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Colorful Solar Panels | Earth Wise

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More and more buildings and public spaces are incorporating solar panels and not only just on rooftops.  Some buildings are incorporating power-generating structures all over their facades.

Using solar panels in this way puts some design constraints on buildings because solar panels are typically a deep black color.  This is because solar panels need to absorb light and making them any other color decreases their ability to do so and generate power.  But the problem is that people don’t necessarily want a black building.

One alternative to traditional solar panel design is to use structural sources of color that include microscopic shapes that only reflect specific light frequencies, like the scales on butterfly wings.  But this approach generally leads to iridescence – which might not be what is wanted – and is often quite expensive to implement.

A team of researchers at a university in Shanghai has now demonstrated a way to give solar panels color that is easy and inexpensive to apply and that does not reduce their ability to produce energy efficiently.

The technique involves spraying a thin layer of a material called a photonic glass onto the surface of solar cells.  The photonic glass is made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres.  Even though most light can pass through the photonic glass, certain colors are reflected back, depending on the sizes of the spheres.  By varying that size, the researchers created solar panels that were blue, green, or purple with only a very small drop in solar panel efficiency.

The solar panels made this way maintained their color and performance under durability testing.  With this new technology, there may soon be colorful solar panels on our buildings.

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Colorful solar panels could make the technology more attractive

Photo, posted December 15, 2021, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Propane Refrigerants | Earth Wise

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About 10% of the world’s total electricity supply is used for air conditioning.  If current temperature trends continue, the energy demands for space cooling will more than triple by the year 2050.  Air conditioning is a double threat to the environment.  Apart from using lots of energy, ACs also make use of halogenated refrigerants that are extremely powerful greenhouse gases.

The most common space cooling appliances are split-air conditioners, which use an indoor unit and an outdoor unit connected by pipes.  These split ACS mostly utilize HCFC-22 and HFC-410 as refrigerants, which have global warming potential scores as high as 2,256 – meaning they trap 2,256 times more heat than carbon dioxide. 

A study by the International Institute of Applied Systems Analysis in Austria has shown that propane is a far better choice as an air conditioning refrigerant.  Its global warming potential is actually less than 1 meaning it traps less heat than carbon dioxide.  According to the study, if air conditioners switched to propane refrigerants, the world would avoid about a tenth of a degree Celsius of additional warming, which is a significant contribution to meeting the goals of the Paris climate agreement.

Propane-based split-ACs are already available commercially in China and India.  Elsewhere, many national regulations prohibit their use, primarily due to codes restricting the use of refrigerants with higher flammability.  Given the increasingly urgent need for climate action, it seems to be time to reconsider regulations on refrigerants.

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Propane — a solution for more sustainable air conditioning

Photo, posted March 24, 2021, courtesy of Phyxter Home Services via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pumped Hydro Storage In Switzerland | Earth Wise

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Pumped hydro energy storage is still by far the largest form of energy storage in the world, representing more than 90% of storage capacity worldwide.  The theory behind it is simple.  Water is pumped into an upper reservoir (that is, one at a higher elevation), and when electricity is needed, the water is allowed to flow downhill to power turbines and then is collected in a lower reservoir.   When there is excess electricity, it is used to pump water back uphill for use later.

Pumped hydro installations can’t be built just anywhere.  Geography and hydrology have to be suitable, which means high voltage transmission lines need to be constructed to link electricity sources like wind and solar farms with the storage location.  But in those situations where pumped hydro makes sense, it is a great solution to the energy storage problem.

Switzerland has just completed one of the largest pumped hydro facilities in the world.  The Nant de Drance installation makes use of the Emosson reservoir, which is an artificial lake built high in the Alps near the French border.  Over the past 14 years, 10 miles of tunnels have been dug into the mountains to connect the Emosson reservoir to the Vieux Emosson reservoir to the south.

In between the two reservoirs is a giant underground cavern where six of the largest water-driven turbines in the world are spun from the water rushing down from above.  The turbines have a capacity of 900 megawatts, making Nant de Drance one of the most powerful generating plants in Europe.  In terms of storage capacity, the installation has a maximum capacity of 20 gigawatt-hours, and can store that energy indefinitely, which is challenging for other storage technologies.

