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Self-Watering Soil | Earth Wise

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Researchers at the University of Texas at Austin have created a new type of soil that can pull water from the air and distribute it to plants.  Such soil has the potential to expand the map of farmable land to previously inhospitable places as well as to reduce water use in agriculture in an era of growing droughts.

The team’s atmospheric water irrigation system makes use of super-moisture-absorbent gels to capture water from the air.  When they are heated to a high enough temperature, the gels release the water, making it available to plants.

The gels in the soil pull water out of the air during cooler, more humid periods at night and when the sun heats the soil during the day, the water-containing gels release their contents into the soil.

Each gram of soil can extract about 3-4 grams of water.  Depending on the specific crop, somewhere between a couple of ounces and 2 pounds of the soil can provide enough water to irrigate a square yard of farmland.

Experiments on the soil found that it retains water better than the sandy soils found in dry areas and needs much less water to grow plants.

In one experiment, radish plants germinated in the soil all survived a 14-day period without any irrigation beyond the initial watering when they were planted.  Radish plants in ordinary sandy soil irrigated for the first four days of the experiments lasted no more than two days further without watering.

The Austin group has been developing gel-polymer materials that work like super-sponges for two years.  These materials extract large amounts of water from the ambient air, clean it, and release it when heated with solar energy.

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Self-Watering Soil Could Transform Farming

Photo, posted October 21, 2020, courtesy of the U.S. Department of Agriculture via Flickr. USDA Media by Lance Cheung.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Solar Panels | Earth Wise

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It is inevitable that the things we make and use eventually outlive their useful lives and become waste that we have to deal with.  Solar panels, despite their impressively long lifetime, can’t escape this general principle.   As pioneering solar panels near the end of their 30-year electronic lives, they could well become the world’s next big wave of e-waste.

According to the International Renewable Energy Agency, nearly 90 million tons of solar panels will have reached their end of life by the year 2050, resulting in about 7 million tons of new solar e-waste per year.

Solar photovoltaic deployment has grown at unprecedented rates in recent years.  The total global installed capacity is about 600 GW today; projections are that there will be 1,600 GW by 2030 and 4,500 GW by 2050.

Solar panels contain valuable materials, including silver and high-purity silicon.  But current recycling procedures are not cost-effective.   Only about 10% of panels are currently recycled in the U.S.   The rest go to landfills or are shipped overseas to become another country’s problem.

Before solar waste becomes a major problem, the industry needs to better address the issue.  Strategies include improving the design of panels to align with recycling capabilities as well as developing new recycling methods that can more efficiently extract and purify the valuable materials in the panels.  Industry researchers are also looking into ways to repair and resell panels that are still in good condition and to repurpose old panels for less demanding functions like e-bike charging stations and housing complexes.

Like most things, solar panels do fail over time and with a rapidly growing number of them in the world, we need to figure out how to avoid them adding to the world’s problems.

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Solar Panels Are Starting to Die. Will We be Able to Recycle the E-Waste?

Photo, posted January 6, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Ocean Currents And Climate Change | Earth Wise

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Oceans cover more than 70% of the earth and absorb 94% of incoming solar radiation.  As a result, oceans play a major role in the climate system.  With their massive size and capacity to store heat, oceans help keep temperature fluctuations in check.  But oceans also play a more active role.  Ocean currents are responsible for moving vast amounts of heat around the planet.  

According to a paper recently published in the journal Nature Communications, the world’s strongest ocean currents will experience more intense marine heatwaves than the global average in the coming decades.  These strong ocean currents play key roles in fisheries and ocean ecosystems.  

Sections of the Gulf Stream near the United States, the Kuroshio Current near Japan, the East Australian Current near Australia, and the Antarctic Circumpolar Current will all see more intense marine heatwaves over the next 30 years. 

Scientists from the University of Tasmania and CSIRO in Australia relied on high-resolution ocean modeling to carry out their research.  They confirmed the model’s accuracy by comparing outputs with observations from 1982-2018.  They then used the same model to project how marine heatwaves would alter with climate change out to 2050.

The model projects, for example, that intense marine heatwaves are more likely to form well off the coast of Tasmania, while more intense marine heatwaves along the Gulf Stream start to appear more frequently close to the shore from Virginia to New Brunswick, Canada. 

