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Better Ways To Make Bioplastics | Earth Wise

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The world produces over 300 million tons of plastics each year, mostly produced from petroleum.  The environmental consequences are substantial and there is a critical need to replace as much of that plastic production with biodegradable plastics as possible.  Thus, there is global research aimed at making bioplastics more economical and as environmentally friendly as possible.

Researchers at Texas A&M University have developed an improved approach for making bioplastics from corn stubble, grasses, and mesquite agricultural production.  Apart from the obvious environmental benefits of having biodegradable plastics, producing bioplastics from common agricultural waste would create new revenue streams for farmers as well as the people who transport harvested feedstock and byproduct crops to refinery operations.

The key to bioplastic production is the efficient extraction and use of lignin, the organic polymer that is the primary structural support material in most plants.  The new research takes five conventional pretreatment technologies for plant materials and modifies them to produce both biofuel and plastics together at a lower cost.  The new method is called “plug-in preconditioning processes of lignin” and it can be directly and economically added into current biorefineries.  The process is designed to integrate dissolving, conditioning, and fermenting lignin, extracting energy from it and making it easily adaptable to biorefinery designs.

The so-called bioeconomy currently supports some 286,000 jobs.  Innovation is the key to achieving more widespread use of biodegradable plastic.  With improved economics of so-called lignocellulosic biorefineries, there can be new avenues to use agricultural waste to produce biodegradable plastics.

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‘Plugging in’ to produce environmentally friendly bioplastics

Photo, posted November 5, 2015, courtesy of Kathryn Faith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Insanely Cheap Energy | Earth Wise

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The International Energy Agency, founded in 1974, keeps track of the world’s energy systems and anticipates how they are likely to change over time.  Policymakers around the world look to the agency’s annual World Energy Outlook publication for guidance.

In 2000, the agency made the prediction that by the year 2020, there would be a total of 18 gigawatts of photovoltaic solar power installed.  Within seven years, that number was already too small.

The IEA was not the only source to miss the mark on solar power.  The head of solar analysis at BloombergNEF in 2005 expected solar to eventually supply 1% of the world’s electricity.  It is already 3% and Bloomberg now predicts that it will be 23% by 2050 and expects that to be an underestimate. 

What has happened is that the world has unexpectedly gotten to the point where solar is the cheapest source of energy in most places.  Over the past decade, every time solar production capacity has doubled, its cost has dropped by 28%.

Historically, a combination of groundbreaking research in Australia and intense Chinese industrial development led to the creation of a massive new industry.  When Germany passed laws encouraging the use of solar power, suddenly there was massive global demand and a struggle to keep up with supply.

The industry had its fits and starts, and many players fell by the wayside.    But at this point, solar technology continues to get better and cheaper.  Market forces are pretty hard to beat and when solar technology can supply insanely cheap energy, it is going to be used in more and more places.

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‘Insanely cheap energy’: how solar power continues to shock the world

Photo, posted January 10, 2020, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Solar Evaporator | Earth Wise

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Water security is a serious global problem.  Nearly 1.5 billion people – including almost half a billion children – live in areas of high or extremely high water vulnerability.  Less than 3% of the world’s water is fresh and demand for it is rising with increasing population growth, urbanization, and growing water needs from a range of sectors.

Researchers at the University of South Australia have developed a promising new technique that could help reduce or eliminate water stress for millions of people.  The technique uses highly efficient solar evaporation to obtain fresh water from seawater, brackish water, or even contaminated water.   According to the researchers, their technique can deliver enough daily fresh drinking water for a family of four from just one square meter of source water.

Solar evaporation has been the focus of a great deal of effort in recent years, but it has generally been found to be too inefficient to be practically useful.  The new technique overcomes those inefficiencies and can deliver fresh water at a fraction of the cost of existing technologies like reverse osmosis.

The system utilizes a highly efficient photothermal structure that sits on the surface of a water source and converts sunlight to heat, focusing energy precisely on the surface to rapidly evaporate the uppermost portion of the liquid.  The technique prevents any loss of solar energy and even draws additional energy from the bulk water and surrounding environment.

The system is built entirely from simple, everyday materials that are low cost, sustainable, and easily obtainable.

The technology has the potential to provide a long-term clean water solution to people who can’t afford other systems, and these are the places where such solutions are most needed.

