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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.

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.

Hacking Photosynthesis | Earth Wise

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A team led by the University of Illinois has been pursuing a project called Realizing Increased Photosynthetic Efficiency or RIPE, which has the aim of improving photosynthesis in order to provide farmers with higher-yielding crops in an increasingly challenging climate.  Photosynthesis is the natural, sunlight-powered process that plants use to convert carbon dioxide into sugars that fuel growth, development, and for us, crop yield.

If we think of photosynthesis as a factory line composed of multiple machines, the growth of plants is limited by the slowest machines in the line.  The RIPE project has identified some steps in photosynthesis that are slower than others and are attempting to enable plants to build more machines to speed up those slower steps.

The researchers modeled a total of 170 steps in the process of photosynthesis to identify how plants could manufacture sugars more efficiently.  In the study, the team increased crop growth by 27% by resolving two constraints:  one in the first part of photosynthesis where plants turn light energy into chemical energy and one in the second part when carbon dioxide is turned into sugars.

The researchers effectively hacked photosynthesis by adding a more efficient transport protein from algae to enhance the energy conversion process. 

In the greenhouse, these changes improved crop productivity by 52%, but in field trials, which are a more important test, these photosynthetic hacks boosted crop production by 27%.

Ultimately, the team hopes to translate these discoveries to a series of staple food crops, such as cassava, cowpea, corn, soybean and rice, which are needed to feed the world’s growing population this century.

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Photosynthetic hacks can boost crop yield, conserve water

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

Earth Wise is a production of WAMC Northeast Public Radio.

Generating Hydrogen From Poor-Quality Water | Earth Wise

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Hydrogen could be the basis of a complete energy system.  It could be stored and transported and could be used to power vehicles and to generate electricity in power plants.  Proponents of the so-called hydrogen economy contend that hydrogen is the best solution to the global energy challenge.  But among the challenges faced by a hydrogen economy is the development of an efficient and green method to produce hydrogen.

The primary carbon-free method of producing hydrogen is to break down water into its constituent elements – hydrogen and oxygen.  This can be done in a number of ways, notably by using electricity in a process called electrolysis.  A method that seems particularly attractive is to use sunlight as the energy source that breaks down the water molecule.

While there is an abundance of water on our planet, only some of it is suitable for people to drink and consume in other ways.    Much of the accessible water on earth is salty or polluted.  So, a technique to obtain hydrogen from water ideally should work with water that is otherwise of little use to people.

Researchers in Russia and the Czech Republic have recently developed a new material that efficiently generates hydrogen molecules by exposing water – even saltwater or polluted water – to sunlight. 

The new material is a three-layer structure composed of a thin film of gold, an ultra-thin layer of platinum, and a metal-organic framework or MOF of chromium compounds and organic molecules.  The MOF layer acts as a filter that gets rid of impurities.

Experiments have demonstrated that 100 square centimeters of the material can generate half a liter of hydrogen in an hour.  The researchers continue to improve the material and increase its efficiency over a broad range of the solar spectrum.

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New Material Can Generate Hydrogen from Salt and Polluted Water

Photo courtesy of Tomsk Polytechnic University.

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.

Massachusetts And Energy Policy | Earth Wise

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The transition to a renewables-based energy future continues to accelerate, but there are still many forces that can slow it down.  Government policy has a major role to play.  At the moment, the federal government is trying to prop up the fossil fuel industry with financial incentives and rampant deregulation.  So more than ever, innovative policies at the state level are essential drivers for revolutionizing the energy system.

One state where policy is trying to make a big difference is Massachusetts, which has created the Clean Peak Energy Standard or CPS, finalized and approved in late March and now taking effect.   A clean peak standard is a regulatory tool to reduce the costs and environmental impact of periods when electricity demand is highest, and generation tends to be the most polluting.  The CPS requires electric retailers to procure a minimum percentage of their annual electricity sales from renewable generation or energy storage.  That minimum amount will increase each year.

The CPS is formulated to incentivize better utilization of clean energy technologies to supply power when energy demand is high.  The problem is that there are times when the sun is not shining and the wind isn’t blowing, but energy demand is at its highest.  The solution is to use energy storage technologies that can supply power when it is needed.  Furthermore, storage can be relied upon during times of extreme weather that cause power outages.

Massachusetts has already started using energy storage in its grid.  The small town of Sterling installed an energy storage system in 2016 that provides crucial backup power to the police station and emergency dispatch center, thereby keeping first responder operations running even during extended power outages.

