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Progress towards electric school buses

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The U.S. has nearly half a million school buses providing daily transportation for about 20 million students.  Most of these buses are powered by diesel engines which not only dump greenhouse gases into the atmosphere but also fill kids’ lungs with harmful fumes.

Thanks to various federal and state incentive programs, this situation is starting to change.  School districts all over the country are beginning to swap out old diesel buses for emissions-free electric-powered school buses.

Electric school buses are finding their way into school districts of all sizes and demographics.  The first district in the country to go fully electric was in Martinsville, Texas, which last year converted its 4-bus fleet.  The first large urban district to go all-electric was the 74-bus fleet in Oakland, California this summer.

The EPA’s $5 billion Clean School Bus program and many state initiatives are providing incentives for the transition.  Five years ago, there were less than 1,000 electric school buses in the U.S.  Now there are about 5,000 and more than 7,000 additional buses are in the pipeline.

Apart from the climate implications, there is urgency to replacing diesel school buses from a health perspective.  Diesel exhaust is classified as a carcinogen by the World Health Organization, and it contains fine particles and nitrogen oxides, both of which are well-documented asthma triggers.

Electric buses are more expensive than diesel buses, but they are much cheaper to operate. School districts need to put in place charging infrastructure.  The transition is not so easy to accomplish, but it is an important step, and more and more school districts are taking it.

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Slowly but Surely, U.S. School Buses Are Starting to Electrify

Photo, posted May 5, 2021, courtesy of California Energy Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Benefits of electric school buses

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There are about half a million school buses in use in the U.S.  A large number of them are older, highly polluting diesel buses.  There are well-established health and climate benefits of switching from diesel vehicles to electric vehicles but making the switch is expensive.  Diesel buses generally cost between $65,000 to $120,000, depending on the type and configuration.  Electric buses cost about $250,000 each.

The substantial cost makes it a difficult decision for local, state, and federal officials, particularly since the actual magnitude of the benefits is not well known.

A new study by researchers at Harvard’s T.H. Chan School of Public Health has quantified these benefits.  According to the study, replacing each bus may yield up to $247,600 in climate and health benefits. These benefits derive from fewer greenhouse gas emissions and from reduced rates of adult mortality and childhood asthma. 

The study compared the amounts of carbon dioxide emitted from diesel bus tailpipes to the emissions associated with generating electricity for the buses and producing their batteries.  It also compared how these respective emissions contribute to fine particulate air pollution, which is linked to adult mortality and the onset of childhood asthma.  The study concluded that particularly in dense urban settings, the savings incurred from electrifying older school buses easily outweigh the costs of replacing them.

An important question not tackled in the study is how electric school buses impact children’s exposure to in-cabin air pollution while riding the bus.  This issue could further inform policy decisions.

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Electric school buses may yield significant health and climate benefits, cost savings

Photo, posted May 9, 2008, courtesy of Christine H. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Cars In Norway | Earth Wise

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We are at a relatively early stage of the electric car revolution.  EV sales are increasing rapidly, but they still comprise only a small fraction of the cars on American roads.  So, there is still lots of speculation and argument about how things will actually work when a large fraction of cars are electric.  But there is at least one place where one doesn’t have to speculate:  Norway.

Last year, 80% of new-car sales in Norway were EVs.  That country is essentially an observatory for figuring out what the electrification of vehicles will mean for the environment, workers, and life in general.  In fact, sales of internal combustion cars in Norway will end in 2025.

Based on Norway’s experience, electric vehicles bring benefits and none of the dire consequences that some critics predict.  The transition isn’t problem-free.  There have been unreliable chargers and long waits during periods of high demand.  Auto dealers and retailers have had to adapt to the changes in their businesses.  The pecking order of car brands has changed dramatically making Tesla the best-selling brand and marginalizing long-established carmakers like Renault and Fiat.

But in the bigger picture, the air in Oslo, the capital of Norway, is measurably cleaner.  The city is quieter as noisy gasoline and diesel vehicles gradually disappear.  Oslo’s greenhouse gas emissions have fallen 30% since 2009.  Meanwhile, there hasn’t been mass unemployment among gas station workers, and the electrical grid has not collapsed.