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14 Years In The Making, 20 GWh Pumped Hydro Storage Facility Comes To Switzerland (With Video)

Photo, posted September 7, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Law To Tackle Climate Change | Earth Wise

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The Inflation Reduction Act signed into law in mid-August is the most comprehensive U.S. legislation addressing climate change ever enacted.   It contains $369 billion in funding for clean energy and electric vehicle tax breaks, domestic manufacturing of batteries and solar panels, and pollution reduction.

The legislation for the most part makes use of carrots rather than sticks to coax American consumers and industry away from reliance on fossil fuels.  Rather than establishing more carbon taxes, mandates, and penalties, the law largely makes use of tax credits to provide incentives for the use of clean energy.

The law provides a large mix of tax breaks intended to bring down the costs of solar, wind, batteries, electric cars, heat pumps, and other clean technology.  For example, consumers will get a $7,500 credit for purchasing many new electric car models and about $4,000 for buying a used vehicle.

On the stick side of the ledger, oil and gas companies that emit methane above certain threshold levels will incur fees that escalate over time.  The law also increases the cost to the oil industry for extracting fossil fuels from public lands.

The act provides $60 billion for overall environmental justice priorities, including $15 billion targeted specifically for low-income and disadvantaged communities. There are many other provisions in the law addressing multiple climate-related issues.

According to three separate analyses by economic modelers, the investments from the Inflation Reduction Act are likely to cut pollution by about 40% below 2005 levels by the year 2030.

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The US finally has a law to tackle climate change

Photo, posted December 15, 2021, courtesy of Mario Duran-Ortiz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar-Powered Desalination | Earth Wise

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About two-thirds of humanity is affected by water shortages.  In the developing world, many areas with water shortages also lack dependable sources of electricity.  Given this situation, there is widespread research on using solar heat to desalinate seawater.  To date, many approaches to this face problems with fouling of equipment with salt buildup.  Tackling this issue has proven to add complexity and expense to solar desalination techniques.

A team of researchers from MIT and China has recently developed a solution to the problem of salt accumulation that is more efficient than previous methods and is less expensive as well.

Previous attempts at solar desalination have relied on some sort of wick to draw saline water through the device.  These wicks are vulnerable to salt accumulation and are difficult to clean.  The MIT-Chinese team has developed a wick-free system instead.  It is a layered system with dark material at the top to absorb the sun’s heat, and then a thin layer of water that sits above a perforated layer of plastic material.  That layer sits atop a deep reservoir of salty water such as a tank or pond.  The researchers determined the optimal size for the holes in the perforated plastic.

The 2.5 millimeter holes are large enough to allow for convective circulation between the warmer upper layer of water above the perforated layer and the colder reservoir below.  That circulation naturally draws the salt from the thin layer above down into the much larger body of water below.

The system utilizes low-cost, easy to use materials.  The next step is to scale up the devices into a size that has practical applications.  According to the team, just a one-square-meter system could provide a family’s daily needs for drinking water.

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Solar-powered system offers a route to inexpensive desalination

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

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Windows | Earth Wise

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Solar windows are an attractive idea.  It is very appealing to have the vertical surfaces on the outside of almost any building generate electricity.  The challenge is to have a transparent window be able to function as an efficient-enough solar panel.

Most conventional solar panels use silicon solar cell technology, which is not based on a transparent material.  Transparent solar cells use dye-sensitized technology, which has been the subject of research for decades but has yet to achieve widespread use.

Researchers at the University of Michigan have recently published work on a new process to manufacture solar windows that can be large (over six feet in each dimension) and efficient at electricity production.

The windows make use of dye-sensitized cells which are connected to lines of metal so small that they are invisible to the naked eye.  The individual cells are fairly small but the connection technology allows the construction of large windows.

The solar window has an efficiency of 7%, meaning 7% of incoming sunlight energy is converted to electricity.  The researchers believe that 10% efficiency should be attainable with their technology.  Conventional solar panels have efficiencies of 15% or more.

However, the goal is not necessarily to compete with silicon solar panels.  The real opportunity is to be able to generate electricity when rooftop solar is not practical or to produce additional electricity even when there is already a solar roof.

Going forward, the goals of solar window development are to increase efficiency and to reduce costs to where installing the windows is economically attractive.  Estimates are that the windows currently would cost about twice as much as a conventional window but would pay for the difference in two to six years depending on such things as the level of sun exposure.

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Inside Clean Energy: What’s Hotter than Solar Panels? Solar Windows.

