Wal-Mart 'Green Store' Cuts Energy

By Associated Press


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Wal-Mart Stores Inc. opens its latest generation of energy-efficient test stores with a Las Vegas Supercenter that uses new cooling technology to cut overall energy use by up to 45 percent.

The Las Vegas store opening builds on advances in earlier pilot stores that reduced energy use in areas including lighting, refrigeration and water flow.

The previous pilot stores in the Midwest cut energy use up to 25 percent compared to a typical Supercenter built in 2005, the year Wal-Mart launched a broad environmental program to reduce energy use and packaging waste and to sell more sustainable products.

Wal-Mart said the new Las Vegas store adds to those savings with a new cooling system based on water evaporation for total energy savings of between 35 percent and 45 percent.

Wal-Mart has said it is the biggest private user of electricity in the world and has huge potential to cut back on greenhouse gases from fossil fuels burned to create electricity. It aims to use technologies proven in the pilot stores to develop a prototype in 2009 for all new Supercenters that will be between 25 percent and 30 percent more energy efficient.

An outside engineering and efficiency expert said Wal-Mart's advances in saving energy, including the new Las Vegas store, are leading the field for big-box retailers.

"This is not just a baby step. This is a big step," said Terry Townsend, past president of the American Society of Heating, Refrigerating and Air-Conditioning Engineers.

Townsend said Wal-Mart's pilot stores are important because they show other retailers how to use available technology to improve energy efficiency. Wal-Mart says it is sharing its lessons with retail industry groups.

The latest store is built specifically for the arid climate of Western states, where water evaporates faster than in the more-humid East.

It uses rooftop cooling towers to chill water that then runs in conduits under the floor of the store. The radiant cooling from the floor replaces traditional electricity-powered air conditioning.

The store also incorporates innovations from the previous pilot stores that include recycling heat from refrigerators and combining low-power LED lights in freezer cases with sensors that turn off those lights when no customers are around.

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Solar-powered pot: Edmonton-area producer unveils largest rooftop solar array

Freedom Cannabis solar array powers an Acheson cannabis facility with 4,574 rooftop panels, a 1,830-kilowatt system by Enmax, cutting greenhouse gas emissions, lowering energy costs, and advancing renewable energy, sustainability, and operational efficiency in Edmonton.

 

Key Points

A 1,830-kW rooftop solar system with 4,574 panels, cutting GHG emissions and energy costs at the Acheson facility.

✅ 1,830-kW array offsets 1,000+ tonnes GHG annually

✅ Supplies ~8% of annual power; saves $200k-$300k per year

✅ 4,574 rooftop panels installed by Enmax in Acheson

 

Electricity consumption is one of the biggest barriers to going green in the cannabis industry, where the energy demands of cannabis cultivation often complicate sustainability, but an Edmonton-area pot producer has come up with a sunny solution.

Freedom Cannabis unveiled the largest rooftop solar system used by a cannabis facility in Canada at its 126,000-square foot Acheson location, 20 kilometres west of Edmonton, as solar power in Alberta continues to surge, on Tuesday.

The "state-of-the-art" 1,830-kilowatt solar array—made up of 4,574 panels—was supplied by Enmax and will offset more than 1,000 tonnes of greenhouse gas emissions each year, reflecting how new Alberta solar facilities are undercutting natural gas on price, the company said.

The state-of-the-art solar array—made up of 4,574 panels—was supplied by Enmax and will offset more than 1,000 tonnes of greenhouse gas emissions at Freedom Cannabis every year. Nov. 12, 2019. (Freedom Cannabis)

That will supply roughly eight per cent of the building's annual power consumption and reduce costs by $200,000 to $300,000 annually.

"This strategy will supplement our operating costs for power by up to eight to 10 per cent, so it is something that in time will save us costs on power requirements," said Troy Dezwart, co-founder of Freedom Cannabis.

Dezwart said sustainability was an important issue to the company from its outset, aligning with an Alberta renewable energy surge that is expected to power thousands of jobs.

