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Solar-powered desalination

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People in remote, low-income regions far from the ocean often need to meet their water needs from groundwater and groundwater is becoming increasingly saline due to climate change.  Desalination of brackish groundwater is a huge and largely untapped source of drinking water, but there are challenges in making the process efficient and reliable.

Engineers at MIT have developed a solar-powered desalination system that requires no batteries or external power sources and is capable of producing large quantities of clean water despite the variations of sunshine throughout the day.

The system is based on the process of electrodialysis and consists of water pumps, an ion-exchange membrane stack, and a solar panel array.  What is unique about it is that it makes use of sensors and a control system that predicts the optimal rate at which to pump water through the system based on the output of the solar panels.  As a result, it uses nearly all of the electricity generated to produce clean water and does not need stored or grid-based energy.

The MIT engineers tested a community-scale prototype on groundwater wells in New Mexico over a six-month period.  The system harnessed on average over 94% of the electricity generated by its solar panels and produced as much as 5,000 liters of water per day despite large variations in weather and sunlight.

The new renewable-powered, battery-free system could provide much-needed drinking water at low cost, especially for communities where access to seawater and to grid power are limited.  The team plans to further test and scale up the system so it can supply larger communities and even whole municipalities with low-cost drinking water.

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Solar-powered desalination system requires no extra batteries

Photo courtesy of Shane Pratt.

Earth Wise is a production of WAMC Northeast Public Radio

Renewables progress

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According to a new report by the International Energy Agency, the world is on track to produce nearly half of the electricity it uses from renewable sources by the end of this decade.  The report also finds that in nearly every country, large wind and solar plants are the cheapest forms of new power.

Between now and 2030, countries will add more than 5,500 gigawatts of new renewable capacity.   That is as much as China, India, the U.S., and the EU combined have at present.  Most of the new capacity will come from solar power.

China is aggressively pursuing renewable power installations with massive solar and wind projects.  By 2030, China will account for nearly half of the world’s renewable power capacity.

This year’s UN Climate Change Conference, held in the United Arab Emirates, established the goal of tripling renewable energy capacity worldwide by 2030. 

The growth in solar power continues to outperform industry expert projections as manufacturing ramps up.  India and the U.S. are both expected to triple their solar manufacturing capacity by the end of this decade.  Manufacturing, largely based in China, is already outstripping demand.

By 2030, solar and wind power are expected to account for about 30% of global electricity generation, hydropower about 13%, and other renewables such as geothermal power about 5%.

These estimates are based on existing policies and market conditions.  Governments could speed up the shift to clean energy by cutting red tape and by making it cheaper for poorer countries to finance solar and wind projects.

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Renewables 2024

Photo, posted November 23, 2023, courtesy of Rick Obst via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric cars and power outages

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As more and more cars are powered by electricity instead of gasoline, people are beginning to worry about what happens during power outages caused by storms and other disruptive events.  It is easy to jump to the conclusion that this is a brand-new problem for drivers.  However, when electricity goes out over a sizeable area, most gas pumps stop working and it isn’t easy to keep gas cars running either.

Electric cars are often charged at home every day and such cars are more likely to be almost fully charged than nearly depleted at any time.  For those drivers, a power failure is unlikely to be much of a concern unless it persists for a very lengthy period.  On road trips, unless a power outage extends over a very wide area, one can probably get to a charger that is still operating.

Nonetheless, the federal government has commissioned researchers at Iowa State University to study potential solutions to possible difficulties in keeping electric cars running during power failures.  The goal of the study is to find ways to reduce the outage frequency of chargers by 75% and the power restoration time by 50%.

The study will evaluate the resiliency of charging stations in extreme weather events and identify ways to quickly restore power to charging stations in the event of outages.  Included are onsite solar power and battery storage at chargers as well as redundant power lines from different electrical substations.  There is even the possibility  of trucks delivering pre-charged batteries to charging stations after a storm.  Identifying and developing technologies to improve the resilience of charging stations is an important goal as the transition to electric vehicles continues.