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Sunlight to solve the world’s clean water crisis

Photo, posted November 13, 2016, courtesy of Steve Austin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Ever Cheaper Solar Power | Earth Wise

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The price of electricity from solar panels has been dropping dramatically over the last decade.  The average cost of utility-scale solar power has gone down more than 80% since 1980, making it the least expensive power source in many places.  The plunging price of solar power is one of the driving forces behind the transition to clean energy. 

The 2020 average cost of solar power was 4.6 cents per kilowatt-hour.  The Department of Energy has recently set a target of reducing the cost of solar power by more than half again by 2030, to an unsubsidized average of 2 cents per kilowatt-hour.  The 2-cent goal is not just the ordinary cost of electricity; it is the levelized cost of energy which is based on a formula that includes the cost of construction and operation of a power plant.

If the least expensive power source becomes that much cheaper, it will really shake the foundation of many energy debates.  One of these debates is how to meet the need for more interstate power lines to transport renewable energy from rural areas to population centers.   If large amounts of additional renewable energy sources are added, policymakers will need to work harder to reform the regulatory system to make sure that new interstate power lines get built.

If the average cost of solar power reaches 2 cents a kilowatt-hour, the actual price will be lower in sunnier regions and higher in those that get less sun.  However, the continuing decrease in solar electricity costs will actually have the greatest impact in the northern, less sunny regions, because solar power may not currently be the least expensive option there but it will become the cheapest alternative over time.

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Inside Clean Energy: What Happens When Solar Power Gets Much, Much Cheaper?

Photo, posted May 14, 2020, courtesy of Courtney Celley/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost Of Invasive Species | Earth Wise

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A new study published in Nature has tried for the first time to put a price tag on the impact of invasive species.  Researchers have been studying the effects of invasive species for decades, but it is a problem that has not really captured the attention of the public and policy makers.

According to the research by scientists at the French National Museum of Natural History, from 1970 to 2017, invasive species have cost the global economy at least $1.28 trillion dollars in damages and efforts to control them.

The team screened over 19,000 published papers, ultimately analyzing nearly 2,000 that detailed costs of various invasions at particular times.   Annual costs roughly doubled every six years, reaching a yearly bill of $162 billion in 2017.

The five costliest invasive species are Aedes mosquitos, rats, cats, termites, and fire ants, collectively accounting for a quarter of the global damage.

Asian tiger mosquitos and yellow fever mosquitos alone accounted for $149 billion in damage to public health as they spread from country to country.  Rats hitchhike on human boats and drive native species to extinction on islands around the world.  Cats inflict damage primarily by their impact on native biodiversity.  By some estimates, they kill a billion birds each year in the US alone.   Termites, as they spread across the globe, wreak havoc on all sorts of infrastructure.  Fire ants can feed on a variety of seedlings, from citrus to soybeans, reduce the size of grazing lands for livestock and bite and sting farm animals and humans.

The study shows invasive species are a massive problem that is getting worse.

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Invasive Species Cost Billions of Dollars in Damages Annually, Researchers Find

Photo, posted March 29, 2012, courtesy of Aleksey Gnilenkov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Red Hot Chili Solar Panels | Earth Wise

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The majority of solar panels in use today are made from either single-crystal or polycrystalline silicon, the same stuff used to make the ubiquitous chips in computers, cell phones, and countless other devices.  In addition, a growing fraction of solar panels utilize thin-film technology, which offers cost and flexibility advantages.

Monocrystal silicon still provides the highest efficiency and longest lifespan in commercially available panels, but the lower costs and some other features of thin-film solar panels are growing that market over time.

More recently, perovskite solar cell technology has been a source of great interest in the research community.  Perovskites are a class of minerals with a specific crystalline structure that already have uses in various applications.  As a solar cell material, perovskites offer the potential for converting more sunlight to electricity, being manufactured far more cheaply using no exotic or expensive materials, being more defect-tolerant, as well as a having number of other advantages.  They also have the potential for having very high efficiency. 

Recently, a group of researchers in China and Sweden published results of studies demonstrating that the addition of a novel ingredient has increased the efficiency of perovskite solar cells to nearly 22%, which is better than most commercial silicon solar cells.  The ingredient is capsaicin, the chemical that gives chili peppers their spicy sting.  Adding capsaicin expands the grains that make up the active material of the solar cell, allowing the more effective transport of electricity. 

