The brains of BC Transmission

BC Hydro COVID-19 Relief offers electricity bill credits for laid-off workers and small business support, announced by Premier John Horgan, while FortisBC customers face deferrals and billing arrangements across Kelowna, Okanagan, and West Kootenay.

Key Points

BC Hydro COVID-19 Relief gives bill credits to laid-off residents; FortisBC offers deferrals and payment plans.

✅ Credit equals 3x average monthly bill for laid-off BC Hydro users

✅ Small businesses on BC Hydro get three months bill forgiveness

✅ FortisBC waives late fees, no disconnections, offers deferrals

On April 1, B.C. Premier John Horgan announced relief for BC Hydro customers who are facing bills after being laid-off during the economic shutdown due to the COVID-19 epidemic, while the utility also explores time-of-use rates to manage demand.

“Giving people relief on their power bills lets them focus on the essentials, while helping businesses and encouraging critical industry to keep operating,” he said.

BC Hydro residential customers in the province who have been laid off due to the pandemic will see a credit for three times their average monthly bill and, similar to Ontario's pandemic relief fund, small businesses forced to close will have power bills forgiven for three months.

But a large region of the province which gets its power from FortisBC will not have the same bail out.

FortisBC is the electricity provider to the tens of thousands who live and work in the Silmikameen Valley on Highway 3, the city of Kelowna, the Okanagan Valley south from Penticton, the Boundary region along the U.S. border. as well as West Kootenay communities.

“We want to make sure our customers are not worried about their FortisBC bill,” spokesperson Nicole Brown said.

FortisBC customers will still be on the hook for bills despite measures being taken to keep the lights on, even as winter disconnection pressures have been reported elsewhere.

Recent storm response by BC Hydro also highlights how crews have kept electricity service reliable during recent atypical events.

“We’ve adjusted our billing practices so we can do more,” she said. “We’ve discontinued our late fees for the time being and no customer will be disconnected for any financial reason.”

Brown said they will work one-on-one with customers to help find a billing arrangement that best suits their needs, aligning with disconnection moratoriums seen in other jurisdictions.

Those arrangement, she said, could include a “deferral, an equal payment plan or other billing options,” similar to FortisAlberta's precautions announced in Alberta.

Global News inquired with the Premier’s office why FortisBC customers were left out of Wednesday’s announcement and were deferred to the Ministry of Energy, Mines and Petroleum Resources.

The Ministry referred us back to FortisBC on the issue and offered no other comment, even as peak rates for self-isolating customers remained unchanged in parts of Ontario.

“We’re examining all options of how we can further help our customers and look forward to learning more about the program that BC Hydro is offering,” Brown said.

Disappointed FortisBC customers took to social media to vent about the disparity.

Related News

• Electricity Forum News

• Utility Operations News

Rooftop solar grids transform urban infrastructure with distributed generation, photovoltaic panels, smart grid integration and energy storage, cutting greenhouse gas emissions, lowering utility costs, enabling net metering and community solar for low-carbon energy systems.

Key Points

Rooftop solar grids are PV systems on buildings that generate power, cut emissions, and enable smart grid integration.

✅ Lowers utility bills via net metering and demand offset

✅ Reduces greenhouse gases and urban air pollution

✅ Enables resiliency with storage, smart inverters, and microgrids

As urban areas expand and the climate crisis intensifies, cities are seeking innovative ways to integrate renewable energy sources into their infrastructure. One such solution gaining traction is the installation of rooftop solar grids. A recent CBC News article highlights the significant impact of these solar systems on urban environments, showcasing their benefits and the challenges they present.

Harnessing Unused Space for Sustainable Energy

Rooftop solar panels are revolutionizing how cities approach energy consumption and environmental sustainability. By utilizing the often-overlooked space on rooftops, these systems provide a practical solution for generating renewable energy in densely populated areas. The CBC article emphasizes that this approach not only makes efficient use of available space but also contributes to reducing a city's reliance on non-renewable energy sources.

The ability to generate clean energy directly from buildings helps decrease greenhouse gas emissions and, as scientists work to improve solar and wind power, promotes a shift towards a more sustainable energy model. Solar panels absorb sunlight and convert it into electricity, reducing the need for fossil fuels and lowering overall carbon footprints. This transition is crucial as cities grapple with rising temperatures and air pollution.

Economic and Environmental Advantages

The economic benefits of rooftop solar grids are considerable. For homeowners and businesses, installing solar panels can lead to substantial savings on electricity bills. The initial investment in solar technology is often balanced by long-term energy savings and financial incentives, such as tax credits or rebates, and evidence that solar is cheaper than grid electricity in Chinese cities further illustrates the trend toward affordability. According to the CBC report, these financial benefits make solar energy a compelling option for many urban residents and enterprises.

