Earth Wise

A look at our changing environment.

You are here: Home / Archives for electricity

electricity

Better Paint For Cooler Buildings | Earth Wise

By 2 Comments

A research team led by scientists at UCLA have developed a super-white paint that reflects as much as 98% of incoming heat from the sun.  Such paint, if used on rooftops and other parts of buildings, could have a major impact on reducing the costs of keeping buildings cool.

Passive daytime radiative cooling is a well-known method to keep buildings cooler.  By having building surfaces reflect sunlight and radiate heat into space, building temperatures can be significantly lowered.  This in turn cuts down on air conditioner use and associated carbon emissions.

A roof painted white will result in lower indoor temperatures than a darker roof.  But a white roof will do even more:  it can reject heat at infrared wavelengths that are invisible to our eyes.  This results in even more radiative cooling.

The best performing white paints currently available reflect about 85% of incoming solar radiation.  The rest is absorbed by materials in the paint.  The new research has identified simple modifications in paint ingredients that lead to a major increase in reflectivity.

Current reflective white paints use titanium dioxide, which absorbs UV radiation and therefore heats up under sunlight.  The researchers studied replacing it with other substances such as barite – an artist’s pigment – or with powdered Teflon, both of which allow the paint to reflect more of the sun’s radiation. 

Many cities are encouraging the use of cool-roof technologies on new buildings.  Using the most reflective coatings possible on rooftops, if applied on a sufficiently large scale, could have a real impact on climate change as well as saving significant amounts of energy used for running air conditioners in buildings.

**********

Web Links

UCLA-led Team Develops Ways to Keep Buildings Cool with Improved Super White Paints

Photo, posted August 15, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Are Slowly Taking Over | Earth Wise

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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.

New Jersey And Offshore Wind | Earth Wise

By Leave a Comment

New Jersey intends to become a major hub for offshore wind in the United States.  The state recently announced a plan to build a 30-acre port along the Delaware River for assembling and deploying wind turbines, as well as an additional 25 acres for manufacturing facilities.   The new port is expected to cost as much as $400 million and create 1,500 jobs in southern New Jersey.

The port will be located on an artificial island that was built by the U.S. Army Corps of Engineers early in the 20th century.  The island is already home to three nuclear reactors.  No bridges exist between the island and the Atlantic Ocean, so turbines that are built at the staging facility could be hoisted upright and towed out to sea without obstruction.  Some components are as tall as 500 feet and when fully constructed on the ocean, the turbines selected for New Jersey’s first offshore wind project will be more than 850 feet tall.

A second phase of the program would add over 150 acres to accommodate extensive manufacturing facilities for turbine components like blades and nacelles.

Construction on the port is expected to start next year.  New Jersey has pledged to produce 7,500 megawatts of offshore wind energy by 2035 and to generate 100% of its electricity from renewables by 2050.  Apart from deploying offshore wind, New Jersey wants to have a significant piece of the supply chain for what is likely to be a growing industry along the northeast coast.  The state views offshore wind as a once-in-a-generation opportunity to not only protect the environment but also greatly expand its economy in a way that has immediate impacts and long-term growth.

**********

Web Links

New Jersey Announces $400 Million Offshore Wind Port

Photo, posted September 18, 2010, courtesy of Vattenfall Nederland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Could Take Over By 2035 | Earth Wise

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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.

Floating Turbines For Offshore Wind | Earth Wise

By Leave a Comment

Offshore wind is big in Europe.  There are more than 5,000 offshore wind turbines across 12 European countries with a total capacity of more than 22 gigawatts.  Almost every one of those turbines sits on a long tower sunk into the seabed and bolted into place in places where the water is 60 to 160 feet deep.

But off the coast of northern Scotland, there is the Hywind Wind Park which has five 574-foot-tall turbines located 15 miles offshore where the water is 300 feet deep.  The giant masts and turbines sit on buoyant concrete-and-steel keels that allow them to stand upright and float on the water like a giant buoy.  The giant cylindrical bases are held in place with mooring cables attached to anchors that sit on the seafloor.

