utilities

Reliability of renewable energy

February 25, 2025 By EarthWise Leave a Comment

Naysayers about renewable energy often claim that it is unreliable. It is true that the sun sets every night and sometimes the wind doesn’t blow. But with the growing use of battery banks to store excess power generated by renewables, the lack of reliability of renewable energy is turning out to be a myth.

A new study published in the journal Renewable Energy looked at the deployment of renewable energy in California last year. From late winter to early summer, renewable sources supplied 100% of the state’s electricity demands for up to 10 hours on 98 out of 116 days. There were no blackouts during that time thanks in part to the presence of battery backup power. During peak generation periods, the renewables provided as much as 162% of the grid’s needs.

The main finding of the study is that the electricity grid can be kept stable even as it adds more and more renewables. Beyond that, every major renewable energy source – geothermal, hydroelectric, wind, and especially solar – is on average lower in cost than fossil fuels.

Despite the low cost of renewable energy, Californians pay the second highest rates for electricity in the country. Part of the reason is that electrical equipment from utilities has set off wildfires, notably the 2018 Camp Fire that devastated the town of Paradise and killed 85 people. California’s utilities are now passing the costs that come from lawsuits and from burying transmission lines to their customers. Overhead power lines are especially prone to falling in high winds and igniting fires.

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California just debunked a big myth about renewable energy

Photo, posted December 16, 2024, courtesy of EDF Renewables / Bureau of Land Management California via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A big year for battery storage

January 29, 2025 By EarthWise Leave a Comment

A decade ago, the ability of utilities to store large amounts of electricity in batteries was basically nonexistent. In the past several years, growth in battery storage systems has exploded. As of the end of November, the US had about 24 gigawatt-hours of storage capacity in place. This is 71% more than just a year ago. Nearly half of the battery storage in the US is located in California. Texas, Arizona, and Nevada are also leaders in deploying battery storage.

Battery storage allows solar and wind generating plants to keep operating when there is reduced demand for their output and have the electricity that they produce be available later when demand rises. Storing this excess electricity essentially extends the hours of the day when clean energy can be used.

Equally important, the existence of battery storage reduces the need for peaker plants, the fossil-fueled power plants that only turn on at times of peak demand, such as during hot afternoons.

There are 1,000 peaker plants in the US and they are generally heavily polluting, inefficient, and expensive to operate. Some 63 million people live within a three-mile radius of one of them and are exposed to harmful pollutants like nitrogen oxides and sulfur dioxide. Peaker plants also release more greenhouse gases than other power plants do for every unit of electricity they generate.

Many battery storage facilities are co-located with, or otherwise support, solar energy plants. The amount of solar energy in the US is growing rapidly and surpassed the 100-gigawatt mark in 2024. As solar power continues to expand, so will battery energy storage.

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Battery projects soared again in 2024

Photo, posted August 3, 2024, courtesy of the Bureau of Ocean Energy Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Neighborhood geothermal energy

December 30, 2024 By EarthWise Leave a Comment

Residential geothermal energy makes use of the constant, year-round temperature of the earth below the surface to efficiently provide both heating and cooling for a home. In the summer, the cool earth beneath a house sits at about 55 degrees and can be tapped into with a heat pump to provide cooling. In the winter, that 55-degree underground expanse provides a much warmer source of air to heat instead of the often freezing-cold air outside. Geothermal systems are appealing because they use far less energy than other sources of heating and cooling.

Using geothermal energy to heat and cool buildings is nothing new. But after years of planning and months of drilling into the ground, the first neighborhood-scale geothermal heating and cooling project has come online in Framingham, Massachusetts.

The project ties together 31 residential and five commercial buildings that share the underground infrastructure needed to heat and cool them. This sort of shared geothermal system has previously been used on college campuses and similar places, but never before across a neighborhood in the United States.

The $14 million project, built by Eversource, broke ground in June 2023, and comprises 90 boreholes or wells drilled 600-700 feet underground. Approximately 135 customers are connected to the system, including low- and moderate-income customers, apartment buildings, a gas station, and a kitchen cabinet showroom.

A total of 13 states, including Massachusetts and New York, are considering pilot projects or advancing legislation that would allow gas utilities to develop networked geothermal heating and cooling.