Why did the researchers think of adding the active ingredient of hot peppers to a solar cell in the first place?  So far, they aren’t saying.

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Solar panels capture more sunlight with capsaicin – the chemical that makes chili peppers spicy

Photo, posted August 16, 2019, courtesy of Pedro via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Energy And Agriculture | Earth Wise

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According to a new study by Oregon State University researchers, co-developing land for both solar voltaic power and agriculture could provide 20% of total electricity generation in the United States with an investment of less than 1% of the annual U.S. budget.

The concept is known as agrivoltaics – using the same land for both growing crops and generating solar energy.  The proponents of agrivoltaics say that it provides more food, more energy, lower water demand, lower carbon emissions, and more prosperous rural communities.

According to the study, wide-scale installation of agrivoltaic systems could lead to an annual reduction of 330,000 tons of carbon dioxide emission in the U.S. – the equivalent of taking 75,000 cars off the road – and the creation of more than 100,000 jobs in rural communities.  All of this could be achieved with minimal effects on crop yields.

The study finds that an area about the size of Maryland would be needed for agrivoltaics to produce 20% of U.S. electricity generation.  That area of 13,000 square miles constitutes about 1% of current U.S. farmland.

The cost of the solar installations would be $1.1 trillion over 35 years and they would pay for themselves from the electricity generated within 17 years.  Installing the arrays would create the equivalent of 117,000 jobs lasting 20 years.

The researchers are going to install a fully functional solar farm on 5 acres of university owned land to demonstrate to the agricultural community and potential future funders how the study’s findings can be applied in real world agricultural systems.

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Combining solar energy and agriculture to mitigate climate change, assist rural communities

Photo, posted October 11, 2011, courtesy of Michael Coghlan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Understanding How To Enhance Desalination | Earth Wise

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Desalination is the process of removing mineral components – notably salt – from saline water, generally seawater.  Over 16,000 desalination plants operate across 177 countries, generating 25 billion gallons of fresh water each year.  Currently, desalination accounts for about 1% of the world’s drinking water.

The leading process for desalination in terms of installed capacity as well as new installations is reverse osmosis that makes use of a thin-film composite membrane based on ultra-thin polyamide.

Despite the fact that these membranes are widely used for desalination, they are actually rather poorly understood.  It has not been known exactly how water moves through them.  As a result, much of the progress made on the technology over the decades has been essentially based on guesswork.

A team of researchers at the University of Texas, Austin has used advanced microscopy techniques to solve some of the mysteries of reverse osmosis membranes.  By mapping membranes at very high resolution – less than half the diameter of a DNA strand – they gained a much better understanding of what makes a membrane better at reverse osmosis.

They found that desalination membranes are inconsistent in mass distribution and density and that these inconsistencies can impair membrane performance.  It turns out that inconsistencies and dead zones in membranes play a bigger role than membrane thickness.  By making the membranes more uniform in density at the nanoscale, they were able to increase desalination efficiency 30 to 40 percent, therefore cleaning more water with less energy and at lower cost.

Producing fresh water is not just essential for public health, it is also crucial for use in agriculture and energy production.

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Nanoscale control of internal inhomogeneity enhances water transport in desalination membranes

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Costs Of Mislabeled Seafood | Earth Wise

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Seafood is the world’s most highly traded food commodity and reports of seafood mislabeling have become increasingly common over time.  A new study by Arizona State University looked at the environmental effects of mislabeled seafood.

What is mislabeled seafood?  Sometimes the snapper you were served was really Pacific Ocean Perch.  Maybe grouper was really whitefin weakfish.  Many times white leg shrimp are actually giant tiger prawns.

Approximately 190,000 to 250,000 tons of mislabeled seafood are sold in the U.S. each year, or 3.4 to 4.3% of consumed seafood.  Previous studies focused on the economic aspects of getting cheaper fish when paying for more expensive fish.  The new research looks at the environmental costs associated with mislabeled seafood.

Substituted seafood is 28% more likely to be imported from other countries, which may have weaker environmental laws than the U.S.  In the United States, fishery management is pretty good.  There is strong monitoring and enforcement to support limits on fishing.  Metrics like fish abundance, fishing mortality, bycatch, and discards are all monitored.  In many other places, this is not the case.