Photo, posted April 17, 2017, courtesy of Shelby Bell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Lives With Air Conditioning | Earth Wise

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This summer, extreme heatwaves struck the United States, Europe, and Africa.  Thousands of people died as a result.  In July, the impact of extreme heat in places ill-prepared for it was evident.  In the U.K., where air conditioning is uncommon, public transportation shut down, schools and offices closed, and hospitals cancelled non-emergency procedures.

Air conditioning, which we mostly take for granted in this country, is a life-saving tool during extreme heat waves.  However, only about 8% of the 2.8 billion people living in the hottest – and often poorest – parts of the world have AC in their homes.

A new study at Harvard modeled the future demand for air conditioning as the number of days with extreme heat continues to increase across the globe.  The researchers identified a massive gap between current AC capacity and what will be needed by 2050 to save lives, particularly in low-income and developing countries.

If the rate of greenhouse gas emissions continues on its present course, the study concluded that that at least 70% of the population in several countries will require air conditioning by 2050.  The number will be even higher in equatorial countries like India and Indonesia.  At this point, even if the goals of the Paris Climate Accords are met, an average of 40-50% of the population in many of the world’s warmest countries will still require AC.

The research looked at various scenarios.  One in which emissions continue to increase leads to widespread need for air conditioning even in temperate countries.  In Germany, 92% of the population would need it, and here in the U.S., 96% would need it.

Planning for future power systems must take into account the essential needs of a warming world.

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In a hotter world, air conditioning isn’t a luxury, it’s a lifesaver

Photo, posted July 24, 2021, courtesy of Phyxter Home Services via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Cars And The Remote Road Test | Earth Wise

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One reason many people are hesitant about switching to an electric car is range anxiety, the fear that their car’s battery will die on them in the middle of a trip.  It is pretty much the same thing as running out of gas, but somehow it seems like more of a danger.

Perhaps this was true when charging stations were few and far between and electric cars couldn’t go very far on a charge, but these days, the average electric car can drive about 200 miles on a charge and there are charging stations all over the place.

A big difference between gas cars and electric cars is that many people can charge their cars at home and start every day with the equivalent of a full tank.  With an electric car, there is little reason to use up all nearly all the charge before filling up the tank again.

The truth is that most people don’t drive all that much on the average day anyway.  In the US, the average driver goes about 39 miles a day.  In Europe, is it considerably less.  Yes, there are some people who drive 200 miles a day, but they are few and far between.

Remote and regional Australia is a place where distances between essential services can be very large.  But a new study from the Australian National University found that even under those trying conditions, the vast majority of residents, about 93%, can go about their business even with the lower-range electric vehicles available on the market without having to recharge en route.

Electric cars may not be practical for some drivers, but for most, they are already a great choice.

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Electric vehicles pass the remote road test

Electric car range and 5 reasons why your range anxiety is unwarranted

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

Earth Wise is a production of WAMC Northeast Public Radio.

Rooftop Solar Taking Off In China | Earth Wise

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The total amount of solar power generating capacity in the world has been growing rapidly.  In 2008, there was a total of only 15 gigawatts installed world-wide.  By 2012, the total was 100 gigawatts.  As of this spring, there is now 1 terawatt – that’s 1,000 gigawatts – of solar power installed in the world.   About a third of that total is in China, and solar power is really booming there.

Estimates are that China will install 108 gigawatts of solar capacity this year, which is about double the amount installed in 2021.  Much of the growth in solar in China is in the form of rooftop solar, as opposed to utility-scale solar farms.

China is aiming to have 50% of new factory rooftops carry solar installations by 2025.   By the end of next year, China’s National Energy Bureau is aiming for solar panels to cover 50% of rooftops on party and government buildings, 40% of schools, hospitals, and other public buildings, 30% of industrial and commercial buildings, and 20% of rural homes.  This new initiative will drive China’s installed solar capacity to impressive levels in the coming years.

After China, the leading installers of solar energy capacity are the European Union, the United States, and Japan. 

These figures are for generating capacity.  What ultimately matters is solar’s share of total electricity consumption.  In China and the EU, solar provides over 6% of the electricity used.  In the US, that figure is about 3.5%.  In Germany and Australia, solar power provides 10% of electricity needs.  All these numbers will continue to go up rapidly as solar installations grow.

