Governor, ranchers welcome the wind

By Knight Ridder Tribune


CSA Z463 Electrical Maintenance

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

  • Live Online
  • 6 hours Instructor-led
  • Group Training Available
Regular Price:
$249
Coupon Price:
$199
Reserve Your Seat Today
Gov. Bill Ritter and officials with the Cedar Creek Wind Farm talked about alternative energy, economic development for rural areas and energy independence when the northern Weld County farm went into operation.

But for ranchers Gene and Sharon Hahn, the near completion of the facility meant some easing of stress of trying to run cattle on ground that has been parched by drought the past few years.

"We have 18 of them (turbines) on our ranch. It might help things just a little," Gene Hahn said with a wry smile on his face. Ranchers and farmers like the Hahns are a major reason the facility was built east of Grover, for it's their land where the almost 275 wind turbines sit on 32,000 acres on the bluffs above Grover, stretching to the north toward Hereford. Ranchers lease and where the turbines are constructed.

David Giordano of Babcock & Brown, which built the facility in partnership with BP Alternative Energy, said the facility is the largest wind energy built as a single project in the world.

"The landowners were critical partners in this project," Giordano told a crowd of more than 100 who attended the official start-up. The wind whipped the double-tents where the ceremony was conducted, a fact that didn't escape Ritter, who based much of his campaign last year on making Colorado the renewable energy capital of the United States. "It's gratifying to feel the wind whip through this tent," Ritter said.

"For all the ranchers and farmers who have cussed the wind, we're here today to bless it." Ritter said the project is a boom for Colorado. "It's good for our economy. It's good for our environment, and it's good for our energy independence," he said.

The facility is expected to be fully operational by year's end, with the first phase up and running by the end of October. The turbines will generate 300 megawatts of carbon-free electricity, which is enough to power 90,000 average-sized homes annually. With a capital investment of more than $480 million, the project will be 67 percent owned by Babcock & Brown Operating Partners and 33 percent owned by BP Alternative Energy North America.

About 400 workers have been at the site of the project for the past two years. The electricity will be bought by Xcel Energy of Denver.

Riley Hill, an Xcel representative, said that company plans to provide 1,000 megawatts of wind energy by the end of this year and 6,000 megawatts by 2020. Sharon Hahn said she doesn't mind the change in the landscape.

"I'd rather have turbines than a housing development. To us it hasn't changed the view; it's like looking through a window. And with the drought we've been dealing with, it's been a blessing," she said. About the farm Cedar Creek Wind Farm, when complete, will be one of the largest single wind-powered facilities in the United States.

It will have 274 wind turbines - 221 Mitsubishi models with a hub height of 226 feet and a rotor diameter of 202 feet, and 53 General Electric models with a hub height of about 262 feet and a rotor diameter of 253 feet.

Above-ground transmission lines will be constructed on private easements in a corridor extending from the wind farm substation near Grover in northeast Weld County south to a Exel Energy switching station near Keenesburg, in southeast Weld.

During construction of the $480 million facility 415 workers were used. The project will employ a full time staff of more than 20 who will monitor and maintain the site once it becomes fully operational.

Related News

Why electric buses haven't taken over the world—yet

Electric Buses reduce urban emissions and noise, but require charging infrastructure, grid upgrades, and depot redesigns; they offer lower operating costs and simpler maintenance, with range limits influencing routes, schedules, and on-route fast charging.

 

Key Points

Battery-electric buses cut emissions and noise while lowering operating and maintenance costs for transit agencies.

✅ Lower emissions, noise; improved rider experience

✅ Requires charging, grid upgrades, depot redesigns

✅ Range limits affect routes; on-route fast charging helps

 

In lots of ways, the electric bus feels like a technology whose time has come. Transportation is responsible for about a quarter of global emissions, and those emissions are growing faster than in any other sector. While buses are just a small slice of the worldwide vehicle fleet, they have an outsize effect on the environment. That’s partly because they’re so dirty—one Bogotá bus fleet made up just 5 percent of the city’s total vehicles, but a quarter of its CO2, 40 percent of nitrogen oxide, and more than half of all its particulate matter vehicle emissions. And because buses operate exactly where the people are concentrated, we feel the effects that much more acutely.

Enter the electric bus. Depending on the “cleanliness” of the electric grid into which they’re plugged, e-buses are much better for the environment. They’re also just straight up nicer to be around: less vibration, less noise, zero exhaust. Plus, in the long term, e-buses have lower operating costs, and related efforts like US school bus electrification are gathering pace too.

So it makes sense that global e-bus sales increased by 32 percent last year, according to a report from Bloomberg New Energy Finance, as the age of electric cars accelerates across markets worldwide. “You look across the electrification of cars, trucks—it’s buses that are leading this revolution,” says David Warren, the director of sustainable transportation at bus manufacturer New Flyer.

