Cliffside power plant construction draws more discussion

By The Shelby Star


NFPA 70e Training

Our customized live online or in‑person group training can be delivered to your staff at your location.

  • Live Online
  • 6 hours Instructor-led
  • Group Training Available
Regular Price:
$199
Coupon Price:
$149
Reserve Your Seat Today
Welchel Road resident Roger Hollis said his backyard sounds like a train riding through it every morning.

He's hearing noise from construction at Duke Energy's Cliffside steam station. Once construction is complete — probably in 2012 — the company plans to shut down four units that were built in the 1940s.

A handful of people stood in a small area on Duke Power Road to protest the coal-fired plant and construction.

"It's a symbolic gesture," said Abby Gage, one of the organizers.

Gage is a farmer from Madison County and brought along her son, Alexander, 7, for the protest.

"The cost of building a coal-fired power plant is going up," she said. "The cost of solar wind power is going down."

Protests are nothing new at the Cliffside location, with arrests happening on the property in the past when protestors chained themselves to equipment.

Earlier, environmentalist groups joined together for a march at Duke Energy's Charlotte headquarters.

Hollis was not involved in the protest, but stopped by to share his support.

"I feel like the people living here are being done a total injustice," he said. "They just say what they are not going to do."

Joyce Norman, who lives nearby, said she doesn't have a problem with the plant or construction. She has lived in her home on Duke Power Road for more than 50 years.

"Whether it's coal or electric, we have to have power," she said.

Bill Conner, who lives about five miles away, is also in favor of the plant. "We always used coal before and never hurt us before," he said. "You don't have enough wind to keep things turning."

Related News

Ontario prepares to extend disconnect moratoriums for residential electricity customers

Ontario Electricity Relief outlines an extended disconnect moratorium, potential time-of-use price changes, and Ontario Energy Board oversight to support residential customers facing COVID-19 hardship and bill payment challenges during the emergency in Ontario.

 

Key Points

Plan to extend disconnect moratorium and weigh time-of-use price relief for residential customers during COVID-19.

✅ Extends winter disconnect ban by 3 months

✅ Considers time-of-use price adjustments

✅ Requires Ontario Energy Board approval

 

The Ontario government is preparing to announce electricity relief for residential electricity users struggling because of the COVID-19 emergency, according to sources.

Sources close to those discussions say a decision has been made to lengthen the existing five-month disconnect moratorium by an additional three months.

Separately, Hydro One's relief fund has offered support to its customers during the pandemic.

News releases about the moratorium extension are currently being drafted and are expected to be released shortly, as the pandemic has reduced electricity usage across Ontario.

Electricity utilities in Ontario are currently prohibited from disconnecting residential customers for non-payment during the winter ban period from November 15 to April 30.

The province is also looking at providing further relief by adjusting time-of-use prices, such as off-peak electricity rates, which are designed to encourage shifting of energy use away from periods of high total consumption to periods of low demand.

For businesses, the province has provided stable electricity pricing to support industrial and commercial operations.

But that would require Ontario Energy Board approval and no decision has been finalized, our sources advise.

 

Related News

View more

Blackout-Prone California Is Exporting Its Energy Policies To Western States, Electricity Will Become More Costly And Unreliable

California Blackouts expose grid reliability risks as PG&E deenergizes lines during high winds. Mandated solar and wind displace dispatchable natural gas, straining ISO load balancing, transmission maintenance, and battery storage planning amid escalating wildfire liability.

 

Key Points

California grid shutoffs stem from wildfire risk, renewables, and deferred transmission maintenance under mandates.

✅ PG&E deenergizes lines to reduce wildfire ignition during high winds.

✅ Mandated solar and wind displace dispatchable gas, raising balancing costs.

✅ Storage, reliability pricing, and grid upgrades are needed to stabilize supply.

 

California is again facing widespread blackouts this season. Politicians are scrambling to assign blame to Pacific Gas & Electric (PG&E) a heavily regulated utility that can only do what the politically appointed regulators say it can do. In recent years this has meant building a bunch of solar and wind projects, while decommissioning reliable sources of power and scrimping on power line maintenance and upgrades.

The blackouts are connected with the legal liability from old and improperly maintained power lines being blamed for sparking fires—in hopes that deenergizing the grid during high winds reduces the likelihood of fires. 

