retired

Electric trains are healthier

May 7, 2025 By EarthWise Leave a Comment

The majority of commuter trains in the U.S. are powered by diesel fuel. This is despite the fact that electric trains are quieter, more reliable, and produce fewer greenhouse gases than diesel locomotives. A new study has found that electric trains are healthier for passengers as well.

Caltrain carries millions of passengers a year along a 47-mile route between San Francisco and San Jose. It is the busiest commuter rail system in the western U.S. Over a six-week period beginning in August 2024, Caltrain retired all 29 of its diesel locomotives and replaced them with electric trains.

As the process began, an environmental engineering and environmental health professor at UC Berkeley noticed the rapid change in the air aboard the trains and decided to study its potential health impacts. With the support of Caltrain, he installed black carbon detectors aboard the trains and tracked the improvements in air quality as old diesel locomotives were being replaced by new electric trains.

Statistical analysis of the reduction in black carbon exposure achieved by the change predicted a reduction in excess cancer deaths by 51 per million people for passengers and 330 per million people for train conductors. EPA policy states that any exposure that increases the average individual’s cancer risk by more than one per million is considered unacceptable.

In the context of the whole U.S. where millions of people commute by rail every day, the study predicts that hundreds of cases of cancer could be prevented each year. California has long-term plans to electrify most of its rail systems. The study indicates that the process shouldn’t be carried over the next 25 years but rather be sped up.

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Electric trains are quieter, more reliable than diesel. New study finds they’re healthier, too.

Photo, posted September 4, 2024, courtesy of J. Kehoe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Artificial reefs

May 8, 2024 By EarthWise Leave a Comment

The coral reefs that surround tropical islands are a refuge for a wide variety of marine life and also form a natural buffer against stormy seas. The changing climate is bleaching coral reefs and breaking them down. Extreme weather events are becoming more common and are threatening coastal communities with flooding and erosion.

Researchers at MIT are designing architected reefs – sustainable offshore structures that mimic the wave-buffering effects of natural reefs and can also provide habitats for fish and other marine life.

There are already artificial reefs in a number of places used to protect coastlines. These are typically made from sunken ships, retired oil and gas platforms, and even assemblies of concrete, metal, car tires, and stones. Generally, it takes quite a lot of material to form an effective barrier to waves.

The MIT group has developed a cylindrical structure surrounded by four rudder-like slats. Their experiments have shown that when this structure stands in the way of a wave, it efficiently breaks the wave and creates turbulent jets that dissipate the energy in the wave. The engineers calculated that the new design could reduce as much wave energy as existing artificial reefs but use 10 times less material.

Based on the initial experiments with lab-scale prototypes, these artificial reefs would reduce the energy of incoming waves by more than 95%.

Coral reefs are only found in tropical waters, whereas these artificial reefs don’t depend on temperature and could be placed along any coastline for protection. In a time of rising seas and increasingly frequent storms, these artificial reefs may be just what coastlines need.

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Artificial reef designed by MIT engineers could protect marine life, reduce storm damage

Photo, posted December 9, 2010, courtesy of Phoenix Wolf-Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling Solar Panels | Earth Wise

September 29, 2023 By EarthWise Leave a Comment

Solar panels generally have a useful life of around 20 to 25 years. The great majority of deployed panels have been installed fairly recently, so they have a long way to go. But the growth in solar technology dates back to the 1990s, so there are growing number of panels that have already or are shortly coming to their end-of-life.

Today, roughly 90% of solar panels that have lost their efficiency due to age, or that are defective, end up in landfills because recycling them is too expensive. Nevertheless, solar panels contain valuable materials, including silver, copper, and crystalline silicon, as well as lower-value aluminum and glass.

The rapid growth of solar technology means that in the coming years, large numbers of retired solar panels will enter the waste stream. The area covered by solar panels that are due to be retired by 2030 in the U.S. alone would cover about 3,000 football fields. Clearly, more cost-effective recycling methods are sorely needed.