A key advantage of floating turbines is that they can access outlying ocean waters up to half a mile deep, which is where the world’s strongest and most consistent winds blow.  Another advantage is that such turbines can be installed over the horizon, out of sight of coastal residents who might not like to have wind turbines visible in their scenic ocean views.

Floating wind power has enormous potential for contributing to the expansion of renewable energy.  Offshore wind is still quite a bit more expensive than land-based turbines, and the cost of electricity from distant floating turbines is more than that from near-shore wind turbines.   But all of these costs are likely to come down with improving technology and increased production volume.

There are real challenges to the expanded used of floating wind farms, but the promise of harnessing so much of the open seas for electricity generation is an attractive proposition.

**********

Web Links

Will Floating Turbines Usher in a New Wave of Offshore Wind?

Photo, posted July 17, 2017, courtesy of Crown Estate Scotland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Concrete Production And Diminishing Coal Burning | Earth Wise

By Leave a Comment

Coal burning is still one of the primary means of generating electricity in the United States, but its use is diminishing and doing so fairly rapidly.  The coal burning process produces residual, incombustible materials.  One of them is fly ash, which is composed of fine, glassy, rounded particles rich in silicon, aluminum, calcium, and iron oxides.  Fly ash is captured from coal plant flue gas by precipitators and bag filters. It turns out that two-thirds of this fly ash is not dumped into landfills or impoundments, but rather is put to use.

Because of its chemical and physical characteristics, fly ash can substitute for a portion of portland cement in concrete.  Using this byproduct material in making cement actually reduces its cost. Beyond cost, the addition of fly ash as a so-called supplementary cementitious material or SCM improves concrete’s long-term strength and reduces porosity and permeability.  It reduces the risk of thermal cracking and provides good long-term mechanical properties.

The amount of fly ash used in concrete products increased by 5% between 2011 and 2017 while the amount produced dropped by 36%.  Concrete production continues to increase steadily while fly ash production is steadily dropping.

Therefore, the concrete industry is looking for alternative sources of SCM.  The most obvious is the approximately 1/3 of fly ash that hasn’t been used to make concrete.  Much of that is landfilled or ponded onsite at power plants.  So, opportunities exist for excavating or dredging and recovering these materials.

As coal burning goes away, concrete manufacturing needs to make some changes.

**********

Web Links

What Does the Changing Face of Electricity Production Mean for Concrete?

Photo, posted February 16, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Coal Plants | Earth Wise

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

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.

Saving Energy At Data Centers | Earth Wise

By Leave a Comment

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.

**********

Web Links

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

By Leave a Comment

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.

**********

Web Links

Denmark Passes Magic 50% In Renewable Electricity Generation Milestone

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

Earth Wise is a production of WAMC Northeast Public Radio.

Harvesting Blue Energy | Earth Wise

By Leave a Comment

There are various ways to generate renewable energy from the world’s oceans, most obviously from the power of tides and waves.  But there is also an oceanic energy source called osmotic or “blue” energy.  Osmotic energy uses the differences in pressure and salinity between freshwater and saltwater to generate electricity. 

When freshwater and saltwater are mixed together, large amounts of energy are released. If the freshwater and seawater are then separated via a semi-permeable membrane, the freshwater will pass through the membrane and dilute the saltwater due to the chemical potential difference. This process is called osmosis. If the salt ions are captured completely by the membrane, the passing of water through the membrane will create a pressure known as osmotic pressure. This pressure can be used to generate electricity by using it to drive a turbine.  This has been demonstrated to work as far back as the 1970s, but the materials we have to use are not adequate to withstand ocean conditions over the long term and tend to break down quickly in the water.

