Earth Wise

A look at our changing environment.

You are here: Home / Archives for advantages

advantages

Better blue LEDs

By Leave a Comment

LEDs have become the standard source of energy-efficient lighting.  They make use of semiconductors to turn electricity into light.  Depending upon the materials used to make them, LEDs produce different colors.  In the early 1990s, the first blue LEDs were discovered, ultimately earning the Nobel Prize in physics, and enabling LEDs to produce white light, which is essential for general lighting applications.

Blue LEDs have shortcomings.  Some have issues with stability, scalability, cost, efficiency, complexity in manufacturing, or have environmental concerns because of the use of toxic components. 

Researchers at Rutgers University in collaboration with scientists at several other institutions have found a way to make blue LEDs more efficient and sustainable.  These LEDs use a new type of hybrid material that is a combination of copper iodide with organic molecules.  The impressive performance of these LEDs was achieved through an innovative technique called dual interfacial hydrogen-bond passivation.  This new manufacturing technique boosts the performance of LEDs by a factor of four.

The material has several advantages.  It has a very high photoluminescence quantum yield, which means that it converts nearly all the photoenergy it receives into blue light.  The LEDs last longer than many others and they work well in larger-scale applications, maintaining high efficiency.  The materials are eco-friendly and cost-effective.

According to the researchers, this new approach could be a versatile strategy for generating high-performance LEDs that can pave the way for better, brighter, and longer-lasting LEDs.

**********

Web Links

Scientists Develop Deep-Blue LEDs Expected to Greatly Enhance General Lighting

Photo, posted February 1, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Advantages of vertical farming

By Leave a Comment

Vertical farming has been increasingly used for leafy greens like lettuce and kale, as well as for herbs and a few fruits like strawberries and tomatoes.  A recent study by the Technical University of Munich has investigated the use of vertical farming for a much broader range of foods.  The study looked at the positive effects of vertical farming on both yield and environmental impact.

Traditional agriculture can reach its limits as a result of extreme weather events or in areas of high population density and resultant high demand.   With vertical farming, food can be grown close to consumers independent of weather and can make very efficient use of space.

The Proteins4Singapore study investigated the potential of a 10-layer vertical farming system cultivating crops, algae, mushrooms, insects, fish, and cultivated meat.  Many of these things are not currently part of many people’s diets.  But these foods can increase the protein yield per cultivation area nearly three hundredfold for crops and 6,000-fold for mushrooms and insects. 

Mushrooms and insects are examples of foods that require little light and cultivating them reduces energy consumption and, therefore, associated costs.

The biggest challenges for controlled environment agriculture – which is what vertical farming is – are the high energy demands for cultivation and the social acceptance.  Some of the foods that are especially well-suited to vertical farming – such as algae and insects – are not generally accepted by many consumers.  Controlled environment agriculture can revolutionize food production, but it will take a combination of technological advances, policy initiatives, and public engagement.

**********

Web Links

Vertical Farming to increase yields and reduce environmental impact

Photo, posted October 21, 2022, courtesy of Fred Miller / University of Arkansas System Division of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A giant plane for giant wind turbines

By Leave a Comment

Wind turbines have been getting bigger all the time.  Larger turbines have real advantages.  They can operate at lower speeds so they can be deployed in more places.  They capture more wind, so they make more power.  Large wind turbines can have blades more than 200 feet long and even larger ones are on the way.  An offshore wind farm in China has turbines with 400-foot blades.

Giant wind turbines face a thorny problem:  getting the blades to where they are to be installed.  The enormous blades can’t be easily shipped across aging roads and bridges.   Tunnels are too narrow, bridges are too low, and roads can be too tight to allow turns when transporting these massive turbine parts.  Some developers have actually had to build special roads for wind projects.

For nearly a decade, a Boulder Colorado company called Radia has been working on what would be the world’s largest plane.  The WindRunner aircraft would have a dozen times the cargo volume of a Boeing 747.  The WindRunner will be 356 feet long and 79 feet tall.  While its primary purpose would be transporting wind turbine blades, the plane could also be used to aid the military or businesses that are thinking really big.  Product developers often don’t even try to invent really big things because there is no way to transport them.  Radia expects the WindRunner to be rolled out before the end of the decade.

