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Wind And Solar Pass Coal | Earth Wise

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For the first five months of this year, wind and solar generated more electricity than coal in the United States.  This is a first.  Total renewable energy generation exceeded coal-fired power in both 2020 and 2022, but that counted hydroelectric power as one of the renewable sources.

This year, wind and solar alone generated a total of 252 terawatt-hours of energy through May compared with coal’s output of 249 terawatt-hours.  Hydropower generated an additional 117 terawatt-hours during that period.

While solar and wind power have been expanding at a rapid rate, the biggest change this year has been a precipitous drop in coal-fired generation due to a combination of low natural gas prices, a mild winter, and a series of coal plant retirements.

Coal generated almost half of the country’s electricity as recently as 2008.  Since then, coal has steadily declined as older coal plants shut down and were replaced by natural gas plants and renewable energy sources.  The coal industry had a bit of a reprieve last year when natural gas prices spiked in response to the disruptions in gas supplies in Europe due to the war in Ukraine.  The benchmark for natural gas prices – known as Henry Hub – was $8.81 in August 2022.  In May of this year, it was $2.15.  Given this trend, the demand for coal has steadily declined. 

The US has retired another 7% of the coal fleet – 14 gigawatts of capacity – since the start of 2022.  Meanwhile, power companies have added 22.5 GW of wind and solar capacity in just the past 12 months.

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In a First, Wind and Solar Generated More Power Than Coal in U.S.

Photo, posted September 20, 2016, courtesy of Bureau of Land Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An Electric Cruise Ship | Earth Wise

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The shipping industry accounts for about 3% of global manmade greenhouse gas emissions.  In 2018, the International Maritime Organization, the UN body that regulates global shipping, set a target to cut the industry’s greenhouse gas emissions by at least half by 2050.

This goal has led to a variety of designs for eco-friendly ships, including car carriers, superyachts, and cargo ships with retractable sails.  But most of the designs still rely to at least some extent on engines that run on fossil fuels.

The Norwegian cruise ship company Hurtigruten has announced that it will build a zero-emissions electric cruise ship with retractable sails covered in solar panels.  The ship is expected to set sail in 2030.  Hurtigruten is a relatively small company, with a fleet of eight ships, each with a capacity of 500 passengers.  But the company hopes that its innovative plan will inspire the entire maritime industry.

The ship will predominantly run off of electric motors powered by 60 megawatt batteries that can be charged in port with renewable energy.  To reduce reliance on the battery, when it is windy, three retractable sails will rise out of the deck, reaching a maximum height of 164 feet.  The sails will be covered in solar panels that will generate energy to top off the batteries while sailing.

The ship will have 270 cabins to hold 500 passengers and 99 crew members.  The streamlined shape of the ship will result in less air resistance to further reduce energy use.

Hurtigruten already has a hybrid, battery-supported cruise ship and is currently in the process of converting its entire fleet to hybrid battery power.

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An electric cruise ship with gigantic solar sails is set to launch in 2030

Photo, posted January 15, 2023, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Renewables In China | Earth Wise

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A couple of years ago, China set an ambitious goal for renewable energy capacity – which includes wind, solar, hydroelectric, and nuclear power – for it to exceed fossil fuel capacity by 2025.  According to a recent report by Reuters, China has hit this goal two years ahead of schedule.  Renewables now make up 50.9% of the country’s power capacity.

The rapid growth in renewable capacity has largely been driven by investments in wind and solar megaprojects in the sparsely populated west of the country that export power to the manufacturing centers in the east.  China’s most recent 5-year plan calls for 570 gigawatts of wind and solar power to be installed over that period, which more than doubles its installed capacity.  The plan makes use of what it called “clean energy bases”, which utilize sandy and rocky deserts, other types of barren lands, and wastelands left behind by coal mining.  The largest clean energy bases make use of vast deserts in Inner Mongolia and Gansu.

One cautionary note is that power capacity refers to the maximum amount of electricity that a power plant can produce under ideal conditions.  Thus, for example, it refers to how much electricity a solar farm can generate at noon on a cloudless day.  So, the new figures from China don’t necessarily reveal how much electricity China is actually drawing from renewables.  In reality, China still gets a great deal of its power from coal.

