Putting a light on bulbs

By Knoxville News Sentinel


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Not all sources of illumination are made equal... or cost the same.

Sometimes the best part of the day is coming home after a hard day's work, retiring to the den, getting comfortable in your favorite chair and curling up with your favorite book or newspaper.

But, alas, on this particular evening, the bulb in your lamp has gone out. A simple matter to replace it, right?

Wrong.

Light bulbs are now available in a variety of types, and they are not all created equal. Let's take the time to learn more about the science behind what makes the different light bulbs work and consider which one is the most cost-efficient to operate.

But first we need to consider something much more basic: the atom.

There are three major types of light bulbs available today: incandescent, halogen and fluorescent. While there are differences in the mechanics and economics of these bulbs, they all operate on the same basic principle: exciting atoms.

The most basic and fundamental model of the atom describes a positively charged nucleus of protons and neutrons surrounded by negatively charged electrons that travel in distinct orbital shells around the nucleus.

Conceptually, it is similar to a model of the planets of the solar system orbiting the sun, but electrostatic forces, not gravity, are at work in the realm of the atom.

While modern physics now describes a very different and exotic subatomic world, this basic model will serve our purposes.

Electrons with greater energy "orbit" farther from the nucleus of an atom. When atoms gain or lose energy, it is often expressed by the movement of electrons from one orbital shell to another.

When an atom gains energy, an electron may be temporarily bumped to a higher orbit. It then almost immediately returns to its original shell, releasing energy in the form of a photon - light.

This is the basic mechanism behind all light sources. What differs is how and to what extreme the electrons are excited.

In the 19th century, Sir Joseph Swan (1878) and Thomas Edison (1879) were independently able to take the relatively new science of electricity and use it to generate artificial light. Within 25 years, millions of people around the world had installed electric lighting.

Surprisingly, its basic design has not changed drastically during the past 130 years.

A light bulb has two metal contacts, called the foot contact and the thread-screw contact, at its base, connecting the bulb to an electric circuit. The metal contacts are connected via two stiff wires to the filament. This is all housed within a glass bulb filled with an inert (inactive) gas, typically argon.

When the electric circuit is activated, the current flows from one contact to the other through the wires and filament. This heats the atoms in the filament, causing the bound (noncurrent) electrons to jump to higher energy levels, and then back to their normal levels, releasing photons of light in the process.

In order for a light bulb to generate photons in the visible range, the filament must be heated to 2,200 degrees Celsius (4,000 degrees Fahrenheit).

The filament is made of tungsten metal, averaging 2 meters (6.5 feet) in length wrapped in a double coil. Yet it is only 1/100th of an inch thick. Tungsten is used because it has a high melting point; that is, most metals would simply melt before reaching the temperatures necessary to produce visible light.

However, tungsten combusts at high temperatures, so the chamber of a light bulb is devoid of oxygen. And while the first light bulbs simply surrounded the filament with a vacuum, today the chamber is filled with an inert gas to slow down the evaporation of the tungsten filament.

When a heated tungsten atom vibrates fast enough to actually leave the filament, it collides with the argon atoms and bounces back toward the filament, rejoining the solid structure.

Bulbs burn out when the evaporation of the tungsten eventually creates a weak spot in the filament.

Incandescent bulbs are very inefficient, with most of the energy being lost in the form of heat (infrared photons). Only about 10 percent of the light produced is actually in the visible spectrum.

Halogen bulbs also utilize a tungsten filament, but it is encased in a smaller quartz envelope. Quartz is used because the closer proximity to the filament would actually melt the housing were it made of glass.

It is the type of gas that surrounds the filament that really makes halogen bulbs different. Instead of an inert gas, halogens (reactive, nonmetallic elements) are used. They actually combine with the tungsten vapor as it evaporates and redeposit the tungsten on the filament.

This recycling allows the filament to last longer.

Halogen bulbs also run hotter, allowing them to give off more visible light per unit of energy, making them more efficient than incandescent bulbs.

Warning: Because the quartz envelope is so close to the hotter-burning filament, halogen bulbs are very hot during and immediately after use. Great care should be used in handling them.

Fluorescent bulbs do not have a filament. Rather, they are composed of a sealed glass tube containing a little mercury and an inert gas, usually argon, under very low pressure. The inside of the tube itself is coated with a fluorescent powder (a blend of metallic and rare-earth phosphor salts). Electrodes are located at each end of the tube, connecting the apparatus to an electric circuit.

