-owned oil company Equinor has been holing away a million tons of CO2 a year for a long time. But overall, CCS – carbon capture and storage – has had very limited use. As of last year, there were only about 30 large-scale projects in operation around the world, capturing only 0.1% of global emissions.

There is now growing interest in CCS and many new projects are underway. A combination of rising carbon prices in Europe, tax breaks for CCS in the US, national net-zero targets, and the increasing need to ramp down global emissions are all driving rising CCS activities.

While recent reports from the Intergovernmental Panel on Climate change still claim that it is possible to remain below 2 degrees Celsius of warming without using carbon capture, there is growing belief that it may be necessary given the present pace of the transition away from fossil fuels.

Two industries that together produce about 14% of global CO2 emissions are cement and steel. These are both industries for which it is difficult to eliminate emissions regardless of the energy sources used. CCS may be the best approach to reducing their emissions.

But there is considerable pushback against CCS. The concern is that CCS is primarily a way to delay decarbonization. It encourages various industries to continue to use fossil fuels instead of shifting away from them. Nonetheless, CCS no doubt has its place as part of the solution to climate change.

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Solution or Band-Aid? Carbon Capture Projects Are Moving Ahead

Photo, posted June 5, 2022, courtesy of Mark Dixon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Storing Sunshine To Make Electricity On Demand | Earth Wise

June 1, 2022 By EarthWise Leave a Comment

Researchers at Chalmers University in Sweden have developed an entirely new way of capturing and storing energy from sunlight. The system is called the Molecular Thermal Energy Storage System or MOST. It is based on a specially designed molecule that changes shape when it is exposed to sunshine.

The molecule is composed of carbon, hydrogen, and nitrogen. When sunlight hits it, it changes into an energy-rich isomer – a molecule made up of the same atoms but arranged together in a different way. That isomer is stable and can be stored for many years. When a specially designed catalyst is applied, the stored energy is released in the form of heat and the molecule returns to its original form and can be reused.

The Chalmers researchers sent some of the energy-laden isomer to researchers in China who used it to operate a micron-thin thermoelectric generator, which used the heat released by the isomer material to generate electricity. The generator is an ultra-thin chip that could be integrated into electronics such as headphones, smart watches, and telephones. It is currently only at the proof-of-concept stage, but the results are quite promising. The integration with the MOST technology provides a way that solar energy can generate electricity regardless of weather, time of day, season, or geographical location. The results of the study were recently published in the journal Cell Reports Physical Science.

In effect, for this demonstration, Swedish sunshine was sent to the other side of the world and converted into electricity in China. The ultimate goal of this research is to create self-charging electronics that uses stored solar energy on demand.

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Converting solar energy to electricity on demand

Photo, posted March 11, 2013, courtesy of Steve Slater via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.