China is the world’s largest emitter of carbon dioxide – more than twice as much as the United States, albeit from nearly 4 times the population.  The rapid growth of renewables is at least moving that country in the right direction.

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Fossil Fuels Now Account for Less Than Half of China’s Power Capacity

Photo, posted December 2, 2015, courtesy of IBM via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Motors For Aviation | Earth Wise

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Aviation contributes about 3% of global greenhouse gas emissions.  Its carbon footprint is one of the more difficult ones to reduce.  Electrifying planes would shrink that footprint considerably, but it represents a significant technical challenge.  To date, only small all-electric planes have gotten off the ground.  The electric motors in those planes generate hundreds of kilowatts of power.  To power large planes, like commercial airliners, megawatt-scale motors are required.

A team of MIT engineers is developing a 1-megawatt motor that could be a key step towards electrifying commercial aircraft.  They have designed and tested major components of the motor and have calculated how the completed design could generate one megawatt of power at a weight and size competitive with existing small aircraft engines.

To be suitable for aircraft use, motors have to be compact and lightweight.  The more power electric motors generate, the bigger they are and the more heat they produce.  Cooling motors requires additional components that take up space and add significant weight.  The MIT motor design and associated power electronics are each about the size of a typical checked suitcase and weigh less than an adult passenger.

Once the MIT team can demonstrate an entire functional motor, the design could be used to power regional aircraft and could be the enabling element of hybrid-electric propulsion systems for jet aircraft.  Possible future configurations could make use of multiple one-megawatt motors powering multiple fans distributed along aircraft wings.

Electrification of aircraft is a slow but steady area of development and technologies such as that being developed at MIT could end up meeting the practical needs of the aircraft of the future.

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Megawatt electrical motor designed by MIT engineers could help electrify aviation

Photo, posted September 14, 2019, courtesy of Dylan Agbagni via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Decontaminating Drinking Water | Earth Wise

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At least two billion people around the world often drink water that is contaminated with disease-causing microbes.  Waterborne diseases are responsible for two million deaths each year, mostly among children under the age of five.

There are various ways to decontaminate water, including chemicals that can themselves produce toxic byproducts as well as using ultraviolet light, which takes fairly long to disinfect the water and requires a source of electricity. 

Scientists at Stanford University and the SLAC National Accelerator Laboratory have recently invented a low-cost, recyclable powder that kills thousands of waterborne bacteria every second when the water containing it is exposed to ordinary sunlight.  The discovery of this ultrafast disinfectant could be a tremendous benefit to the nearly 30% of the world’s population with no reliable access to safe drinking water.

The new disinfectant is a harmless metallic powder that works by absorbing both ultraviolet and high-energy visible light from the sun.  It consists of nano-sized flakes of aluminum oxide, molybdenum sulfide, copper, and iron oxide.  The key innovation is that when these four metallic ingredients are immersed in water, they all function together by reacting with the surrounding water and generating chemicals that quickly kill bacteria. The chemicals themselves don’t last long.  They quickly break down in the water leaving completely safe drinking water.

The nontoxic powder is recyclable.  It can be removed from water with a magnet.  It can also be reused at least 30 times.  Apart from its uses in less developed parts of the world, it could be valuable for hikers and backpackers who want to drink water from natural sources of unknown quality.

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New nontoxic powder uses sunlight to quickly disinfect contaminated drinking water

Photo, posted February 27, 2013, courtesy of Petras Gagilas via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Big Year For Rooftop Solar | Earth Wise

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The global capacity of rooftop solar power grew by 49% in 2022.  Overall, the installed amount of rooftop solar grew from 79 gigawatts to 118 gigawatts last year and it is projected to reach 159 gigawatts by the end of this year.  By comparison, a typical nuclear power plant can produce 1 gigawatt; a gas-powered power plant is typically half a gigawatt.

Rooftop solar constitutes a relatively small fraction of the total global installed solar capacity, which is dominated by utility-scale solar arrays.  Total installed solar capacity rose from 950 gigawatts to 1,177 gigawatts last year and is projected to reach 1,518 gigawatts this year.  That is enough power to meet more than half the electricity demand of the European Union.