To really evaluate the overall effects of seafood mislabeling, one has to take into account both the rates of substitution and the levels of consumption. 

Consuming fish from a well-managed fishery should not have a negative impact in terms of the population now or in the future.  But even inadvertently consuming fish from poorly managed fisheries in not sustainable.  It is good to get your seafood from a trusted source.

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ASU Study Looks At The Environmental Effects Of Purchasing, Consuming Mislabeled Fish

Photo, posted August 1, 2014, courtesy of Ralph Daily via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recyclable Wind Turbines | Earth Wise

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The blades of modern wind turbines can be longer than the wing of a Boeing 747. Their useful lifetime is perhaps 20 years and after that, they can’t just be hauled away.  They end up being cut up with special industrial saws to create pieces small enough to be strapped to a tractor-trailer.  Then, they end up in landfills.  There are thousands of blades being removed each year and those numbers are growing.

Wind turbine blades are currently manufactured using thermoset resin, which cannot be recycled.  It is also energy-intensive and manpower-intensive to produce.

Researchers at the National Renewable Energy Laboratory in partnership with Arkema Inc of Pennsylvania have demonstrated the feasibility of using thermoplastic resin instead to make wind turbine blades.  That material can be recycled and can also enable longer, lighter-weight, and lower-cost blades.  Using thermoplastic could also allow manufacturers to build blades on site, alleviating the problems of transporting ever larger turbine blades.

Current blades are made primarily of composite materials like fiberglass infused with thermoset resin.  The manufacturing process requires additional heat to cure the resin, which adds cost and time.  Thermoplastic resin cures at room temperature and requires less labor.  With regard to recycling, thermoplastic resin, when heated above a certain temperature, melts into its original liquid resin and can be reused. 

NREL has demonstrated the feasibility of the thermoplastic resin system by manufacturing nearly identical blades using both the standard materials and the thermoplastics.  NREL has also developed a technoeconomic model to evaluate the cost benefits of using thermoplastic resin.

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News Release: NREL Advanced Manufacturing Research Moves Wind Turbine Blades Toward Recyclability

Photo, posted June 28, 2008, courtesy of Patrick Finnegan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Replacing Plastic Tableware | Earth Wise

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Plastics have been described as the “ubiquitous workhorse material of the modern economy.”  But their versatility, pliability, and durability comes at a heavy price to the environment.  Plastic pollution is quite literally everywhere.  Plastic debris and microplastic particles can be found in every corner of the globe, including the Arctic and Antarctic. 

The scourge of plastic pollution is driving scientists to create ecologically-friendly alternatives.  According to a paper recently published in the journal Matter, scientists have developed “green” tableware made from sugarcane and bamboo that doesn’t sacrifice on convenience or functionality.  This eco-friendly tableware could serve as a permanent replacement for plastic cups and other disposable plastic containers. 

Traditional plastic polymers, a product of petroleum, can take as long as 1,000 years to decompose in landfills.  The new material only takes 60 days to break down.

To create this material, scientists used bamboo and bagasse, also known as sugarcane pulp.  Bagasse is one of the largest food-industry waste products.  The researchers wound the fibers together to form a mechanically stable and biodegradable material.  They added an alkyl ketene dimer, an eco-friendly chemical, to increase the oil and water resistance of the material.  The green material is durable enough to hold liquids like hot coffee and hot greasy foods like pizza.   

There’s another advantage: the green material’s manufacturing process emits 97% less CO2 than the process to make commercial plastic containers.  The next step is to lower the manufacturing cost.  While the cost of cups made from the green material is $2,333 per ton, traditional cups made from plastic are still slightly cheaper at $2,177 per ton.

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This tableware made from sugarcane and bamboo breaks down in 60 days

Photo, posted May 19, 2013, courtesy of Henry Burrows via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost of Cleaning Up Ocean Plastic | Earth Wise

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Small island developing states increasingly find themselves with large amounts of plastic waste.  A recent study looked at the financial cost for removing it.

Aldabra Atoll is a UNESCO World Heritage Site in the Seychelles.  It is the world’s second-largest coral atoll and is the home of 307 species of animals and plants, including the largest population of giant tortoises in the world.  Aldabra has been called one of the wonders of the world and one of the crown jewels of the Indian Ocean.