The wind industry is currently facing strong opposition from the Trump administration, but wind energy is not going away and bigger and better wind turbines will ultimately be built and will have to be transported.

**********

Web Links

Building the World’s Biggest Plane to Help Catch the Wind

Photo, October 10, 2013, courtesy of Allan Der via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hydrogen-powered aviation

By Leave a Comment

The transportation sector is responsible for about a quarter of human-generated greenhouse gas emissions.  Most of the energy used by transport systems comes from fossil fuels.  The transition to electric vehicles – cars, trucks, and buses – is making a real difference.  However, the emissions from the aviation industry have continued to grow faster than those of other forms of transportation.  There have been increased efforts to develop hydrogen-powered aircraft, but the challenges are substantial.

Hydrogen can be used for aviation both as a directly combusted fuel, or to power electric fuel cells.  Its advantages are that its use produces no carbon dioxide, and, in fact, hydrogen produces more energy per pound than jet fuel.

A study by researchers at MIT looked at the prospects for hydrogen use in aircraft and what needs to be done to make it practical.  The biggest issue is that the extra bulk of a hydrogen fuel tank and fuel cells in a plane would have to be offset by weight reductions elsewhere, such as reducing payload (cargo or passengers).  This would mean there would need to be more flights, thereby reducing the gains made.  The researchers argued that improvements in fuel cell power and more weight efficient fuel systems could eliminate the need for additional flights.

The bigger challenge is the infrastructure for generating and distributing hydrogen.  There needs to be green hydrogen – hydrogen produced without carbon emissions – and the infrastructure for getting it to planes where it is needed has to also not produce substantial emissions.

The study suggests that the rollout of hydrogen-based aviation should start at locations that have favorable conditions for hydrogen production.

**********

Web Links

Fueling greener aviation with hydrogen

Photo, posted December 20, 2016, courtesy of Dylan Agbagni via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Who wins: Wind or solar?

By Leave a Comment

A new study by the University of Exeter in the UK suggests that the world may have crossed a tipping point that will inevitably make solar power our main source of energy.  This data-driven model of technology seems to fly in the face of the current situation in which wind power contributes considerably more generation than solar power – by a factor of 3 in the U.S. and nearly double worldwide.

Wind and solar power both have advantages and disadvantages.  Solar power is quiet, requires little maintenance, and presents little danger to wildlife.  It is also practical for individual homes.  Residential wind power is not really a viable option for most people in most places.  But on the other hand, wind energy can produce more power than solar, can work both day and night, and can be located offshore far away from people.  On land, both wind and solar power take up lots of space and compete with other land use needs as well as countering people’s aesthetic preferences.

Both technologies continue to get cheaper over time, although solar has especially seen significant cost reductions.  The cost of solar power, which is already the cheapest form of electricity production, is estimated to fall to as low as $20 per megawatt hour over time from the current level of $40 per megawatt hour.

Wind and solar energy are on track to account for more than a third of the world’s electricity by 2030, according to the Rocky Mountain Institute.  Despite the predictions of various studies and the ambitions of specific technologies, it seems likely that wind and solar power will both play an expanding role in our energy systems for a long time to come.

**********

Web Links

World may have crossed solar power ‘tipping point’

Photo, posted November 22, 2008, courtesy of Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Better Zinc Batteries | Earth Wise

By Leave a Comment

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. 

**********

Web Links

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

The Carbon Footprint Of Electric Vehicles | Earth Wise

By Leave a Comment

Electric vehicles are widely known to be the environmentally friendly alternative to internal combustion-based cars.   But there are skeptics who argue that EVs actually have a larger carbon footprint than nonelectric vehicles.  The argument is that the manufacturing and disposal of vehicle batteries is very carbon intensive.  They also point to the reliance on coal to produce the electricity that powers the cars.

These claims have led to multiple studies in the form of life-cycle analyses comparing the amount of greenhouse gases created by the production, use, and disposal of a battery electric vehicle to that associated with a gasoline-powered car of a similar size.

In short, the studies have found that while it is true that the production of a battery electric vehicle results in more emissions than a gasoline-powered one, this difference disappears as the vehicle is driven. 