"We're fortunate enough to be able to have these types of options and pursue them," said Dezwart.

The entire system cost Freedom Cannabis $2.6 million to build, but nearly a million of that came from a provincial rebate program that has since been cancelled by the UCP government, even as a federal green electricity deal with an Edmonton company signals ongoing support.

The company cited a 2017 report that found cannabis growers in the U.S. used enough electricity to power 1.7-million homes, and said cannabis-related power consumption is expected to increase by 1,250 per cent in Ontario over the next five years, even though Canadian solar demand has been lagging overall.

“It’s more important than ever for businesses to manage their energy footprint, and solar is an important part of that solution,” Enmax director Jason Atkinson, said. “This solar installation will help reduce operating costs and offset a significant portion of GHG emissions for decades to come.”

Freedom says it has other initiatives underway to reduce its footprint, in a region planning the Edmonton airport solar farm among other projects, including water remediation and offering 100 per cent recyclable cannabis packaging tins.

The company's first crops are expected to go to market in December.

 

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Experts warn Albertans to lock in gas and electricity rates as prices set to soar

Alberta Energy Price Spike signals rising electricity and natural gas costs; lock in fixed rates as storage is low, demand surged in heat waves, and exports rose after Hurricane Ida, driving volatility and higher futures.

 

Key Points

An anticipated surge in Alberta electricity and natural gas prices, urging consumers to lock fixed rates to reduce risk.

✅ Fixed-rate gas near $3.79/GJ vs futures approaching $6/GJ

✅ Low storage after heat waves and U.S. export demand

✅ Switch providers or plans; UCA comparison tool helps

 

Energy economists are warning Albertans to review their gas and electricity bills and lock in a fixed rate if they haven't already done so because prices are expected to spike in the coming months.

"I have been urging anyone who will listen that every single Albertan should be on a fixed rate for this winter," University of Calgary energy economist Blake Shaffer said Monday. "And I say that for both natural gas and power."

Shaffer said people will rightly point out energy costs make up only roughly a third of their monthly bill. The rest of the costs for such things as delivery fees can't be avoided. 

But, he said, "there is an energy component and it is meaningful in terms of savings." 

For example, Shaffer said, when he checked last week, a consumer could sign a fixed rate gas contract for $3.79 a gigajoule and the current future price for gas is nearly $6 a gigajoule.

A typical household would use about 15 gigajoules a month, he said, so a consumer could save $30 to $45 a month for five months. For people on lower or fixed incomes, "that is a pretty significant saving."

Comparable savings can also be achieved with electricity, he said.

Shaffer said research has shown households that are least able to afford sharp increases in gas and electrical bills are less likely to pick up the phone and call their energy provider and either negotiate a lower fixed rate contract or jump to a new provider. 

But, he said, it is definitely worth the time and effort, particularly as Calgary electricity bills are rising across the city. Alberta's Utilities Consumer Advocate has a handy cost comparison tool on its website that allows consumers to conduct regional price comparisons that will assist in making an informed decision.

"Folks should know that for most providers you can change back to a floating rate any time you want," Shaffer said.

Summer heat wave affected natural gas supply
Why are energy prices set to spike in Alberta, which is a major producer of natural gas?

Sophie Simmonds, managing director of the brokerage firm Anova Energy, said Alberta is now generating the majority of its power using natural gas. 

The heat wave in June and July created record electrical demand. Normally, natural gas is stored in the summer for use in the winter. But this year, there was much greater gas consumption in the summer and so less was stored. 

Alberta also set a new electricity usage record during a recent deep freeze, underscoring system stress.

On top of that, Alberta has been exporting much more natural gas to the United States since August and September because Hurricane Ida knocked out natural gas assets in the Gulf of Mexico.

"So what this means is we are actually going into winter with very, very low storage numbers," Simmonds said.

Why natural gas prices have surged to some of their highest levels in years
Canadians to remain among world's top energy users even as government strives for net zero
Consultant Matt Ayres said he believes rising electricity prices also are being affected by Alberta's transition from carbon-intensive fuel sources to less carbon-intensive fuel sources.

