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Floating Turbines For Offshore Wind | Earth Wise

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Offshore wind is big in Europe.  There are more than 5,000 offshore wind turbines across 12 European countries with a total capacity of more than 22 gigawatts.  Almost every one of those turbines sits on a long tower sunk into the seabed and bolted into place in places where the water is 60 to 160 feet deep.

But off the coast of northern Scotland, there is the Hywind Wind Park which has five 574-foot-tall turbines located 15 miles offshore where the water is 300 feet deep.  The giant masts and turbines sit on buoyant concrete-and-steel keels that allow them to stand upright and float on the water like a giant buoy.  The giant cylindrical bases are held in place with mooring cables attached to anchors that sit on the seafloor.

A key advantage of floating turbines is that they can access outlying ocean waters up to half a mile deep, which is where the world’s strongest and most consistent winds blow.  Another advantage is that such turbines can be installed over the horizon, out of sight of coastal residents who might not like to have wind turbines visible in their scenic ocean views.

Floating wind power has enormous potential for contributing to the expansion of renewable energy.  Offshore wind is still quite a bit more expensive than land-based turbines, and the cost of electricity from distant floating turbines is more than that from near-shore wind turbines.   But all of these costs are likely to come down with improving technology and increased production volume.

There are real challenges to the expanded used of floating wind farms, but the promise of harnessing so much of the open seas for electricity generation is an attractive proposition.

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Will Floating Turbines Usher in a New Wave of Offshore Wind?

Photo, posted July 17, 2017, courtesy of Crown Estate Scotland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Concrete Production And Diminishing Coal Burning | Earth Wise

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Coal burning is still one of the primary means of generating electricity in the United States, but its use is diminishing and doing so fairly rapidly.  The coal burning process produces residual, incombustible materials.  One of them is fly ash, which is composed of fine, glassy, rounded particles rich in silicon, aluminum, calcium, and iron oxides.  Fly ash is captured from coal plant flue gas by precipitators and bag filters. It turns out that two-thirds of this fly ash is not dumped into landfills or impoundments, but rather is put to use.

Because of its chemical and physical characteristics, fly ash can substitute for a portion of portland cement in concrete.  Using this byproduct material in making cement actually reduces its cost. Beyond cost, the addition of fly ash as a so-called supplementary cementitious material or SCM improves concrete’s long-term strength and reduces porosity and permeability.  It reduces the risk of thermal cracking and provides good long-term mechanical properties.

The amount of fly ash used in concrete products increased by 5% between 2011 and 2017 while the amount produced dropped by 36%.  Concrete production continues to increase steadily while fly ash production is steadily dropping.

Therefore, the concrete industry is looking for alternative sources of SCM.  The most obvious is the approximately 1/3 of fly ash that hasn’t been used to make concrete.  Much of that is landfilled or ponded onsite at power plants.  So, opportunities exist for excavating or dredging and recovering these materials.

As coal burning goes away, concrete manufacturing needs to make some changes.

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What Does the Changing Face of Electricity Production Mean for Concrete?

Photo, posted February 16, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewable Energy And The Post-COVID World | Earth Wise

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As is the case for virtually all sectors of the global economy, the short-term prospects for wind and solar power look pretty grim.  Lockdowns, social distancing requirements, and financial upheavals have put many new projects on ice and have halted production at factories making solar panels and wind turbines.  Sales of home solar have struggled as people have put off spending during the economic slowdown.

Ironically, the shutdowns aimed at reducing the spread of the Coronavirus have led to renewable sources accounting for an increased share of power generation.  Global energy demand has plummeted and, because of the low cost of solar and wind power, sources like coal and nuclear power have been curtailed in favor of the renewables.  The dramatically reduced demand has pushed oil and gas prices to historic lows and has left fossil fuel companies struggling to find storage space for the glut of product.

When the world emerges from the pandemic, the question is whether renewable energy will end up on a faster track than before or will end up in a long-term slowdown.  The answer will depend to large extent on the choices political leaders make.

Leaders will unquestionably be designing economic recovery packages.  Such packages could accelerate the shift towards wind and solar power, or they could prop up the fossil fuel economy.  Unfortunately, leaders are prone to be motivated by lobbyists more than by the greater needs of society.  The global economic upheaval represents a real opportunity to change the pace of efforts to address climate change.  Whether that change is a positive one or a negative one is just another looming question facing society when we emerge from the pandemic.

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How Renewable Energy Could Emerge on Top After the Pandemic

Photo, posted April 12, 2020, courtesy of Jeremy Segrott 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.