Marine heatwaves are on the rise globally, but knowing where they will occur and how much hotter they will be will help policymakers, ecologists, and fisheries experts in their regional decision-making. 

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Where marine heatwaves will intensify fastest: New analysis

Photo, posted April 17, 2016, courtesy of Nicolas Henderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar On Commercial Buildings | Earth Wise

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The United States installed 3.6 gigawatts of photovoltaic solar capacity in the first quarter of this year to reach a total installed capacity of 81.4 GW.  That is enough to power about 16 million American homes.  More than 2/3 of that capacity has been installed during the past five years.  

There has been a boom in solar installations in recent years and, until the Covid-19 pandemic stuck, 2020 was expected to be the biggest year yet.  Now the unprecedented health, social, and economic conditions in our country creates great uncertainty in such forecasts.

Nevertheless, the opportunities for growth in solar power continue to be substantial.  A new report from the energy research firm Wood Mackenzie looked at the prospects for using the roof space of commercial buildings for solar power.

Currently, just 3.5% of commercial buildings in the U.S. have solar panels on their roofs.  Another 1% of those buildings are attached to solar projects located off-site.  The report looked at how many buildings are potential targets for solar projects.

After accounting for buildings that are too small or that use too little electricity to make solar power a worthwhile investment, the report estimated that 70% of commercial buildings in the U.S. – amounting to some 600,000 sites – are candidates for solar installations.  Doing this would provide 145 GW of new solar capacity, which is nearly twice as much as currently exists in this country. 

Commercial solar installations have their own unique logistical and financial challenges.  While utility solar can scale to lower costs and residential solar has financing opportunities, commercial solar has neither.  But ultimately, it represents an important opportunity for our future energy system.

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U.S. Commercial Rooftops Hold 145 Gigawatts of Untapped Solar Potential

Photo, posted June 25, 2014, courtesy of Rob Baxter via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Are Slowly Taking Over | Earth Wise

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According to data released by the Federal Energy Regulatory Commission, wind, solar, and hydropower provided 100% of the 1.3 GW in new U.S. electrical generating capacity added in April 2020.  Furthermore, the FERC report revealed that renewable sources accounted for 56% of the 9 GW added during the first four months of the year.  Apart from renewables, the balance of new generation was almost entirely made up of new natural gas capacity.   There have been no new capacity additions by coal, oil, nuclear power, or geothermal energy since the beginning of the year.

Renewable energy sources now account for nearly 23% of the nation’s total available installed generating capacity and continue to increase their lead over coal, which now accounts for only 20% of the nation’s electricity generation.

FERC data also suggests that renewables’ share of generating capacity should increase significantly over the next three years.  So-called “high probability” generation capacity additions for wind, minus anticipated retirements, project a net increase of nearly 27 GW, while solar is projected to grow by 24 GW.  By comparison, net growth for natural gas is expected to be just over 20 GW. 

Hydropower, geothermal, and biomass are all expected to experience net growth while the generating capacity of coal and oil are expected to plummet.   Nuclear power is forecasted to remain essentially unchanged.

In total, over the next three years,  the mix of all renewables is predicted to add more than 50 times the net new generating capacity added by natural gas, coal, oil, and nuclear power combined.  Renewables are truly on the rise.

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Renewable Energy Provides All New US Generating Capacity in April – Forecast to Add Almost 50x More Than Coal, Oil, Gas & Nuclear Over Next Three Years

Photo, posted May 24, 2011, courtesy of Michael Mees via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Could Take Over By 2035 | Earth Wise

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A study by UC Berkeley looked at the prospects for renewable energy sources to become the primary source of energy in the United States over the next 15 years.  Even though fossil fuels continue to fill that role at present, the plummeting costs of alternative energy sources – primarily solar and wind power – are making them increasingly attractive on the competitive market.

These cost reductions have occurred much faster than what was anticipated even just a few years ago.  According to the study, it is technically and economically feasible for renewable sources to provide 90% of our electricity by 2035.

The Berkeley researchers took the available data on renewable energy and created two scenarios for the next 15 years.  The first has energy policy remaining as it is now, without ambitious policy changes that encourage the growth of renewable energy.  In that scenario, they estimated that 55% of the US energy infrastructure would come from renewables.  That amount will not produce the change needed to meet Paris Climate Agreement goals but would simply come about because of the dramatically lower costs for renewable energy.