"That transition is not always smooth," said Ayres, who is also an adjunct assistant professor at the University of Calgary's School of Public Policy. 

"It is my view that at least some of the price increases we are seeing on electricity comes down to difficulties imposed by that transition and also by a reduction in competition amongst generators, as well as power market overhaul debates shaping policy." 

In 2019, under the leadership of Premier Jason Kenney the UCP government removed the former NDP government's rate cap on electricity at the time.

The NDP has called for the government to reinstate the cap but the UCP government has dismissed that as unsustainable and unrealistic.

 

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Renewable electricity powered California just shy of 100% for the first time in history

California Renewable Energy Record highlights near-100% clean power as CAISO reports solar, wind, and storage meeting demand, with Interstate 10 arrays and distributed rooftop photovoltaics boosting the grid during Stagecoach, signaling progress toward 100%.

 

Key Points

CA Renewable Energy Record marks CAISO's peak when renewables nearly met total load, led by utility solar and storage.

✅ CAISO hit 99.87% renewables serving load at 2:50 p.m.

✅ Two-thirds of power came from utility-scale solar along I-10.

✅ Tariff inquiry delays solar-storage projects statewide.

 

Renewable electricity met just shy of 100% of California's demand for the first time on Saturday, officials said, much of it from large amounts of solar power, part of a California solar boom, produced along Interstate 10, an hour east of the Coachella Valley.

While partygoers celebrated in the blazing sunshine at the Stagecoach music festival,  "at 2:50 (p.m.), we reached 99.87 % of load served by all renewables, which broke the previous record," said Anna Gonzales, spokeswoman for California Independent System Operator, a nonprofit that oversees the state's bulk electric power system and transmission lines. Solar power provided two-thirds of the amount needed.

Environmentalists who've pushed for years for all of California's power to come from renewables and meet clean energy targets were jubilant as they watched the tracker edge to 100% and slightly beyond. 

"California busts past 100% on this historic day for clean energy!" Dan Jacobson, senior adviser to Environment California, tweeted.

"Once it hit 100%, we were very excited," said Laura Deehan, executive director for Environment California. She said the organization and others have worked for 20 years to push the Golden State to complete renewable power via a series of ever tougher mandates, even as solar and wind curtailments increase across the grid. "California solar plants play a really big role."

But Gonzales said CAISO double-checked the data Monday and had to adjust it slightly because of reserves and other resource needs, an example of rising curtailments in the state. 

Environment California pushed for 1 million solar rooftops statewide, which has been achieved, adding what some say is a more environmentally friendly form of solar power, though wildfire smoke can undermine gains, than the solar farms, which eat up large swaths of the Mojave desert and fragile landscapes.

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'Need to act with that same boldness':A record 10% of the world's power was generated by wind, solar methods in 2021

Deehan said in a statement that more needs to be done, especially at the federal level. "Despite incredible progress illustrated by the milestone this weekend, and the fact that U.S. renewable electricity surpassed coal in 2022, a baffling regulatory misstep by the Biden administration has advocates concerned about backsliding on California’s clean energy targets." 

Deehan said a Department of Commerce inquiry into tariffs on imported solar panels is delaying thousands of megawatts of solar-storage projects in California, even as U.S. renewable energy hit a record 28% in April across the grid.

Still, Deehan said, “California has shown that, for one brief and shining moment, we could do it! It's time to move to 100% clean energy, 100% of the time.”

 

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For Hydro-Québec, selling to the United States means reinventing itself

Hydro-Quebec hydropower exports deliver low-carbon electricity to New England, sparking debate on greenhouse gas accounting, grid attributes, and REC-style certificates as Quebec modernizes monitoring to verify emissions, integrate renewables, and meet ambitious climate targets.

 

Key Points

Low-carbon electricity to New England, with improved emissions tracking and verifiable grid attributes.