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First-in-the-Nation Geothermal Heating and Cooling System Comes to Massachusetts

Photo, posted September 30, 2019, courtesy of Stephen D. Strowes via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Offshore wind and the wake effect

May 28, 2024 By EarthWise Leave a Comment

Electricity demand in the U.S. continues to grow and, in the summer, homes and businesses crank up their air conditioning which drives demand even further. Many East Coast cities are banking on offshore wind projects that are underway in the Atlantic Ocean to help meet that growing demand. The first offshore turbines are now producing power off the coasts of Massachusetts and New York.

Electric power utilities need to know how much power they can get from offshore wind farms, and this is not that easy to predict. Wind is variable, so there is some built-in uncertainty. But there is also a phenomenon known as the wake effect to contend with.

When wind passes through a series of giant turbines, the ones in front extract some energy from the wind and, as a result, the wind slows down and becomes more turbulent behind the turbines. So, the downstream turbines get slower wind and may produce less power.

A study by the University of Colorado has modeled this phenomenon for planned wind farms in the Atlantic Coast region and has found that power output could be reduced by over 30%. Researchers are installing weather monitors and radar sensors in islands off the New England coast to better understand the behavior of the wind in the area and improve prediction models.

The New England grid covers Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. Even with the wake effect, offshore wind is predicted to be able to provide 60% of the electricity needs of the grid, but it is important to be able to accurately predict what it can produce.

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How much energy can offshore wind farms in the US produce? New study sheds light

Photo, posted August 31, 2022, courtesy of Nina Ali via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium in Arkansas

April 11, 2024 By EarthWise Leave a Comment

There are more and more electric cars on the road and utilities are installing record amounts of battery storage to back up solar and wind power generation. Both of these things currently use lithium-ion batteries so the need for them keeps growing.

There is actually plenty of lithium in the world. Sources of more than 100 million tons have been identified, which is enough to meet the projected needs for decades. But lithium is not easy, cheap, or environmentally friendly to extract. It is either blasted out of rocks that are then roasted at 2000-degree temperatures, or it is extracted from brine in places like the high Andes where it leaves behind toxic residues. Ramping up lithium production could greatly diminish the environmental benefits derived from green technologies.

A technique called direct lithium extraction, or DLE, may be a possible solution. The lithium is pulled out of brine while leaving other dissolved compounds behind. It is being tested in many places around the world and appears to offer the lowest negative impacts of available extraction technologies.

The Salton Sea area in California has rich deposits of lithium and is a good candidate for DLE. But conditions may be even better in Arkansas whose Smackover Formation is a brine-rich expanse of limestone.

The area was a productive oil field a hundred years ago and then undertook brine-processing in the 1950s to extract bromine. So, the area already has industrial infrastructure and no new land would need to be cleared.

The former oil fields of Arkansas may become an important domestic source of lithium.

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In Rush for Lithium, Miners Turn to the Oil Fields of Arkansas

Photo, posted February 26, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Aluminum In Batteries | Earth Wise

September 1, 2023 By EarthWise 1 Comment

Batteries are playing a bigger and bigger role in our lives. Apart from their use in ubiquitous smartphones, laptops, and other devices, millions of electric vehicles are hitting the roads, and utilities are installing giant banks of batteries to store energy generated by wind and solar farms.

The necessary characteristics of batteries are high energy density and stability. The latter is needed so that batteries can be safely and reliably recharged thousands of times. For decades, lithium-ion batteries have been the go-to for all these modern battery applications. And they have gradually gotten better and cheaper all the time. But the improvements are getting smaller, and the price reductions have limits.

For these reasons, researchers are always looking for batteries with higher energy density – so that, for example, electric cars can drive farther on a charge – and that can be made more cheaply, are not flammable, and are very stable.

Since the 1970s, researchers have investigated the use of aluminum for the anode of batteries because its properties would allow more energy to be stored. However, when used in lithium-ion batteries, aluminum developed fractures and failed after a few cycles.

Researchers at Georgia Tech University have developed a type of aluminum foil with small amounts of other materials that create specific microstructures. Used in battery anodes, this material does not degrade and appears to be a path to a better battery. When incorporated into a solid-state battery that does not contain the flammable liquid found in standard lithium-ion batteries, the result is a battery that checks most of the boxes in the search for a better battery.