When the circuit is turned on, the current flows to the electrodes, yielding a voltage (electrical potential difference) across the two electrodes. As a result, electrons migrate from one end of the tube to the other. This energy causes some of the mercury in the tube to become a gas.

Electrons traveling through the tube then collide with the mercury vapor, exciting the atoms and bumping electrons to a higher energy level.

With mercury, however, photons are released in the ultraviolet range when the electrons return to their original states. This is beyond the sensitivity of our eyes.

So how does a fluorescent bulb generate visible light?

When ultraviolet photons from the mercury atoms strike the tube's phosphor coating, those atoms become excited, and they release photons in the lower-energy visible range. The remainder of the energy is lost as heat.

The color of the emitted light is controlled by the mixture of phosphors.

Therefore, unlike incandescent and halogen bulbs that operate by heating a tungsten filament, fluorescent bulbs require a multi-step process to generate visible light.

Because they are not using heat to generate light, a typical fluorescent bulb is much more efficient than an incandescent bulb, which loses so much of its energy to heat.

However, note that because of the mercury and phosphor, fluorescent bulbs cannot be discarded with regular household waste. Recycling of the tubes is highly recommended.

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Climate change: Electrical industry's 'dirty secret' boosts warming

Sulphur Hexafluoride (SF6) Emissions drive rising greenhouse gas impacts in electrical switchgear, power grids, and renewables, with extreme global warming potential, long atmospheric lifetime, and leakage risks challenging climate targets and grid decarbonization.

 

Key Points

SF6 emissions are leaks from electrical switchgear and grids, a high-GWP gas with ~1,000-year lifetime.

✅ 23,500x CO2 global warming potential (GWP)

✅ Leaks from switchgear, breakers, gas-insulated substations

✅ Clean air and vacuum alternatives emerging for MV/HV

 

Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road.

Levels are rising as an unintended consequence of the green energy boom and the broader global energy transition worldwide.

Cheap and non-flammable, SF6 is a colourless, odourless, synthetic gas. It makes a hugely effective insulating material for medium and high-voltage electrical installations.

It is widely used across the industry, from large power stations to wind turbines to electrical sub-stations in towns and cities.

It prevents electrical accidents and fires.

However, the significant downside to using the gas is that it has the highest global warming potential of any known substance. It is 23,500 times more warming than carbon dioxide (CO2).

Just one kilogram of SF6 warms the Earth to the same extent as 24 people flying London to New York return.

It also persists in the atmosphere for a long time, warming the Earth for at least 1,000 years.

 

So why are we using more of this powerful warming gas?

The way we make electricity around the world is changing rapidly, with New Zealand's push to electrify in its energy system.

Where once large coal-fired power stations brought energy to millions, the drive to combat climate change and to move away from coal means they are now being replaced by mixed sources of power including wind, solar and gas.

This has resulted in many more connections to the electricity grid, and with EU electricity use could double by 2050, a rise in the number of electrical switches and circuit breakers that are needed to prevent serious accidents.

Collectively, these safety devices are called switchgear. The vast majority use SF6 gas to quench arcs and stop short circuits.

"As renewable projects are getting bigger and bigger, we have had to use it within wind turbines specifically," said Costa Pirgousis, an engineer with Scottish Power Renewables on its new East Anglia wind farm, which doesn't use SF6 in turbines.

"As we are putting in more and more turbines, we need more and more switchgear and, as a result, more SF6 is being introduced into big turbines off shore.

"It's been proven for years and we know how it works, and as a result it is very reliable and very low maintenance for us offshore."

 

How do we know that SF6 is increasing?

Across the entire UK network of power lines and substations, there are around one million kilograms of SF6 installed.

A study from the University of Cardiff found that across all transmission and distribution networks, the amount used was increasing by 30-40 tonnes per year.

This rise was also reflected across Europe with total emissions from the 28 member states in 2017 equivalent to 6.73 million tonnes of CO2. That's the same as the emissions from 1.3 million extra cars on the road for a year.

Researchers at the University of Bristol who monitor concentrations of warming gases in the atmosphere say they have seen significant rises in the last 20 years.

"We make measurements of SF6 in the background atmosphere," said Dr Matt Rigby, reader in atmospheric chemistry at Bristol.

"What we've seen is that the levels have increased substantially, and we've seen almost a doubling of the atmospheric concentration in the last two decades."

 

How does SF6 get into the atmosphere?