Last year, a team from the University of Oxford and the Seychelles Island Foundation, spent five weeks removing litter that had washed up on Aldabra’s shores.  In total, they removed 25 tons of plastic litter which, to their surprise, was dominated by waste from the fishing industry.  The researchers now estimate that over 500 tons of litter remain on the island, 83% of which consists of buoys, ropes, nets, and, of all things, over 300,000 individual flipflops.  This is the largest accumulation of plastic waste reported for any single island in the world.

According to the study, the cost to clean up the entire island would be nearly $5 million, requiring 18,000 person-hours of labor.  A project of this magnitude is beyond the capacity of non-profit organizations like the Seychelles Islands Foundation.

The plastic pollution in Aldabra is related to the fishing industry in Seychelles, which provides tuna to high-income markets around the world.  The research highlights how even remote highly protected island ecosystems are impacted by global pollution and how difficult and costly it is to remedy.

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Millions of dollars to clean up tuna nets and flip flops from island state

Photo, posted December 27, 2016, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Fabric To Keep You Cool | Earth Wise

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About 10% of all electricity consumption in the U.S. is devoted to keeping us cool with air conditioning and other methods.  Researchers at two universities in Shanghai, China have developed a new material that can be made into clothing that cools the wearer without using any electricity.

The new fabric transfers heat, allows moisture to evaporate from the skin, and repels water.  Cooling off a person’s body is much more efficient than cooling off an entire room or a building.  There have been textiles and types of clothing designed to perform the cooling function, but most of those have disadvantages.  These include some combination of poor cooling capacity, high energy consumption, complex and time-consuming manufacturing, and high cost.

The researchers wanted to develop a personal cooling fabric that can efficiently transfer heat away from the body while at the same time being breathable, water resistant and easy to make.

The new fabric is made by electrospinning an ordinary polyurethane polymer with a water-repelling fluorinated version of polyurethane polymer along with a thermally conductive filler composed of boron nitride nanosheets.  The resultant material is a nanofibrous membrane that repels water from the outside but has large enough pores to allow sweat to evaporate from the skin and air to circulate. 

Tests of the membrane demonstrated higher thermal conductivity than other conventional or high-tech fabrics.  Used in clothing, the material would be more effective than previous fabrics in conducting heat away from the body. It may be possible to beat the heat without turning on the AC.   These membranes could also be useful for solar energy collection, seawater desalination, and thermal management of electronic devices.

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New fabric could help keep you cool in the summer, even without A/C

Photo courtesy of the American Chemical Society on Youtube.

Earth Wise is a production of WAMC Northeast Public Radio.

The Menace Of Abandoned Oil Wells | Earth Wise

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More than a century of oil and gas drilling has left behind millions of abandoned wells and many of them are leaching pollutants into the air and water.  Drilling companies continue to abandon even more wells as demand for oil diminishes and bankruptcies become more common.

Leaks from abandoned wells have long been known to be an environmental problem and a health hazard.  They have been linked to many instances of groundwater contamination and to dangerous fumes near homes and farms.

There have recently been efforts to track the amounts of methane leaching from abandoned oil and gas wells, and the figures in United States are alarming.  According to the most recent EPA report, more than 3.2 million abandoned oil and gas wells emitted a total of 281,000 tons of methane in 2018.  That is the climate-damage equivalent of consuming about 16 million barrels of crude oil, which is as much as the U.S. uses in a typical day.  According to the EPA, the actual amount could be as much as three times higher, because of incomplete data.   The agency believes that most of the methane comes from more than 2 million abandoned wells that were never properly plugged.

New York’s Department of Environmental Conservation has records of over 2,000 abandoned wells, but the state believes the actual number could be much higher.  This is a problem that won’t just go away.  Wells don’t leak for a year and then stop.  They can continue to leak for a century or more.  Cleaning up and plugging an abandoned well runs from $20,000 to $145,000, meaning that countrywide, cleaning up this environmental menace could cost somewhere between $60 billion and $435 billion.

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Special Report: Millions of abandoned oil wells are leaking methane, a climate menace

Photo, posted October 13, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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.

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.

Building The World’s Largest Battery Energy Storage Plant | Earth Wise

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The Monterey County Planning Commission has unanimously approved a joint project between Tesla and Pacific Gas and Electric to turn the Moss Landing Power Plant in California into the world’s largest battery energy storage facility.