The second scenario includes state and federal governments leading the way to finance and facilitate the energy reform needed for a greener 2035.  It also relies on the large-scale use of grid-scale batteries to store the energy collected from solar and wind installations for when it is needed.

Which scenario is more realistic will depend on several major influential factors, notably the trajectory and consequences of the COVID-19 pandemic as well as the results of the November elections.   These things will have a huge impact on the future of our energy system.

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Report: By 2035, 90 Percent of the US Could Be Powered by Renewables

Photo, posted May 25, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Surpass Coal | Earth Wise

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In 2019, energy consumption in the U.S. from renewable sources exceeded consumption from coal for the first time since before 1885.  This has come about from a combination of the continued decline in the amount of coal used for electricity generation as well as the continued growth in renewable energy, mostly from wind and solar.

Until the mid-1800s, burning wood was the main source of energy in the U.S. and, in fact, it was the only commercial-scale renewable energy source until the first hydroelectric plants came online in the 1880s.  Coal was used as fuel for steamboats and trains and making steel but only started to be used to generate electricity in the 1880s.

In 2019, U.S. coal consumption decreased for the sixth consecutive year and fell to its lowest level in 42 years.  Natural gas has displaced much of the energy generation from retired coal plants.

At the same time, renewable energy consumption in the U.S. grew for the fourth year in a row to a record high level, almost entirely as a result of the growing use of wind and solar power.  In 2019, wind power surpassed hydroelectric power for the first time and is now the most-used source of renewable energy for electricity generation in the U.S.

Coal was once commonly used in the industrial, transportation, residential, and commercial sectors.  Today, in the U.S., it is mostly used to generate electricity, and that use is rapidly declining.

Electricity consumption for 2020 is likely to be anomalous in many ways as a result of the Covid-19 pandemic shutdowns.  From all indications, however, the role of renewable energy will only have been increased during the shutdown period.

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U.S. renewable energy consumption surpasses coal for the first time in over 130 years

Photo, posted July 26, 2013, courtesy of Don Graham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Powering Amazon By The Sun | Earth Wise

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Amazon.com is a multinational conglomerate company that sells nearly $300 billion dollars a year worth of products, employs over 800,000 people, and by any measure, consumes a tremendous amount of resources.  In terms of its environmental impact, Amazon is estimated to be responsible for the emission of 50 million tons of CO2 annually, which is more than the yearly total for countries like Switzerland, Ireland, New Zealand, Denmark, and about 140 other countries.

Amazon is trying to reduce its environmental impact.  The company recently announced five new renewable energy projects in China, Australia and the U.S. as part of its commitment to reach 80% renewable energy by 2024, 100% renewable energy by 2030, and to reach net zero carbon by 2040.

The projects include a 100 MW solar project in Shandong, China, a 105 MW solar project in New South Wales, Australia, two solar projects in Ohio (one 200 MW and one 80 MW), and a 130 MW solar project in Virginia.

To date, Amazon has announced 31 utility-scale wind and solar renewable energy projects as well as 60 solar rooftops on fulfillment centers and sort centers around the world.  Taken together, these projects provide almost 3 GW of capacity and will deliver more than 7.6 million MWh of renewable energy annually.

In order for the world to meet the climate goals set by the Paris Agreement, it will take more than just countries to make and keep commitments.   Whatever else one may think about Amazon’s place in the world, their latest efforts for the environment are a big step in the right direction.

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Amazon announces five new utility-scale solar projects to power operations in China, Australia, and the US

Photo, posted November 16, 2018, courtesy of Todd Van Hoosear via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Second Life For Electric Car Batteries | Earth Wise

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The number of electric cars around the world is growing steadily.  Battery technology continues to improve and the battery packs in the cars can have a long life.  Generally, the batteries are considered to require replacement only when their range has dropped below 80% of its original value.  Many are warranted to last for 8 to 10 years or more than 100,000 miles.  Some seem to do much better than that.

But however long it takes, there will eventually be a wave of used batteries whose performance is no longer deemed sufficient for vehicle use.  A new study, published in the journal Applied Energy, looked at the application of used vehicle batteries as backup storage for grid-scale solar photovoltaic installations where they could perform for more than a decade in this less demanding role.

The study looked at the economics of several scenarios including running a solar farm with no battery back up, running the same farm with brand-new batteries, and running the farm with a battery array made of repurposed vehicle batteries.