Today, about 17 percent of the world’s buses are electric—425,000 in total. But 99 percent of them are in China, where a national mandate promotes all sorts of electric vehicles. In North America, a few cities have bought a few electric buses, or at least run limited pilots, to test the concept out, and early deployments like Edmonton's first e-bus offer useful lessons as systems ramp up. California has even mandated that by 2029 all buses purchased by its mass transit agencies be zero-emission.

But given all the benefits of e-buses, why aren’t there more? And why aren’t they everywhere?

“We want to be responsive, we want to be innovative, we want to pilot new technologies and we’re committed to doing so as an agency,” says Becky Collins, the manager of corporate initiative at the Southeastern Pennsylvania Transportation Authority, which is currently on its second e-bus pilot program. “But if the diesel bus was a first-generation car phone, we’re verging on smartphone territory right now. It’s not as simple as just flipping a switch.”

One reason is trepidation about the actual electric vehicle. Some of the major bus manufacturers are still getting over their skis, production-wise. During early tests in places like Belo Horizonte, Brazil, e-buses had trouble getting over steep hills with full passenger loads. Albuquerque, New Mexico, canceled a 15-bus deal with the Chinese manufacturer BYD after finding equipment problems during testing. (The city also sued). Today’s buses get around 225 miles per charge, depending on topography and weather conditions, which means they have to re-up about once a day on a shorter route in a dense city. That’s an issue in a lot of places.

If you want to buy an electric bus, you need to buy into an entire electric bus system. The vehicle is just the start.

The number one thing people seem to forget about electric buses is that they need to get charged, and emerging projects such as a bus depot charging hub illustrate how infrastructure can scale. “We talk to many different organizations that get so fixated on the vehicles,” says Camron Gorguinpour, the global senior manager for the electric vehicles at the World Resources Institute, a research organization, which last month released twin reports on electric bus adoption. “The actual charging stations get lost in the mix.”

But charging stations are expensive—about $50,000 for your standard depot-based one. On-route charging stations, an appealing option for longer bus routes, can be two or three times that. And that’s not even counting construction costs. Or the cost of new land: In densely packed urban centers, movements inside bus depots can be tightly orchestrated to accommodate parking and fueling. New electric bus infrastructure means rethinking limited space, and operators can look to Toronto's TTC e-bus fleet for practical lessons on depot design. And it’s a particular pain when agencies are transitioning between diesel and electric buses. “The big issue is just maintaining two sets of fueling infrastructure,” says Hanjiro Ambrose, a doctoral student at UC Davis who studies transportation technology and policy.

“We talk to many different organizations that get so fixated on the vehicles. The actual charging stations get lost in the mix as the American EV boom gathers pace across sectors.”

Then agencies also have to get the actual electricity to their charging stations. This involves lengthy conversations with utilities about grid upgrades, rethinking how systems are wired, occasionally building new substations, and, sometimes, cutting deals on electric output, since electric truck fleets will also strain power systems in parallel. Because an entirely electrified bus fleet? It’s a lot to charge. Warren, the New Flyer executive, estimates it could take 150 megawatt-hours of electricity to keep a 300-bus depot charged up throughout the day. Your typical American household, by contrast, consumes 7 percent of that—per year. “That’s a lot of work by the utility company,” says Warren.

For cities outside of China—many of them still testing out electric buses and figuring out how they fit into their larger fleets—learning about what it takes to run one is part of the process. This, of course, takes money. It also takes time. Optimists say e-buses are more of a question of when than if. Bloomberg New Energy Finance projects that just under 60 percent of all fleet buses will be electric by 2040, compared to under 40 percent of commercial vans and 30 percent of passenger vehicles.

Which means, of course, that the work has just started. “With new technology, it always feels great when it shows up,” says Ambrose. “You really hope that first mile is beautiful, because the shine will come off. That’s always true.”

 

Related News

View more

Germany considers U-turn on nuclear phaseout

Germany Nuclear Power Extension debated as Olaf Scholz weighs energy crisis, gas shortages from Russia, slow grid expansion in Bavaria, and renewables delays; stress test results may guide policy alongside coal plant reactivations.

 

Key Points

A proposal to delay Germany's nuclear phaseout to stabilize power supply amid gas cuts and slow grid upgrades.

✅ Driven by Russia gas cuts and Nord Stream 1 curtailment

✅ Targets Bavaria grid bottlenecks; renewables deployment delays

✅ Decision awaits grid stress test; coalition parties remain split

 

The German chancellor on Wednesday said it might make sense to extend the lifetime of Germany's three remaining nuclear power plants.

Germany famously decided to stop using atomic energy in 2011, and the last remaining plants were set to close at the end of this year.

However, an increasing number of politicians have been arguing for the postponement of the closures amid energy concerns arising from Russia's invasion of Ukraine. The issue divides members of Scholz's ruling traffic-light coalition.

What did the chancellor say?
Visiting a factory in western Germany, where a vital gas turbine is being stored, Chancellor Olaf Scholz was responding to a question about extending the lifetime of the power stations.

He said the nuclear power plants in question were only relevant for a small proportion of electricity production. "Nevertheless, that can make sense," he said.

The German government has previously said that renewable energy alternatives are the key to solving the country's energy problems.