Norway is perhaps 10 years ahead of us with respect to electric cars.  There are still problems to solve, and difficulties to overcome, but so far, it looks like it will all turn out well.

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In Norway, the Electric Vehicle Future Has Already Arrived

Photo, posted October 15, 2018, courtesy of Mario Duran-Ortiz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning Up Diesel With Bacteria | Earth Wise

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Mothballed military outposts with piles of rusting oil drums are not an unusual sight in Greenland.  There are about 30 abandoned military installations in Greenland and diesel that was once used to operate generators and other machinery has, in many cases, seeped into the ground.

Removing tons of contaminated soil from these sites is incredibly resource-intensive involving the use of aircraft and ships, so it has not really been practical.  As a result, Danish Defense and the engineering company NIRAS instead conducted a five-year experiment to optimize the conditions for naturally occurring soil bacteria to break down the contaminating diesel.

The experiment was performed at Station 9117 Mestersvig, an abandoned military airfield on the coast of East Greenland.  Forty tons of diesel fuel contaminated the soil there.

The remediation method using bacteria is known as landfarming and has most often been applied in warmer climates around the world.  This was the first large-scale test under Arctic conditions.

Landfarming works by distributing contaminated soil in a thin layer, which is then plowed, fertilized, and oxygenated every year to optimize conditions for bacteria to degrade hydrocarbons.

The site was monitored by scientists from the University of Copenhagen, and they found that after five years, the bacteria had bioremediated as much as 82 percent of the 5,000 tons of contaminated soil on the site. 

Based on these results, it appears to be feasible for naturally occurring bacteria to be used to remediate contamination in all of the 30 deserted military installations in Greenland as well as in other Arctic sites contaminated by diesel pollution.

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Bacteria used to clean diesel-polluted soil in Greenland

Photo, posted September 6, 2013, courtesy of Maj. Matthew J. Sala/The U.S. Air National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Have We Reached Peak Internal Combustion Engine? | Earth Wise

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According to new analysis from Bloomberg New Energy Finance, global sales of gas-powered cars may well have peaked in 2017, representing a significant milestone in the transition to electric vehicles.

Demand for gas cars dropped in 2018 and 2019, and then plummeted in 2020 as a result of the coronavirus pandemic.  While sales are surely picking up as the pandemic ebbs, the increasing demand (and supply as well) for plug-in vehicles is likely to put gas-powered cars in a state of permanent decline.

Global EV sales are projected to go from 3.1 million last year to 14 million in 2025.  The growth is being driven by falling battery prices, government policies, and increasing choices of vehicles.  Virtually all automobile manufacturers are introducing electric vehicles over the next couple of years and increasing numbers of them are planning a complete transition to EVs in the near future.  Projections are that EVs will account for the majority of new car sales by 2035.

While all this progress is encouraging, there are still over a billion gas- and diesel-powered cars on the road and the fleet turns over slowly.  The current average operating life of cars here in the US is 12 years.

To reach the net-zero carbon emission goals by 2050 as many governments have mandated, additional policies and regulations will be needed.  For example, electric cars will need to account for essentially all new sales by 2035, not just the majority.  Reaching net-zero by mid-century will require all hands on deck, including trucks and heavy commercial vehicles that have barely started to become electrified.

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New Analysis Suggests We Have Already Hit Peak Internal Combustion Engine

Photo, posted December 23, 2017, courtesy of Davide Gambino via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildlife Reclaims Yosemite National Park | Earth Wise

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Our stories often discuss how human activities change the natural environment.  With most of us confined to our homes, the lack of human activities is having profound effects on the environment.  We are talking about some of these this week.

Yosemite National park is normally awash in humanity – there were over 300,000 visitors in April of 2019 and typically 4 million people visit each year.  But as of March 20, the park was closed to tourists to prevent the spread of the coronavirus.  Only a skeleton crew of employees remains in the park.