Much more work is needed to assess the potential for the aluminum-based battery, but it looks very promising.

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Aluminum Materials Show Promising Performance for Safer, Cheaper, More Powerful Batteries

Photo, posted August 27, 2019, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving Money By Predicting The Wind | Earth Wise

July 1, 2022 By EarthWise Leave a Comment

Managing an electrical grid that utilizes significant amounts of intermittent generation sources – solar and wind power – brings with it some unique challenges. There are abundant wind resources in this country and more and utilities are taking advantage of these resources. But there are times when there is more wind, times when there is less wind, and times when there is no wind at all. Utilities need accurate wind forecasts to determine when they need to generate or purchase energy from alternative sources.

Poor wind forecasts can cost utilities a lot of money. If there is overprediction – that is, when there is less wind than predicted – utilities have to purchase energy off the spot market at higher prices. If there is underprediction – more wind than predicted – utilities may needlessly burn fossil fuels and waste money that way.

The National Oceanic and Atmospheric Administration produces wind forecasts using its High-Resolution Rapid Refresh (HRRR) weather model, which provides hourly updated forecasts for every part of the United States looking forward up to 48 hours. The model generates predictions of wind speed and direction at multiple levels of the atmosphere, information that utilities can use to predict the output of their wind turbines.

A new study by economists and scientists from Colorado State University and NOAA estimated the financial impact of the HRRR model on wind farm production. The research team calculated that increasingly accurate weather forecasts over the last decade have saved consumers over $150 million a year. Estimates are that if the newest model was in use in previous years, the savings would have been over $300 million a year.

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NOAA wind forecasts result in $150 million in energy savings every year

Photo, posted May 2, 2022, courtesy of California Energy Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Canopies | Earth Wise

December 31, 2021 By EarthWise Leave a Comment

There are plenty of solar panels on residential rooftops but there are also increasing numbers of arrays of them on croplands, arid lands, and grasslands. Large solar arrays are mostly built in open spaces like these rather than in developed areas. The reason is that it is cheaper to build on undeveloped land than on rooftops or construct covered parking lots.

However, building on undeveloped land is not necessarily the smartest idea. Undeveloped land is a dwindling resource that is needed for many different things: growing food, sheltering wildlife, storing and purifying water, preventing erosion, and sequestering carbon.

Putting solar panels on parking lots has the appeal that they are abundant, close to electricity customers, and are on land that already has been stripped of much of its biological value.

Putting a solar canopy over a parking lot can produce large amounts of electricity and has the added benefit that it would provide shade for cars. For example, a typical Walmart supercenter might have a five-acre parking lot, which is enough to support a 3-megawatt solar array. If Walmart put solar canopies on all of its 3,500+ super centers, it would provide 11 gigawatts of solar power – as much as a dozen large coal-fired power plants.

Solar canopies are still pretty uncommon, but some examples are ones at four DC Metro rail stations, one at JFK Airport, and a large one at the Rutgers University Piscataway campus.

Building parking lot solar canopies is much more expensive than putting solar arrays on open space, but they do eventually pay for themselves. Despite active opposition by utility and fossil fuel interests, solar canopies may eventually be a common sight.

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Why Putting Solar Canopies on Parking Lots Is a Smart Green Move

Photo, posted January 10, 2020, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Iron Flow Batteries | Earth Wise

November 15, 2021 By EarthWise Leave a Comment

Lithium-ion batteries power computers, cell phones, and increasingly, automobiles. They started out being rather expensive but have become dramatically cheaper over the last decade, with prices dropping about 90%. Batteries are needed to store clean power from wind and solar generation and lithium-ion batteries are increasingly being used for that purpose as well.

Utility-scale energy storage requires substantial battery installations and battery cost is still very much an inhibiting factor in the widespread adoption of the technology. Lithium-ion battery costs continue to drop but because they require expensive materials like lithium and cobalt, there are limits to how low their prices are likely to get.

As a result, researchers have continued to seek ways to produce batteries made out of cheaper materials. Among the more promising technologies are flow batteries, which are rechargeable batteries in which electrolyte flows through electrochemical cells from tanks.