According to a study conducted by the University of Michigan and financed by the Ford Motor Company, the emissions equation evens out in 1.4-1.5 years for sedans, 1.6-1.9 years for S.U.V.s, and about 1.6 years for pickup trucks.

Emissions from driving come from burning gas in the nonelectric vehicles and from the generation of electricity used by the battery-powered cars.  In the current average power mix across the U.S., driving an EV results in a 35% reduction in emissions.  However, it varies tremendously by location.  There are some places with very dirty power and some with very clean power.  But of the more than 3,000 counties in the U.S., only 78 end up with higher emissions from electric cars.  Of course, as the electric grid gets greener, the advantages of electric cars only become greater.

**********

Web Links

E.V.s Start With a Bigger Carbon Footprint. But That Doesn’t Last.

Photo, posted May 21, 2022, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Busting Electric Vehicle Myths | Earth Wise

By Leave a Comment

From the early days of hybrid vehicles right on through the current booming market for electric cars, there has been the contention by some people that these cars are responsible for comparable or even greater amounts of greenhouse gas emissions over their product lifetimes.  The arguments generally centered around the carbon costs of creating batteries for the cars as well as the emissions associated with generating the electricity used to charge them.

A new study published by the International Council for Clean Transportation reports a life cycle assessment (or LCA) that considers every source of carbon generated from the cradle to the grave of the vehicle.

Included in the assessment are the mining costs of the lithium to make batteries, the transportation of batteries across the world by container ship, the end-of-life burden, the mix of energy generation in various places around the world, and so on.

The results of the analysis are that even in India and China, which are the biggest burners of coal and oil on earth, it still results in lower emissions to drive an EV instead of an internal combustion vehicle.

Lifetime emissions of today’s average medium-size EVs are lower than comparable gasoline cars by 66-69% in Europe, 60-68% in the US, 37-45% in China, and 19-34% in India.  As electricity generation continues to further decarbonize, all these numbers will only get better.  While it is somewhat more carbon-intensive to manufacture an EV, it doesn’t take very long in the car’s life to come out ahead owning one.

Early skeptics of EVs and hybrids had more legitimate concerns a decade or so ago, but the advantages of these vehicles are now unambiguous.

**********

Web Links

One of the Biggest Myths About EVs is Busted in New Study

Photo, posted December 30, 2020, courtesy of Chris Yarzab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Promoting Biodiversity In Agriculture | Earth Wise

By Leave a Comment

The organic foods industry is one of the fastest growing agricultural segments in the United States.  According to the Organic Trade Association, U.S. organic sales reached $61.9 billion in 2020, a jump of more than 12% over the previous year. 

Organic food has many benefits.  Organic food is free of antibiotics, growth hormones, and GMOs, and is grown using fewer pesticides.  Organic farming tends to be better for the environment by reducing pollution, conserving water, reducing soil erosion, increasing soil fertility, and using less energy.   And it’s also better for the health of nearby wildlife as well as the people who live close to farms. 

But when it comes to promoting biodiversity in agriculture, is organic farming the only alternative to conventional agriculture? It turns out it’s not – at least according to a new study recently published in the journal Trends in Ecology and Evolution. 

According to an international research team led by the University of Göttingen in Germany, a landscape mosaic of natural habitats and small-scale and diverse cultivated areas is the key to promoting biodiversity on a large scale in both conventional and organic agriculture.

According to the research team, areas cultivated to organic standards have one third more species, but don’t reach the yield level of conventional farming.  This means that more land would need to be cultivated organically in order to produce the same amount of food.  But as larger areas are cultivated, the advantages for biodiversity would disappear.    

Landscapes with small fields, long edges, high crop diversity, and at least 20% near-natural habitats can promote biodiversity significantly more than just organic certification.   

**********

Web Links

U.S. Organic Industry Survey 2021

Promoting biodiversity-friendly landscapes – beyond organic farming

Photo, posted August 29, 2019, courtesy of Lance Cheung/USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Red Hot Chili Solar Panels | Earth Wise

By Leave a Comment

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.

**********

Web Links

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.

WAMC Northeast Public Radio

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