How did the land of Silicon Valley and Hollywood come to have developing world electricity?

California’s Democratic majority, from Gov. Gavin Newsom to the solidly progressive legislature, to the regulators they appoint, have demanded huge increases in renewable energy. Renewable electricity targets have been pushed up, and policymakers are weighing a revamp of electricity rates to clean the grid, with the state expected to reach a goal of 33% of its power from renewable sources, mostly solar and wind, by next year, and 60% of its electricity from renewables by 2030.

In 2018, 31% of the electricity Californians purchased at the retail level came from approved renewables. But when rooftop solar is added to the mix, about 34% of California’s electricity came from renewables in 2018. Solar photovoltaic (PV) systems installed “behind-the-meter” (BTM) displace utility-supplied generation, but still affect the grid at large, as electricity must be generated at the moment it is consumed. PV installations in California grew 20% from 2017 to 2018, benefiting from the state’s Self-Generation Incentive Program that offers hefty rebates through 2025, as well as a 30% federal tax credit.

Increasingly large amounts of periodic, renewable power comes at a price—the more there is, the more difficult it is to keep the power grid stable and energized. Since electricity must be consumed the instant it is generated, and because wind and solar produce what they will whenever they do, the rest of the grid’s power producers—mostly natural gas plants—have to make up any differences between supply and immediate demand. This load balancing is vital, because without it, the grid will crash and widespread blackouts will ensue.

California often produces a surplus of mandated solar and wind power, generated for 5 to 8 cents per kilowatt hour. This power displaces dispatchable power from natural gas, coal and nuclear plants, resulting in reliable power plants spending less time online and driving up electricity prices as the plants operate for fewer hours of the day. Subsidized and mandated solar power, along with a law passed in California in 2006 (SB 1638) that bans the renewal of coal-fired power contracts, has placed enormous economic pressure on the Western region’s coal power plants—among them, the nation’s largest, Navajo Generating Station. As these plants go off line, the Western power grid will become increasingly unstable. Eventually, the states that share their electric power in the Western Interconnect may have to act to either subsidize dispatchable power or place a value on reliability—something that was taken for granted in the growth of the America’s electrical system and its regulatory scheme.

California law regarding electricity explicitly states that “a violation of the Public Utilities Act is a crime” and that it is “…the intent of the Legislature to provide for the evolution of the ISO (California’s Independent System Operator—the entity that manages California’s grid) into a regional organization to promote the development of regional electricity transmission markets in the western states.” In other words, California expects to dictate how the Western grid operates.

One last note as to what drives much of California’s energy policy: politics. California State Senator Kevin de León (the author served with him in the State Assembly) drafted SB 350, the Clean Energy and Pollution Reduction Act. It became law in 2015. Sen. de León followed up with SB 100 in 2018, signed into law weeks before the 2018 election. SB 100 increased California’s renewable portfolio standard to 60% by 2030 and further requires all the state’s electricity to come from carbon-free sources by 2045, a capstone of the state’s climate policies that factor into the blackout debate.  

Sen. de León used his environmental credentials to burnish his run for the U.S. Senate against Sen. Dianne Feinstein, eventually capturing the endorsements of the California Democratic Party and billionaire environmentalist Tom Steyer, now running for president. Feinstein and de León advanced to the general in California’s jungle primary, where Feinstein won reelection 54.2% to 45.8%.

De León may have lost his race for the U.S. Senate, but his legacy will live on in increasingly unaffordable electricity and blackouts, not only in California, but in the rest of the Western United States—unless federal or state regulators begin to place a value on reliability. This could be done by requiring utility scale renewable power providers to guarantee dispatchable power, as policymakers try to avert a looming shortage of firm capacity, either through purchase agreements with thermal power plants or through the installation of giant and costly battery farms or other energy storage means.

 

Related News

View more

Global Energy War Escalates: Price Hikes and Instability

Russia-Ukraine Energy War disrupts infrastructure, oil, gas, and electricity, triggering supply shocks, price spikes, and inflation. Global markets face volatility, import risks, and cybersecurity threats, underscoring energy security, grid resilience, and diversified supply.

 

Key Points

It is Russia's strategic targeting of Ukraine's energy system to disrupt supplies, raise prices, and hit global markets.