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Researchers working to keep electric vehicles charging, even when the lights go out

Photo, posted July 29, 2013, courtesy of Jeff Cooper via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar farms and pollinators

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Two important environmental challenges are finding some literal common ground:  the need to reduce carbon emissions and the fight to stave off global biodiversity collapse.  Both issues can be addressed at solar farms.

Solar energy is an important weapon in the battle against climate change.  But utility-scale solar farms take up large amounts of land.  Large-scale solar farms already take up nearly a thousand square miles of land in the US and will take up much more in the coming decades.

In the meantime, the biodiversity collapse is being driven in large part by habitat loss.

Given all this, solar farm operators, biologists, and environmentalists are teaming up to grow pollinator-friendly plants in and around solar farms. The plantings attract insects, birds and even mammals. The more plant diversity in the solar farms, the more environmental benefits can be achieved. 

There are costs associated with creating pollinator-friendly solar farms. Ideally, solar panels need to be installed at greater height than otherwise in order to permit growing many of the plants that attract bees and butterflies.  But there are economic benefits associated with attracting and sustaining pollinators.  On a cautionary note, there have already been cases of greenwashing, where solar operators claim environmental benefits far in excess of the scope of the actual efforts they have made. 

There are both governmental and non-governmental agencies seeking to assess and certify pollinator-friendly solar farms.  There is considerable variability in the ecological value of existing farms.  Pollinator-friendly solar farms are in their early days, but they have a lot to offer as a win-win strategy for the environment.

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Solar Farms Have a Superpower Beyond Clean Energy

Photo, posted December 4, 2014, courtesy of Juwi Renewable Energies Limited via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Big Tech and emissions

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Most of the well-known largest technology companies have established ambitious clean energy goals.  They are on record for achieving net-zero emissions for all their operations and supply chains in many cases by 2030.  As a result, they have been investing heavily in renewable energy in various ways.  Despite these lofty goals and sincere efforts, many of them are struggling to reduce emissions.  The reason is simple:  big data.

A good example is Google, which started investing in renewable energy in 2010 and since 2017 has been purchasing renewable energy on an annual basis to match the electricity consumption of its global operations. However, Google’s greenhouse gas emissions have increased nearly 48% since 2019.  This is primarily a result of data center energy consumption.

The expanding use of artificial intelligence technology is consuming large amounts of electricity.  For example, a single ChatGPT query uses nearly 10 times as much electrical energy as a traditional Google search.

Google is by no means unique in having this problem.  Microsoft’s carbon emissions have risen by nearly 30% since 2020.  Amazon is struggling to reach net-zero across its operations by 2040.

All of these companies are entering into large power agreements with renewable energy companies all across the country.  The AI arms race for more and more computational power is driving a race to install more and more large-scale renewable energy.   Power purchase agreements for solar power, wind power, and even geothermal power are becoming a major activity for most of the largest tech companies.

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Can Google gobble up enough renewables?

Photo, posted February 12, 2023, courtesy of Geoff Henson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar grazing

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Agrivoltaics is the combination of solar power generation with agriculture.  Generally, this has involved growing crops under and around solar panels harvesting both food and electricity.  More recently, there has been increasing interest in grazing animals to manage lands used for solar power.

Enel North America, a large operator of solar farms and utility-scale battery storage facilities in Texas, has announced a partnership with Texas Solar Sheep Company to deploy more than 6,000 sheep to chow down on the greenery on eight large Texas solar sites.  This is the largest known solar grazing agreement executed in the United States

Texas Solar Sheep’s flocks will graze on more than 10,000 acres of land being used for solar generation, an area roughly ¾ the size of Manhattan.  Most of these sites are situated in areas with high rainfall and long growing seasons. 