✅ Deep, narrow reservoirs cut lifecycle GHGs in cold boreal waters

✅ Attribute certificates trace source, type, and carbon intensity

✅ Contracts require facility-level tagging for compliance

 

For 40 years, through the most vicious interprovincial battles, even as proposals for bridging the Alberta-B.C. gap aimed to improve grid resilience, Canadians could agree on one way Quebec is undeniably superior to the rest of the country.

It’s hydropower, and specifically the mammoth dam system in Northern Quebec that has been paying dividends since it was first built in the 70s. “Quebec continues to boast North America’s lowest electricity prices,” was last year’s business-as-usual update in one trade publication, even as Newfoundland's rate strategy seeks relief for consumers.

With climate crisis looming, that long-ago decision earns even more envy and reflects Canada's electricity progress across the grid today. Not only do they pay less, but Quebeckers also emit the least carbon per capita of any province.

It may surprise most Canadians, then, to hear how most of New England has reacted to the idea of being able to buy permanently into Quebec’s power grid.

​​​​​​Hydro-Québec’s efforts to strike major export deals have been rebuffed in the U.S., by environmentalists more than anyone. They question everything about Quebec hydropower, including asking “is it really low-carbon?”

These doubts may sound nonsensical to regular Quebeckers. But airing them has, in fact, pushed Hydro-Québec to learn more about itself and adopt new technology.

We know far more about hydropower than we knew 40 years ago, including whether it’s really zero-emission (it’s not), how to make it as close to zero-emission as possible, and how to account for it as precisely as new clean energies like solar and wind, underscoring how cleaning up Canada's electricity is vital to meeting climate pledges.

The export deals haven’t gone through yet, but they’ve already helped drag Hydro-Québec—roughly the fourth-biggest hydropower system on the planet—into the climate era.

Fighting to export
One of the first signs of trouble for Quebec hydro was in New Hampshire, almost 10 years ago. People there began pasting protest signs on their barns and buildings. One citizens’ group accused Hydro of planning a “monstrous extension cord” across the state.

Similar accusations have since come from Maine, Massachusetts and New York.

The criticism isn’t coming from state governments, which mostly want a more permanent relationship with Hydro-Québec. They already rely on Quebec power, but in a piecemeal way, topping up their own power grid when needed (with the exception of Vermont, which has a small permanent contract for Quebec hydropower).

Last year, Quebec provided about 15 percent of New England’s total power, plus another substantial amount to New York, which is officially not considered to be part of New England, and has its own energy market separate from the New England grid.

Now, northeastern states need an energy lynch pin, rather than a top-up, with existing power plants nearing the end of their lifespans. In Massachusetts, for example, one major nuclear plant shut down this year and another will be retired in 2021. State authorities want a hydro-based energy plan that would send $10 billion to Hydro-Québec over 20 years.

New England has some of North America’s most ambitious climate goals, with every state in the region pledging to cut emissions by at least 80 percent over the next 30 years.

What’s the downside? Ask the citizens’ groups and nonprofits that have written countless op-eds, organized petitions and staged protests. They argue that hydropower isn’t as clean as cutting-edge clean energy such as solar and wind power, and that Hydro-Québec isn’t trying hard enough to integrate itself into the most innovative carbon-counting energy system. Right as these other energy sources finally become viable, they say, it’s a step backwards to commit to hydro.

As Hydro-Québec will point out, many of these critics are legitimate nonprofits, but others may have questionable connections. The Portland Press Herald in Maine reported in September 2018 that a supposedly grassroot citizens’ group called “Stand Up For Maine” was actually funded by the New England Power Generators Association, which is based in Boston and represents such power plant owners as Calpine Corp., Vistra Energy and NextEra Energy.

But in the end, that may not matter. Arguably the biggest motivator to strike these deals comes not from New England’s needs, but from within Quebec. The province has spent more than $10 billion in the last 15 years to expand its dam and reservoir system, and in order to stay financially healthy, it needs to double its revenue in the next 10 years—a plan that relies largely on exports.