New research, published in the journal Joule, looked to living organisms for inspiration to develop an improved osmotic energy system.  Scientists from the U.S. and Australia combined multiple materials to mimic the kind of high-performance membranes that are found in living organisms.  They created a hybrid membrane made from aramid microfibers (like those used in Kevlar) and boron nitride.  The new material provides both the flexibility of cartilage and the strength and stability of bone.

The researchers believe that the low cost and high stability of the new hybrid membrane will allow it to succeed in volatile marine environments.  They also expect the technology will be both efficient and scalable. 

**********

Web Links

Inspired by the Tissues of Living Organisms, Researchers Take One Step Closer to Harvesting “Blue Energy”

Photo, posted February 14, 2017, courtesy of Marian May via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Extreme Heat From Solar Power | Earth Wise

By Leave a Comment

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.

**********

Web Links

Secretive energy startup backed by Bill Gates achieves solar breakthrough

Photo courtesy of Heliogen.

Earth Wise is a production of WAMC Northeast Public Radio.

A Plan For New England Offshore Wind | Earth Wise

By Leave a Comment

Last December, the Bureau of Ocean Energy Management auctioned off lease rights for developing offshore wind in the New England Wind Energy Area.  The auction brought in hundreds of millions of dollars.

Recently, the five New England offshore wind leaseholders – Equinor, Mayflower Wind, Ørsted, Eversource, and Vineyard Wind – jointly submitted a uniform turbine layout proposal to the U.S. Coast Guard.

The five developers joined forces to respond to feedback from key stakeholders in the region including the fisheries industry, the Coast Guard, the Bureau of Ocean Energy Management, and coastal communities.

The proposed layout specifies that wind turbines will be spaced one nautical mile apart, arranged in east-west rows an north-south columns, and the rows and columns will be continuous across all New England lease area.  Independent expert analysis confirmed that this uniform layout would provide for robust navigational safety and search-and-rescue capability by providing hundreds of transit corridors to accommodate the region’s vessel traffic.

Vessels up to 400 feet in length can safely operate within the proposed turbine layout and will allow the region’s many fishing vessels to follow a wide range of transit paths as they come from many different ports and head to a variety of fishing grounds.

The New England Wind Energy Area is expected to be able to provide as much as 8 GW of electricity generation for the states in the region.  Getting approval for this planned layout is one of multiple steps required before the offshore wind complex becomes a reality.  Overall, states along the U.S. East Coast are seeking to procure more than 19,300 MW of offshore wind capacity through 2035

**********

Web Links

New England offshore wind developers submit uniform layout proposal to the U.S. Coast Guard

Photo courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Possible Storage Breakthrough: Solar Energy | Earth Wise

By 2 Comments

Solar energy is a nearly unlimited resource, but it is only available to us when the sun is shining.  For solar power to provide for the majority of our energy needs, there needs to be a way to capture the energy from the sun, store it, and release it when we need it.  There are many approaches to storing solar energy, but so far none have provided an ideal solution.

Scientists at the Chalmers Institute of Technology in Sweden have developed a way to harness solar energy and keep it in reserve so it can be released on demand in the form of heat—even decades after it was captured. Their solution combines several innovations, including an energy-trapping molecule, a storage system, and an energy-storing laminate for windows and textiles.

The energy-trapping molecule is made up of carbon, hydrogen, and nitrogen.  When hit by sunlight, the molecule captures the sun’s energy and holds on to it until it is released as heat by a catalyst.  The specialized storage unit is claimed to be able to store energy for decades.  The transparent coating that the team developed also collects solar energy and releases heat.  Using it would reduce the amount of electricity required for heating buildings.

So far, the team has concentrated on producing heat from stored solar energy.  It is unclear whether the technology can be adapted to produce electricity, which would be even more valuable.  In any event, the team does not yet have precise cost estimates for its technology, but there are no rare or expensive elements required, so the economics seem promising.  There is much more work to be done, but this could be a very important technology for the world’s energy systems.

**********

Web Links

An Energy Breakthrough Could Store Solar Power for Decades

Photo courtesy of 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...)