Environmentally, the advantages are equally compelling. Solar energy is a renewable and clean resource, and increasing the number of rooftop solar installations can play a pivotal role in meeting local and national renewable energy targets, as illustrated when New York met its solar goals early in a recent milestone. The reduction in greenhouse gas emissions from fossil fuel energy sources directly contributes to mitigating climate change and improving air quality.

Challenges in Widespread Adoption

Despite the clear benefits, the adoption of rooftop solar grids is not without its challenges. One of the primary hurdles is the upfront cost of installation. While prices for solar panels have decreased over time, the initial financial outlay remains a barrier for some property owners, and regions like Alberta have faced solar expansion challenges that highlight these constraints. Additionally, the effectiveness of solar panels can vary based on factors such as geographic location, roof orientation, and local weather patterns.

The CBC article also highlights the importance of supportive infrastructure and policies for the success of rooftop solar grids. Cities need to invest in modernizing their energy grids to accommodate the influx of solar-generated electricity, and, in the U.S., record clean energy purchases by Southeast cities have signaled growing institutional demand. Furthermore, policies and regulations must support solar adoption, including issues related to net metering, which allows solar panel owners to sell excess energy back to the grid.

Innovative Solutions and Future Prospects

The future of rooftop solar grids looks promising, thanks to ongoing technological advancements. Innovations in photovoltaic cells and energy storage solutions are expected to enhance the efficiency and affordability of solar systems. The development of smart grid technology and advanced energy management systems, including peer-to-peer energy sharing, will also play a critical role in integrating solar power into urban infrastructures.

The CBC report also mentions the rise of community solar projects as a significant development. These projects allow multiple households or businesses to share a single solar installation, making solar energy more accessible to those who may not have suitable rooftops for solar panels. This model expands the reach of solar technology and fosters greater community engagement in renewable energy initiatives.

Conclusion

Rooftop solar grids are emerging as a key element in the transition to sustainable urban energy systems. By leveraging unused rooftop space, cities can harness clean, renewable energy, reduce greenhouse gas emissions, and, as developers learn that more energy sources make better projects, achieve long-term economic savings. While there are challenges to overcome, such as initial costs and regulatory hurdles, the benefits of rooftop solar grids make them a crucial component of the future energy landscape. As technology advances and policies evolve, rooftop solar grids will play an increasingly vital role in shaping greener, more resilient urban environments.

Related News

• Electricity Forum News

• Grid Technologies News

Australia's greenhouse gas emissions rose in Q2 as electricity and transport pollution increased, despite renewable energy growth. Net zero targets, carbon dioxide equivalent metrics, and land use changes underscore mixed trends in decarbonisation.

Key Points

About 499-500 Mt CO2-e annually, with a 2% quarterly rise led by electricity and transport.

✅ Q2 emissions rose to 127 Mt from 124.4 Mt seasonally adjusted

✅ Electricity sector up to 41.6 Mt; transport added nearly 1 Mt

✅ Land use remains a net sink; renewables expanded capacity

Australia’s greenhouse gas emissions rose in the June quarter by about 2% as pollution from the electricity sector and transport increased.

Figures released on Tuesday by the Morrison government showed that on a year to year basis, emissions for the 12 months to last June totalled 498.9m tonnes of carbon dioxide equivalent. That tally was down 2.1%, or 10.8m tonnes compared with the same period a year earlier.

However, on a seasonally adjusted quarterly basis, emissions increased to 127m tonnes, or just over 2%, from the 124.4m tonnes reported in the March quarter. For the year to March, emissions totalled 494.2m tonnes, underscoring the pickup in pollution in the more recent quarter even as global coal power declines worldwide.

A stable pollution rate, if not a rising one, is also implied by the government’s release of preliminary figures for the September quarter. They point to 125m tonnes of emissions in trend terms for the July-September months, bringing the year to September total to about 500m tonnes, the latest report said.

The government has made much of Australia “meeting and beating” climate targets. However, the latest statistics show mostly emissions are not in decline despite its pledge ahead of the Glasgow climate summit that the country would hit net zero by 2050, and AEMO says supply can remain uninterrupted as coal phases out over the next three decades.

“Nothing’s happening except for the electricity sector,” said Hugh Saddler, an honorary associate professor at the Australian National University. Once Covid curbs on the economy eased, such as during the current quarter, emission sources such as from transport will show a rise, he predicted.

Falling costs for new wind and solar farms, with the IEA naming solar the cheapest in history worldwide, are pushing coal and gas out of electricity generation, as well as pushing down power prices. In seasonally adjusted terms, though, emissions for that sector rose from 39.7m tonnes the March quarter to 41.6m in the June one.

Most other sectors were steady, with pollution from transport adding almost 1m tonnes in the June quarter.