The rapid growth of solar power can only continue if there is more energy storage put in place to manage the peaks and troughs in solar output.  Countries will also need to upgrade their power grids to be able to transport excess solar power from where it is generated to where it is needed.   Bottlenecks in the grids of most of the leading solar-producing nations are already interfering with further solar development.

The overall potential for rooftop solar is based on the number of rooftops that would be suitable for solar power, which depends on the size, shading, orientation, and location of the roofs.  According to the National Renewable Energy Laboratory, rooftops in the United States have the potential for more than 1,000 gigawatts of solar capacity. Currently, only about 4% of US homes have rooftop solar. 

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Rooftop Solar Grew Nearly 50 Percent Globally Last Year

Photo, posted November 16, 2022, courtesy of Oliver Knight via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Water For Arizona | Earth Wise

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The Phoenix area is the fastest growing region in the country.  Arizona’s two major sources of water – groundwater and the Colorado River – are dwindling from drought, climate change, and overuse.  Officials in the state are considering a radical plan to construct a desalination plant off the Mexican coast that will take the salt out of seawater, and then pipe that water hundreds of miles, much of it uphill, to Phoenix.

The project is the brainchild of the Israeli company, IDE, which is one of the world’s largest desalination companies.  IDE has asked Arizona to sign a 100-year contract to buy water from the project. 

There are multiple complications surrounding the plan.  Desalination plants are common in California, Texas, and Florida, and in more than 100 other countries.  But the Arizona project is unusual because of the distance involved and because the state is landlocked.  The water would have to travel 200 miles and climb 2,000 feet along the way.

There is also the issue of waste brine, which is a major output of desalination plants.  In this case, the brine would flood the northern Gulf of California, potentially threatening a productive fishery.  In addition, the pipeline, as well as electrical transmission lines, would have to go through the Organ Pipe Cactus National Monument, a UNESCO biosphere reserve.

The plant would be located in Puerto Peñasco, a struggling town with its own water problems.

With booming home construction going on in the Phoenix area, the need for more water continues to grow.  Whether this plan will be approved by Arizona and by Mexico remains to be seen.

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Arizona, Low on Water, Weighs Taking It From the Sea. In Mexico.

Photo, posted September 26, 2008, courtesy of Dan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Cars And Apartments | Earth Wise

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The transition to electric cars is underway.  People are increasingly buying them, carmakers are switching over to making them, and governments are providing incentives as well as legislating the changeover.  More and more consumers want to lower their carbon footprints and stop burning fossil fuels.  But one very large group of consumers faces an uphill battle in switching to electric cars:  people who rent their dwellings.

About one third of our country lives in rented apartments or houses.  These nearly 110 million Americans are more likely to be in the bottom half of income and net worth and are more likely to be people of color.  These people are less likely to have the spare cash to make upgrades to their property such as car chargers and may not be able to get permission from their landlords to do it anyway.

Renters face what is known as the “split-incentive problem” or the “landlord-tenant problem.”  Three-quarters of tenants in the US pay their own utility bills, so they have a strong incentive to conserve electricity, water, and gas.  Their landlords, on the other hand, have little incentive to upgrade appliances and systems to be more environmentally responsible.  Studies have shown that on average renters use 3% more energy than homeowners for this reason.

There are some landlords who are being proactive and installing facilities for charging cars on their properties.   This will undoubtedly become an increasingly sought-after feature for renters.  But in the meantime, millions of them have a more difficult time driving electric cars.  They can charge at public chargers or perhaps at work.  But at the moment, homeowners are three times more likely than renters to own an electric car.

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The coming battle between Americans who want to go electric and their landlords

Photo, posted July 22, 2022, courtesy of Chris Yarzab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Keeping The Colorado River Flowing | Earth Wise

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The Colorado River supplies drinking water to 40 million Americans in seven states as well as to many Mexicans and provides irrigation to 5.5 million acres of farmland.  Electricity generated by dams on the Colorado powers millions of homes and businesses in the West.