The most important means by which SF6 gets into the atmosphere is from leaks in the electricity industry.

Electrical company Eaton, which manufactures switchgear without SF6, says its research indicates that for the full life-cycle of the product, leaks could be as high as 15% - much higher than many other estimates.

Louis Schaeffer, electrical business manager at Eaton, said: "The newer gear has very low leak rates but the key question is do you have newer gear?

"We looked at all equipment and looked at the average of all those leak rates, and we didn't see people taking into account the filling of the gas. Plus, we looked at how you recycle it and return it and also included the catastrophic leaks."

 

How damaging to the climate is this gas?

Concentrations in the atmosphere are very small right now, just a fraction of the amount of CO2 in the air.

However, the global installed base of SF6 is expected to grow by 75% by 2030, as data-driven electricity demand surges worldwide.

Another concern is that SF6 is a synthetic gas and isn't absorbed or destroyed naturally. It will all have to be replaced and destroyed to limit the impact on the climate.

Developed countries are expected to report every year to the UN on how much SF6 they use, but developing countries do not face any restrictions on use.

Right now, scientists are detecting concentrations in the atmosphere that are 10 times the amount declared by countries in their reports. Scientists say this is not all coming from countries like India, China and South Korea.

One study found that the methods used to calculate emissions in richer countries "severely under-reported" emissions over the past two decades.

 

Why hasn't this been banned?

SF6 comes under a group of human-produced substances known as F-gases. The European Commission tried to prohibit a number of these environmentally harmful substances, including gases in refrigeration and air conditioning, back in 2014.

 

But they faced strong opposition from industries across Europe.

"In the end, the electrical industry lobby was too strong and we had to give in to them," said Dutch Green MEP Bas Eickhout, who was responsible for the attempt to regulate F-gases.

"The electric sector was very strong in arguing that if you want an energy transition, and you have to shift more to electricity, you will need more electric devices. And then you also will need more SF6.

"They used the argument that otherwise the energy transition would be slowed down."

 

What do regulator and electrical companies say about the gas?

Everyone is trying to reduce their dependence on the gas, and US control efforts suggest targeted policies can drive declines, as it is universally recognised as harmful to the climate.

In the UK, energy regulator Ofgem says it is working with utilities to try to limit leaks of the gas.

"We are using a range of tools to make sure that companies limit their use of SF6, a potent greenhouse gas, where this is in the interest of energy consumers," an Ofgem spokesperson told BBC News.

"This includes funding innovation trials and rewarding companies to research and find alternatives, setting emissions targets, rewarding companies that beat those targets, and penalising those that miss them."

 

Are there alternatives - and are they very expensive?

The question of alternatives to SF6 has been contentious over recent years.

For high-voltage applications, experts say there are very few solutions that have been rigorously tested.

"There is no real alternative that is proven," said Prof Manu Haddad from the school of engineering at Cardiff University.

"There are some that are being proposed now but to prove their operation over a long period of time is a risk that many companies don't want to take."

Medium voltage operations there are several tried-and-tested materials. Some in the industry say that the conservative nature of the electrical industry is the key reason that few want to change to a less harmful alternative.

 

"I will tell you, everyone in this industry knows you can do this; there is not a technical reason not to do it," said Louis Schaffer from Eaton.

"It's not really economic; it's more a question that change takes effort and if you don't have to, you won't do it."

 

Some companies are feeling the winds of change

Sitting in the North Sea some 43km from the Suffolk coast, Scottish Power Renewables has installed one of world's biggest wind farms, in line with a sustainable electric planet vision, where the turbines will be free of SF6 gas.

East Anglia One will see 102 of these towering generators erected, with the capacity to produce up to 714MW (megawatts) of power by 2020, enough to supply half a million homes.

Previously, an installation like this would have used switchgear supplied with SF6, to prevent the electrical accidents that can lead to fires.

Each turbine would normally have contained around 5kg of SF6, which, if it leaked into the atmosphere, would add the equivalent of around 117 tonnes of carbon dioxide. This is roughly the same as the annual emissions from 25 cars.

"In this case we are using a combination of clean air and vacuum technology within the turbine. It allows us to still have a very efficient, reliable, high-voltage network but to also be environmentally friendly," said Costa Pirgousis from Scottish Power Renewables.

"Once there are viable alternatives on the market, there is no reason not to use them. In this case, we've got a viable alternative and that's why we are using it."