The American Solar Grazing Association, an organization with 950 members across 45 states, facilitates research, provides education, and develops best practices in support of a unique population of shepherds and solar developers.  Their recent survey estimates that 100,000 acres of U.S. solar sites are currently being chewed on by sheep.  Texas has the most installed utility-scale solar power in the country.

According to Enel, its existing solar grazing program has demonstrated substantial improvements in soil health by the additional of organic matter to the soil.  Managing vegetation with sheep is also better for pollinators because sheep don’t cut down all plants the way mowing does.

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No more sheepless nights: Enel inks largest solar grazing contract

Photo, posted April 7, 2020, courtesy of Sean Nealon / Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

More wind power than coal power

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The U.S. used to get more of its electricity from burning coal than by any other means.  It wasn’t all that long ago; coal produced 51% of our electricity in 2001. But as of 2022, it was less than 20%.

In March and April, the U.S. generated more electricity from wind power than from coal.  This was the first time that wind outstripped coal for two consecutive months.

This crossover between wind and coal power is just another milestone in the energy transition to renewable energy sources.  Renewables collectively produce more electricity than coal and their share is steadily growing.  The explosive growth in renewable energy is primarily the result of three factors:  federal tax credits, state energy mandates away from fossil fuels, and, most importantly, shifts in the economics of energy.  Breakthroughs in technology and economies of scale have lowered the cost of building new wind turbines, solar panels, and battery storage. 

Coal plants have retired at a rapid pace over the past 25 years.  During that time, natural gas capacity has nearly tripled.   Gas began to replace coal starting around 2005 when the fracking boom led to the availability of large quantities of cheap natural gas. Because of this, fossil fuels are still the largest source of electricity generation in the U.S., but that is not likely to be the case for very long.

Analysts expect that wind energy will grow to provide about 35% of the country’s electricity by 2050.  The Department of Energy predicts that solar power will produce 45% of U.S. electricity by that year.

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Wind Beat Coal Two Months in a Row for U.S. Electricity Generation

Photo, posted August 5, 2024, courtesy of Samir Luther via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Where do states get their electricity?

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How the United States produces its electricity has changed dramatically over the past few decades.  Coal used to be the dominant source of power in this country, but natural gas surpassed it in 2016, and coal’s share has been shrinking ever since.  Fossil fuel still generates the majority of America’s electricity, but renewable power is increasing its contribution all the time.

On a state-by-state basis, there are very large variations in the mix of power sources.  Ten states still get their largest amount of power from coal, but this is down from 32 states in 2001.  Four states have hydroelectric power as their largest source, including Vermont which gets more than half of its power that way. 

Texas produces more electricity than any other state by a wide margin.  It’s not just because it has a large population. It is because it uses huge amounts of power to refine petroleum products.  Coal produces only 13% of Texas’ electricity and the state is by far the country’s largest producer of wind power.

New York gets nearly half of its power from natural gas, 21% from hydroelectric power, and 21% from nuclear power.  Wind and solar power are still small, but both are growing in the state.

When people try to assess the climate impact of driving electric cars, based on the origins of the electricity they use to power the car, the results can vary dramatically based on what state they live in.  Nationwide, electricity is getting cleaner and greener, but the process is by no means uniform across the country.

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How Does Your State Make Electricity?

Photo, posted March 17, 2021, courtesy of Bureau of Reclamation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

China and carbon emissions

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China has been the biggest source of greenhouse emissions for nearly 20 years.  Its emissions surpassed those of the United States in 2006 and its fraction of the world’s emissions is now nearly a third.  Therefore, unless China’s emissions stop growing, the world’s emissions won’t either.

Recent data from China’s government and by energy analysts provides some reasons for optimism.  What is happening is that how China produces its electricity is changing.  Renewable sources are gradually replacing coal.

Last year alone, China installed more solar panels than the United States has in its entire history.  Nearly two-thirds of utility-scale wind and solar plants under construction are in China.  According to a report from Global Energy Monitor, China is developing more than eight times the wind and solar capacity currently being planned for the US.