A combination of drought, population growth, and climate change has reduced the river’s flows by a third in recent years compared with historical averages.  Further reductions could trigger a water and power catastrophe across the Western states.

California, Arizona, and Nevada all get water from Lake Mead, the reservoir formed by the Colorado at Hoover Dam.  The Interior Department determines how much water each of these three states receives.  The other states that use Colorado River water get it directly from the river and its tributaries.  Last summer, water levels in Lake Mead and Lake Powell fell enough that officials feared that the hydroelectric turbines at the Colorado’s dams would soon cease functioning.

The three states have recently struck an agreement with the federal government to take less water from the Colorado.  The reductions amount to about 13% of the total water use in the lower Colorado.  The government will pay about $1.2 billion to irrigation districts, cities, and Native American tribes for temporarily using less water.  The states have also agreed to make additional cuts to generate the total reductions needed to prevent the collapse of the river.

The agreement runs only through the end of 2026.  At that point, all seven states that rely on the river – which includes Colorado, New Mexico, Utah, and Wyoming – may well be facing a deeper reckoning.  The forces driving the decline of the Colorado are not going away.

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A Breakthrough Deal to Keep the Colorado River From Going Dry, for Now

Photo, posted June 16, 2017, courtesy Karen and Brad Emerson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Nantucket Residents Still Fighting Offshore Wind | Earth Wise

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Offshore wind in the US has had to fight to exist for a long time.  The Cape Wind project in Nantucket Sound off the coast of Cape Cod was envisioned over 20 years ago as a 1.5-gigawatt wind farm.  Years of legal battles and other controversies saw the project start and stop multiple times with only minimal actual construction.  Primary opposition came from residents who considered the turbines far off on the distant horizon to be an eyesore and threat to their property values.  Eventually, the project was terminated in 2017.

Since then, offshore wind has gained substantial support in the US and multiple projects are either ongoing or in the permitting process.  The 800 MW Vineyard Wind project is on track to be the first commercial-scale offshore wind farm in the US, with plans to eventually generate enough electricity to power 400,000 homes.

Once again, Nantucket residents are fighting against an offshore wind farm.  Once again, they are making arguments that are not really what concerns them, in this case, saying that the wind turbines are a threat to the survival of endangered North Atlantic right whales.

A federal judge has recently rejected a lawsuit brought by the group Nantucket Residents Against Turbines that sought to stop the project.  The judge found that the group failed to show that either the US Bureau of Ocean Energy Management or the National Marine Fisheries Service violated the Endangered Species Act or the National Environmental Policy Act in its 2021 rulings on the impact of the proposed wind farm on the whales.

Undoubtedly there will be additional challenges from the group, possibly based on entirely different complaints.  It’s tough to build offshore wind in Massachusetts.

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Judge rejects lawsuit by Nantucket residents to block offshore wind farm

Photo, posted November 21, 2016, courtesy of Adrian Scottow via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Energy From Fruit Waste | Earth Wise

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In the Back to the Future films, Doc Brown ran his DeLorean time machine on food scraps.  It was a fun bit of science fiction.  But researchers at the University of British Columbia Okanagan in Canada are investigating the potential for using food waste to generate power.

Food waste is not a candidate to replace solar or wind power, but it could be a source of energy for powering fuel cells.  As it is, food waste represents a sustainability challenge because of its detrimental impacts on the economy and the environment.  Organic waste represents a significant fraction of the material in landfills and contributes to methane production, air pollution, and other harmful pollutants.

The UBC researchers focused on fruit waste, which is abundantly available in agricultural regions.  They have devised microbial fuel cells that convert fruit waste into electrical energy using an anaerobic anode compartment.  That is a chamber in which anaerobic microbes – ones that don’t need oxygen – utilize the organic matter to convert it into energy.  The microbes consume the fruit waste and produce water while generating bioelectricity.

It is not like the Back to the Future time machine where you can just toss in scraps of whatever is on hand.  Different types of fruits provide different results when used in the microbial fuel cell. The process works best when the food waste is separated and ground into small particles.  There is a long way to go before the technology could produce bioenergy on a commercial scale, but there is considerable potential for doing something useful with something that is currently worthless.