They found that the used EV battery array, if managed properly, could be a good, profitable investment provided that the batteries cost less than 60% of their original price.  They looked at the technical issues of screening batteries and combining batteries from different cars to work together.  They also looked at the economics of removing batteries from cars, collecting them, checking them over, and repackaging them.

Overall, they found that reusing vehicle batteries could ultimately meet half the forecasted demand for renewable energy backup storage over the next 10 years and would be both a technical and an economic success story.

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Solar energy farms could offer second life for electric vehicle batteries

Photo, posted June 10, 2011, courtesy of Nick Ares via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewable Energy And The Post-COVID World | Earth Wise

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

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

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

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

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How Renewable Energy Could Emerge on Top After the Pandemic

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

Earth Wise is a production of WAMC Northeast Public Radio.

The Largest U.S. Solar Project | Earth Wise

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The largest solar project to date in the U.S. has received final approval from the Department of the Interior.   A $1 billion, 690-megawatt solar array will be built on federal land in the Mojave Desert in Nevada.   The project includes battery energy storage and is expected to produce enough electricity to power more than a quarter million homes.  It will also offset the greenhouse gas emissions equivalent to about 83,000 cars a year.

The current largest U.S. installation, the Solar Star Farm in Southern California, completed in 2015, generates 579 megawatts of power.

Construction of the Gemini Solar Array is expected to start sometime this year and be completed by 2022 or 2023.  The first phase of the project will cover 11 square miles of desert land about 30 miles northeast of Las Vegas.

Some conservation groups have fought against the project, saying that it will destroy thousands of acres of habitat for endangered desert tortoises as well as other rare plant and animal species.  The groups agree that solar energy is a good thing but are convinced that the location selected is the wrong one. 

Interior Department representatives note that the Gemini Project will provide jobs and economic growth at a time when many Americans in general and Nevada citizens in particular are struggling with the impact of the COVID-19 pandemic.

The project is projected to generate $713 million in economic activity and employ about 2,000 people during construction.  However, once it is up and running, it will employ just 19 full-time workers.

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The Largest Solar Project in the U.S. Gets Green Light

Photo, posted January 26, 2014, courtesy of Jannes Glas via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Coal Plants | Earth Wise

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Over 300 coal-fired power plants in the US have stopping burning coal over the past decade.  Only about 224 plants still produce power by burning coal.  As a result, a new sort of recycling industry is taking shape:  repurposing of coal plants.

Across the country, utilities are finding ways to redevelop these facilities.  Some are industrial in nature and others a far cry from their original purpose.

In January, Beloit College in Wisconsin opened a student union and recreation center in what used to be an Alliant Energy coal-fired power plant.  On the southern coast of Massachusetts, a shuttered 1,600 MW coal plant is being demolished to make way for a logistical port and support center for a planned wind farm 35 miles off shore.

In Independence, Missouri, the city is considering competing plans to recycle the Blue Valley Power plant.  It may become a 50 MW battery storage facility, or possibly a biofuel plant.

Another popular reuse strategy is data centers.  Data centers use tremendous amounts of power and therefore can make use of the former coal plants’ capacity to handle large amounts of electricity.

Retired coal-fired plants have built-in infrastructure and components that can be repurposed for new industry.  The plants typically have access to rail, ports and waterways, as well as proximity to good highway transportation.  The electrical grids to which they are connected can be reused for solar or wind farms at the site.

Given that coal plants are continuing to close, the potential to redevelop them in various ways continues to grow as well.   There is a surge in interest in coal plant redevelopment because these facilities are assets of value.

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Coal-fired power plants finding new uses as data centers, clean energy hubs

Photo, posted January 10, 2017, courtesy of Rusty Clark via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coronavirus And European Energy | Earth Wise

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As people all over the world shelter in place and much ordinary commerce and other activities have ground to a halt, there have been big changes in energy usage.   With production halted, offices shut down, schools closed, and public transport operated on reduced timetables, the demand for energy has decreased dramatically.

In Europe, as a result of all this, during the first quarter of this year, renewables’ share of total energy production was greater than 60%.  Wind farms provided more than 40% of the renewables’ share of total electricity generation.   During February, Denmark, Germany and Ireland saw nearly 50% of their electricity demand met with wind power.  Hydroelectric power was the second largest source of renewable energy during the first quarter, with Norway providing the largest share of this.  In contrast, generation from nuclear plants was at its lowest first quarter figure for the past five years.