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China Sees Rooftop Solar Take Off as New Policies Bolster Growth

Photo, posted June 17, 2022, courtesy of Nguyễn Mỹ Hoa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Progress On Artificial Photosynthesis | Earth Wise

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Photosynthesis is the process by which plants use the energy from sunlight to turn water and carbon dioxide into biomass and ultimately the foods we and other organisms eat.  Scientists at the University of California Riverside and the University of Delaware have found a way to create food from water and carbon dioxide without using biological photosynthesis and without needing sunlight.

The research, recently published in the journal Nature Food, uses a two-step electrocatalytic process to convert carbon dioxide, electricity, and water into acetate, which is the primary component of vinegar.   Food-producing microorganisms then consume the acetate in order to grow.   Solar panels are used to generate the electricity to power the electrocatalysis.  The result is a hybrid organic-inorganic system that is far more efficient in converting sunlight into food than biological photosynthesis.

The research showed that a wide range of food-producing organisms can be grown in the dark directly on the acetate output of the electrolyzer.  These include green algae, yeast, and the fungal mycelium that produce mushrooms.   Producing algae with this technology is about 4 times more energy efficient than growing it with photosynthesis.  Yeast production is about 18 times more energy efficient than the typical method of cultivating it using sugar extracted from corn.

Artificial photosynthesis has the potential to liberate agriculture from its complete dependence on the sun, opening the door to a wide range of possibilities for growing food under the increasingly difficult conditions imposed by the changing climate.

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Artificial photosynthesis can produce food without sunshine

Photo, posted September 7, 2016, courtesy of Kevin Doncaster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lithium-Sulfur Batteries | Earth Wise

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Existuje také spousta přípravků ve formě vitaminových a minerálních komplexů, které nasycují tělo všemi užitečnými zdroji pro správné fungování celého těla a sexuálního systému. Nejoblíbenější jsou dnes syntetické stimulanty, protože poskytují silný apothekeein.com a stabilní účinek, doplňky stravy a homeopatické léky se častěji používají pro prevenci problémů tohoto druhu.

The growing use of electric vehicles as well as energy storage systems has created a major focus on the batteries for these applications.  Lithium-ion batteries dominate these applications and the demand for the materials needed to manufacture them continues to grow.

The raw materials for these batteries include not only lithium, but also can include nickel, manganese, and cobalt. 

Sulfur has been a desirable alternative for use in lithium-based batteries for quite a while because it is an abundant element and can be extracted in ways that are safe and environmentally friendly.  However, previous attempts to create lithium batteries that combine sulfur cathodes and the standard carbonate electrolytes used in lithium-ion batteries have not been successful because of irreversible chemical reactions between intermediate sulfur products and the electrolytes.

A group of chemical engineers at Drexel University has now found a way to introduce sulfur into lithium-ion batteries that solves the stability problem and also has major performance advantages.  The new batteries have three times the capacity of conventional lithium-ion batteries, and last more than 4,000 recharges, which is also a substantial improvement.

The new battery technology involves creating a stable form of sulfur called monoclinic gamma sulfur by depositing the sulfur on carbon nanofibers.   Previously, this sulfur phase was only observed at high temperatures and was only stable for 20 or 30 minutes.  This chemical phase of sulfur does not react with carbonate electrolytes and therefore produces a battery that is chemically stable over time.

 Incorporating this sulfur into battery cathodes results in a better battery that doesn’t need any cobalt, nickel, or manganese.  It could be the next big thing in electric vehicle batteries.

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Breakthrough in Cathode Chemistry Clears Path for Lithium-Sulfur Batteries’ Commercial Viability

Photo, posted April 5, 2022, courtesy of Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Race For American Lithium Mining | Earth Wise

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The auto industry is making a massive transition from gas-powered cars to electric cars.  The exploding electric vehicle market has set off what some call a global battery arms race.  Battery manufacturers are urgently trying to source the raw materials needed to make batteries, which presently include cobalt, nickel, graphite, and lithium.  There is encouraging progress in reducing and even eliminating cobalt and nickel from electric car batteries, but so far lithium seems to be essential.

The International Energy Agency has named lithium as the mineral for which there is the fastest growing demand in the world.  Estimates are that if the world is to meet the global climate targets set by the Paris Agreement, at least 40 times more lithium will be needed in 2040 compared with today.

According to the US Geological Survey, the US has about 9 million tons of lithium, which puts it in the top 5 most lithium-rich countries in the world.  Despite this, our country mines and processes only 1% of global lithium output.  Most of the rest comes from China, Chile, and Australia.  Being dependent upon these foreign sources is a serious concern for national security.