But even for companies that are trying to limit the use of SF6, there are still limitations. At the heart of East Anglia One sits a giant offshore substation to which all 102 turbines will connect. It still uses significant quantities of the highly warming gas.

 

What happens next ?

The EU will review the use of SF6 next year and will examine whether alternatives are available. However, even the most optimistic experts don't think that any ban is likely to be put in place before 2025.

 

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Does Providing Electricity To The Poor Reduce Poverty? Maybe Not

Rural Electrification Poverty Impact examines energy access, grid connections, and reliability, testing economic development claims via randomized trials; findings show minimal gains without appliances, reliable supply, and complementary services like education and job creation initiatives.

 

Key Points

Study of household grid connections showing modest poverty impact without reliable power and appliances.

✅ Randomized grid connections showed no short-term income gains.

✅ Low reliability and few appliances limited electricity use.

✅ Complementary investments in jobs, education, health may be needed.

 

The head of Swedfund, the development finance group, recently summarized a widely-held belief: “Access to reliable electricity drives development and is essential for job creation, women’s empowerment and combating poverty.” This view has been the driving force behind a number of efforts to provide electricity to the 1.1 billion people around the world living in energy poverty, such as India's village electrification initiatives in recent years.

But does electricity really help lift households out of poverty? My co-authors and I set out to answer this question. We designed an experiment in which we first identified a sample of “under grid” households in Western Kenya—structures that were located close to but not connected to a grid. These households were then randomly divided into treatment and control groups. In the treatment group, we worked closely with the rural electrification agency to connect the households to the grid for free or at various discounts. In the control group, we made no changes. After eighteen months, we surveyed people from both groups and collected data on an assortment of outcomes, including whether they were employed outside of subsistence agriculture (the most common type of work in the region) and how many assets they owned. We even gave children basic tests, as a frequent assertion is that electricity helps children perform better in school since they are able to study at night.

When we analyzed the data, we found no differences between the treatment and control groups. The rural electrification agency had spent more than $1,000 to connect each household. Yet eighteen months later, the households we connected seemed to be no better off. Even the children’s test scores were more or less the same. The results of our experiment were discouraging, and at odds with the popular view that supplying households with access to electricity will drive economic development. Lifting people out of poverty may require a more comprehensive approach to ensure that electricity is not only affordable (with some evidence that EV growth can benefit all customers in mature markets), but is also reliable, useable, and available to the whole community, paired with other important investments.

For instance, in many low-income countries, the grid has frequent blackouts and maintenance problems, making electricity unreliable, as seen in Nigeria's electricity crisis in recent years. Even if the grid were reliable, poor households may not be able to afford the appliances that would allow for more than just lighting and cell phone charging. In our data, households barely bought any appliances and they used just 3 kilowatt-hours per month. Compare that to the U.S. average of 900 kilowatt-hours per month, a figure that could rise as EV adoption increases electricity demand over time.

There are also other factors to consider. After all, correlation does not equal causation. There is no doubt that the 1.1 billion people without power are the world’s poorest citizens. But this is not the only challenge they face. The poor may also lack running water, basic sanitation, consistent food supplies, quality education, sufficient health care, political influence, and a host of other factors that may be harder to measure but are no less important to well-being. Prioritizing investments in some of these other factors may lead to higher immediate returns. Previous work by one of my co-authors, for example, shows substantial economic gains from government spending on treatment for intestinal worms in children.

It’s possible that our results don’t generalize. They certainly don’t apply to enhancing electricity services for non-residential customers, like factories, hospitals, and schools, and electric utilities adapting to new load patterns. Perhaps the households we studied in Western Kenya are particularly poor (although measures of well-being suggest they are comparable to rural households across Sub-Saharan Africa) or politically disenfranchised. Perhaps if we had waited longer, or if we had electrified an entire region, the household impacts we measured would have been much greater. But others who have studied this question have found similar results. One study, also conducted in Western Kenya, found that subsidizing solar lamps helped families save on kerosene, but did not lead children to study more. Another study found that installing solar-powered microgrids in Indian villages resulted in no socioeconomic benefits.

 

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Prepare for blackouts across the U.S. as summer takes hold

US Summer Grid Blackout Risk: NERC and FERC warn of strained reliability as drought, heat waves, and transmission constraints hit MISO, hydro, and renewables, elevating blackout exposure and highlighting demand response and storage solutions.