Despite all this progress, China still generates 53% of its electricity from coal.  While this is the lowest share reported since its government began publishing energy data decades ago, it is still a major source of carbon emissions.  China is responsible for two-thirds of the world’s newly operating coal plants and still plans to build many more.  China accounts for about 60% of the world’s coal use.

China is investing heavily in pumped-storage hydropower along with its massive efforts in solar and wind power.  But if it is to meet existing and proposed new commitments to reduce emissions, it will need to be much more aggressive in reducing its dependence on coal.  Current predictions are that China’s emissions may soon no longer be increasing.  But what is needed is for them to start dropping and the sooner the better.

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Why the Era of China’s Soaring Carbon Emissions Might Be Ending

Photo courtesy of Mike Locke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Expanding solar and wind in the U.S.

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According to new data from the Federal Energy Regulatory Commission, solar and wind now make up more than 20% of the total US electrical generating capacity.  Adding up all renewable energy sources – which also include biomass, geothermal, and hydropower – renewable energy is now nearly 30% of the total electrical generating capacity in this country.

During the first five months of 2024, 10.669 gigawatts of solar and 2.095 gigawatts of wind power came online.  There were also 212 megawatts of hydropower and 3 megawatts of biomass added to generating capacity.  All told, renewables constituted 89.91% of new generating capacity added this year.  This does not include 1.1 gigawatts of nuclear power added at the Vogtle-4 reactor in Georgia. 

Solar power is booming.  The amount added this year was more than double the amount added over the same period last year.  Solar has been the largest source of new generating capacity for nine months straight.  Wind was the second largest.

About one-third of US solar capacity is in the form of small-scale – that is, rooftop – solar.  The statistics quoted in this report do not take that into account.  If it was included, solar plus wind would be closer to 25% of the US total.

Predictions are that over the next three years, nearly 90 gigawatts of additional solar power will be added to the grid as well as 23 gigawatts of wind power.  Over that period, coal, natural gas, and oil are projected to shrink by more than 20 gigawatts.

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Solar and wind now make up more than 20% of US electrical generating capacity

Photo, posted October 28, 2016, courtesy of Daxis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Clean energy investment at record levels

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According to a new study by the International Energy Agency, global clean energy investment will be nearly twice that of fossil fuels this year.  The surging funding for clean energy is being driven by a combination of lower costs for renewable energy and by improving supply chains.

In 2024, the world’s investments in energy are expected to surpass $3 trillion dollars for the first time.  About $2 trillion of that will be directed at green technologies that include renewable power sources, grids, and energy storage; electric vehicles; low-emission fuels; nuclear power; and heat pumps and efficiency improvements.  The remaining amount of just over $1 trillion will fund oil, gas, and oil projects.

The record growth in clean energy investments is taking place in spite of challenging economic conditions related to high interest rates, which demonstrates the momentum behind the global energy transition.

The IEA report does caution that there are big imbalances and shortages in energy investment in various places around the world.  For example, there is a low amount of green energy spending in developing and emerging economies outside of China.  Countries like Brazil and India are leading the way for this sector by having investments in excess of $300 billion.

More money is currently going into solar power development than all other electricity generation technologies combined.  In 2024, solar photovoltaic power investment is set to grow to $500 billion as the falling price of solar modules spurs new investments.

The largest renewable investments will come from China at $675 billion, followed by Europe and the U.S. at $370 billion and $315 billion, respectively.

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Global Clean Energy Investment Will Nearly Double That of Fossil Fuels in 2024: IEA Report

Photo, posted October 2, 2015, courtesy of John Englart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A surprising drop in renewable power

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Renewable power – which includes wind farms, solar farms, and hydroelectric dams – constitutes over 21% of the country’s utility-scale electricity generation, behind only natural gas power plants at 43%.  Nuclear power provides nearly 19% of our electricity and coal, which is gradually diminishing, is at 16%.