There is only one operational lithium mine in the US at present.  Multiple companies are pressing to get more mining projects in operation, including sites in North Carolina and Nevada.  But there are serious environmental problems associated with lithium mining and there is considerable local opposition to establishing the mines.

The US wants to be a leader in the global race to build the batteries that will power the green transition but it is a complicated situation that combines both undeniably important benefits as well as very real dangers.

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Powering electric cars: the race to mine lithium in America’s backyard

Photo, posted January 18, 2022, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Dioxide Levels Higher Again | Earth Wise

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The National Oceanic and Atmospheric Administration reported that carbon dioxide levels measured in May at the Mauna Loa Observatory reached a value of 421 parts per million.  This is 50% greater than pre-industrial levels and is in a range not seen on earth for millions of years.

Before the Industrial Revolution, CO2 levels fairly steadily measured around 280 parts per million, pretty much for all 6,000 years of human civilization.  Since the Industrial Revolution began in the 18th century, humans have generated an estimated 1.5 trillion tons of CO2 pollution, much of which will continue to warm the atmosphere for thousands of years.

The present levels of carbon dioxide are comparable to those of an era known as the Pliocene Climatic Optimum, which took place over 4 million years ago. 

The bulk of the human-generated carbon dioxide comes from burning fossil fuels for transportation and electrical generation, from cement and steel manufacturing, and from the depletion of natural carbon sinks caused by deforestation, agriculture, and other human impacts on the natural environment.

Humans are altering the climate in ways that are dramatically affecting the economy, infrastructure, and ecosystems across the planet.  By trapping heat that would otherwise escape into space, greenhouse gases are causing the atmosphere to warm steadily, leading to increasingly erratic weather episodes ranging from extreme heat, droughts, and wildfires, to heavier precipitation, flooding, and tropical storm activity.

The relentless increase of carbon dioxide measured at Mauna Loa is a sober reminder that we need to take serious steps to try to mitigate the effects of climate change.

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Carbon dioxide now more than 50% higher than pre-industrial levels

Photo, posted December 20, 2016, courtesy of Kevin Casey Fleming via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Boom In Auto Battery Manufacturing | Earth Wise

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Nearly all automobile manufacturers are in a global race to build electric cars and trucks.  There is a rapidly growing need for the battery packs that power those vehicles and therefore manufacturers are in a race to build battery factories to address that need.

The latest battery plant announcement comes from Stellantis – the new company created in 2021 through the merger of Fiat Chrysler and Peugeot.  Stellantis aims to sell five million electric cars by 2030, which means they will need a lot of batteries.  They will be spending $2.5 billion in partnership with Samsung to build a battery factory in Kokomo, Indiana.  The facility is expected to create 1,400 jobs.  Stellantis already had announced that it would build a battery factory in Windsor, Ontario in partnership with LG Energy Solutions. 

They are not alone in their aggressive efforts on electric vehicle battery development.  Ford Motor is building two battery plants in Kentucky and a third one in Tennessee.   Ford has recently started production of its F-150 electric pickup truck which has attracted large numbers of pre-orders.  The gas-powered Ford F-150 has been the best-selling vehicle in America for years.

General Motors is opening a new battery production plant in Ohio this summer and has two others under construction in Tennessee and Michigan.   Hyundai plans to spend $5.5 billion on an electric vehicle and battery manufacturing facility near Savannah, Georgia that is expected to begin operations in 2025.

The auto industry has been struggling in recent times, but there is clearly a massive boom underway as the industry makes the transition from internal combustion engines to battery electric power.

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Stellantis and Samsung to spend $2.5 billion on an electric vehicle battery plant in Indiana

Photo, posted July 29, 2017, courtesy of Steve Jurvetson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Solar | Earth Wise

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The largest floating solar array in Europe, 12,000 panels sitting on top of the Alqueva Reservoir in Portugal – will come online in July.  Installing floating solar arrays, which are sometimes called “floatovoltaics”, produce renewable energy while shielding significant expanses of water from the sun’s heat.  These dual benefits have led to floatovoltaic projects in multiple countries around the world.