Flow batteries are much larger than lithium-ion batteries and include physical pumps to move electrolytes. They typically are sold inside shipping containers. Clearly, such batteries are not suitable for use in vehicles, much less in consumer electronics. Nevertheless, they represent a practical option for grid storage.

A company called ESS has developed an iron flow battery suitable for utility energy storage. Clean energy firm CSB Energy plans to install iron flow batteries at several solar projects across the U.S. that will store enough energy to provide power 50,000 homes for a day. According to ESS, the iron-based batteries should sell for about half the price of lithium-ion batteries by 2025 and be able to store energy for longer periods.

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New Iron-Based Batteries Offer an Alternative to Lithium

Photo, posted March 21, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Clean Energy In Rochester | Earth Wise

October 26, 2021 By EarthWise Leave a Comment

New York’s largest community choice clean energy program has been activated in the City of Rochester. The program, offered by Rochester Community Power, offers 57,000 residences and small businesses access to clean energy from hydropower and wind sources. It requires customers to opt out rather than enroll in order to provide clean energy to the greatest number of people.

Rochester Community Power is the city’s local community choice aggregation (CCA) program that leverages the collective buying power of participating residents to purchase renewable electricity and negotiate better terms for energy supply contracts.

The program will supply customers with more than 300 million kWh of renewable energy each year, which will avoid the emission of about 250,000 tons of carbon dioxide. Rochester plans to add a community solar program next year which will provide additional clean energy opportunities, including offering guaranteed savings to thousands of participants in its Home Energy Assistance Program.

The project will be managed by Joule Assets, which is a provider of energy reduction market analysis, tools, and financing. Joule Assets, as program administrator for the Rochester program, managed the competitive bidding process that secured a fixed rate for electricity for the next two years, shielding participating residences and businesses from volatile market prices.

Community choice aggregation programs are local, not-for-profit public agencies that are an alternative to investor-owned utilities. They give municipalities the ability to make decisions about the procurement, sourcing, and rates for energy for its residents.

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New York activates its largest opt-out 100% renewable energy program

Photo, posted June 25, 2011, courtesy of Paulo Valdivieso via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Offshore Wind In New Jersey | Earth Wise

August 26, 2021 By EarthWise Leave a Comment

The New Jersey Board of Public Utilities recently selected to fund Ocean Wind 2, a 1,148-MW offshore wind energy project proposed by the Danish company Ørsted. The agency also awarded Atlantic Shores Offshore Wind a contract to develop 1,410-MW of offshore wind capacity.

Ocean Wind 2 will develop the second section of the Ocean Wind federal lease area and will provide enough power for half a million New Jersey homes. The first Ocean Wind project, also under development by Ørsted, was awarded in 2019. It’s expected to come online in 2024, and is located 15 miles off the coast of southern New Jersey. (The second project will be located adjacent to the first).

As part of the project, Ørsted is contributing to an expansion for the EEW facility in Paulsboro, where monopiles, which are foundation supports for offshore wind turbines, are manufactured. That facility will be home to 500 full-time jobs and represents a $250 million investment into southern New Jersey. The project is also bringing a commitment from GE Renewables to locate one of the country’s first offshore wind nacelle assembly facilities in New Jersey. (This facility will assemble the nacelles for Ocean Wind 2 as well as other American offshore wind projects).

Overall, Ocean Wind 2 is expected to generate nearly $5 billion in net economic benefits for the state of New Jersey.

The Atlantic Shores Offshore Wind project will be located 10-20 miles off the coast of New Jersey between Atlantic City and Barnegat Light and will bring about $850 million in local economic benefits to the state, including a variety of investments in local communities.

Overall, New Jersey has the goal of supplying more than 3.2 million homes with offshore wind power by 2035.

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New Jersey moves forward with two offshore wind projects representing almost 3 GW of capacity

Photo, posted March 24, 2016, courtesy of TEIA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Coal Plants | Earth Wise

April 27, 2020 By EarthWise 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.

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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.

Falling U.S. Carbon Emissions

September 16, 2019 By EarthWise Leave a Comment

Reducing carbon emissions is a goal embraced by nearly every country in the world, but actually accomplishing it isn’t easy. It is true that renewable energy sources are playing a growing role in energy systems, but counterbalancing that trend is growing energy demand, especially in developing countries.