✅ Attacks weaponize energy to strain Ukraine and allies

✅ Supply shocks risk oil, gas, and electricity price spikes

✅ Urgent need for cybersecurity, grid resilience, diversification

 

Russia's targeting of Ukraine's energy infrastructure has unleashed an "energy war" that could lead to widespread price increases, supply disruptions, and ripple effects throughout the global energy market, felt across the continent, with warnings of Europe's energy nightmare taking shape.

This highlights the unprecedented scale and severity of the attacks on Ukrainian energy infrastructure. These attacks have disrupted power supplies, prompting increased electricity imports to keep the lights on, hindered oil and gas production, and damaged refineries, impacting Ukraine and the broader global energy system.


Energy as a Weapon

Experts claim that Russia's deliberate attacks on Ukraine's energy infrastructure represent a strategic escalation, amid energy ceasefire violations alleged by both sides, demonstrating the Kremlin's willingness to weaponize energy as part of its war effort. By crippling Ukraine's energy system, Russia aims to destabilize the country, inflict suffering on civilians, and undermine Western support for Ukraine.


Impacts on Global Oil and Gas Markets

The ongoing attacks on Ukraine's energy infrastructure could significantly impact global oil and gas markets, leading to supply shortages and dramatic price increases, even as European gas prices briefly returned to pre-war levels earlier this year, underscoring extreme volatility. Ukraine's oil and gas production, while not massive in global terms, is still significant, and its disruption feeds into existing anxieties about global energy supplies already affected by the war.


Ripple Effects Beyond Ukraine

The impacts of the "energy war" won't be limited to Ukraine or its immediate neighbours. Price increases for oil, gas, and electricity are expected worldwide, further fueling inflation and exacerbating the global cost of living crisis.  Additionally, supply disruptions could disproportionately affect developing nations and regions heavily dependent on energy imports, making targeted energy security support to Ukraine and other vulnerable importers vital.


Vulnerability of Energy Infrastructure

The attacks on Ukraine highlight the vulnerability of critical energy infrastructure worldwide, as the country prepares for winter under persistent threats. The potential for other state or non-state actors to use similar tactics raises concerns about security and long-term stability in the global energy sector.


Strengthening Resilience

Experts emphasize the urgent need for global cooperation in strengthening the resilience of energy infrastructure. Investments in cybersecurity, diverse energy sources, and decentralized grids are crucial for mitigating the risks of future attacks, with some arguing that stepping away from fossil fuels would improve US energy security over time. International cooperation will be key in identifying vulnerable areas and providing aid to nations whose infrastructure is under threat.


The Unpredictable Future of Energy

The "energy war" unleashed by Russia has injected a new level of uncertainty into the global energy market. In addition to short-term price fluctuations and supply issues, the conflict could accelerate the long-term transition towards renewable energy sources and reshape how nations approach energy security.

 

Related News

View more

Clean B.C. is quietly using coal and gas power from out of province

BC Hydro Electricity Imports shape CleanBC claims as Powerex trades cross-border electricity, blending hydro with coal and gas supplies, affecting emissions, grid carbon intensity, and how electric vehicles and households assess "clean" power.

 

Key Points

Powerex buys power for BC Hydro, mixing hydro with coal and gas, shifting emissions and affecting CleanBC targets.

✅ Powerex trades optimize price, not carbon intensity

✅ Imports can include coal- and gas-fired generation

✅ Emissions affect EV and CleanBC decarbonization claims

 

British Columbians naturally assume they’re using clean power when they fire up holiday lights, juice up a cell phone or plug in a shiny new electric car. 

That’s the message conveyed in advertisements for the CleanBC initiative launched by the NDP government, amid indications that residents are split on going nuclear according to a survey, which has spent $3.17 million on a CleanBC “information campaign,” including almost $570,000 for focus group testing and telephone town halls, according to the B.C. finance ministry.

“We’ll reduce air pollution by shifting to clean B.C. energy,” say the CleanBC ads, which feature scenic photos of hydro reservoirs. “CleanBC: Our Nature. Our Power. Our Future.” 

Yet despite all the bumph, British Columbians have no way of knowing if the electricity they use comes from a coal-fired plant in Alberta or Wyoming, a nuclear plant in Washington, a gas-fired plant in California or a hydro dam in B.C. 

Here’s why. 