The city of Cohoes, in New York’s Albany County, has proposed an 8,000-panel floating solar array on the city reservoir.  Federal funding of $3 million for the project was obtained by local Congressman Paul Tonko and, in May, utility National Grid donated $750,000 towards the project.  Engineering work will shortly be underway on the 3.2 megawatt grid of solar panels.

The city of Cohoes pumps its drinking water supplies from the Mohawk River into the 10-acre, manmade reservoir.  The surface of the water is the largest undeveloped open space in the city.  Such reservoirs constitute prime sites for solar arrays since the space cannot be used for other purposes.  In addition, covering the water’s surface with the solar panels greatly reduces evaporation and helps to inhibit the growth of algae.

There are currently only 14 floating solar arrays in the U.S. and all of those are privately owned.  The Cohoes municipal array will be the first of its kind.  There are nearly 500 reservoirs in New York State and 24,000 nationwide that could be sites for floating arrays.   Drought-stricken Western reservoirs like Lake Mead and Lake Powell could be ideal locations of solar arrays.  Those reservoirs lose huge amounts of water to evaporation.  There are estimates that floating arrays could provide as much as 10% of the nation’s electrical needs.

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National Grid gives Cohoes $750,000 for floating solar array project

Photo, posted August 25, 2010, courtesy of Martin Abegglen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electricity From Bacteria | Earth Wise

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Microbiologists at Radboud University in the Netherlands have demonstrated in the laboratory that methane-consuming bacteria can generate electrical power.  Their study was recently published in the journal Frontiers in Microbiology.

The bacteria studied is called Candidatus Methanoperedens and in the natural environment it consumes methane in water sources that are contaminated with nitrogen including places like water-filled ditches and some lakes. The bacteria in the study make use of the nitrates in the water to break down and digest the methane. Methanogens, which are bacteria that reduce carbon dioxide to form methane, are the source of the methane in these places. 

The researchers exploited these complex interactions of bacteria to create a source of electrical power that is essentially a kind of battery with two terminals.  One of the terminals is a chemical terminal and one is a biological terminal.  They grew the bacteria on one of the electrodes where the bacteria donate electrons that result from its conversion of methane.  (Other microbiologists at the same institution had previously demonstrated electrical generation from a similar battery containing anammox bacteria that use ammonium rather than methane in their metabolic processing).

In the study, the Radboud scientists managed to convert 31% of the methane in the water into electricity but they are aiming at higher efficiencies. 

This approach represents a potential alternative to conventional biogas electricity generation.  In those installations, methane is produced by microorganisms digesting plant materials and the methane is subsequently burned to drive a turbine to generate power.  Those systems in fact have an efficiency of less than 50%.  The researchers want to determine whether microorganisms can do a better job of generating electricity from biological sources than combustion and turbines can do.

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Bacteria generate electricity from methane

Photo, posted December 3, 2008, courtesy of Martin Sutherland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Weaning Off Fossil Fuels | Earth Wise            

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We recently talked about California producing 97% of its electricity from renewables on one sunny afternoon in April.  On May 8th, the state produced enough renewable electricity to meet 103% of consumer demand.  These sorts of records are likely to be increasingly commonplace in the spring when the weather is still fairly mild.

But even while renewables were producing more electricity than California needed, natural gas power plants in the state were still running.

Turning off the gas power plants is not possible.  The reason is that as the sun sets and solar farms stop producing power, California has to quickly replace the power with electricity from other sources.  Natural gas plants are massive industrial facilities that cannot be turned on and off rapidly.  Some take as many as 4 to 8 hours to switch on.  Operators back them down as far as they can go, but even when there is plenty of solar power during the day, natural gas plants are still running.

The state is rapidly building huge battery storage projects as an alternative to gas plants, but so far, they are still only a small fraction of what is needed.   Wind power is another part of the solution along with hydropower.  California imports some power from other states as well and, in fact, also exports power when there is excess.  But keeping the energy system balanced and stable is an ongoing challenge.

California is building huge amounts of solar, huge amounts of wind, and huge amounts of energy storage, which should get the state to at least 90% of the way to a clean grid.  It’s the last 5-10% that is much harder to accomplish before natural gas is no longer part of the energy system.

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California just ran on 100% renewable energy, but fossil fuels aren’t fading away yet

Photo, posted January 10, 2014, courtesy of F.G. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Storing Sunshine To Make Electricity On Demand | Earth Wise

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Researchers at Chalmers University in Sweden have developed an entirely new way of capturing and storing energy from sunlight.  The system is called the Molecular Thermal Energy Storage System or MOST.  It is based on a specially designed molecule that changes shape when it is exposed to sunshine.

