plentiful

Coal Isn’t Even Cheap Anymore

May 15, 2019 By EarthWise Leave a Comment

Coal has historically been very cheap compared with many other energy sources and the reason is that it is so plentiful. The United States has especially abundant quantities of the stuff – perhaps a quarter of the world’s estimated recoverable reserves. Estimates are that at the rate at which we are currently using coal here, the remaining reserves would last about 325 years.

That would be great, of course, if the use of coal was not relentlessly destructive to the environment, hazardous to human health, and a major driver for global warming. Despite all of that, the Trump administration is a big booster of coal.

But coal has little chance of holding on to its current status, much less having some kind of renaissance. According to a new report from renewables analysis firm Energy Innovation, nearly 75% of coal-fired power plants in the United States generate electricity that is more expensive than local wind and solar resources. Wind power, in particular, can at times provide electricity at half the cost of coal.

Wind and solar power are growing by leaps and bounds. The Guardian reported that by 2025, enough wind and solar power will be generated at low enough prices in the U.S. that it could replace 86% of the entire U.S. coal fleet with lower-cost electricity.

It has been known for some time that there are places where the so-called coal crossover has already taken place. But this is actually far more widespread than previously thought. Substantial coal capacity is currently at risk in North Carolina, Florida, Georgia and Texas. By 2025, Indiana, Michigan, Ohio, and Wisconsin will join their ranks.

The biggest threat to coal is not regulators or environmentalists; it is economics.

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Renewables Cheaper Than 75 Percent of U.S. Coal Fleet, Report Finds

Photo, posted May 1, 2011, courtesy of Alan Stark via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rare Earths From Mining Waste

May 3, 2019 By EarthWise Leave a Comment

The 17 rare earth elements have become important parts of much of modern technology. Despite their name, most of these elements are relatively plentiful in the earth’s crust, but because of their geochemical properties they are typically dispersed and not often found concentrated in minerals. As a result, economically exploitable ore deposits are uncommon. There are no significant sources in the U.S.

Rare earths play important roles in high-performance magnets, electric motors in vehicles, wind turbines, microphones and speakers, and in portable electronics like cell phones. As these applications become ever larger, the need for additional sources of rare earths increases.

Researchers at Idaho National Laboratory and Rutgers University have studied a method for extracting rare-earth elements from mining waste that could greatly increase the world’s supply of these valuable materials.

It turns out that large amounts of rare earths exist in phosphogypsum, a waste product from producing phosphoric acid from phosphate rock. The U.S. alone mined 28 million tons of phosphate rock in 2017. (Phosphoric acid is used in the production of fertilizers and other products).

The researchers estimate that more than a billion tons of phosphogypsum waste sits in piles at storage sites across the U.S. alone. World-wide, about 100,000 tons of rare earth elements per year end up in phosphogypsum waste. This compares to the total current world-wide production of rare earth oxides of 126,000 tons.

The researchers studied methods for extracting the elements from the waste. A method utilizing a common environmental bacterium showed great promise.

There are concerns about residual radioactivity and other environmental issues in dealing with the waste material, but the world’s supply of rare earth elements might become much greater based on this research.

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Critical Materials: Researchers Eye Huge Supply of Rare-Earth Elements from Mining Waste

Photo, posted June 19, 2015, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Coal To Fight Climate Change

April 19, 2019 By EarthWise Leave a Comment

Coal is the most harmful fossil fuel for the environment and, furthermore, for human health. Its use has stubbornly persisted because it is so plentiful and, therefore, cheap. As a result, a big part of efforts to fight climate change is finding a way to remove the carbon dioxide dumped into the atmosphere by the combustion of coal.

Researchers at the Royal Melbourne Institute of Technology in Australia have developed a remarkable technology that in effect reverses the process that has led to soaring CO2 levels in the atmosphere. They have found a way to pull carbon dioxide from the atmosphere and turn it into coal, after which it can be stored cheaply and safely underground.

Most previous carbon capture and storage technologies have focused on compressing carbon dioxide gas into a liquid form and then pumping it into rock formations. Such techniques are rather expensive, require lots of energy, and pose risks that the liquid CO2 could escape from its underground storage sites. More recently, research on solid metal catalysts has led to the possibility of turning CO2 into solid carbon, but most of these reactions require very high temperatures and use a lot of energy.

The new technique developed at RMIT uses a new class of catalysts based on metal alloys. With a small jolt of electricity applied at room temperature, CO2 can be converted into solid carbon – basically, coal.

If this technique can be industrialized economically, it would be like turning back the clock by taking carbon dioxide that entered the atmosphere by the combustion of coal and turning it back into coal and putting it back underground. It seems like excellent environmental justice.

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Scientists Turn Atmospheric CO2 Into Coal

Photo, posted March 16, 2015, courtesy of Will Fisher via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.