The large shift to renewable generation was in great part due to the overall reduction in demand.  This impacts nuclear and fossil-fuel generation much more than renewables because those plants can be throttled back or shut down entirely so as not to needlessly consume costly fuels.   Generation that runs on sunlight, wind, or flowing water does not require fuel expenses, so it makes sense to prefer them when demand is reduced.

The reduction in demand has in turn had a major effect on fuel costs as oil reached low prices that haven’t been seen in years.

The decline in demand and fuel prices and the enhanced role of renewables are expected to continue in the current quarter as the timetable for renewed economic activity remains unknown.

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Renewables achieve clean energy record as COVID-19 hits demand

Photo, posted June 25, 2010, courtesy of Martin Abegglen 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.

Solar And Wind Power In China | Earth Wise

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

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

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

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

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

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China’s rapid development of solar and wind power

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

Earth Wise is a production of WAMC Northeast Public Radio.

Companies Promise Climate Action | Earth Wise

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A growing number of major corporations are making promises on climate and the promises are getting more ambitious and for faster action.  More companies are disclosing their carbon emissions and more of those companies have emissions reduction targets. 

There has also been an acceleration in the rate at which companies set so-called science-based targets, which are specific, measurable carbon reduction goals that align the company with the Paris Agreement.  Among the hundreds of companies with such targets are Coca-Cola, Nike, Best Buy, Walmart, and Hilton Hotels.  According to one analysis, the number of Fortune 500 companies with concrete, ambitious carbon targets quadrupled in the past four year to 23%.

Environmental advocates have been pressuring companies for decades, but companies seem to be far more proactive now despite the fact that the U.S. government has largely dropped the ball on climate issues.

The reasons include the fact that the effects of climate change are becoming clearer to companies.  Wildfires, rising sea levels, droughts and other aspects of the crisis both make headlines and affect business operations.

Meanwhile, solar and wind energy have gotten significantly cheaper, making it more attractive for companies to shift away from fossil fuels.

At the same time, investors are increasingly asking companies to act on climate issues.  Consumers, employees, and the general public are increasingly demanding action and even children are adding to the pressure to act.

Making these commitments is one thing; following through on them and sticking to them is another.  There are real concerns that there is a great deal of green-washing going on among companies trying to project a favorable image.  In any case, if companies really want to lead on climate, they need to put their money where their mouths are.

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Better Late Than Never? Big Companies Scramble To Make Lofty Climate Promises

Photo, posted June 22, 2016, courtesy of Mike Mozart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar-Powered Desalination | Earth Wise

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About 1% of the world’s population is dependent on desalinated water to meet daily needs, but water scarcity is a growing problem that experts believe will affect 14% of the world’s population within the next five years.

Desalination takes much more energy than, for example, transporting fresh water over large distances.  In general, desalination costs are much higher than those associated with fresh water, but beyond costs, freshwater is simply not always available.

Researchers at MIT and Shanghai Jiao Tong University in China have developed a completely passive solar-powered desalination system that could provide more than 1.5 gallons of fresh drinking water per hour for every square meter of solar collecting area.   Such a system could provide an efficient, low-cost water source for coastal areas that are off the grid.

The system uses multiple layers of flat solar evaporators and condensers topped with transparent aerogel insulation.  The key to its efficiency is the way it uses each of its multiple stages to desalinate water.  At each stage, heat released by the previous stage is harnessed instead of wasted.  The proof-of-concept device, which was tested on an MIT building rooftop, produced more than twice as much water as the record amount produced by any previous passive solar-powered desalination system.

The researchers plan further experiments aimed at optimizing the choice of materials and configurations and to test the system under realistic conditions.  The hope is to have a technology that can play a role in alleviating water scarcity in parts of the world where electricity is scarce, but seawater and sunlight are abundant.

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Simple, solar-powered water desalination

Photo courtesy of MIT/researchers.

Earth Wise is a production of WAMC Northeast Public Radio.

Figuring Out Photosynthesis | Earth Wise

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Plants have been harnessing the sun’s energy for hundreds of millions of years. Algae and photosynthetic bacteria have been doing the same for even longer, all with remarkable efficiency and resiliency. 