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UBCO researchers aim to energize fruit waste

Photo, posted July 24, 2011, courtesy of Andrew Girdwood via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Chatbots Are Thirsty | Earth Wise

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We hear a lot about artificial intelligence these days.  ChatGPT has found its way into education, technology, and many other aspects of life.  It and its brethren are a source of fascination, enthusiasm, and even fear.  Many of us have given queries to the bot to see what kind of results we can obtain.  But a recent study has found out something about AI systems that we probably didn’t know – they use up lots of fresh water.

According to researchers at the University of California, Riverside, running a few dozen queries on ChatGPT uses up about half a quart of fresh water from already overtaxed reservoirs.

Running artificial intelligence systems like ChatGPT relies on cloud computations done in racks of servers in warehouse-sized data processing centers.  Google’s data centers in the U.S. alone consumed nearly 3.5 billion gallons of fresh water in 2021 in order to keep their servers cool.

Data processing centers consume water in two ways.  They often draw much of their electricity from power plants that use large cooling towers that convert water into steam emitted into the atmosphere.  In addition, the servers themselves need to be cooled to keep running and are typically connected to cooling towers as well.

It isn’t going to be easy for AI systems to reduce their water use.  The study’s authors noted that people make use of AI at all hours of the day and night.  But a significant amount of AI activity is actually the training of the systems.  That could be scheduled for the cooler hours, when less water is lost to evaporation.

In an era of scarce fresh water and droughts, it is important to make AI less thirsty.

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AI programs consume large volumes of scarce water

Photo, posted May 22, 2023, courtesy of Jernej Furman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Offshore Wind In Maine | Earth Wise

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There are currently only two small offshore wind farms operating in the United States, but there are now several more under construction or in the permitting process.  Substantial wind farms are expected to come online over the next five years off the coasts of Virginia, New Jersey, Massachusetts. North Carolina, Delaware, Rhode Island, and New York.   There has been a recent auction for offshore wind sites off the California coast as well.

In April, the Bureau of Ocean Energy Management issued its Gulf of Maine Call for Information and Nominations, inviting public comment and assessing the interest in areas offshore of Maine, New Hampshire, and Massachusetts.  This is the first official step in the lengthy process that leads to offshore wind development in new areas.  Last year, the Department of the Interior defined an area of about 13.7 million acres in the Gulf of Maine that could end up providing energy leases for windfarm development.

The Biden administration has set a goal of deploying 30 gigawatts of offshore wind electricity generation by 2030, which is enough to power more than 10 million homes. It would also create thousands of jobs across manufacturing, shipbuilding, port operations, construction, and other industrial sectors.  Existing offshore wind projects have been structured to develop American-based supply chains for the offshore wind industry.

The European Union currently has over 15 gigawatts of installed offshore wind, has a target of 60 gigawatts by 2030, and 300 gigawatts by 2050.  The EU has five substantial sea basins which have tremendous potential for wind energy generation.  As a result, offshore wind is the centerpiece of the ambitious European Green Deal.

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U.S. moves to develop offshore wind in the Gulf of Maine

Photo, posted August 31, 2022, courtesy of Nina Ali 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

Explosive Growth Of Electric Vehicles | Earth Wise

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Not long ago, electric cars were a rarity.  Ten years ago, annual global sales of EVs were only a few hundred thousand.  As of today, globally, still less than one percent of all the cars on the road are electric.  But that is changing rapidly.

In fact, electric vehicles are expected to capture nearly 20% of the global market this year.  Global sales of EVs were 3 million in 2020 and 6.6 million in 2021.  Last year, sales of electric vehicles hit 10 million and are expected to reach 14 million this year according to the International Energy Agency.

Analysts at the IEA have had to repeatedly revise their projections for future EV sales as the numbers keep going up faster than predicted.  Last year, they projected that EVs would account for 21% of global sales by 2030.  Now, they expect that EVs will reach 35% of sales by that year.

In the US, the EU, and China, policy efforts are in place to boost EV sales.  In the US, the Inflation Reduction Act both supports the EV industry and subsidizes consumer purchases with tax credits. As a result of such policies, the IEA expects electric vehicles to account for 60% of sales across these three large markets by 2030.