The Moss Landing Power Plant is a natural gas-powered electricity generation plant located at the midpoint of California’s Monterey Bay.  At one time, it was the largest power plant in the state of California with a generation capacity of 2560 MW but has been gradually shutting down over time.

The new facility will incorporate 1.2 GWh of storage capacity for energy generated by solar and wind systems.  The stored energy will be available for use during periods of high energy demand and lower output.  This is about ten times larger than Tesla’s Hornsdale energy storage project in Australia, which was three times bigger than any other batter storage facility when it was built a few years ago.  In 2018, the battery system at Hornsdale made back a third of its cost in just one year.  The systems make use of Tesla’s Megapack battery products which come in pre-assembled units that provide 3 MWh of energy storage capacity.

The project will make use of existing power lines to transmit energy around Monterey County and parts of Silicon Valley.  Tesla and PG&E hope to break ground in early spring with completion scheduled for the end of the year.  California has been adding massive amounts of wind and solar power to its electrical grid and incorporating energy storage is an important step towards creating a truly resilient power system.

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Humongous Tesla Battery Plant Approved In California Is 10× Bigger Than World’s Biggest Battery Plant

Photo, posted September 22, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Foods of the Future? | Earth Wise

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In a world where many go hungry in the context of rapidly changing environments, many experts contend that alternative food sources will be necessary to solve global food security problems.  So-called novel food sources are central to this conversation, defined as foods with no history of consumption in a region – or perhaps anywhere.

Three popular examples are lab-grown meat, insect farming, and seaweed aquaculture.  Each of these offer opportunities as well as challenges.

Lab-grown meat can refer to actual animal tissues raised in vats as well as the increasingly common cultured plant products made to resemble meat.  Lab-grown meat faces push back from the livestock industry that contends it should not be labeled as any kind of meat. While results to date are positive, barriers still remain including concerns over product taste, healthiness, and cost.  And while less land- and water-intensive than conventional livestock, cultured meat production is still energy intensive.

Insects do form a significant part of diets across the globe but have yet to be embraced in any substantial way in western cultures.  Nutritionally, numerous species of insects are rich in key proteins, micronutrients, and minerals.  But the “yuck factor” is a big barrier to cross.

Seaweed is a long-established part of many East Asian diets and has many potential dietary uses.  Several selectively bred varieties of seaweed supply a range of valuable nutrients.  Growing seaweed does not tax freshwater and terrestrial resources.  But intensively cultivated seaweeds would have potential negative effects on local marine ecosystems.

There is no single solution to complex issues like food security.  Novel foods may very well form part of the solution to a growing food crisis.

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Insects, seaweed and lab-grown meat could be the foods of the future

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

Earth Wise is a production of WAMC Northeast Public Radio.

An Ecological Trap For Polar Bears | Earth Wise

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Climate change has been shrinking Arctic sea ice and this is causing changes in the behavior of polar bears.   The Southern Beaufort Sea, located where the northern edges of Alaska and Canada meet, is home to one of the 19 population groups of polar bears.  Historically, the polar bears in this region remained on sea ice year-round.  But in recent decades, about a quarter of them have chosen to come on land instead of staying on the shrinking summer ice platform.

A recent study by San Diego Zoo Global, the U.S. Geological Survey, and Polar Bears International looked at the energetic consequences of the bears’ behavior.  The decision of each individual bear to stay on the ice or move to land appears to be linked to the energetic cost or benefit of the choice.

Bears who moved to land expended more energy during the summer than bears that remained on the sea ice.  In late summer, as the ice became even more restricted, a greater amount of energy was expended by bears swimming to land.  So, the immediate energy cost of moving to land is much greater than remaining on the receding pack ice.

On the other hand, bears on land in this region have access to whale carcasses in the summer while bears on the sea ice appear to be fasting.  As a result, it may be the case that the declining population of bears in this region is in part caused by the ecological trap of bears staying on the ice to avoid expending all the energy needed to move to land.  The shrinking polar ice is a real problem for polar bears.

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Energetics Study Indicates that Shrinking Sea Ice Is Creating an Ecological Trap for Polar Bears

Photo, posted October 30, 2011, courtesy of Martin Lopatka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

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