Both solar and wind power capacity have been growing rapidly in recent years and will be providing an increasing percentage of our electricity.  That being said, it turns out that utility-scale renewable electricity generation actually decreased slightly in 2023 as a result of weather-related issues.

Utility-scale renewables generated about 894,000 gigawatt hours of energy last year, which was 0.8% less than the record amount generated in 2022.

The reasons?  The biggest factor was slower wind speeds in the Midwest during the warmer weather months.  In 2023, there were fewer warm fronts and cold fronts passing through the region.  The passage of fronts is often associated with wind and precipitation. 

The other factor affecting renewable generation was a 5.9% drop in hydropower in 2023.  The main reason for the decrease was a drop in water levels at many hydroelectric dams in areas experiencing drought.

Experts explain that there is no reason to overreact to a one-year blip in renewables generation.  All three major sources of power – sun, wind, and hydroelectric – are tied to natural forces and all of them fluctuate over time.  Putting aside minor variations year-over-year, renewable electricity is on pace to more than double by the end of this decade.

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Federal Data Reveals a Surprising Drop in Renewable Power in 2023, as Slow Winds and Drought Took a Toll

Photo, posted July 5, 2014, courtesy of Patrick Finnegan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A giant underground battery

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Two up-and-coming energy technologies are coming together near a tiny town in central Utah.  Outside of the town of Delta, population 3,600, two caverns, each as deep as the Empire State Building, are being created from an underground salt formation to be used to store hydrogen gas.  The gas will be used as a fuel in a new electricity generation plant.

The plant will replace an aging local coal-fired power plant.  The new plant will burn a mixture of natural gas and hydrogen – green hydrogen produced without emitting greenhouse gases. To produce the hydrogen, the facility will operate 40 giant electrolyzers that will use excess solar and wind power generated at times of low demand to split water molecules into hydrogen and oxygen.

The caverns were created by a process called solution mining in which high-pressure water is pumped down into salt deposits that are dissolved. The resulting caverns are 200 feet in diameter and 1,200 deep and lie 3,000 to 4,000 feet below the surface.  Hydrogen cannot escape through the thick salt layers.

The amount of energy that can be stored in the form of hydrogen fuel in these caverns is massive – far more than all the battery storage installed in the U.S. to date.  Chevron has a majority stake in one of the projects and will supply the natural gas.  The facility is expected to go online in 2025.

While this will produce far fewer emissions than existing coal plants, it is not carbon-free.  Currently, turbine technology cannot operate with pure hydrogen fuel.  The Delta plant will run on only 30% hydrogen.  The hope is that turbine technology will improve in the future and permit operation on pure hydrogen.

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A Huge Underground Battery Is Coming to a Tiny Utah Town

Photo, posted September 9, 2013, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Brownfields and solar power

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Brownfields are blighted lands that have suffered environmental contamination, making it very difficult to redevelop them or make good use of them.  Generally, they are previously used lands that have the presence or at least the potential presence of hazardous substances, pollutants, or other contaminants at levels exceeding health-based or environmental standards.  There are nearly half a million brownfields in the U.S. that are ripe for repurposing.

One very attractive use for brownfields is to convert them to “brightfields,” which is the colloquial term for brownfields redeveloped into solar projects.  Estimates are that nearly 200,000 U.S. brownfield sites are eligible for brightfield conversion, which could provide hundreds of gigawatts of energy production.  Over 10,000 of these sites are inactive landfills, which alone could power 8 million homes.  Many of these sites have sat unused for decades.

A recent success story took place in Old Bridge Township, New Jersey where an abandoned waste site – designated a Superfund site by the EPA for decades – has now become a solar project that will generate more than $1.2 million a year for the township and will provide reduced-cost electricity for 400 homes, half of which are low- and moderate-income residents.