With so much at stake, it has spent the last decade trying to prove it can be an energy of the future.

“Learning as you go”
American critics, justified or not, have been forcing advances at Hydro for a long time.

When the famously huge northern Quebec hydro dams were built at James Bay—construction began in the early 1970s—the logic was purely economic. The term “climate change” didn’t exist. The province didn’t even have an environment department.

The only reason Quebec scientists started trying to measure carbon emissions from hydro reservoirs was “basically because of the U.S.,” said Alain Tremblay, a senior environmental advisor at Hydro Quebec.


Alain Tremblay, senior environmental advisor at Hydro-Québec. Photograph courtesy of Hydro-Québec
In the early 1990s, Hydro began to export power to the U.S., and “because we were a good company in terms of cost and efficiency, some Americans didn't like that,” he said—mainly competitors, though he couldn’t say specifically who. “They said our reservoirs were emitting a lot of greenhouse gases.”

The detractors had no research to back up that claim, but Hydro-Québec had none to refute it, either, said Tremblay. “At that time we didn’t have any information, but from back-of-the envelope calculations, it was impossible to have the emissions the Americans were expecting we have.”

So research began, first to design methods to take the measurements, and then to carry them out. Hydro began a five-year project with a Quebec university.

It took about 10 years to develop a solid methodology, Tremblay said, with “a lot of error and learning-as-you-go.” There have been major strides since then.

“Twenty years ago we were taking a sample of water, bringing it back to the lab and analyzing that with what we call a gas chromatograph,” said Tremblay. “Now, we have an automated system that can measure directly in the water,” reading concentrations of CO2 and methane every three hours and sending its data to a processing centre.

The tools Hydro-Québec uses are built in California. Researchers around the world now follow the same standard methods.

At this point, it’s common knowledge that hydropower does emit greenhouse gases. Experts know these emissions are much higher than previously thought.

Workers on the Eastmain-1 project environmental monitoring program. Photography courtesy of Alain Tremblay.
​But Hydro-Québec now has the evidence, also, to rebut the original accusations from the early 1990s and many similar ones today.

“All our research from Université Laval [found] that it’s about a thousand years before trees decompose in cold Canadian waters,” said Tremblay.

Hydro reservoirs emit greenhouse gases because vegetation and sometimes other biological materials, like soil runoff, decay under the surface.

But that decay depends partly on the warmth of the water. In tropical regions, including the southern U.S., hydro dams can have very high emissions. But in boreal zones like northern Quebec (or Manitoba, Labrador and most other Canadian locations with massive hydro dams), the cold, well-oxygenated water vastly slows the process.

Hydro emissions have “a huge range,” said Laura Scherer, an industrial ecology professor at Leiden University in the Netherlands who led a study of almost 1,500 hydro dams around the world.

“It can be as low as other renewable energy sources, but it can also be as high as fossil fuel energy,” in rare cases, she said.

While her study found that climate was important, the single biggest factor was “sizing and design” of each dam, and specifically its shape, she said. Ideally, hydro dams should be deep and narrow to minimize surface area, perhaps using a natural valley.

Hydro-Québec’s first generation of dams, the ones around James Bay, were built the opposite way—they’re wide and shallow, infamously flooding giant tracts of land.


Alain Tremblay, senior environmental advisor at Hydro-Québec testing emission levels. Photography courtesy of Alain Tremblay
Newly built ones take that new information into account, said Tremblay. Its most recent project is the Romaine River complex, which will eventually include four reservoirs near Quebec’s northeastern border with Labrador. Construction began in 2016.

The site was picked partly for its topography, said Tremblay.

“It’s a valley-type reservoir, so large volume, small surface area, and because of that there’s a pretty limited amount of vegetation that’s going to be flooded,” he said.

There’s a dramatic emissions difference with the project built just before that, commissioned in 2006. Called Eastmain, it’s built near James Bay.

“The preliminary results indicate with the same amount of energy generated [by Romaine] as with Eastmain, you’re going to have about 10 times less emissions,” said Tremblay.