 

Key Points

A forecast of summer power shortfalls across the US grid, driven by heat, drought, transmission limits, and a changing resource mix.

✅ NERC and FERC warn of elevated blackout risk and reliability gaps.

✅ MISO region strained by drought, heat, and limited hydro.

✅ Mitigations: demand response, storage, and stronger transmission.

 

Just when it didn’t seem things couldn’t get worse — gasoline at $5 to $8 a gallon, supply shortages in everything from baby formula to new cars — comes the devastating news that many of us will endure electricity blackouts this summer, and that the U.S. has more blackouts than other developed nations according to one study.

The alarm was sounded by the nonprofit North American Electric Reliability Corp. and the Federal Energy Regulatory Commission, following a recent power grid report card highlighting vulnerabilities.

The North American electric grid is the largest machine on earth and the most complex, incorporating everything from the wonky pole you see at the roadside with a bird’s nest of wires to some of the most sophisticated engineering ever devised. It runs in real-time, even more so than the air traffic control system: All the airplanes in the sky don’t have to land at the same time, but electricity must be there at the flick of every switch.

Except it may not always be there this summer. Rod Kuckro, a respected energy journalist, says it depends on Mother Nature, with extreme weather impacts increasingly straining the grid, but the prognosis isn’t good.

Speaking on “White House Chronicle,” the weekly news and public affairs program on PBS that I host and produce, Kuckro said: “There is a confluence of factors that could affect energy supply across the majority of the (lower) 48 states. These are continued reduced hydroelectric production in the West, and the continued drought in the Southwest.”

The biggest threat to power supply, according to the NERC and the FERC, is in the vast central region, reaching from Manitoba in Canada, where grids are increasingly exposed to harsh weather in recent years, down to the Gulf of Mexico. It is served by the regional transmission organization, the Midcontinent Independent System Operator.

These operational entities are nonprofit companies that organize and distribute their regions’ bulk power for utilities. In California, it is the California Independent System Operator, working to keep the lights on as the state enters a new energy era; in the Mid-Atlantic, it is PJM; and in the Northeast, it is the New England System Independent Operator. They generate no power, but they control power flows and could initiate brownouts and blackouts.

With record storm activity and high temperatures predicted this summer, blackouts are likely to be deadly. The old, the young and the sick are all vulnerable. If the electric supply fails, with it goes everything from air conditioning to refrigeration to lights and even the ability to pump gas or access money from ATMs.

The United States, along with other modern nations, runs on electricity and when that falls short, it is catastrophic. It is chaos writ large, especially if the failure lasts more than a few hours.

On the same episode of “White House Chronicle,” Daniel Brooks, vice president of integrated grid and energy systems at the Electric Power Research Institute, also referred to a “confluence of factors” contributing to the impending electricity crisis. Brooks said, “We’re going through a significant change in terms of the energy mix and resources, and the way those resources behave under certain weather conditions.”

If power supply is stressed this summer, change in the generating mix will get a lot of political attention. At heart is the switch from fossil fuel generation to renewables. If there are power outages, a political storm will ensue. The Biden administration will be accused of speeding the switch to renewables, although the utilities don’t say that.

The weather is deteriorating, and, as experts note, the grid’s biggest challenge isn’t demand but climate change pressures that compound risks, and the grid is stretched in dealing with new realities as well as coping with old bugaboos, like the extreme difficulty in building transmission lines. Better transmission would relieve a lot of grid stress.

Peter Londa, president of Tantalus Systems, which helps its 260 utility customers digitize and cope with the new realities, explained some of the difficulties facing the utilities not only in the shifting sources of generation but also in the new shape of the electric demand. For example, he said, electric vehicles, particularly the much-awaited Ford F-150 Lightning pickup, could be an asset to homeowners and utilities, as California increasingly turns to batteries to stabilize its grid. During a blackout, their EVs could be used to power their homes for days. They could be a source of storage if thousands of owners signed up with their utilities in a storage program.

The fact is that utilities are facing three major shifts: in the generation to wind and solar, in customer demand, and especially in weather. Mother Nature is on a rampage and we all must adjust to that.
 

 

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COVID-19 Response: Electric Power Industry Closely Coordinating With Federal Partners

ESCC COVID-19 Response coordinates utilities, public power, and cooperatives to protect the energy grid and electricity reliability, aligning with DOE, DHS, CDC, FERC, and NERC on continuity of operations, mutual assistance, and supply chain resilience.