The site was on the EPA list of Superfund National Priorities , meaning it was considered one of the most serious abandoned hazardous waste sites.  Such sites required continuous monitoring, modifications, and cleanup. 

Projects like the Old Bridge solar project are likely to become increasingly common in the future, as legacy liabilities can be turned into valuable assets.

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How solar installations give new life to blighted brownfields

Photo, posted November 11, 2015, courtesy of Martin Malec via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Who wins: Wind or solar?

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

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

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

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

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World may have crossed solar power ‘tipping point’

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

Earth Wise is a production of WAMC Northeast Public Radio

More renewable energy for New York

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In late October, New York announced its largest state investment in renewable energy to date that includes three offshore wind projects, and 22 land-based clean energy projects totaling more than 6 GW of power generation.

The portfolio of projects is expected to create approximately 8,300 jobs and spur $20 billion in economic investments statewide.

The projects support the state’s goal to have 70% of its electricity come from renewable sources by 2030 and to have 9 GW of offshore wind operating by 2035.  The announcement represents the first set of actions taken by the State as part of New York’s 10-Point Action Plan.

The three offshore wind projects include Attentive Energy One, a 1.4 GW project that seeks to retire fossil fuel power generation in New York City.  Community Offshore Wind, a 1.3 GW project will make use of a new grid interconnection in downtown Brooklyn.  Excelsior Wind, another 1.3 GW project, will provide robust energy deliverability to Long Island. 

Apart from the offshore wind projects, there will be 14 new solar projects, six wind upgrading projects, one new wind project, and one return-to-service hydroelectric project.

The average bill impact for customers over the life of the land-based projects is estimated to be approximately 0.31%, or about 32 cents a month for the average customer.  The bill impact for customers utilizing the offshore wind projects is estimated to be about 2.7%, or $2.93 per month.

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NY to invest in 3 offshore wind farms, 22 land-based renewable projects

Photo, posted October 21, 2016, courtesy of B Sarangi via Flickr.

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Fossil-free fertilizer

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Ammonia is a major industrial commodity.  About 70% of it is used to make fertilizer, with the rest for a wide range of industrial applications.  Ammonia is the starting point for all mineral nitrogen fertilizers. 

Typically, ammonia is a byproduct of isolating hydrogen from natural gas, which releases large amounts of carbon dioxide.  On a global scale, the climate impact of ammonia production is comparable to that of air travel.  The world needs more ammonia but really cannot afford the emissions that come with its production.

There are also political implications of ammonia production.  Because it relies so heavily on natural gas, ammonia supply is vulnerable to disruptions from events like the Russian invasion of Ukraine.  Sanctions imposed after the invasion have hindered fertilizer exports, driving up costs, especially in places like Africa.

A small fertilizer plant near Nairobi, Kenya will be the first farm in the world to produce its own nitrogen fertilizer on site that is free of fossil fuels.  The plant is being built by an American startup company Talus Renewables and will use solar power to strip hydrogen from water.  The hydrogen will then bond with nitrogen from the air to form liquid ammonia.  The plant will produce one ton of ammonia each day.

The typical bag of fertilizer in sub-Saharan Africa travels 6,000 miles to get there, which of course only adds to the environmental burden of using it as well as its cost.  By building a small green ammonia plant like the one coming online in Kenya, it is possible to locally produce a critical raw material in a carbon-free manner.

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Farm in Kenya First to Produce Fossil-Free Fertilizer On Site

Photo courtesy of Talus Renewables via LinkedIn.

Earth Wise is a production of WAMC Northeast Public Radio

Powering Britain with sun and wind

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The United Kingdom is quite small in size compared with the US, but its population of 67 million makes it a fairly large country with substantial energy needs.  A recent study by Oxford University looked at the ability of wind and solar power to provide for those energy needs over the course of time.

According to the study, Britain’s energy needs could easily be met entirely by the two sources of clean power.  Wind and solar can provide significantly more energy than the highest energy demand forecasted for 2050 and nearly 10 times the current electricity demand. 