Natural Habitats And Strawberry Farms | Earth Wise

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According to a new study led by researchers from the University of California – Davis, conserving natural habitat around strawberry fields can protect farmers’ yields, their bottom line, and the environment.  The study also suggests that conserving natural habitat in this way has no detectable threat to food safety. 

In this study, which was recently published in the journal Ecological Applications, the research team conducted surveys and experiments at 20 strawberry farms along California’s Central Coast.  This region is responsible for 43% of the nation’s strawberry production. 

The researchers found that strawberry farmers were better off with natural habitat, like forests, grasslands, wetlands, and shrubs, around their farms than without it.  According to the study’s models, adding natural habitat can reduce crop damage costs by 23%.  Removing natural habitat can increase costs by as much as 76%. 

Importantly, the strawberry farms with natural habitat surrounding them showed no signs of increased fecal contamination.  While bird feces were regularly encountered on the ground, only 2 of 10,000 strawberries examined show signs of direct fecal contamination.  Those contaminated berries would be discarded during the hand-harvesting process.   

These findings run contradictory to current best practice recommendations that support natural habitat removal around strawberry farms in order to decrease bird fecal contamination and crop damage.  These food safety requirements were a consequence of the deadly outbreak of E. coli in 2006, which was traced back to spinach grown in this region.   

It seems like our agricultural landscapes can both support and benefit from biodiversity. 

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Natural habitat around farms a win for strawberry growers, birds and consumers

Photo, posted June 16, 2011, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Cars And The Environment | Earth Wise

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There are articles in the media all the time questioning whether electric cars are really better for the environment than those powered by fossil fuels.  The usual argument is that once emissions from vehicle production and electricity generation are taken into account, electric cars are no greener than gas cars, or even worse for the environment.  Of course, these arguments tend to be made by oil companies and their supporters.

A new study by three European universities looked at this very issue in detail. They carried out a life-cycle assessment in which they not only calculated greenhouse gas emissions generated when using cars, but also in the production chain and waste processing.

Their conclusions are that under current conditions, driving an electric car is better for the climate than conventional gasoline cars in 95% of the world.  The only exceptions are places like Poland, where almost all electricity comes from coal-fired plants.

Average lifetime emissions associated with electric cars are up to 70% lower than gas cars in countries like Sweden and France and about 30% lower in England.

It is important to note than in a few years, even inefficient electric cars will be less emission-intensive than gas cars because electricity generation is becoming less carbon-intensive all the time.  The study projects that by 2050, half of the world’s cars will be electric resulting in carbon dioxide emission reductions of 1.5 billion tons.

The study states that the idea that electric cars could increase emissions is a myth.  The detailed study has run the numbers for all around the world and even in the worst-case scenario, there would be a reduction in emissions in almost all cases.

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Electric cars better for climate in 95% of the world

Photo, posted February 13, 2019, courtesy of Guillaume Vachey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar And Wind Power In China | Earth Wise

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Reducing greenhouse gas emissions is a global challenge and nowhere is that challenge greater than in China.  China accounts for 30% of the world’s emissions and much of that comes from coal power plants.  If the world is going to reach its climate targets, China is going to have to replace as much as possible of its current power mix with renewable energy.

As of 2018, China still made 69% of its electricity from fossil fuels.  Its vast coal reserves have driven its rapid industrialization and better standard of living.  But terrible air pollution problems along with climate issues have led to heavy investments and rapid expansion of both wind and solar power in China.

China is now a world leader in renewable energy, both in terms of producing and using renewable power.  At the start of 2016, China had installed a total of 145,000 megawatts of wind power, which is 3,000 MW more than all 28 European Union countries combined.  And this has occurred even though China only started developing their wind power industry 30 years later than the first EU countries.

Until 2009, China exported almost all the solar panels it produced.  But gradually China began to use solar energy in a big way.  The industry took off in 2014, and growth has been exponential.  Solar power production in China is now almost as extensive as wind power.

One has to consider that much of China’s electricity production is used by industries that produce products for the rest of the world.  In effect, these are exported emissions.  China has a long way to go in replacing its fossil fuel generation and we all have a stake in China succeeding in the task.

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China’s rapid development of solar and wind power

Photo, posted November 12, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Food Waste And Access To Groceries | Earth Wise

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One-third of all food produced is wasted, which turns out to be a major contributor to carbon emissions.  Most of the carbon emissions associated with food waste are related to the production of the food.  Reducing waste would trickle through the supply chain over time and ultimately less food would be produced.