 

Key Points

An industry government effort ensuring reliability, operations continuity and supply chain stability during COVID-19.

✅ Twice weekly ESCC calls align DOE, DHS, HHS, CDC, FERC, NERC priorities.

✅ Focus on control centers, generation, quarantine access, mutual aid.

✅ Resource Guide supports localized decisions and supply chain resilience.

 

The nation’s investor-owned electric companies, public power utilities, and electric cooperatives are working together to protect the energy grid as the U.S. grid addresses COVID-19 challenges and ensure continued access to safe and reliable electricity during the COVID-19 global health crisis.

The electric power industry has been planning for years, including extensive disaster planning across utilities, for an emergency like the COVID-19 pandemic, as well as countless other types of emergencies, and the industry is coordinating closely with government partners through the Electricity Subsector Coordinating Council (ESCC) to ensure that organizations have the resources they need to keep the lights on.

The ESCC is holding high-level coordination calls twice a week with senior leadership from the Departments of Energy, Homeland Security, and Health and Human Services, the Centers for Disease Control and Prevention, the Federal Energy Regulatory Commission, and the North American Electric Reliability Corporation. These calls help ensure that industry and government work together to resolve any challenges that arise during this health emergency and that electricity remains safe for customers.

“Electricity and the energy grid are indispensable to our society, and one of our greatest strengths as an industry is our ability to convene and adapt quickly to changing circumstances and challenging events,” said Edison Electric Institute President Tom Kuhn. “Our industry plans for all types of contingencies, with examples such as local response planning, and strong industry-government coordination and cross-sector collaboration are critical to our planning and response. We appreciate the ongoing leadership and support of our government partners as we all respond to COVID-19 and power through this crisis together.”

The ESCC quickly mobilized and established strategic working groups dedicated to identifying and solving for short-, medium-, and long-term issues facing the industry during the COVID-19 pandemic, with utilities implementing necessary precautions to maintain service across regions.

The five current areas of focus are:

1. Continuity of operations at control centers, including on-site staff lockdowns when needed
2. Continuity of operations at generation facilities
3. Access to, and operations in, restricted or quarantined areas
4. Protocols for mutual assistance
5. Supply chain challenges

“The electric power industry has taken steps to prepare for the evolving coronavirus challenges, while maintaining our commitment to the communities we serve, including customer relief efforts announced by some providers,” said National Rural Electric Cooperative Association CEO Jim Matheson. “We have a strong track record of preparing for many kinds of emergencies that could impact the ability to generate and deliver electricity. While planning for this situation is unique from other business continuity planning, we are taking actions to prepare to operate with a smaller workforce, potential disruptions in the supply chain, and limited support services for an extended period of time.”

The ESCC has developed a COVID-19 Resource Guide linked here and available at electricitysubsector.org. This document was designed to support electric power industry leaders in making informed localized decisions in response to this evolving health crisis. The guide will evolve as additional recommended practices are identified and as more is learned about appropriate mitigation strategies.

“The American Public Power Association (APPA) continues to work with our communityowned public power members and our industry and government partners to gather and share upto-date information, best practices, and guidance to support them in safely maintaining operational integrity,” said APPA CEO Joy Ditto.

 

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A new approach finds materials that can turn waste heat into electricity

Thermoelectric Materials convert waste heat into electricity via the Seebeck effect; quantum computations and semiconductors accelerate discovery, enabling clean energy, higher efficiency, and scalable heat-to-power conversion from abundant, non-toxic, cost-effective compounds.

 

Key Points

Thermoelectric materials turn waste heat into electricity via the Seebeck effect, improving energy efficiency.

✅ Convert waste heat to electricity via the Seebeck effect

✅ Quantum computations rapidly identify high-performance candidates

✅ Target efficient, low-thermal-conductivity, non-toxic, abundant compounds

 

The need to transition to clean energy is apparent, urgent and inescapable. We must limit Earth’s rising temperature to within 1.5 C to avoid the worst effects of climate change — an especially daunting challenge in the face of the steadily increasing global demand for energy and the need for reliable clean power, with concepts that can generate electricity at night now being explored worldwide.

Part of the answer is using energy more efficiently. More than 72 per cent of all energy produced worldwide is lost in the form of heat, and advances in turning thermal energy into electricity could recover some of it. For example, the engine in a car uses only about 30 per cent of the gasoline it burns to move the car. The remainder is dissipated as heat.