Tracing energy to its source
These signs of progress likely won’t satisfy the critics, who have publicly argued back and forth with Hydro about exactly how emissions should be tallied up.

But Hydro-Québec also faces a different kind of growing gap when it comes to accounting publicly for its product. In the New England energy market, a sophisticated system “tags” all the energy in order to delineate exactly how much comes from which source—nuclear, wind, solar, and others—and allows buyers to single out clean power, or at least the bragging rights to say they bought only clean power.

Really, of course, it’s all the same mix of energy—you can’t pick what you consume. But creating certificates prevents energy producers from, in worst-case scenarios, being able to launder regular power through their clean-power facilities. Wind farms, for example, can’t oversell what their own turbines have produced.

What started out as a fraud prevention tool has “evolved to make it possible to also track carbon emissions,” said Deborah Donovan, Massachusetts director at the Acadia Center, a climate-focused nonprofit.

But Hydro-Québec isn’t doing enough to integrate itself into this system, she says.

It’s “the tool that all of our regulators in New England rely on when we are confirming to ourselves that we’ve met our clean energy and our carbon goals. And…New York has a tool just like that,” said Donovan. “There isn’t a tracking system in Canada that’s comparable, though provinces like Nova Scotia are tapping the Western Climate Initiative for technical support.”

Hydro Quebec Chénier-Vignan transmission line crossing the Outaouais river. Photography courtesy of Hydro-Québec
Developing this system is more a question of Canadian climate policy than technology.

Energy companies have long had the same basic tracking device—a meter, said Tanya Bodell, a consultant and expert in New England’s energy market. But in New England, on top of measuring “every time there’s a physical flow of electricity” from a given source, said Bodell, a meter “generates an attribute or a GIS certificate,” which certifies exactly where it’s from. The certificate can show the owner, the location, type of power and its average emissions.

Since 2006, Hydro-Québec has had the ability to attach the same certificates to its exports, and it sometimes does.

“It could be wind farm generation, even large hydro these days—we can do it,” said Louis Guilbault, who works in regulatory affairs at Hydro-Québec. For Quebec-produced wind energy, for example, “I can trade those to whoever’s willing to buy it,” he said.

But, despite having the ability, he also has the choice not to attach a detailed code—which Hydro doesn’t do for most of its hydropower—and to have it counted instead under the generic term of “system mix.”

Once that hydropower hits the New England market, the administrators there have their own way of packaging it. The market perhaps “tries to determine emissions, GHG content,” Guilbault said. “They have their own rules; they do their own calculations.”

This is the crux of what bothers people like Donovan and Bodell. Hydro-Québec is fully meeting its contractual obligations, since it’s not required to attach a code to every export. But the critics wish it would, whether by future obligation or on its own volition.

Quebec wants it both ways, Donovan argued; it wants the benefits of selling low-emission energy without joining the New England system of checks and balances.

“We could just buy undifferentiated power and be done with it, but we want carbon-free power,” Donovan said. “We’re buying it because of its carbon content—that’s the reason.”

Still, the requirements are slowly increasing. Under Hydro-Québec’s future contract with Massachusetts (which still has several regulatory steps to go through before it’s approved) it’s asked to sell the power’s attributes, not just the power itself. That means that, at least on paper, Massachusetts wants to be able to trace the energy back to a single location in Quebec.

“It’s part of the contract we just signed with them,” said Guilbault. “We’re going to deliver those attributes. I’m going to select a specific hydro facility, put the number in...and transfer that to the buyers.”

Hydro-Québec says it’s voluntarily increasing its accounting in other ways. “Even though this is not strictly required,” said spokeswoman Lynn St. Laurent, Hydro is tracking its entire output with a continent-wide registry, the North American Renewables Registry.

That registry is separate from New England’s, so as far as Bodell is concerned, the measure doesn’t really help. But she and others also expect the entire tracking system to grow and mature, perhaps integrating into one. If it had been created today, in fact, rather than in the 1990s, maybe it would use blockchain technology rather than a varied set of administrators, she said.