Engineers at the University of New South Wales in Sydney Australia have developed a new, more effective way of recycling solar panels that can recover silver at high efficiency. The panel frames and glass are removed leaving just the solar cells themselves. The cells are then crushed and sieved in a vibration container that effectively separates 99% of the materials contained in them.

Silver is the most valuable material contained in solar cells. The Australian researchers estimate that between 5 and 10 thousand tons of silver could potentially be recycled from retired solar panels by the year 2050. But even the other materials contained in solar panels are well worth recovering if it can be done cost-effectively.

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New environmentally friendly solar panel recycling process helps recover valuable silver

Photo, posted November 22, 2008, courtesy of Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling Coal Plants | Earth Wise

April 27, 2020 By EarthWise Leave a Comment

Over 300 coal-fired power plants in the US have stopping burning coal over the past decade. Only about 224 plants still produce power by burning coal. As a result, a new sort of recycling industry is taking shape: repurposing of coal plants.

Across the country, utilities are finding ways to redevelop these facilities. Some are industrial in nature and others a far cry from their original purpose.

In January, Beloit College in Wisconsin opened a student union and recreation center in what used to be an Alliant Energy coal-fired power plant. On the southern coast of Massachusetts, a shuttered 1,600 MW coal plant is being demolished to make way for a logistical port and support center for a planned wind farm 35 miles off shore.

In Independence, Missouri, the city is considering competing plans to recycle the Blue Valley Power plant. It may become a 50 MW battery storage facility, or possibly a biofuel plant.

Another popular reuse strategy is data centers. Data centers use tremendous amounts of power and therefore can make use of the former coal plants’ capacity to handle large amounts of electricity.

Retired coal-fired plants have built-in infrastructure and components that can be repurposed for new industry. The plants typically have access to rail, ports and waterways, as well as proximity to good highway transportation. The electrical grids to which they are connected can be reused for solar or wind farms at the site.

Given that coal plants are continuing to close, the potential to redevelop them in various ways continues to grow as well. There is a surge in interest in coal plant redevelopment because these facilities are assets of value.

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Coal-fired power plants finding new uses as data centers, clean energy hubs

Photo, posted January 10, 2017, courtesy of Rusty Clark via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Taking Over In Britain

March 14, 2019 By EarthWise Leave a Comment

A year-and-a-half ago, we reported on the steep decline in the use of coal in Britain, including the conversion of the giant Drax Power Station from burning coal to running on wood chips. Since then, Britain has been steadily moving away from fossil fuels and towards renewable energy sources. The transformation is being driven by a surge in offshore wind farms currently under construction or about to begin operating. Britain is in the process of adding over 6 GW of offshore wind to its current total of 8 GW. Renewables generated one-third of the UK’s electricity last year, and half of that came from wind power.

In 2018, coal- and gas-fired power stations generated about 131 terawatt-hours of electricity in Britain. Renewable energy plants – including wind, solar, biomass, and hydropower – produced about 96 terawatt-hours. Based on the new projects coming online, renewable sources could generate 121 TWh by 2020 and fossil fuel plants are likely to fall to 105.6 TWh as more coal plants are retired. Thus, within the next year or so, renewables in Britain are likely to surpass fossil fuels in electricity generation.

The transformation in Britain has been rapid and dramatic. In 1974, the country generated 80% of its electricity using coal. By 2016, that number had dropped to 9%. Last April, the British power grid went three days in a row without burning any coal. The UK is expected to shut down its remaining coal plants by 2025, if not sooner.

At the same time, Britain’s renewable energy capacity has more than quadrupled since 2010, jumping from 21 TWh that year to 96 TWh last year. Britain’s energy mix is changing fast and getting significantly cleaner every year.

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Renewables Could Surpass Fossil Fuels in Britain by 2020

Photo, posted August 2, 2008, courtesy of Richard Allaway via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.