BC Hydro’s wholly-owned corporate subsidiary, Powerex Corp., exports B.C. power when prices are high and imports power from other jurisdictions when prices are low. 

In 2018, for instance, B.C. imported more electricity than it exported — not because B.C. has a power shortage (it has a growing surplus due to the recent spate of mill closures and the commissioning of two new generating stations in B.C.) but because Powerex reaps bigger profits when BC Hydro slows down generators to import cheaper power, especially at night.

“B.C. buys its power from outside B.C., which we would argue is not clean,” says Martin Mullany, interim executive director for Clean Energy BC. 

“A good chunk of the electricity we use is imported,” Mullany says. “In reality we are trading for brown power” — meaning power generated from conventional ‘dirty’ sources such as coal and gas. 

Wyoming, which generates almost 90 per cent of its power from coal, was among the 12 U.S. states that exported power to B.C. last year. (Notably, B.C. did not export any electricity to Wyoming in 2018.)

Utah, where coal-fired power plants produce 70 per cent of the state’s energy amid debate over the costs of scrapping coal-fired electricity, and Montana, which derives about 55 per cent of its power from coal, also exported power to B.C. last year. 

So did Nebraska, which gets 63 per cent of its power from coal, 15 per cent from nuclear plants, 14 per cent from wind and three per cent from natural gas.   

Coal is responsible for about 23 per cent of the power generated in Arizona, another exporter to B.C., while gas produces about 44 per cent of the electricity in that state.  

In 2017, the latest year for which statistics are available, electricity imports to B.C. totalled just over 1.2 million tonnes of carbon dioxide emissions, according to the B.C. environment ministry — roughly the equivalent of putting 255,000 new cars on the road, using the U.S. Environmental Protection Agency’s calculation of 4.71 tonnes of annual carbon emissions for a standard passenger vehicle. 

These figures far outstrip the estimated local and upstream emissions from the contested Woodfibre LNG plant in Squamish that is expected to release annual emissions equivalent to 170,000 new cars on the road.

Import emissions cast a new light on B.C.’s latest “milestone” announcement that 30,000 electric cars are now among 3.7 million registered vehicles in the province.

BC Electric Vehicles Announcement Horgan Heyman Mungall Weaver
In November of 2018 the province announced a new target to have all new light-duty cars and trucks sold to be zero-emission vehicles by the year 2040. Photo: Province of B.C. / Flickr

“Making sure more of the vehicles driven in the province are powered by BC Hydro’s clean electricity is one of the most important steps to reduce [carbon] pollution,” said the November 28 release from the energy ministry, noting that electrification has prompted a first call for power in 15 years from BC Hydro.

Mullany points out that Powerex’s priority is to make money for the province and not to reduce emissions.

“It’s not there for the cleanest outcome,” he said. “At some time we have to step up to say it’s either the money or the clean power, which is more important to us?”

Electricity bought and sold by little-known, unregulated Powerex
These transactions are money-makers for Powerex, an opaque entity that is exempt from B.C.’s freedom of information laws. 

Little detailed information is available to the public about the dealings of Powerex, which is overseen by a board of directors comprised of BC Hydro board members and BC Hydro CEO and president Chris O’Reilly. 

According to BC Hydro’s annual service plan, Powerex’s net income ranged from $59 million to $436 million from 2014 to 2018. 

“We will never know the true picture. It’s a black box.” 

Powerex’s CEO Tom Bechard — the highest paid public servant in the province — took home $939,000 in pay and benefits last year, earning $430,000 of his executive compensation through a bonus and holdback based on his individual and company performance.  

“The problem is that all of the trade goes on at Powerex and Powerex is an unregulated entity,” Mullany says. 

“We will never know the true picture. It’s a black box.” 

In 2018, Powerex exported 8.7 million megawatt hours of electricity to the U.S. for a total value of almost $570 million, according to data from the Canada Energy Regulator. That same year, Powerex imported 9.6 million megawatt hours of electricity from the U.S. for almost $360 million. 

Powerex sold B.C.’s publicly subsidized power for an average of $87 per megawatt hour in 2018, according to the Canada Energy Regulator. It imported electricity for an average of $58 per megawatt hour that year. 

In an emailed statement in response to questions from The Narwhal, BC Hydro said “there can be a need to import some power to meet our electricity needs” due to dam reservoir fluctuations during the year and from year to year.