People have used the energy of the sun in one way or another for millennia, but only recently have we gotten sophisticated about it by using devices like solar panels and sensors.  And we still have a long way to go to get anywhere close to the efficiency of plants. It’s no wonder, then, that scientists have long sought to understand exactly how photosynthesis works.

Scientists from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, and collaborators at Washington University in St. Louis, recently solved a critical part of the age-old mystery of photosynthesis, studying the initial, ultra-fast events through which photosynthetic proteins capture light and use it to initiate a series of electron transfer reactions.  Electrons in plants have two possible pathways to travel but only use one.   

But as a result of their efforts, the scientists are now closer than ever to being able to design electron transfer systems in which they can send an electron down a pathway of their choosing. 

By gaining the ability to harness the flow of energy, it may be possible to incorporate new design principles in non-biological energy systems. This could allow us to greatly improve the efficiency of many solar-powered devices, potentially making them far smaller. Understanding the intricacies of photosynthesis creates a tremendous opportunity to open up completely new disciplines of light-driven biochemical reactions, perhaps even ones that haven’t been envisioned by nature.

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Scientists unravel mystery of photosynthesis

Photo, posted June 14, 2017, courtesy of Alex Holyoake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Clouds And Global Warming | Earth Wise

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Recent climate models from multiple organizations project that the amount of warming that doubling atmospheric carbon dioxide would cause would be much more than previously estimated.  And one of the significant changes to the models relates to the role of clouds.

Clouds have long been a major uncertainty in climate calculations.  Clouds can shade the earth and thereby provide cooling.  But clouds can also trap heat.  Which effect dominates depends on how reflective the clouds are, how high up they are, and whether it is day or night.  The dynamics of clouds are complicated.

If you fly across the ocean, you will see blankets of low clouds extending for hundreds of miles.  These marine stratus and stratocumulus clouds predominantly cool the Earth.  In fact, they shade roughly a fifth of the oceans and reflect 30-60% of the solar radiation that hits them back into space.

Recent studies indicate that as global temperatures rise, these clouds are likely to become thinner or burn off entirely, leaving more clear skies through which the sun may add another degree Celsius or more to global warming.

The concerns about clouds are part of the larger issue about feedbacks in warming the world.  It has long been clear that the greenhouse effect of doubling CO2 levels in the atmosphere would raise global temperature.  But there are amplifying feedback effects.  Melting large areas of snow and ice reduces reflectivity and allows the land and oceans to absorb more heat.  More water vapor entering the atmosphere traps more heat.  And now clouds are another concern.

Overall, these effects are leading to climate models predicting much larger global temperature increases, which is a scary prospect for the world.

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Why Clouds Are the Key to New Troubling Projections on Warming

Photo, posted September 10, 2006, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Extreme Heat From Solar Power | Earth Wise

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Renewable sources are playing a growing role in meeting our energy needs, but one place where they have continued to fall short is in industrial processes that require extreme heat.  These include the cement, steel, and glass industries, among others.  These industries account for a significant amount of CO2 emissions because the most effective way to reach the necessary temperatures continues to be combustion of fossil fuels.  The cement industry alone accounts for 7% of global emissions and the need for cement continues to grow.

A previously stealthy startup company backed by Bill Gates and fellow billionaire Soon-Shiong has made a breakthrough in the area of using solar energy to achieve high temperatures.  The company, called Heliogen, has created a solar oven that is capable of generating heat above 1800 degrees Fahrenheit, which is enough for high-temperature industrial processes.

The Heliogen technology uses concentrated solar power to generate heat.  Concentrated solar power uses arrays of mirrors to reflect sunlight and focus it to a single point.  That technology is not new;  there are systems that use it to produce electricity and, to some extent, heat for industry.  But it could not achieve high enough temperatures for producing cement or steel.

The new system uses computer vision software, automatic edge detection and other sophisticated technologies to focus the sun’s rays far more finely than ever before and thereby generate far higher temperatures at the focal point.

Heliogen is now focused on demonstrating how the technology can be used in a large-scale application, such as cement-making.  The selling points to industry are that not only will there be no emissions generated, but that the fuel needed to obtain their extreme heat will be free.

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Secretive energy startup backed by Bill Gates achieves solar breakthrough

Photo courtesy of Heliogen.

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