Britain currently requires 299 TWh per year.  The Oxford study found that wind and solar could generate as much as 2,896 TWh per year. Furthermore, the researchers stated that these estimates are intentionally conservative, taking into account concerns around land use and the visual impact of installations.

The analysis assumes that offshore wind would produce nearly three-quarters of the energy required.  Onshore wind would contribute about 7%, while taking up only 0.07% of the country’s land.  Utility-scale solar would add about 19% of the power.  The small remainder comes from rooftop solar.  The researchers do point out that the power grid would require significant upgrades to handle all this renewable energy and that there would need to be appropriate quantities of energy storage. 

According to the authors of the study, achieving these results is a question of ambition rather than technical feasibility.  So far, the UK government has not been aggressive in making the transition to renewable energy.

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Wind and solar power could significantly exceed Britain’s energy needs

Photo, posted November 4, 2021, courtesy of Steve Knight via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Sea Farms | Earth Wise

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Researchers at the University of South Australia have designed a self-sustaining solar-driven system that turns seawater into fresh water and grows crops without any involvement.  In theory, such a system could help address the growing problems of freshwater shortages and inadequate food supplies as the world’s population continues to increase.

The system can be described as a vertical floating sea farm.  It is made up of two chambers:  an upper layer similar to a greenhouse and a lower chamber for water harvesting.

Clean water is supplied by an array of solar evaporators that soak up seawater, trap the salts in the evaporator body and, heated by the sun, release clean water vapor into the air which is then condensed on belts that transfer the water into the upper plant growth chamber.

The researchers tested the system by growing broccoli, lettuce and bok choi on seawater surfaces without maintenance or additional clean water irrigation.  The system was powered entirely by solar light.

The design is only a proof-of-concept at this point.   The next step is to scale it up using an array of individual devices to increase plant production. 

The futuristic potential for such technology would be huge farm biodomes floating on the ocean.  The UN estimates that by 2050, nearly 2.5 billion people are likely to experience water shortages while the global supply of water for irrigation is expected to decline by 19%.  Nearly 98% of the world’s water is in the oceans.  Harnessing the sea and the sun to address growing global shortages could be the way to go.

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Floating sea farms: a solution to feed the world and ensure freshwater by 2050

Photo, posted February 11, 2015, courtesy of Ed Dunens via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Solar And Hydropower | Earth Wise

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Installing solar panels on the surface of reservoirs is an up-and-coming trend.  The arrays of solar panels produce renewable energy while at the same time shielding significant expanses of water from the sun’s heat, thereby reducing evaporation.  The panels also help to inhibit the growth of algae.

Two recent floating solar installations are demonstrating the synergy between solar power and hydroelectric power.

The Lazer floating solar plant in France comprises over 50,000 solar panels and is capable of producing 30 MW of power.  The reservoir serves a 16.5 MW hydropower plant.  During the summer, the water from Lazer Reservoir is used primarily for crop irrigation and the solar plant supplements power generation as the reservoir water level experiences variations.  This is the first facility of its kind to be installed in France.  The company that built it – the EDF Group – had already built four floating solar power plants in Israel and the US. 

In Colombia, the Aquasol solar project is installed at the 340 MW Urrá hydropower plant.  Its 2,800 solar panels produce enough power to offset the amount of energy it takes to operate the dam.  The floating solar system is designed to withstand water-level fluctuations of up to 120 feet.

Floating solar systems can help keep power flowing when low water levels or other adverse conditions reduce hydroelectric output.  About 60% of the world’s renewable energy comes from hydropower.  Given this fact, there are countless opportunities to deploy floating solar that maximizes zero-emission energy generation as well as diversifying clean energy sources.

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Floating solar and hydropower: A match made in renewable energy heaven

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

Earth Wise is a production of WAMC Northeast Public Radio

WAMC Northeast Public Radio

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