‘Impossible’ to determine if electricity is from coal or wind power
Emissions associated with electricity imports are on average “significantly lower than the emissions of a natural gas generating plant because we mostly import electricity from hydro generation and, increasingly, power produced from wind and solar,” BC Hydro claimed in its statement. 

But U.S. energy economist Robert McCullough says there’s no way to distinguish gas and coal-fired U.S. power exports to B.C. from wind or hydro power, noting that “electrons lack labels.” 

Similarly, when B.C. imports power from Alberta, where generators are shifting to gas and 48.5 per cent of electricity production is coal-fired and 38 per cent comes from natural gas, there’s no way to tell if the electricity is from coal, wind or gas, McCullough says.

“It really is impossible to make that determination.” 

Wyoming Gilette coal pits NASA
The Gillette coal pits in Wyoming, one of the largest coal-producers in the U.S. Photo: NASA Earth Observatory

Neither the Canada Energy Regulator nor Statistics Canada could provide annual data on electricity imports and exports between B.C. and Alberta. 

But you can watch imports and exports in real time on this handy Alberta website, which also lists Alberta’s power sources. 

In 2018, California, Washington and Oregon supplied considerably more power to B.C. than other states, according to data from Canada Energy Regulator. 

Washington, where about one-quarter of generated power comes from fossil fuels, led the pack, with more than $339 million in electricity exports to B.C. 

California, which still gets more than half of its power from gas-fired plants even though it leads the U.S. in renewable energy with substantial investments in wind, solar and geothermal, was in second place, selling about $18.4 million worth of power to B.C. 

And Oregon, which produces about 43 per cent of its power from natural gas and six per cent from coal, exported about $6.2 million worth of electricity to B.C. last year. 

By comparison, Nebraska’s power exports to B.C. totalled about $1.6 million, Montana’s added up to $1.3 million,  Nevada’s were about $706,000 and Wyoming’s were about $346,000.

Clean electrons or dirty electrons?
Dan Woynillowicz, deputy director of Clean Energy Canada, which co-chaired the B.C. government’s Climate Solutions and Clean Growth Advisory Council, says B.C. typically exports power to other jurisdictions during peak demand. 

Gas-fired plants and hydro power can generate electricity quickly, while coal-fired power plants take longer to ramp up and wind power is variable, Woynillowicz notes. 

“When you need power fast and there aren’t many sources that can supply it you’re willing to pay more for it.”

Woynillowicz says “the odds are high” that B.C. power exports are displacing dirty power.

Elsewhere in Canada, analysts warn that Ontario's electricity could get dirtier as policies change, raising similar concerns.

“As a consumer you never know whether you’re getting a clean electron or a dirty electron. You’re just getting an electron.” 

 

Related News

View more

France Demonstrates the Role of Nuclear Power Plants

France Nuclear Power Strategy illustrates a low-carbon, reliable baseload complementing renewables in the energy transition, enhancing grid reliability, energy security, and emissions reduction, offering actionable lessons for Germany on infrastructure, policy, and public acceptance.

 

Key Points

France's nuclear strategy is a low-carbon baseload model supporting renewables, grid reliability, and energy security.

✅ Stable low-carbon baseload complements intermittent renewables

✅ Enhances grid reliability and national energy security

✅ Requires long-term investment, safety, and waste management

 

In recent months, France has showcased the critical role that nuclear power plants can play in an energy transition, offering valuable lessons for Germany and other countries grappling with their own energy challenges. As Europe continues to navigate its path towards a sustainable and reliable energy system, France's experience with nuclear energy underscores its potential benefits and the complexities involved, including outage risks in France that operators must manage effectively.

France, a long-time proponent of nuclear energy, generates about 70% of its electricity from nuclear power, making it one of the most nuclear-dependent countries in the world. This high reliance on nuclear energy has allowed France to maintain a stable and low-carbon electricity supply, which is increasingly significant as nations aim to reduce greenhouse gas emissions, even as Europe's nuclear capacity declines in several markets, and combat climate change.

Recent events in France have highlighted several key aspects of nuclear power's role in energy transition:

  1. Reliability and Stability: During periods of high renewable energy generation or extreme weather events, nuclear power plants have proven to be a stable and reliable source of electricity. Unlike solar and wind power, which are intermittent and depend on weather conditions, nuclear plants provide a consistent and continuous supply of power. This stability is crucial for maintaining grid reliability and ensuring that energy demand is met even when renewable sources are not producing electricity.