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Massachusetts is setting the benchmark for nationwide clean energy transformation

Photo, posted March 30, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A High-Tech Fire Alarm | Earth Wise

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In recent years, wildfires have been a global problem, notably in California, Brazil, and Australia.  It has become increasingly important to be able to respond to new fires as soon and as quickly as possible.  Such response can make the task of extinguishing them easier, thereby reducing the amount of damage and the loss of property and life.

Traditional methods for detecting forest fires include satellite monitoring, ground patrols, and watch towers, all of which have high labor and financial costs but suffer from low efficiency.  Remote sensing technologies are becoming increasingly common but rely on batteries for power, requiring servicing in remote locations to replace depleted batteries.  Solar cells represent an alternative to batteries, but it is challenging to use them in forests because of shading and foliage coverage.

A team of researchers at Michigan State University has developed a remote forest fire detection and alarm system powered by nothing more than the movement of tree limbs in the wind.  The device is known as an MC-TENG, which is an acronym for multilayered cylindrical triboelectric nanogenerator.  The triboelectric effect is a phenomenon where certain materials become electrically charged when they separate from a second material with which they were previously in contact.  In the new device, two cylindrical sleeves fit within one another – one anchored and the other free to slide.  The device is tied to a tree branch and when the branch sporadically moves in the wind, electricity is generated and stored in a carbon-nanotube-based micro supercapacitor.  This powers a sensing system that can continuously monitor environmental conditions without requiring any maintenance.

A combination of carbon monoxide and temperature sensors provides a high-tech fire alarm that can operate continuously in the most remote forest.

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Self-Powered Alarm Fights Forest Fires, Monitors Environment

Photo, posted August 3, 2012, courtesy of Lukas Schlagenhauf 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.

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.

Global Emissions And The Coronavirus Shutdown | Earth Wise

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With so much of industry and personal activity curtailed by coronavirus shutdowns across the globe, it is no surprise that greenhouse gas emissions have declined.  According to new research published in the journal Nature Climate Change, average daily global greenhouse gas emissions declined 17% by early April compared to 2019 levels.

If the reopenings around the world continue and the world actually reaches pre-crisis levels by the middle of June, total CO2 emissions for the year would likely end up lower by about 4%.   If various restrictions continue until the end of the year, total global emissions could decline by 7%.

The study analyzed emissions estimates for three levels of coronavirus shutdowns and across six sectors of the economy.  It looked at trends in 69 countries, all 50 U.S. states, and 30 Chinese provinces, representing in total 86% of the world’s population and 97% of global CO2 emissions.

For the first 4 months of the year, emissions from industry declined 19%, the power sector 7%, and public buildings and commerce 21%, compared to last year.  Unsurprisingly, home energy use actually went up by about 3%.

The findings of this study only represent the effects of a short-lived decline in emissions.  As economies open back up, there is no doubt that greenhouse gas emissions will rise back to pre-Covid-19 levels.

The study also reveals that making real changes in emissions will require more than just behavior changes.  Despite billions of people staying home, companies shut down, planes grounded, and cars off the road, we still managed to pump more than 80% of the usual amount of greenhouse gases into the air for the first quarter of the year.

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Global Emissions Fell 17 Percent Due to Coronavirus Shutdowns

Photo, posted May 7, 2020, courtesy of the MTA 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.

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.

Electric Cars And The Environment | Earth Wise

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

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

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

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

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

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

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Electric cars better for climate in 95% of the world

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

Earth Wise is a production of WAMC Northeast Public Radio.

Last New York Coal Plant Closing | Earth Wise

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The last coal-fired power plant in New York State is closing.  The plant, located in Barker, about an hour’s drive from Buffalo, employs 44 people.  The plant’s closure is an early test of New York’s new climate law, which is one of the most ambitious in the country.  The law is supposed to transform the state’s energy grid to carbon-free by 2040. 

Coal plants across the country are going offline, priced out by natural gas and targeted by regulations and incentives aimed at reducing greenhouse gas emissions.  Coal plant closures bring common challenges:  lost tax revenues and jobs as well as efforts to retrain workers and clean up sites.  Every plant has a specific place in a community, and each community has its own story.

The new climate law is supposed to create thousands of new jobs, including high-paying union jobs like the ones the employees in Barker are losing.  But jobs are scarce in the northwest corner of the state where Barker is located.

The state government has recently issued rules that would make it easier to get permission to build renewable energy sites, including wind turbines and solar farms, allowing applicants to bypass zoning rules and other local regulations.  But residents of rural towns have environmental and aesthetic concerns about these potential new energy plants.

In 2010, the United States had 580 coal-fired power plants providing 45% of the country’s electricity. By March 2018, there were fewer than 350 plants and coal’s market share had dropped to 30%.  At this point, there are about 224 plants producing 18% of the country’s power.  The writing is on the wall for coal power.