Recovering even a tiny fraction of that lost energy would have a tremendous impact on climate change. Thermoelectric materials, which convert wasted heat into useful electricity, can help, especially as researchers pursue low-cost heat-to-electricity materials for scalable deployment.

Until recently, the identification of these materials had been slow. My colleagues and I have used quantum computations — a computer-based modelling approach to predict materials’ properties — to speed up that process and identify more than 500 thermoelectric materials that could convert excess heat to electricity, and help improve energy efficiency.


Making great strides towards broad applications
The transformation of heat into electrical energy by thermoelectric materials is based on the “Seebeck effect.” In 1826, German physicist Thomas Johann Seebeck observed that exposing the ends of joined pieces of dissimilar metals to different temperatures generated a magnetic field, which was later recognized to be caused by an electric current.

Shortly after his discovery, metallic thermoelectric generators were fabricated to convert heat from gas burners into an electric current. But, as it turned out, metals exhibit only a low Seebeck effect — they are not very efficient at converting heat into electricity.

In 1929, the Russian scientist Abraham Ioffe revolutionized the field of thermoelectricity. He observed that semiconductors — materials whose ability to conduct electricity falls between that of metals (like copper) and insulators (like glass) — exhibit a significantly higher Seebeck effect than metals, boosting thermoelectric efficiency 40-fold, from 0.1 per cent to four per cent.

This discovery led to the development of the first widely used thermoelectric generator, the Russian lamp — a kerosene lamp that heated a thermoelectric material to power a radio.


Are we there yet?
Today, thermoelectric applications range from energy generation in space probes to cooling devices in portable refrigerators, and include emerging thin-film waste-heat harvesters for electronics as well. For example, space explorations are powered by radioisotope thermoelectric generators, converting the heat from naturally decaying plutonium into electricity. In the movie The Martian, for example, a box of plutonium saved the life of the character played by Matt Damon, by keeping him warm on Mars.

In the 2015 film, The Martian, astronaut Mark Watney (Matt Damon) digs up a buried thermoelectric generator to use the power source as a heater.

Despite this vast diversity of applications, wide-scale commercialization of thermoelectric materials is still limited by their low efficiency.

What’s holding them back? Two key factors must be considered: the conductive properties of the materials, and their ability to maintain a temperature difference, as seen in nighttime electricity from cold concepts, which makes it possible to generate electricity.

The best thermoelectric material would have the electronic properties of semiconductors and the poor heat conduction of glass. But this unique combination of properties is not found in naturally occurring materials. We have to engineer them, drawing on advances such as carbon nanotube energy harvesters to guide design choices.

Searching for a needle in a haystack
In the past decade, new strategies to engineer thermoelectric materials have emerged due to an enhanced understanding of their underlying physics. In a recent study in Nature Materials, researchers from Seoul National University, Aachen University and Northwestern University reported they had engineered a material called tin selenide with the highest thermoelectric performance to date, nearly twice that of 20 years ago. But it took them nearly a decade to optimize it.

To speed up the discovery process, my colleagues and I have used quantum calculations to search for new thermoelectric candidates with high efficiencies. We searched a database containing thousands of materials to look for those that would have high electronic qualities and low levels of heat conduction, based on their chemical and physical properties. These insights helped us find the best materials to synthesize and test, and calculate their thermoelectric efficiency.

We are almost at the point where thermoelectric materials can be widely applied, but first we need to develop much more efficient materials. With so many possibilities and variables, finding the way forward is like searching for a tiny needle in an enormous haystack.

Just as a metal detector can zero in on a needle in a haystack, quantum computations can accelerate the discovery of efficient thermoelectric materials. Such calculations can accurately predict electron and heat conduction (including the Seebeck effect) for thousands of materials and unveil the previously hidden and highly complex interactions between those properties, which can influence a material’s efficiency.

Large-scale applications will require themoelectric materials that are inexpensive, non-toxic and abundant. Lead and tellurium are found in today’s thermoelectric materials, but their cost and negative environmental impact make them good targets for replacement.

Quantum calculations can be applied in a way to search for specific sets of materials using parameters such as scarcity, cost and efficiency, and insights can even inform exploratory devices that generate electricity out of thin air in parallel fields. Although those calculations can reveal optimum thermoelectric materials, synthesizing the materials with the desired properties remains a challenge.