Here in the US, energy-related CO2 emissions actually went up nearly 3% in 2018 compared with 2017. But the US Energy Information Administration is now forecasting a 2% drop in emissions this year.

The main reason energy-related emissions are headed lower at this point is coal-fired power plant retirements. More than 90% of the coal used in the US goes toward electric power and utilities are increasingly turning away from coal.

The rapid shift away from coal has mostly been due to the increasing use of natural gas. Natural gas is not actually a clean and green fuel, but it is definitely less carbon-intensive than coal. Overall, the total installed capacity of renewable sources – hydropower, wind, solar, geothermal, and biomass – has now actually surpassed the capacity of coal plants. Given that renewables have in many places become the cheapest power option, there is little chance that coal has much of a future, despite efforts by the current administration.

The electric power sector is gradually moving away from all carbon-emitting sources – a trend that is being reinforced by legislation in many states. The real CO2 emissions leader is petroleum, which accounts for nearly half of the total. We have a long way to go to reduce emissions from the use of petroleum. There are over 250 million cars and trucks on US roads and only a little over a million of them don’t burn fossil fuels.

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Photo, posted November 6, 2017, courtesy of Cindy Shebley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Complications For New York Solar Farms

July 12, 2019 By EarthWise Leave a Comment

A study by engineers at Cornell University looked at the implications of adding utility-scale solar farms throughout New York State. Adding such farms could reduce demand for electricity from conventional sources by nearly 10% in some places. But the engineers caution that winters in upstate New York could create some novel problems for the state’s power system.

Electrical energy demand tends to be low around midday when many people are not home. Electrical production from solar farms is high at that time when the sun is at its highest position in the sky. This can lead to what power system operators call “ramping”, which is the term for rapid increases or decreases in demand.

This sort of ramping was first discussed in California years ago. When people wake up and prepare for the day, there is a morning peak in electrical load, which occurs before solar production ramps up. When people get home from work in the evening, energy demands create a second peak. A graph of this lack of synchronicity of load and supply looks a little like the shape of a duck and is popularly known as the duck curve.

The Cornell engineers figured out that maximum ramping in New York – where electrical demand and electricity supply from solar farms are out of synch- will take place in the winter. In fact, when there are several days of sunshine in a row during winter, the largest ramping in the New York power system will take place.

The general issue of having solar energy available when it is most needed is one that is the driver for energy storage technology. If the energy can be provided when demand calls for it, there would be no more ramping.

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Winter could pose solar farm ‘ramping’ snag for power grid

Photo, posted September 8, 2015, courtesy of New York National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Quiet Clean Energy Revolution

March 5, 2019 By EarthWise Leave a Comment

While the Trump administration seeks to prop up and promote use of fossil fuels, the country continues to move in the opposite direction. Last year was actually a pretty positive year for clean energy in the U.S.

In terms of public opinion, 70% of Americans surveyed believe the country should produce 100% of its electricity from renewable energy sources and more than half of survey respondents think renewables are a good idea even if they raise energy bills.

Companies in the U.S. purchased a record 6.43 gigawatts of renewable power, enough to power 1.5 million homes. The number of corporations entering into renewable energy deals doubled last year.

More than 300 U.S. cities, towns or counties have made commitments to climate action and, as of November, 99 cities have committed to 100% renewable energy, doubling the total from a year ago.

A number of gubernatorial candidates running on ambitious renewable energy platforms were elected in November including those in Illinois, Colorado, New Mexico, Maine and Nevada.

Utilities are responding to the growing demand for clean energy. Consumers Energy in Michigan plans to cut carbon emissions by 80% and stop using coal. Iowa-based MidAmerican Energy will become the first U.S. utility to source 100% of its electricity from renewable sources next year. Xcel Energy, one of the biggest utilities in the country, has committed to be 80% carbon-free by 2030 and go completely carbon-free by 2050.

The fossil fuel industry with its supporters in high places is still kicking and screaming, but there is no doubt that the U.S. energy system is changing, and the quiet clean energy revolution will only pick up more steam in 2019.

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