Counting emissions through tracking still has a long way to go, as well, said Donovan, and it will increasingly matter in Canada's race to net-zero as standards tighten. For example, natural gas is assigned an emissions number that’s meant to reflect the emissions when it’s consumed. But “we do not take into account what the upstream carbon emissions are through the pipeline leakage, methane releases during fracking, any of that,” she said.

Now that the search for exactitude has begun, Hydro-Québec won’t be exempt, whether or not Quebeckers share that curiosity. “We don’t know what Hydro-Québec is doing on the other side of the border,” said Donovan.

 

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Turning thermal energy into electricity

Near-Field Thermophotovoltaics captures radiated energy across a nanoscale gap, using thin-film photovoltaic cells and indium gallium arsenide to boost power density and efficiency, enabling compact Army portable power from emitters via radiative heat transfer.

 

Key Points

A nanoscale TPV method capturing near-field photons for higher power density at lower emitter temperatures.

✅ Nanoscale gap boosts radiative transfer and usable photon flux

✅ Thin-film InGaAs cells recycle sub-band-gap photons via reflector

✅ Achieved ~5 kW/m2 power density with higher efficiency

 

With the addition of sensors and enhanced communication tools, providing lightweight, portable power has become even more challenging, with concepts such as power from falling snow illustrating how diverse new energy-harvesting approaches are. Army-funded research demonstrated a new approach to turning thermal energy into electricity that could provide compact and efficient power for Soldiers on future battlefields.

Hot objects radiate light in the form of photons into their surroundings. The emitted photons can be captured by a photovoltaic cell and converted to useful electric energy. This approach to energy conversion is called far-field thermophotovoltaics, or FF-TPVs, and has been under development for many years; however, it suffers from low power density and therefore requires high operating temperatures of the emitter.

The research, conducted at the University of Michigan and published in Nature Communications, demonstrates a new approach, where the separation between the emitter and the photovoltaic cell is reduced to the nanoscale, enabling much greater power output than what is possible with FF-TPVs for the same emitter temperature.

This approach, which enables capture of energy that is otherwise trapped in the near-field of the emitter is called near-field thermophotovoltaics or NF-TPV and uses custom-built photovoltaic cells and emitter designs ideal for near-field operating conditions, alongside emerging smart solar inverters that help manage conversion and delivery.

This technique exhibited a power density almost an order of magnitude higher than that for the best-reported near-field-TPV systems, while also operating at six-times higher efficiency, paving the way for future near-field-TPV applications, including remote microgrid deployments in extreme environments, according to Dr. Edgar Meyhofer, professor of mechanical engineering, University of Michigan.

"The Army uses large amounts of power during deployments and battlefield operations and must be carried by the Soldier or a weight constrained system," said Dr. Mike Waits, U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "If successful, in the future near-field-TPVs could serve as more compact and higher efficiency power sources for Soldiers as these devices can function at lower operating temperatures than conventional TPVs."

The efficiency of a TPV device is characterized by how much of the total energy transfer between the emitter and the photovoltaic cell is used to excite the electron-hole pairs in the photovoltaic cell, where insights from near-light-speed conduction research help contextualize performance limits in semiconductors. While increasing the temperature of the emitter increases the number of photons above the band-gap of the cell, the number of sub band-gap photons that can heat up the photovoltaic cell need to be minimized.

"This was achieved by fabricating thin-film TPV cells with ultra-flat surfaces, and with a metal back reflector," said Dr. Stephen Forrest, professor of electrical and computer engineering, University of Michigan. "The photons above the band-gap of the cell are efficiently absorbed in the micron-thick semiconductor, while those below the band-gap are reflected back to the silicon emitter and recycled."

The team grew thin-film indium gallium arsenide photovoltaic cells on thick semiconductor substrates, and then peeled off the very thin semiconductor active region of the cell and transferred it to a silicon substrate, informing potential interfaces with home battery systems for distributed use.