A study at Cornell’s SC Johnson College of Business looked at a particular strategy for reducing food waste’s environmental impact:  opening more grocery stores.

It turns out that the more stores there are, the lower food waste will be.  Cornell Professor Elena Belavina created a model that incorporates data from the grocery industry, the U.S. Census Bureau, and other academic studies.

When applied to Chicago, which is typical of many American cities, the model predicts that by adding just three or four markets within four-square-mile area, food waste would be reduced by 6 to 9 percent.  This would achieve an emissions reduction comparable to converting more than 20,000 cars from fossil fuels to electric power.  According to the model, not only would food waste be reduced, but so would grocery bills.  By trimming food waste and travel costs, consumers would spend up to 4% less.

Most big cities are well below their ideal density of grocery stores that would minimize food waste. When consumers can purchase perishable goods nearby, they shop more often but buy less each time.  There is less food sitting at home, so there is a much lower likelihood that food will spoil.

New York City, which has an abundance of produce stands and neighborhood markets, comes close to having the ideal density of markets.  Basically, the way to reduce food waste is to bring less groceries home.

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Better access to groceries could reduce food waste, emissions

Photo, posted March 22, 2009, courtesy of Nick Saltmarsh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lots Of Wind Power In Denmark | Earth Wise

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Many states and countries have established goals to generate at least half of their electricity from renewable sources by some future date, typically 2030.  A number of countries have already been able to achieve 50% or greater renewable generation for brief periods measured in days.  Australia did it this past November.  Germany has seen it on occasion as well.

Denmark has managed to complete an entire year with half of its energy coming from renewable generation.  Almost all of it – 47% of the country’s power – came from wind turbines.

Denmark has been generating much of its energy from wind power for quite a while and actually produced about 46% of its electricity from renewable sources in 2017.  Denmark was a pioneer in developing commercial wind power during the 1970s, is a major manufacturer of wind turbines, and the small country has installed over 6,000 of them.  The gains this past year mostly came from the Horns Rev 3 offshore wind farm that went online in the fall.  The 407 MW wind farm has the capacity to cover the annual electricity consumption of about 425,000 households, which is about 20% of the country.

The growth of wind power in Denmark is still ramping up.  A 600 MW wind farm in the Baltic Sea will be connected to the Danish and German electricity grid by 2021, and a wind farm of at least 800 MW capacity in the North Sea is scheduled to come online in 2025.

The Danish Parliament has passed an ambitious climate law with the goal of reducing CO2 emissions by 70% in 2030 compared with 1990.  The country’s overall goal of being carbon-neutral by 2050 does not seem like a pipe dream.

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Denmark Passes Magic 50% In Renewable Electricity Generation Milestone

Photo, posted July 12, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Plastic Pollution On The Way | Earth Wise

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Public concern about plastic pollution has been rising.  More and more of us are choosing reusable grocery bags, metal straws, and reusable water bottles.  We shake our heads at images of immense plastic garbage patches in the ocean. We see reports of birds with 15% of their body weight in plastic.

While all of this is going on, companies like ExxonMobil, Shell, and Saudi Aramco are ramping up production of plastic – which is mostly made from oil, gas, and their byproducts.  They are doing this as a hedge against the growing possibility that the global response to climate change will reduce demand for their fuels.  Plastics are part of the category called petrochemicals, which currently account for 14% of oil use.  Petrochemicals are expected to drive half of oil demand growth over the next 30 years.

The World Economic Forum predicts plastic production will double in the next 20 years.  The fracking boom in the United States has turned this country into a big growth area for plastic production.  Natural gas prices are low which is hurting profits at fracking operations.  But fracking also unearths ethane, which is a feedstock for plastic production.  So plastic is becoming a kind of subsidy for fracking.

The American petroleum industry’s hub has historically been the Gulf Coast of Texas and Louisiana as well as a stretch along the lower Mississippi River.  There is a slew of new projects there.  The industry is also seeking to create a new plastics corridor in Ohio, Pennsylvania, and West Virginia, where fracking wells are rich in ethane.

Society in general may be increasingly concerned about the impact of things like carbon emissions and plastic pollution, but the fossil fuel industry continues to focus entirely on growth and profits.

