discharge

Battery life in electric cars

January 9, 2025 By EarthWise Leave a Comment

Most of us have lots of experience with the batteries in phones, computers, and other gadgets. Batteries don’t last forever, and we sometimes have to replace them. It’s a fact of life. These days, it’s becoming more common to drive electric cars and the fundamental principle is the same. However, the battery pack in an EV is the most expensive part of the car, so its reliability and lifespan is a greater concern.

EV batteries generally have generous warranties. In the US, EV batteries are required by federal law to be covered for at least 8 years or 100,000 miles, whichever comes first. So, the financial exposure from the battery pack is reasonably limited. Even so, EV owners would like to know that their car’s battery pack is likely to last a long time.

Battery life is generally determined by laboratory tests involving repeated charge-discharge cycles over a relatively short period of time, as opposed to those cycles being spaced out over years.

A new study by Stanford University looked at battery performance under conditions much more like what would be experienced in the real world. Cars experience frequent acceleration, braking that charges the batteries a bit, lots of stops, periods of rest, and so forth. Nothing like just charging and discharging repeatedly.

The study found that today’s EV batteries may last up to 40% longer than expected. Real-world stop-and-go driving benefits batteries more than standard test conditions.

The cost of EV batteries continues to get lower all the time and it is likely to be quite a long time before one is likely to need a new battery assuming one even keeps the car long enough.

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Existing EV batteries may last up to 40% longer than expected

Photo, posted August 27, 2021, courtesy of Ron Frazier via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rising Seas And Wastewater Leakage | Earth Wise

April 28, 2021 By EarthWise Leave a Comment

Global mean sea level has risen nearly 9 inches since 1880, with over two inches of that over just the last 25 years. The rising water level is primarily due to two factors: additional water in the oceans coming from melting glaciers and ice sheets; and the thermal expansion of seawater as it warms. Climate models estimate that over the course of the century, global sea levels will rise at least a foot even if efforts to reduce greenhouse gas emissions are quite successful and, in the worst case, levels could rise as much as 8 feet.

Faced with this situation, the greatest concerns are, initially, increasing amounts of coastal flooding and erosion and, as things get worse, inundation of coastal regions making many places uninhabitable and creating millions of climate refugees.

Recently, computer modeling studies have focused on an additional imminent problem: the flooding of coastal wastewater infrastructure, which includes sewer lines and cesspools.

A new study by the University of Hawaii at Manoa is the first to provide direct evidence that tidally driven groundwater inundation of wastewater infrastructure is already occurring in urban Honolulu. The study shows that higher ocean water levels are leading to wastewater entering storm drains and the coastal ocean. The result is degradation of coastal water quality and ecological health.

The researchers used chemical tracers to detect groundwater discharge and wastewater present at multiple low-lying areas during spring tides. During high tides, storm drains become channels for untreated wastewater to flood streets and sidewalks.

People tend to think of sea-level rise as a future problem, but there are already serious effects going on today that are only going to get worse.

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Sea-level rise drives wastewater leakage to coastal waters

Photo, posted August 23, 2011, courtesy of Eric Tessmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Victory For Clean Water | Earth Wise

May 19, 2020 By EarthWise Leave a Comment

Many of the nation’s environmental laws are under siege from the current administration, but a recent decision by the U.S. Supreme Court has solidified the Clean Water Act’s place as one of the country’s most effective environmental laws.

The case in question was about whether a wastewater treatment plant in Maui has been violating the Clean Water Act by polluting the ocean indirectly through groundwater. Since the 1980s, the Lahaina wastewater treatment facility has been discharging millions of gallons of treated sewage each day into groundwater that reaches the waters off of Kahekili Beach, which is a popular snorkeling spot. Groundwater, like any water beneath the land’s surface, can flow into major waterways such as rivers, streams, and, in this case, the ocean.

In 2012, the nonprofit Earthjustice sued Maui county on behalf of four Maui community groups. Over the years, the Hawaii district court and the 9^th Circuit appeals court ruled in favor of Earthjustice. Last year, Maui County successfully petitioned the U.S. Supreme court to hear the case, which could have endangered the Clean Water Act.

On April 23, by a 6-3 vote, the court ruled that point source discharges to navigable waters through groundwater are regulated by the Clean Water Act when the addition of pollutants through groundwater is the functional equivalent of a direct discharge into navigable waters.

With this ruling, the Court rejected the Trump administration’s polluter-friendly position in the clearest of terms. According to the opinion, written by Justice Breyer, the Court could not see how Congress could have intended to create such a large and obvious loophole in one of the key innovations of the Clean Water Act. This is a victory for clean water.

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The Clean Water Case of the Century

Photo, posted June 30, 2018, courtesy of Kirt Edblom via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.