All these innovations in device design and experimental approach resulted in a novel near-field TPV system that could complement distributed resources in virtual power plants for resilient operations.

"The team has achieved a record ~5 kW/m2 power output, which is an order of magnitude larger than systems previously reported in the literature," said Dr. Pramod Reddy, professor of mechanical engineering, University of Michigan.

Researchers also performed state-of-the-art theoretical calculations to estimate the performance of the photovoltaic cell at each temperature and gap size, informing hybrid designs with backup fuel cell solutions that extend battery life, and showed good agreement between the experiments and computational predictions.

"This current demonstration meets theoretical predictions of radiative heat transfer at the nanoscale, and directly shows the potential for developing future near-field TPV devices for Army applications in power and energy, communication and sensors," said Dr. Pani Varanasi, program manager, DEVCOM ARL that funded this work.

 

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Hydro One and Alectra announce major investments to strengthen electricity infrastructure and improve local reliability in the Hamilton area

Hydro One and Alectra Hamilton Grid Upgrades will modernize electricity infrastructure with new transformers, protection devices, transmission and distribution improvements, tree trimming, pole replacements, and line refurbishments to boost reliability and reduce outages across region.

 

Key Points

A $250M plan to modernize Hamilton transmission and distribution, reducing outages and improving reliability by 2022.

✅ New transformers and protection devices to cut outages

✅ Refurbished 1915 line powering Hamilton West Mountain

✅ Tree trimming and pole replacements across 1,260 km

 

Hydro One Networks Inc. (Hydro One), Ontario's largest electricity transmission and distribution company whose delivery rates recently increased, and Alectra Utilities have announced they expect to complete approximately $250 million of work in the Hamilton area by 2022 to upgrade local electricity infrastructure and improve service reliability.

As part of these plans to strengthen the electricity grid in the Hamilton region, where utilities must adapt to climate change pressures, investments are expected to include:

installing quieter, more efficient transformers in four stations across Hamilton to assist in reducing the number of outages;
replacing protection and switching devices across the city to shorten outage restoration times, reflecting how transmission line work underpins reliability;
refurbishing a power line originally installed in 1915 that is critical to powering the Hamilton West Mountain area; and,
trimming hazardous trees across more than 1,260 km of overhead powerlines and replacing more than 270 poles.
Hydro One will be working with Alectra Utilities to replace aging infrastructure at Elgin transmission station.

"A loss of power grinds life to a halt, impacting businesses, families and productivity. That's why Hydro One is partnering with Alectra Utilities to support a growing local economy in Hamilton, while improving power reliability for its residents," said Jason Fitzsimmons, Chief Corporate Affairs and Customer Care Officer. "Replacing aging infrastructure and modernizing equipment is part of our plan to build a stronger, safer and more reliable electricity system for Ontario now and into the future." 

"Partnering with Hydro One to invest in our local community will create a safer, more resilient and reliable system for the future," said Max Cananzi, President, Alectra Utilities.  "In addition to investments in the transmission system, Alectra Utilities also plans to invest $235 million over the next five years to renew, upgrade and connect customers to the electrical distribution and supporting systems in Hamilton. Investments in the transmission and distribution systems in Hamilton will contribute to the long-term sustainability of our communities."

"I am pleased to see Hydro One and Alectra investing in modernizing local electricity infrastructure and improving reliability," said Member of Provincial Parliament, Donna Skelly.  "Safe and reliable power is essential to supporting local families, businesses and our community."

Across Ontario, First Nations call for action on urgently needed transmission lines highlight the importance of timely grid investments.

Hydro One's investments included in this announcement are captured in its previously disclosed future capital expenditures, amid proposed projects like the Meaford hydro project across Ontario.

Much of Hydro One's electricity system was built in the 1950s, and replacing aging assets is critical as delays affecting a cross-border transmission line elsewhere have shown. Its three-year, $5 billion investment plan supports safe and reliable power to communities across Ontario, and strong regulatory oversight illustrated by the ATCO Electric penalty helps maintain public trust.


 

 

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