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The Plastics Pipeline: A Surge of New Production Is on the Way

Photo, posted January 10, 2015 , courtesy of Daniel Orth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Problem Of Gas Flaring | Earth Wise

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Gas flaring is the burning off of flammable gas released by pressure relief values during over-pressuring of plant equipment at petroleum refineries, chemical plants, natural gas processing plants, and a variety of oil and gas production plants.  Flaring is also used during plant startups and shutdowns.

A new study by Rice University concludes that reducing gas flaring would benefit both the environment and the economy. Flaring and venting of gas in West Texas’s Permian Basin and certain other parts of the U.S. have reached levels that the intended result of burning gas to allow oil extraction now looks more like wasting one resource to produce another.

At current rates, enough gas is flared in the Permian Basin to yield nearly 5 million metric tons of exportable liquid natural gas if it was captured and liquified.  At these rates, the wasted gas could fill the largest sized LNG carrier every ten days.  If that liquified natural gas was exported to China and used in a power plant, it would displace 440,000 metric tons of coal burned to generate electricity.

Burning natural gas to heat homes, power industrial processes, or generate electricity all emit carbon dioxide, but at least these things also perform valuable functions. Flaring gas produces CO2 as well as other combustion products but doesn’t even do anything useful.  The venting of unburned gas, which also takes place with some frequency, is even worse since it is dumping methane directly into the atmosphere.

Across the U.S., some 14.1 billion cubic meters of natural gas was flared in 2018, equivalent to nearly 9 million metric tons per year of LNG.  In energy terms, that is equivalent to more than one-third of the total LNG volume U.S. firms actually exported that year.

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Reducing gas flaring will benefit economy and environment, says Baker Institute expert

Photo courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Safe And Simple Hydrogen Peroxide

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We don’t think about hydrogen peroxide very often.  Perhaps we have a bottle of it under our bathroom sink that we haven’t touched in a few years.   But it is an important product manufactured in the millions of tons each year and the basis of a $6 billion global business.

Hydrogen peroxide is widely used as an antiseptic, a detergent, in cosmetics, as a bleaching agent, in water purification, and in many other applications.  It is produced in industrial concentrations of up to 60% in solution with water in order to maximize the economics of transportation.  This makes transportation hazardous and costly because the concentrated form is unstable.  Most applications use a far more diluted form.

Researchers at Rice University have developed a new method for producing hydrogen peroxide that is much simpler and safer than the current technology, which actually dates back to the 1930s.  The Rice technique requires only air, water and electricity to produce the chemical.  The electrosynthesis process, which is detailed in the journal Science, uses an oxidized carbon nanoparticle-based catalyst.

The process could enable point-of-use production of pure hydrogen peroxide solutions, which would eliminate the need to transport the hazardous concentrated chemical.  The use of a solid electrolyte instead of the traditional liquid electrolyte eliminates the need for product separation or purification that is part of the current technology.

In the future, instead of storing containers of hydrogen peroxide, hospitals that use it as a disinfectant could turn on a spigot and get, for example a 3% solution on demand.  Instead of storing chemicals to disinfect swimming pool water, future homeowners could flick a switch and turn on their peroxide reactor to clean their pools.

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Water + air + electricity = hydrogen peroxide

Photo, posted April 19, 2009, courtesy of Robert Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Agrivoltaics

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A new study by Oregon State University has found that the most productive places on Earth for solar power are farmlands.   In fact, if less than 1% of agricultural land was converted to solar panels, it would be sufficient to fulfill global electricity demand.

The concept of co-developing the same area of land for both solar photovoltaic power and conventional agriculture is known as agrivoltaics.

The synergy between agriculture and solar power is not surprising.   People have been growing crops around the planet for at least 8,000 years and, long ago, farmers found the best places to grow them which turn out to also the best places to harvest solar energy.  The needs for solar panels are pretty similar to those of food crops.  The efficiency of the panels decreases if they get too hot.  Barren land is hotter than cropland, so the productivity of solar panels is less in such places.

The Oregon State Study analyzed power production data collected by Tesla, which had installed five large grid-tied, ground-mounted solar electric arrays owned by Oregon State.  The researchers monitored air temperature, relative humidity, wind speed, wind direction, soil moisture, and incoming solar energy.  With the data, they developed a model for the best conditions for solar panel productivity and they coincide with excellent conditions for agriculture.  Solar panels are kind of like people with regard to the weather:  they are happier when it is cool and breezy and dry.

Previously-published research shows that solar panels actually increase crop yields on pasture or agricultural fields.

These new results have implications for the current practice of constructing large solar arrays in deserts.  Agricultural lands may be a much better option for both solar production and crop production.