A multi-institutional effort involving government-run laboratories and universities in the United States, Canada and Europe has revealed more than 500 previously unexplored materials with high predicted thermoelectric efficiency. My colleagues and I are currently investigating the thermoelectric performance of those materials in experiments, and have already discovered new sources of high thermoelectric efficiency.

Those initial results strongly suggest that further quantum computations can pinpoint the most efficient combinations of materials to make clean energy from wasted heat and the avert the catastrophe that looms over our planet.

 

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BC Hydro to begin reporting COVID-19 updates at Site C

BC Hydro COVID-19 Site C updates detail monitoring, self-isolation at the work camp, Northern Health coordination, social distancing, reduced staffing, progress on diversion tunnels, Highway 29 realignment, and public reports to Peace River Regional District.

 

Key Points

Regular reports on COVID-19 monitoring, isolation protocols, staffing, and Site C work with Northern Health.

✅ Daily updates to Peace River Regional District

✅ Isolation rooms reserved in camp dorms

✅ Construction continues with social distancing

 

BC Hydro says it will begin giving regular updates to the public and the Peace River Regional District about its monitoring of the coronavirus COVID-19 at Site C, reflecting broader industry alerts such as a U.S. grid warning on pandemic risks.

BC Hydro met with the Peace River Regional District Sunday via phone call to discuss the forthcoming measures.

"We did a make a commitment to provide regular updates to Peace River Regional District member communities on an ongoing basis," said spokesman Dave Conway.

"(It's) certainly one of the things that we heard that they want and we heard that strongly and repeatedly."

Conway said updates could be posted as early as Monday on BC Hydro's website for the project.

As of March 23, there were sixteen people in self-isolation at the work camp just outside Fort St. John. Conway did not know how many of the workers have been tested for the virus, but said there are no confirmed cases on site. Provincial guidelines are being followed, he said.

"If they show any of the following symptoms, so sneezing, sore throat, muscle aches, headaches, coughs, or difficulty breathing, they're isolated for 14 days," Conway said.

"We're being very cautious of our application of the guidelines. We're asking anybody to self isolate if they have any slight symptoms."

BC Hydro has set aside one 30-room dorm at the camp for workers who need to isolate themselves, similar to measures in other jurisdictions where the power industry may house staff on-site to maintain operations, and has another four dorms with another 120 rooms that can be used as necessary. Conway could not immediately say whether additional rooms at hotels or at its apartment block have also been reserved.

There have been  700 workers home since a scale-back in construction was announced on March 18, and more workers are expected to be sent home this week. There were 940 people in camp on March 23, Conway said.

"To put that into perspective, the number of people staying in camp at this time of year, based on previous years, usually averages around 1,700," Conway said.

Brad Sperling, board chair for the Peace River Regional District, said BC Hydro has committed to formulating a strategy over the next few days to keep local government and public informed.

Electoral director Karen Goodings said she was pleased by that, and that it's important to everyone that BC Hydro works with Northern Health and adheres to provincial guidelines.

"The senior governments are critical to what measures will be undertaken not only on the project, including the camp, but also on the rules around transportation of workers and on addressing workplace conduct investigations at other utilities," Goodings wrote in an email.

On Sunday, the Site C leisure bus was seen at Totem Mall with two passengers on board.

Conway said the ongoing use of the shuttle is being monitored and evaluated, and is operating under social distancing and extra cleaning guidelines aligned with public transportation changes that have come under BC Transit.

The bus makes 10 trips per day from the camp, with an average of two passengers per trip, Conway said.

"We still have, of course, people in camp, and it's an opportunity for guests to get out and go for a walk and re-provision themselves for essentials for personal needs," Conway said.

Construction of the river diversion tunnels continues to meet a fall deadline, while work also carries on to realign Highway 29, build the transmission line, and clear the valley and future reservoir. Other site security and environmental monitoring work also continues, as utilities confront a dangerous dam-climbing trend driven by social media.

BC Hydro has said measures have been put into place, amid concerns similar to those voiced by nuclear plant workers about precautions at industrial sites, to minimize the potential spread of the COVID-19 on site, such as closing the camp gym and theatre, eliminating self serve dining stations, as well as non-essential travel, tours, and meetings.

Some workers, however, have raised worries about the tight working conditions on site, noting field safety incidents that highlight risks in the sector.

The province announced Monday 48 new cases in B.C., including one more in the Northern Health region, bringing the region's total to five, while Saskatchewan's numbers show how the crisis has reshaped that province. Their precise whereabouts are not being reported by B.C. public health officials.

 

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