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Planting Rocks To Capture Carbon | Earth Wise

September 8, 2023 By EarthWise Leave a Comment

Getting humanity to stop dumping carbon dioxide into the atmosphere continues to be very challenging regardless of how increasingly apparent the need to do so becomes. For this reason, climate change mitigation strategies increasingly include interventions in the form of removing carbon dioxide that is already there. There are a variety of ways to draw carbon dioxide out of the atmosphere, but they face a host of technological, economic, and even environmental difficulties.

A new study at Yale University evaluated a type of climate intervention called enhanced rock weathering. Rock weathering is a natural chemical process by which certain minerals absorb carbon dioxide over time. Enhanced rock weathering is simply speeding up weathering such so it can have beneficial results soon enough to make a difference.

The study explored the potential of applying crushed basalt, which is a fast-weathering rock that forms when lava cools, to agricultural fields around the world. Basically, the idea is for farmers to mix the crushed rocks into their fields. There is no real downside to doing this. In fact, adding crushed basalt to fields rejuvenates depleted soils and helps counter ocean acidification.

The study simulated the results of enhanced rock weathering on 1,000 agricultural sites around the world. Over a 75-year period, these sites would remove 64 billion tons of carbon dioxide from the atmosphere. This is roughly the amount climate scientists believe is needed to take out of the atmosphere.

Enhanced rock weathering has been used on a small scale on farms around the world. Perhaps it is time to ramp up its use.

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‘Planting’ rocks in farms, along with emissions reductions, could help meet key IPCC carbon removal goal

Photo, posted January 14, 2023, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Renewable Energy | Earth Wise

July 22, 2021 By EarthWise Leave a Comment

A team of researchers at Texas A&M University believes that the next generation of offshore energy could come in the form of a synergistic combination of multiple renewable energy generators installed on a floating offshore platform.

Their concept for the ocean renewable energy station comprises wind, wave, ocean current, and solar energy elements that could generate electricity for anything from a coastal or island community to a research lab or military unit. The station would be tethered to the sea bottom and could be used in locations where the water depth increases quickly, such as along the U.S. Pacific Coast or Hawaii.

Offshore wind is already commercially competitive, while wave-energy converters so far have been less cost-effective and only useful for specialized, smaller-scale applications. The proposed ocean renewable energy station would make use of multiple different methods of electricity generation and incorporate innovative smart materials in the wave energy converters that respond to changes in wave height and frequency and allow for more consistent power production.

Denmark is already building a huge multi-source, multi-purpose ocean energy island. This world’s first energy island will be 30 acres in area and serve as a hub for 200 giant offshore wind turbines generating 3 GW of electric power. It is the largest construction project in Danish history, and will cost an estimate $34 billion. As well as supplying other European countries with electricity, the goal is to use the new offshore island to produce green hydrogen from seawater, which can also be exported. Large battery banks on the island will store surplus electricity for use in times of high demand.

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Research Underway On Floating Renewable Energy Station

Photo, posted September 27, 2014, courtesy of Eric Gross via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Using CO2 To Convert Seawater Into Drinking Water | Earth Wise

October 27, 2020 By EarthWise Leave a Comment

A chemist at the University of Copenhagen has invented a technology that uses carbon dioxide to convert seawater into drinking water within minutes. This desalination technology has the potential to replace electricity with CO2 and be used in survival gear and in large-scale industrial plants in places where people don’t have clean drinking water.

Over 800 million people worldwide lack access to clean drinking water and that number is growing rapidly. Seawater is a vital source of drinking water in many parts of the world, but desalination faces the major challenge of being highly energy intensive. Desalination plants use huge amounts of fossil fuel-generated electricity and therefore contribute to climate change.

The Copenhagen technology is reminiscent of a SodaStream machine. Carbon dioxide is added to water, initiating a chemical reaction. But instead of using it for bubbly carbonation, it is used to separate salt from water. It works by adding a chemical called CO2-responsive diamine to saltwater. The diamine compound binds with the added CO2 and acts as a sponge to absorb the salt, which can then be separated. The entire process takes one to ten minutes. Once the CO2 is removed, the salt is released again, allowing the diamine to be reused for several more rounds of desalination.

In the laboratory, the method removed 99.6% of the salt in seawater. The technology is still being developed to lower its price and optimize the recycling process. It is also being tested on a small scale in the form of water bottles fitted with special filters that can be used in lifeboats or in other outdoor settings. Ultimately, it could be used to greatly reduce the energy consumption of desalination plants.

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Chemist uses CO2 to convert seawater into drinking water

Photo, posted January 10, 2015, courtesy of Daniel Orth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Solar And Wind Power In The U.S.

January 2, 2020 By EarthWise Leave a Comment

According to the U.S. Energy Information Administration, both wind and solar power are contributing more and more to total electrical generation in the United States. For the first 8 months of 2019, the combination of wind and solar power accounted for almost 10% of U.S. electrical generation.

Solar, including small-scale PV systems on home rooftops, grew by almost 14% compared to the first eight months of 2018 and accounted for more than 2.7% of total electrical output. In fact, small-scale solar generation increased by 19% and provided nearly a third of all the solar power in the country.

Wind energy in the U.S. increased by 4.4%, accounting for almost 7% of the country’s electricity.

Overall, renewable energy sources – which include biomass, geothermal, hydropower, solar, and wind – accounted for 18.49% of net domestic electrical generation during the first 8 months of 2019. The non-hydro renewable sources actually accounted for over 11% of total electricity production and saw a year-over-year growth of 6%.

Outside of renewables, nuclear-generated electricity declined by 0.6% and coal power dropped by almost 14%. Much of the coal generation was replaced by natural gas, which grew by 6.5% compared to the previous year.

Renewables now accounting for nearly 20% of overall electricity generation in the US represents significant progress. But the variations by state continue to be substantial. For example, while Vermont gets 99% of its power from renewables, Ohio gets only 2%.

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Solar and wind energy provide almost 10 percent of total generation in the US in 2019

Photo, posted April 8, 2019, courtesy of City of St. Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cooling Cities With White Roofs

April 16, 2018 By EarthWise Leave a Comment

The phenomenon of urban heat islands has been well known since the 19th century. The materials from which city buildings and roads are made reflect much less solar radiation and absorb more of it than the vegetation they have replaced. The absorbed energy is then radiated in the form of heat into the surrounding air making cities warmer.