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Installing solar panels on agricultural lands maximizes their efficiency, new study shows

Photo, posted April 20, 2011, courtesy of U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Nutrients

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Ending hunger isn’t a question of producing enough food.  Globally, enough food is produced to feed all 7.7 billion people on the planet.  But despite this, approximately 1 in 9 people go hungry.  Conflict, natural disasters, and extreme poverty are some of the main drivers of global hunger. 

Climate change is another.  The more frequent and intense extreme weather events increase food insecurity and malnutrition by destroying land, livestock, crops, and food supplies.  Climate change makes growing crops harder every year, especially for those who lack the tools and technology to adapt. 

But the challenge of reducing hunger and malnutrition is to not only produce foods that provide enough calories, but to also produce foods that make enough necessary nutrients widely available.  According to new research, climate change is projected to significantly reduce the availability of critical nutrients such as protein, iron, and zinc over the next 30 years.  The total impact of climate change could reduce global per capita nutrient availability of protein, iron, and zinc by 19.5%, 14.4%, and 14.6%, respectively.

While higher levels of carbon dioxide can boost growth in plants, wheat, rice, corn, barley, potatoes, soybeans, and vegetables are all projected to suffer nutrient losses of about 3% on average by 2050 due to the elevated CO2 levels.

The study, which was co-authored by an international group of researchers and published in the peer-reviewed journal, Lancet Planetary Health, represents the most comprehensive synthesis of the impacts of climate change on the availability of nutrients in the global food supply to date. 

Climate change is complicating the quest to end global hunger and malnutrition. 

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Rising CO2, climate change projected to reduce availability of nutrients worldwide

Photo, posted April 30, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Choose Chicken Over Beef?

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Food production is a major driver of climate change.  It’s responsible for more than a quarter of all greenhouse gas emissions.  But the environmental impact of different foods varies greatly, and making seemingly insignificant changes can actually have significant impacts. 

According to a first-ever national study of U.S. eating habits and their carbon footprints, choosing chicken over beef will cut your dietary carbon footprint in half.

The National Health and Nutrition Examination Survey asked more than 16,000 participating Americans to name all the foods they consumed in the past 24 hours. The research team then calculated the carbon footprint of what people said they ate.  If a respondent consumed broiled beef steak, for example, researchers calculated what the carbon footprint would have been had broiled chicken been consumed instead.   

The study’s findings illustrate how making one simple substitution can significantly reduce a person’s dietary carbon footprint.  A diet’s carbon footprint is the amount of greenhouse gas emissions that result from the energy, fertilizer, land use, and other inputs necessary to produce food.

In general, animal-based foods have a bigger carbon footprint than plant-based foods.  For example, producing beef uses 20 times the land and emits 20 times the emissions as growing beans (per gram of protein), and requires 10 times more resources than producing chicken. 

According to the World Resources Institute, keeping the increase in global warming below 2°C will be impossible without limiting the global rise in meat consumption. 

Last year, the EAT-Lancet Commission report found that a radical transformation of the global food system was needed because it’s threatening the stability of the climate. 

Make a change – big or small – today. 

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Choosing chicken over beef cuts our carbon footprints a surprising amount

Photo, posted August 30, 2011, courtesy of Ken Hawkins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Complications For New York Solar Farms

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A study by engineers at Cornell University looked at the implications of adding utility-scale solar farms throughout New York State.  Adding such farms could reduce demand for electricity from conventional sources by nearly 10% in some places.  But the engineers caution that winters in upstate New York could create some novel problems for the state’s power system.

Electrical energy demand tends to be low around midday when many people are not home.  Electrical production from solar farms is high at that time when the sun is at its highest position in the sky.  This can lead to what power system operators call “ramping”, which is the term for rapid increases or decreases in demand.

This sort of ramping was first discussed in California years ago.  When people wake up and prepare for the day, there is a morning peak in electrical load, which occurs before solar production ramps up.   When people get home from work in the evening, energy demands create a second peak.  A graph of this lack of synchronicity of load and supply looks a little like the shape of a duck and is popularly known as the duck curve.

The Cornell engineers figured out that maximum ramping in New York – where electrical demand and electricity supply from solar farms are out of synch- will take place in the winter.  In fact, when there are several days of sunshine in a row during winter, the largest ramping in the New York power system will take place.

The general issue of having solar energy available when it is most needed is one that is the driver for energy storage technology. If the energy can be provided when demand calls for it, there would be no more ramping.