  2. Low Carbon Footprint: France’s commitment to nuclear energy has significantly contributed to its low carbon emissions. By relying heavily on nuclear power, France has managed to reduce its greenhouse gas emissions substantially compared to many other countries. This achievement is particularly relevant as Europe strives to meet ambitious climate targets, with debates over a nuclear option in Germany highlighting climate trade-offs, and reduce overall carbon footprints. The low emissions associated with nuclear power make it an important tool for achieving climate goals and transitioning away from fossil fuels.

  3. Energy Security: Nuclear power has played a vital role in France's energy security. The country’s extensive network of nuclear power plants ensures a stable and secure supply of electricity, reducing its dependency on imported energy sources. This energy security is particularly important in the context of global energy market fluctuations and geopolitical uncertainties. France’s experience demonstrates how nuclear energy can contribute to a nation’s energy independence and resilience.

  4. Economic Benefits: The nuclear industry in France also provides significant economic benefits. It supports thousands of jobs in construction, operation, and maintenance of power plants, as well as in the supply chain for nuclear fuel and waste management. Additionally, the stable and relatively low cost of nuclear-generated electricity can contribute to lower energy prices for consumers and businesses, enhancing economic stability.

Germany, in contrast, has been moving away from nuclear energy, particularly following the Fukushima disaster in 2011. The country has committed to phasing out its nuclear reactors by 2022 and focusing on expanding renewable energy sources such as wind and solar power. While Germany's renewable energy transition has made significant strides, it has also faced challenges related to grid stability, as Germany's energy balancing act illustrates for policymakers, energy storage, and maintaining reliable power supplies during periods of low renewable generation.

France’s experience with nuclear energy offers several lessons for Germany and other nations considering their own energy strategies:

  • Balanced Energy Mix: A diverse energy mix that includes nuclear power alongside renewable sources can help ensure a stable and reliable electricity supply, as ongoing discussions about a nuclear resurgence in Germany emphasize for policymakers today. While renewable energy is essential for reducing carbon emissions, it can be intermittent and may require backup from other sources to maintain grid reliability. Nuclear power can complement renewable energy by providing a steady and consistent supply of electricity.

  • Investment in Infrastructure: To maximize the benefits of nuclear energy, investment in infrastructure is crucial. This includes not only the construction and maintenance of power plants but also the development of waste management systems and safety protocols. France’s experience demonstrates the importance of long-term planning and investment to ensure the safe and effective use of nuclear technology.

  • Public Perception and Policy: Public perception of nuclear energy can significantly impact its adoption and deployment, and ongoing Franco-German nuclear disputes show how politics shape outcomes across borders. Transparent communication, rigorous safety standards, and effective waste management are essential for addressing public concerns and building trust in nuclear technology. France’s successful use of nuclear power is partly due to its emphasis on safety and regulatory compliance.

In conclusion, France's experience with nuclear power provides valuable insights into the role that this technology can play in an energy transition. By offering a stable, low-carbon, and reliable source of electricity, nuclear power complements renewable energy sources and supports overall energy security. As Germany and other countries navigate their energy transitions, France's example underscores the importance of a balanced energy mix, robust infrastructure, and effective public engagement in harnessing the benefits of nuclear power while addressing associated challenges, with industry voices such as Eon boss on nuclear debate underscoring the sensitivity of cross-border critiques.

 

Related News

View more

Cheap material converts heat to electricity

Polycrystalline Tin Selenide Thermoelectrics enable waste heat recovery with ZT 3.1, matching single crystals while cutting costs, powering greener car engines, industrial furnaces, and thermoelectric generators via p-type and emerging n-type designs.

 

Key Points

Low-cost tin selenide devices that turn waste heat into power, achieving ZT 3.1 and enabling p-type and n-type modules.

✅ Oxygen removal prevents heat-leaking tin oxide grain skins.

✅ Polycrystalline ingots match single-crystal ZT 3.1 at lower cost.

✅ N-type tin selenide in development to pair with p-type.