On an annual basis, a 500m tonnes tally is the lowest since records began in the 1990s, and IEA reported global emissions flatlined in 2019 for context. That lower trajectory, though, is lower due much to the land sector remaining a net sink even as some experts raise questions about the true trends when it comes to land clearing.

According to the government, this sector – known as land use, land-use change and forestry – amounted to a net reduction of emissions of 24.4m tonnes, or almost negative 5% of the national total, in the year to June.

Sign up to receive an email with the top stories from Guardian Australia every morning

“The magnitude of this net sink has decreased by 0.6% (0.2 Mt CO2-e) on the previous 12 months due to an increase in emissions from agricultural soils, partially offset by a continuing decline in land clearing emissions,” the latest report said.

For its part, the government also touted the increase of renewable energy, as seen in Canada's electricity progress too, as central to driving emissions lower.

“Since 2017, Australia’s consumption of renewable energy has grown at a compound annual rate of 4.6%, with more than $40bn invested in Australia’s renewable energy sector,” Angus Taylor, the federal energy minister said, while UK net zero policy changes show a different approach. “Last year, Australia deployed new solar and wind at eight times the global per capita average.”

ANU’s Saddler said the main driver had been the 2020 Renewable Energy Target that the Coalition government had cut, and had anyway been implemented “a very considerable time ago”.

Tim Baxter, the Climate Council’s senior researcher, said “the time for leaning on the achievements of others is long since past”.

“We need a federal government willing to step up on emissions reductions and take charge with real policy, not wishlists,” he said, referring to the government’s net zero plan to rely on technologies to cut pollution in pursuit of a sustainable electric planet in practice, some of which don’t exist now.

Related News

• Electricity Forum News

• Climate Change News

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

• Electricity Forum News

• Power Generation News

25% Tariff on Canadian Imports threatens New York energy markets, disrupting hydroelectric power and natural gas supply chains, raising electricity prices, increasing gas costs, and intensifying trade tensions, policy uncertainty, and cross-border logistics risks.

Key Points

A U.S. policy imposing 25% duties on Canadian goods, risking higher New York electricity and natural gas costs.

✅ Hydroelectric and gas imports face costlier cross-border flows

✅ Higher utility bills for NY households and businesses

✅ Supply chain volatility and policy uncertainty increase

President Donald Trump announced the imposition of a 25% tariff on all imports from Canada, citing concerns over drug trafficking and illegal immigration. This decision has raised significant concerns among experts and residents in New York, who warn that the tariff could lead to increased electricity and gas prices in the state.

Impact on New York's Energy Sector

New York relies heavily on energy imports from Canada, particularly electricity and natural gas. Canada is a major supplier of hydroelectric power to the northeastern United States, including New York, with its electricity exports at risk amid trade tensions. The imposition of a 25% tariff on Canadian goods could disrupt this supply chain, leading to higher energy costs for consumers and businesses in New York. Justin Wilcox, an energy analyst, stated, "If the tariff is implemented, it could lead to increased costs for electricity and gas, affecting both consumers and businesses."

Potential Economic Consequences

The increased energy costs could have broader economic implications for New York, and some experts advise against cutting Quebec's exports to avoid exacerbating market volatility. Higher electricity and gas prices may lead to increased operational costs for businesses, potentially resulting in higher prices for goods and services, while tariff threats have boosted support for Canadian energy projects that could reshape regional supply. This could exacerbate the cost-of-living challenges faced by residents and strain the state's economy.

Political and Diplomatic Reactions

The tariff has also sparked political and diplomatic reactions, including threats to cut U.S. electricity exports from Ontario that raised tensions. New York Governor Kathy Hochul expressed concern over the potential economic impact, stating, "We are closely monitoring the situation and are prepared to take necessary actions to protect New York's economy." Additionally, Canadian officials have expressed their disapproval of the tariff, and Ontario Premier Doug Ford's Washington meeting underscored ongoing discussions, emphasizing the importance of the trade relationship between the two countries.

Historical Context

This development is part of a broader pattern of trade tensions between the United States and its neighbors. In 2018, the U.S. imposed tariffs on Canadian steel and aluminum, leading to retaliatory measures from Canada. The current situation underscores the ongoing challenges in international trade relations, where a recent tariff threat delayed Quebec's green energy bill and highlighted the potential domestic impacts of such policies.

The imposition of a 25% tariff on Canadian imports by President Trump has raised significant concerns in New York regarding potential increases in electricity and gas prices. Experts warn that this could lead to higher costs for consumers and businesses, with broader economic implications for the state. As the situation develops, it will be crucial to monitor the responses from both state and federal officials, as well as how Canadians support tariffs on energy and minerals may influence policy, and the potential for diplomatic negotiations to address these trade tensions.

Related News

• Electricity Forum News

• Energy Policy News

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

• Electricity Forum News

• Power Generation News