Part of what is driving the boom in EV sales is that prices continue to come down for the vehicles.  When operating and maintenance costs are figured in, the EVs come out considerably cheaper to own.  In addition, there are starting to be price wars in the EV industry as competition heats up in the sector.

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EVs to Capture One-Fifth of Global Market This Year Amid ‘Explosive Growth’

Photo, posted May 7, 2022, courtesy of Sharon Hahn Darlin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenhouse Gases Continue To Rise | Earth Wise

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Despite all the focus on reducing emissions of greenhouse gases, there continues to be little progress toward actually accomplishing reductions.  A combination of growing populations, increasing industrialization in the developing world, and just plain reluctance on the part of many sectors of society to act, have all contributed to the continuing buildup of climate-altering gases in the atmosphere.

Levels of carbon dioxide, methane, and nitrous oxide – the three greenhouse gases produced by human activity that are the major contributors to climate change – all continued historically high rates of growth in 2022.

CO2 levels rose by 2.13 parts per million last year, roughly the same rate observed during the past decade.  The current level of 417 ppm is 50% higher than pre-industrial levels.  Increases of more than 2 ppm have occurred for 11 consecutive years.  Prior to 2013, there had never even been 3 years in row with increases of that size.

Methane levels increased by 14 parts per billion, the fourth largest increase over the past 40 years.  Methane levels in the atmosphere are now two-and-a-half times greater than their pre-industrial level. 

The third most significant greenhouse gas – nitrous oxide – also saw a large increase, reaching 24% above pre-industrial levels.

Carbon dioxide emissions are by far the most important contributor to climate change and the continuing widespread burning of fossil fuels is the primary source.  There are widespread intentions to reduce carbon dioxide emissions, but those intentions have not yet resulted in sufficient actions.

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Greenhouse gases continued to increase rapidly in 2022

Photo, posted May 16, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Geothermal Energy Storage | Earth Wise

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About 12% of the energy consumed by humanity is used to heat and cool homes and businesses.  A study by researchers at Lawrence Berkeley National Laboratory and Princeton University looked at a novel approach to making use of underground water to maintain comfortable temperatures and reduce consumption of natural gas and electricity.

The idea is to use aquifer thermal energy storage (known as ATES) to provide both heat in the winter and cooling in the summer.  The concept leverages the heat-absorbing property of water and natural geological features.  The idea is to pump up water from existing underground reservoirs and heat it at the surface using environmental heat or even excess energy from solar or wind generation.  Then the warm water is pumped back down. It stays warm for a long time – even months – because the earth is a good insulator.  When the water is pumped back up in the winter, it is much hotter than the ambient air and can be used to supply heat to buildings.

Alternately, water can be pumped up and cooled in the winter and then put back down underground and stored until cooling is needed in the summer months.

This technology has not been used much in the US, but it is gaining recognition internationally, particularly in the Netherlands.  It can perform very well in areas with large seasonal fluctuations.

The research study used modeling and various simulations to estimate how much energy ATES could save on the US grid.  The results showed that adding ATES to the grid could reduce consumption of petroleum products for heating and  cooling by up to 40%.  The system could also help prevent blackouts by reducing high power demand during extreme weather events.

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Underground Water Could be the Solution to Green Heating and Cooling

Photo, posted February 19, 2012, courtesy of Sanjay via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Better Zinc Batteries | Earth Wise

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The rapid growth of wind and solar power continues to drive a global quest for new battery technologies that can be used to store the energy generated by these sources when the sun isn’t shining, and the wind isn’t blowing.

For the most part, current battery energy storage systems use lithium-ion batteries – the same sort of batteries found in cellphones and electric vehicles.  There are many other battery chemistries, but they mostly have shortcomings in performance, economy, or longevity. 

Batteries store electricity in the form of chemical energy and chemical reactions convert that energy into electrical energy. Every battery has two electrodes:  the anode, from which electrons flow into external circuits, and the cathode, which receives electrons from the external circuit.  The electrolyte is the chemical medium through which the electrons flow.