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Winter could pose solar farm ‘ramping’ snag for power grid

Photo, posted September 8, 2015, courtesy of New York National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Schools And Solar Power

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A new study from Stanford University looked at the benefits of installing solar panels on the rooftops of schools.  According to the study, taking advantage of all the viable space for solar panels could allow schools to meet up to 75% of their electricity needs and reduce the education sector’s carbon footprint by as much as 28%.

Given the long list of spending priorities for schools, solar power seems like a luxury item.  But the Department of Energy estimates that K-12 schools spend more than $6 billion a year on energy and, in many districts, energy costs are second only to salaries.  In the higher education sector, yearly energy costs add up to more than $14 billion.  In total, educational institutions account for approximately 11% of energy consumption by U.S. buildings and 4% of the nation’s carbon emissions.

The Stanford study suggests that investments in the right solar projects combined with the right incentives from states could free up much-needed money in school budgets.

To no surprise, the study finds that three large, sunny states – Texas, California, and Florida – have the greatest potential for generating electricity from solar panels on school rooftops.

Apart from measurable effects on air pollution and electricity bills, solar installations at schools can also provide new learning opportunities for students.  In fact, some schools are already using data from their on-site solar energy systems to teach students basic ideas about fractions, as an example, as well as more sophisticated concepts such how shifting solar panel angles can affect power production.

According to the study, nearly all states could reap value from school solar projects.

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What happens when schools go solar?

Photo, posted February 28, 2011, courtesy of Black Rock Solar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Our Growing Appetite For Energy

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Energy consumption in the United States set a record high in 2018.  Overall, energy consumption reached 101.2 quadrillion BTUs or quads last year, breaking the previous record of 101.0 set in 2007.  Most of us are not too familiar with quadrillions of anything, nor with BTUs for that matter.  If it is any more illuminating, 101 quads are the equivalent of about 300 billion kilowatt hours.  Our energy use increased by 3.6% from 2017, which was the largest annual increase since 2010.

Wind, solar, and natural gas provided the largest increases in energy supply.  In 2018, solar and wind energy were both up by 0.18 quads, representing a 22% gain for solar and a 7.5% increase for wind.  Over the past ten years, overall renewable energy has doubled in the U.S., with wind increasing by a factor of 5 since 2008 and solar by an amazing factor of 48. 

Natural gas generation increased by 10.7%, or a total of 3 quads over the previous year.   The growth in natural gas use isn’t good news, but since much of it represents replacing coal, it at least corresponds to reduced greenhouse gas emissions.

The unfortunate part of our energy consumption is that the majority of it is still in the form of “rejected energy”.  It most often takes the form of waste heat, such as the warm exhaust from automobiles and furnaces.  The efficiency of our cars, lightbulbs and factories determines how much waste heat is produced and in turn how much fuel and electricity can be put to productive use.

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US energy consumption hits record high in 2018, solar/wind/natural gas grow

Photo, posted April 27, 2015, courtesy of Mathias Appel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Meal Kits And The Environment

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Meal kit services have become extremely popular in recent years.  These are companies that deliver a box of pre-portioned ingredients and a chef-created recipe to your door to make home-cooked meals easy and practical for busy people.  Leading companies like Blue Apron, HelloFresh, and Plated have been joined by dozens of others competing in the meal kit market.  As of last year, annual sales for these things were over $3 billion and growing at more than a 20% annual rate.

A major rap against meal kits has been their environmental impact, mostly centered around the amount of packaging waste they generate.  While there is most certainly lots of packaging waste associated with meal kits, it turns out that their overall carbon footprint is actually rather good compared with conventional ways to make homecooked meals.

A study from the University of Michigan looked at the cradle-to-grave impact of meal kits, taking into account every major step in the lifetime of the food ingredients and the packaging – agricultural production, packaging production, distribution, supply chain losses, consumption, and waste generation.

Surprisingly, meal kits have a much lower overall carbon footprint than the same meals made from ingredients purchased at the grocery store – even including their packaging.  The main reason is that pre-portioned ingredients and a streamlined supply chain lower overall food losses and waste for meal kits compared to store-bought meals.  Pre-portioning simply results in fewer ingredients that end up being wasted.  Meal kits also have radically different supply chain structures than foods sold in supermarkets.

Whether the economics and culinary aspects of meals kits are advantageous for many people is an open question, but apparently from an environmental perspective, they are just fine.

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Climate change has worsened global economic inequality

Photo, posted June 11, 2018, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rare Earths From Mining Waste

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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.

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