Without all the people, wildlife is coming out of hiding.  It did so in previous park closures during government shutdowns, but those closures were pretty short.  This one is expected to be the longest on record.

The bear population within the park has quadrupled and many larger animals – such as bobcats and coyotes – are congregating outside of cabins and other buildings and prowling empty roads and walkways instead of hanging back at the edges of human settlements. 

In addition, the air at Yosemite is cleaner due to the lack of exhaust and diesel, and Yosemite Valley is nearly silent, apart from natural sounds from the river and the wind.  According to some observers, the park’s current condition is probably similar to what visitors in the 19th century witnessed. 

The few park employees sheltering in place are taking advantage of the virtually unimpeded natural amenities of the park.  Many are hiking to its lakes and waterfalls, enjoying trails that are empty apart from animals.  As some of the people staying in the park have noted, one could not ask for a better place to be isolated.

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Coyotes, bobcats and bears: Wildlife is reclaiming Yosemite National Park

Photo, posted October 30, 2019, courtesy of Ania Mendrek via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plants Paying For Biofuels | Earth Wise

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Biofuels are an important element in broader strategies to replace petroleum in transportation fuels like gasoline, diesel, and jet fuel.  The idea is that biofuels recycle carbon by getting it from growing plants rather than from fossil sources.  The biggest problem with biofuels is that they cost more than conventional petroleum fuels, so there is economic incentive to keep burning the fossil fuels.

One strategy to make biofuels cost competitive is to have the plants provide additional economic benefits beyond being a feedstock for fuel.  This in principle can be done by engineering plants to produce valuable chemical compounds, or bioproducts, as they grow.  Bioproducts include such things as flavoring agents and fragrances as well as biodegradable plastic.  These bioproducts can be extracted from the plants and then the remaining plant material can be converted to fuel. 

Researchers at Lawrence Berkeley National Laboratory recently published a study to determine what quantities of bioproducts plants need to produce to result in cost-effective biofuel production.

The study looked at a compound called limonene, which is used for flavoring and fragrance.  They calculated that if this compound was accumulated at 0.6% of the biomass dry weight, it would offer net economic benefits to biorefineries.  This corresponds to recovering 130 pounds of limonene from 10 tons of sorghum on an acre of land.

Such quantities are completely practical but, on the other hand, none of these substances are needed in huge quantities. Just six refineries could supply the world with limonene.  So, fuel crops would need to be engineered to produce a broad range of bioproducts to enable a viable cost-effective biofuel industry.

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Making Biofuels Cheaper by Putting Plants to Work

Photo, posted September 28, 2019, courtesy of Michele Dorsey Walfred via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewable Natural Gas

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Small-scale biogas systems have collected methane from landfills, sewage plants, and farms for decades.  Here in the US, biogas is finally catching up with modern techniques with the advent of third-party operators introducing more sophisticated technology to capture methane and pump it directly into pipelines.

Renewable methane or natural gas represents a significant mostly unexploited source of energy.  Examples include the vast amounts methane generated by manure from some of the 2,300 hog farms in eastern North Carolina, biodigesters that can turn clusters of large California dairy farms into energy hubs, as well as diverting food waste from landfills and transforming it into vehicle and heating fuels.

According to a 2014 EPA study, the U.S. could support at least 13,000 biogas facilities, fed by manure, landfill gas, and biosolids from sewage treatment plants.  Those facilities could produce over 650 billion cubic feet of biogas per year – enough renewable energy to power 3 million homes.

A study by the World Resources Institute estimated that the 50 million tons of organic waste sent to landfills or incinerated every year in the U.S. has the energy content of 6 billion gallons of diesel fuel, amounting to 15% of all diesel consumed by heavy-duty trucks and buses.

Utilizing all that biogas could help lower greenhouse gas emissions from some of the most difficult sectors to decarbonize – transportation, industry, and heating buildings.  In addition, ramped up renewable gas could keep organic waste out of landfills and prevent manure runoff into rivers and water supplies.

Renewable natural gas could be the next big thing in green energy.

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Could Renewable Natural Gas Be the Next Big Thing in Green Energy?