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New York’s Last Coal-Fired Power Plant Is Closing

Photo, posted March 13, 2018, courtesy of Joed Viera via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wind Power Overtakes Hydroelectric Power | Earth Wise

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In 2019, the amount of electricity generated by wind power surpassed hydroelectric power for the first time, making wind the largest renewable source of electricity generation in the country.

Total wind generation in 2019 was 300 million MWh, which was 26 million MWh more than was produced by hydroelectric plants.

Hydroelectric generation has fluctuated between 250 and 320 million MWh over the past decade.  The capacity base has been stable, so the fluctuations were a result of variable annual precipitation.   Hydroelectric generation is generally greatest in the spring when rain and melting snow pack increase water runoff.

The growth in wind power is primarily a result of increasing capacity rather than any major fluctuations in wind caused by changing weather.  The U.S. added about 10 GW of wind capacity in 2019, making it the second largest year for capacity additions ever, second only to 2012.

Wind energy is an intermittent source, meaning that it isn’t windy all the time.  The average annual capacity factor for the U.S. wind fleet over the past decade has been 28 to 35%, meaning that is the amount of energy actually produced compared with the systems running at continuous full power all the time.  By comparison, the U.S. hydroelectric fleet operated at 35 to 43% of capacity during that period.  So, wind power is actually not that much less a steady source than hydroelectric power.

According to the U.S. Energy Information Administration, the government’s production tax credit, which was extended through this year, means that wind power capacity in the U.S. will continue to grow at a robust pace.  Meanwhile, some dams are being decommissioned and there is little new construction in the hydropower sector.

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Wind has overtaken the top position for renewable generation in the U.S., EIA says

Photo 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.

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.

Stretchable Batteries | Earth Wise

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Wearable technology is an ever-increasing part of our world.  Fitness trackers have become commonplace for people of all ages.  Smart watches perform a growing range of functions.   There are wearable health monitoring systems of many types for assisted living, elderly patients, and people with specific health problems.  Virtual reality headsets are increasingly popular and there is now even smart technology footwear that is integrated with smartphones and mapping software.

The adoption of wearable electronics has so far been limited by their need to derive power from relatively bulky, rigid batteries that reduce comfort and even may present safety hazards related to chemical leakage or combustion.  To date, there has not been a power source that can stretch and bend the way our bodies do, which would enable electronic designs that people can comfortably wear.

Researchers at Stanford have recently announced the development of a soft and stretchable battery that relies on a special type of plastic to store power more safely than the flammable formulations used in conventional batteries today.

The lithium ion batteries in our phones, computers, cameras and electric cars already make use of plastic electrolytes.  These polymer electrolytes are in the form of flowable gels.  The Stanford researchers developed a new polymer that is solid and stretchable rather than gooey and potentially leaky.  But it still carries an electric charge and maintains a constant power output even when squeezed, folded or stretched to nearly twice its original length.

The prototype battery is thumbnail-sized and stores only about half as much energy for its size as a conventional battery.  But the researchers are working to increase both the size and the energy density of the battery. 

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A new stretchable battery can power wearable electronics

Photo, posted November 28, 2016, courtesy of Timo Newton-Syms via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Energy At Data Centers | Earth Wise

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A data center is a building, dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and data storage systems.  Data centers are the backbone of internet services and cloud computing, which together are increasingly dominant elements of modern life.

Energy use is a central issue for data centers. Power used by them ranges from a few kilowatts for a rack of servers in a closet at a local business to several tens of megawatts for large facilities. Some data centers have power densities more than 100 times that of a typical office building and use as much electricity as several thousand homes. For such facilities, electricity costs are a dominant operating expense and account for over 10% of the total cost of ownership of a data center.  These centers, with their numerous racks of computer servers, consume 90 billion kilowatt-hours of electricity each year in the United States, as much as all of our residences use for lighting. 

A research group at Princeton University is developing a family of devices that can dramatically reduce power consumption at data centers.  The team’s technology focuses on the process by which the AC power from the grid is converted to the low-voltage direct current used by computer equipment.  With existing technology, this power conversion takes place in each individual computer, which ends up wasting about 40% of the original energy.   The new device aggregates power conversion into a single unit, which then distributes the power to the individual computers and storage units.

As data centers get bigger and more numerous, the opportunity to save a lot of energy becomes increasingly important.

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New technology boosts energy efficiency in data centers

Photo, posted June 8, 2007, courtesy of Sean Ellis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lots Of Wind Power In Denmark | Earth Wise

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

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

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

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

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

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Denmark Passes Magic 50% In Renewable Electricity Generation Milestone

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

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