One technology that has great potential is zinc-based batteries.  Zinc itself is a metal that is safe and abundant.  Batteries based on it are energy dense. However, zinc batteries have faced the challenge of having a short cycle life.  The batteries end up plating zinc on their anodes and battery performance degrades. 

A team of researchers at Oregon State University and three other universities have recently developed a new electrolyte for zinc batteries that raises the efficiency of the zinc metal anode to nearly 100% – actually slightly better than lithium-ion batteries.

Zinc batteries have a number of potential advantages over lithium-ion.  The new hybrid electrolyte developed by the researchers is non-flammable, cost-effective, and has low environmental impact.  Lithium-ion batteries rely on the supplies of relatively rare metals that are often difficult and environmentally harmful to obtain. 

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Researchers develop electrolyte enabling high efficiency of safe, sustainable zinc batteries

Photo, posted May 13, 2017, courtesy of Jeanne Menjoulet via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Banning Gas-Powered Cars | Earth Wise

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The European Union has banned the sale of new gas-powered cars starting in 2035.  The vote came after weeks of negotiations related to possible exemptions to the rule.

Germany lobbied for an exemption to be made for cars powered by e-fuels.  These are made by combining hydrogen with carbon dioxide that has been removed from the atmosphere using processes powered by renewable energy.  Because of this source of the carbon dioxide, such fuels are considered to be carbon neutral.  The EU agreed to grant this exemption, so there can be cars that run only on e-fuels after 2035.

About a quarter of carbon emissions in the EU come from transportation.  The new law requires a 55% drop in carbon emissions from new cars by 2030.  Poland voted against the new law, while Bulgaria, Romania, and Italy abstained.  (Italy wanted an exemption for biofuels, but it was not granted).

Here in the US, seven states have adopted rules banning the sale of new gas-powered cars in 2035.  These are California, Maryland, Massachusetts, New Jersey, New York, Oregon, and Washington. 

California has committed to having 35% of new car sales being zero-emission vehicles by 2026, and the number rising to 68% by 2030.

As these policies proliferate around the world, the auto industry is moving ahead to keep up with them.  Most automakers are planning to have substantial parts of their product line be electric by 2030.  Given the financial and physical inertia involved in shifting to electric vehicle production, regardless of what happens with policies around the world, there is little possibility of turning back from the electric vehicle transition.

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EU Approves 2035 Ban on Sales of Gas-Powered Cars

Photo, posted May 31, 2012, courtesy of Mike Norton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Concrete And Carbon | Earth Wise

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After water, concrete is the world’s second most consumed material.  It is the cornerstone of modern infrastructure.  Its production accounts for 8% of global carbon dioxide emissions.  The carbon dioxide is a result of chemical reactions in its manufacture and from the energy required to fuel the reactions.

About half of the emissions associated with concrete come from burning fossil fuels to heat up the mixture of limestone and clay that ultimately becomes ordinary Portland cement.  These emissions could eventually be eliminated by using renewable-generated electricity to provide the necessary heat.  However, the other half of the emissions is inherent in the chemical process.

When the minerals are heated to temperatures above 2500 degrees Fahrenheit, a chemical reaction occurs producing a substance called clinker (which is mostly calcium silicates) and carbon dioxide.  The carbon dioxide escapes into the air.

Portland cement is then mixed with water, sand, and gravel to produce concrete.  The concrete is somewhat alkaline and naturally absorbs carbon dioxide albeit slowly.  Over time, these reactions weaken the concrete and corrode reinforcing rebar.

Researchers at MIT have discovered that the simple addition of sodium bicarbonate (aka baking soda) to the concrete mixture accelerates the early-stage mineralization of carbon dioxide, enough to make a real dent in concrete’s carbon footprint.  In addition, the resulting concrete sets much more quickly.  It forms a new composite phase that doubles the mechanical performance of early-stage concrete.

The goal is to provide much greener, and possibly even carbon-negative construction materials, turning concrete from being a problem to part of a solution.

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New additives could turn concrete into an effective carbon sink

Photo, posted April 4, 2009, courtesy of PSNH via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)