Photo, posted June 19, 2013, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can Germany Meet Its Energy Goals?

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Germany has been a global leader in efforts to decarbonize its massive economy.  A national initiative known as Energiewende – or clean energy transition – has been in place since 2010 and relies heavily on renewable energy sources, energy efficiency, and energy demand management.

The program has involved some of the most aggressive deployment of renewable energy sources in the world.  Germany was the first country to install 1 GW of solar energy and still has the 5th largest amount of solar power in the world despite actually being a country with fairly limited sunshine.  Germany has nearly 30,000 wind turbines, most of which are onshore, unlike many other countries in northern Europe.  Over the past five years, government support and cost to consumers for the shift to clean energy have totaled over $180 billion.

However, despite these efforts, Germany’s greenhouse gas emissions have not declined as rapidly as expected, even though nearly 40% of the country’s electricity now comes from renewable sources.

This lack of expected success comes as a shock to the environmentally conscious German population, nearly 90% of which supports the program.

There are two major problems Germany faces.  One is that Germany is Europe’s largest producer of coal, which still generates more than a third of the country’s power.  The other is that Germany’s large auto industry is still married to gas- and diesel-fueled cars and emissions from the country’s cars are a big problem.

The Energiewende program was driven by political will and investment certainty.  It is unclear whether Germany can muster these forces again.  The Merkel government has dragged its feet on environmental issues in recent years.  It remains to be seen what effect shifting political power in Germany will have.

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Carbon Crossroads: Can Germany Revive Its Stalled Energy Transition?

Photo, posted August 15, 2011, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Buses On The Rise

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Electric buses are replacing conventional diesel-fueled buses at an accelerating rate that is outpacing the adoption of battery-powered cars.  According to forecasts by Bloomberg New Energy Finance, by 2030 some 28% of car sales will be electric vehicles while 84% of new buses will be electric buses.  So far, some 12 years away, the actual adoption of electric buses is outpacing this optimistic projection.

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Diesel Is Dirty

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Three years ago, Volkswagen was found to have illegally cheated federal emissions tests in the US using devious programming of emission control devices.  The subterfuge enabled 11 million passenger cars to meet U.S. emissions standards in the laboratory despite that fact that they actually produced up to 40 times higher emissions than the legal limit in real-world driving.

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Emissions From Electric Buses

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Municipalities and transit agencies are gradually replacing conventional diesel buses with cleaner alternatives such as natural-gas-powered, diesel-electric hybrid, or fully electric buses.  The goal is to reduce the substantial carbon emissions associated with buses as well as reducing unhealthy air pollution. Diesel buses on average get less than 5 miles per gallon as they transport passengers around, so there is plenty of motivation to find more efficient ways to power them.

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A Battle For The Automobile Fuel Business

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Energy giant BP predicts that electric vehicle sales will increase by an incredible 8,800 percent between now and 2040.  That creates a major business opportunity for oil companies as well as a real problem because demand for gasoline and diesel is destined to slow.

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Hydrogen Progress

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As low-cost solar and wind energy become increasingly pervasive, the prospects for hydrogen-based transportation systems are improving.  The reason is that cheap electricity makes it practical to produce hydrogen by breaking down water rather than getting it from reforming natural gas, which results in carbon dioxide emissions.  The real goal is for hydrogen to be a renewable and carbon-free fuel.

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Electrifying Shipping Fleets

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Container ships, tankers, freighters, and cruise ships are a significant source of carbon dioxide emissions and other pollutants.  They currently account for 3% of global emissions – which doesn’t sound like much – but most other sectors such as power plants and automobiles are gradually decarbonizing.  As a result, experts believe that shipping could account for as much as 17% of global emissions by the year 2050.

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Ditching Gas And Diesel Cars

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Electric cars represent only a tiny fraction of the overall auto market.  The numbers are growing, most certainly, but they are still quite small in most places.   The recent start of production of the Tesla Model 3 has attracted quite a bit of attention to electric cars, but in many countries, there is much more to the story than just media buzz about a new car.

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