 

So-called thermoelectric generators turn waste heat into electricity without producing greenhouse gas emissions, providing what seems like a free lunch. But despite helping power the Mars rovers, the high cost of these devices has prevented their widespread use. Now, researchers have found a way to make cheap thermoelectrics that work just as well as the pricey kind. The work could pave the way for a new generation of greener car engines, industrial furnaces, and other energy-generating devices.

“This looks like a very smart way to realize high performance,” says Li-Dong Zhao, a materials scientist at Beihang University who was not involved with the work. He notes there are still a few more steps to take before these materials can become high-performing thermoelectric generators. However, he says, “I think this will be used in the not too far future.”

Thermoelectrics are semiconductor devices placed on a hot surface, like a gas-powered car engine or on heat-generating electronics using thin-film converters to capture waste heat. That gives them a hot side and a cool side, away from the hot surface. They work by using the heat to push electrical charges from one to the other, a process of turning thermal energy into electricity that depends on the temperature gradient. If a device allows the hot side to warm up the cool side, the electricity stops flowing. A device’s success at preventing this, as well as its ability to conduct electrons, feeds into a score known as the figure of merit, or ZT.

 Over the past 2 decades, researchers have produced thermoelectric materials with increasing ZTs, while related advances such as nighttime solar cells have broadened thermal-to-electric concepts. The record came in 2014 when Mercouri Kanatzidis, a materials scientist at Northwestern University, and his colleagues came up with a single crystal of tin selenide with a ZT of 3.1. Yet the material was difficult to make and too fragile to work with. “For practical applications, it’s a non-starter,” Kanatzidis says.

So, his team decided to make its thermoelectrics from readily available tin and selenium powders, an approach that, once processed, makes grains of polycrystalline tin selenide instead of the single crystals. The polycrystalline grains are cheap and can be heated and compressed into ingots that are 3 to 5 centimeters long, which can be made into devices. The polycrystalline ingots are also more robust, and Kanatzidis expected the boundaries between the individual grains to slow the passage of heat. But when his team tested the polycrystalline materials, the thermal conductivity shot up, dropping their ZT scores as low as 1.2.

In 2016, the Northwestern team discovered the source of the problem: an ultrathin skin of tin oxide was forming around individual grains of polycrystalline tin selenide before they were pressed into ingots. And that skin acted as an express lane for the heat to travel from grain to grain through the material. So, in their current study, Kanatzidis and his colleagues came up with a way to use heat to drive any oxygen away from the powdery precursors, leaving pristine polycrystalline tin selenide, whereas other devices can generate electricity from thin air using ambient moisture.

The result, which they report today in Nature Materials, was not only a thermal conductivity below that of single-crystal tin selenide but also a ZT of 3.1, a development that echoes nighttime renewable devices showing electricity from cold conditions. “This opens the door for new devices to be built from polycrystalline tin selenide pellets and their applications to be explored,” Kanatzidis says.

Getting through that door will still take some time. The polycrystalline tin selenide the team makes is spiked with sodium atoms, creating what is known as a “p-type” material that conducts positive charges. To make working devices, researchers also need an “n-type” version to conduct negative charges.

Zhao’s team recently reported making an n-type single-crystal tin selenide by spiking it with bromine atoms. And Kanatzidis says his team is now working on making an n-type polycrystalline version. Once n-type and p-type tin selenide devices are paired, researchers should have a clear path to making a new generation of ultra-efficient thermoelectric generators. Those could be installed everywhere from automobile exhaust pipes to water heaters and industrial furnaces to scavenge energy from some of the 65% of fossil fuel energy that winds up as waste heat. 

 

Related News

View more

Sign Up for Electricity Forum’s Newsletter

Stay informed with our FREE Newsletter — get the latest news, breakthrough technologies, and expert insights, delivered straight to your inbox.

Electricity Today T&D Magazine Subscribe for FREE

Stay informed with the latest T&D policies and technologies.
  • Timely insights from industry experts
  • Practical solutions T&D engineers
  • Free access to every issue

Live Online & In-person Group Training

Advantages To Instructor-Led Training – Instructor-Led Course, Customized Training, Multiple Locations, Economical, CEU Credits, Course Discounts.

Request For Quotation

Whether you would prefer Live Online or In-Person instruction, our electrical training courses can be tailored to meet your company's specific requirements and delivered to your employees in one location or at various locations.