The molecule is composed of carbon, hydrogen, and nitrogen.  When sunlight hits it, it changes into an energy-rich isomer – a molecule made up of the same atoms but arranged together in a different way.  That isomer is stable and can be stored for many years.  When a specially designed catalyst is applied, the stored energy is released in the form of heat and the molecule returns to its original form and can be reused. 

The Chalmers researchers sent some of the energy-laden isomer to researchers in China who used it to operate a micron-thin thermoelectric generator, which used the heat released by the isomer material to generate electricity.  The generator is an ultra-thin chip that could be integrated into electronics such as headphones, smart watches, and telephones.  It is currently only at the proof-of-concept stage, but the results are quite promising.  The integration with the MOST technology provides a way that solar energy can generate electricity regardless of weather, time of day, season, or geographical location.  The results of the study were recently published in the journal Cell Reports Physical Science.

In effect, for this demonstration, Swedish sunshine was sent to the other side of the world and converted into electricity in China. The ultimate goal of this research is to create self-charging electronics that uses stored solar energy on demand.

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Converting solar energy to electricity on demand

Photo, posted March 11, 2013, courtesy of Steve Slater via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wind And Solar And Meeting Climate Goals | Earth Wise

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According to a new report from the climate think tank Ember, the rapid growth that has been going on for solar and wind power could allow the global electricity sector to do its part in limiting global warming to 1.5 degrees Celsius.

In 2021, solar power grew by 23% worldwide and wind power grew by 14%.  The Netherlands, Australia, and Vietnam had the largest gains in renewable energy.  Solar power in Vietnam grew by 337%.

The trends over the past decade, if continued across the globe, would result in the power sector being on track for meeting climate goals.  But not all the news is good.  The overall power sector has not been adequately reducing emissions.  Coal power actually grew by 9% last year as a result of increased demand for power during the rapid economic recovery in the easing of the pandemic shutdowns.  A spike in natural gas prices made coal more cost-competitive.

In order for the power sector to do its part in keeping warming below 1.5 degrees, wind and solar power will need to provide 40% of the world’s power by 2030 and nearly 70% by 2050.  Today, they supply only 10% of the world’s electricity.

With rising gas prices during Russia’s war with Ukraine, there is real danger of increased use of coal, threatening the gains made by renewable energy.

Nonetheless, a study published in Oxford Open Energy modeled various scenarios for the growth of renewable energy and found that it is feasible to meet climate goals.  In order to achieve this, countries’ policies will need to stimulate significant increases in energy and resource efficiency and rapid deployment of low-carbon technologies, promote strong environmental actions, and encourage low population growth.

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Rapid Growth of Wind and Solar Could Help Limit Warming to 1.5 degrees C

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

Earth Wise is a production of WAMC Northeast Public Radio.

Record Renewable Use In California | Earth Wise

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California, the most populous state, is the second largest electricity user.  Only Texas, the second most populous state, uses more energy, in part because it consumes large amounts in refining fossil fuels. Overall, California uses about 8% of the electricity generated in the U.S.

Thus, it was a significant milestone when briefly, on April 3, a record 97.6% of the energy on California’s statewide grid came from renewable energy resources.  (The previous record of 96.4% was set just a few days earlier).

Renewable energy’s share of the power typically peaks in the spring when mild temperatures keep demand relatively low and higher sun angles drive greater solar energy production.

On April 8, a record peak solar power production was set at 13,628 megawatts just after noon.  On March 4, the state set an all-time wind generation record of 6,265 megawatts. 

California now has over 15,000 MW of grid-connected solar power and 8,000 MW of wind.  Another 600 MW of solar and 200 MW of wind are coming online by June.  The state also has about 2,700 MW of energy storage online and that will climb to 4,000 MW by June.

In 2020, 34.5% of the state’s retail electricity sales came from wind and solar sources.  Adding in hydropower and nuclear power, nearly 60% of the state’s electricity came from non-fossil fuel.  Despite the effects of drought on hydropower generation and the impact of the pandemic on the pace of renewable energy projects, California continues its dramatic transition to sustainable energy.

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Solar and wind notched records as renewables met California’s energy demand

Photo, posted September 20, 2016, courtesy of Tom Brewster Photography / BLM 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...)