However, Scholz said this was not happening quickly enough in some parts of Germany, such as Bavaria.

"The expansion of power line capacities, of the transmission grid in the south, has not progressed as quickly as was planned," the chancellor said.

"We will act for the whole of Germany, we will support all regions of Germany in the best possible way so that the energy supply for all citizens and all companies can be guaranteed as best as possible."

The phaseout has been planned for a long time. Germany's Social Democrat government, under Merkel's predecessor Gerhard Schröder, had announced that Germany would stop using nuclear power by 2022 as planned.

Schröder's successor Angela Merkel — herself a former physicist — had initially sought to extend to life of existing nuclear plants to as late as 2037. She viewed nuclear power as a bridging technology to sustain the country until new alternatives could be found.

However, Merkel decided to ditch atomic energy in 2011, after the Fukushima nuclear disaster in Japan, setting Germany on a path to become the first major economy to phase out coal and nuclear in tandem.

Nuclear power accounted for 13.3% of German electricity supply in 2021. This was generated by six power plants, of which three were switched off at the end of 2021. The remaining three — Emsland, Isar and Neckarwestheim — were due to shut down at the end of 2022. 

Germany's energy mix 1st half of 2022
The need to fill an energy gap has emerged after Russia dramatically reduced gas deliveries to Germany through the Nord Stream 1 pipeline, though nuclear power would do little to solve the gas issue according to some officials. Officials in Berlin say the Kremlin is seeking to punish the country — which is heavily reliant on Moscow's gas — for its support of Ukraine and sanctions on Russia.

Germany has already said it will temporarily fire up mothballed coal and oil power plants in a bid to solve the looming power crisis.

Social Democrat Scholz and Germany's energy minister, Robert Habeck, from the Green Party, a junior partner in the three-way coalition government, had previously ruled out any postponement of the nuclear phasout, despite debate over a possible resurgence of nuclear energy among some lawmakers. The third member of Scholz's coalition, the neoliberal Free Democrats, has voiced support for the extension, as has the opposition conservative CDU-CSU bloc.

Berlin has said it will await the outcome of a new "stress test" of Germany's electric grid before deciding on the phaseout.

 

Related News

View more

Ontario Breaks Ground on First Small Modular Nuclear Reactor

Ontario SMR BWRX-300 leads Canada in next-gen nuclear energy at Darlington, with GE Vernova and Hitachi, delivering clean, reliable power via modular design, passive safety, scalability, and lower costs for grid integration.

 

Key Points

Ontario SMR BWRX-300 is a 300 MW modular boiling water reactor at Darlington with passive safety and clean power.

✅ 300 MW BWR supplies power for about 300,000 homes

✅ Passive safety enables safe shutdown without external power

✅ Modular design reduces costs and speeds grid integration

 

Ontario has initiated the construction of Canada's first small modular nuclear reactor (SMR), supported by OPG's SMR commitment to deployment, marking a significant milestone in the province's energy strategy. This development positions Ontario at the forefront of next-generation nuclear technology within the G7 nations.

The project, known as the Darlington New Nuclear Project, is being led by Ontario Power Generation (OPG) in collaboration with GE Vernova and Hitachi Nuclear Energy, and through its OPG-TVA partnership on new nuclear technology development. The chosen design is the BWRX-300, a 300-megawatt boiling water reactor that is approximately one-tenth the size and complexity of traditional nuclear reactors. The first unit is expected to be operational by 2029, with plans for additional units to follow.

Each BWRX-300 reactor is projected to supply electricity to about 300,000 homes, contributing to Ontario's efforts, which include the decision to refurbish Pickering B for additional baseload capacity, to meet the anticipated 75% increase in electricity demand by 2050. The compact design of the SMR allows for easier integration into existing infrastructure, reducing the need for extensive new transmission lines.

The economic impact of the project is substantial. The construction of four such reactors is expected to create up to 18,000 jobs and contribute approximately $38.5 billion CAD to the Canadian economy, reflecting the economic benefits of nuclear projects over 65 years. The modular nature of SMRs also allows for scalability, with each additional unit potentially reducing costs through economies of scale.

Safety is a paramount consideration in the design of the BWRX-300. The reactor employs passive safety features, meaning it can safely shut down without the need for external power or operator intervention. This design enhances the reactor's resilience to potential emergencies, aligning with stringent regulatory standards.

Ontario's commitment to nuclear energy is further demonstrated by its plans for four SMRs at the Darlington site. This initiative reflects a broader strategy to diversify the province's energy mix, incorporating clean and reliable power sources to complement renewable energy efforts.

While the development of SMRs in Ontario is a significant step forward, it also aligns with the Canadian nuclear initiative positioning Canada as a leader in the global nuclear energy landscape. The successful implementation of the BWRX-300 could serve as a model for other nations exploring advanced nuclear technologies.

Ontario's groundbreaking work on small modular nuclear reactors represents a forward-thinking approach to energy generation. By embracing innovative technologies, the province is not only addressing future energy demands but also, through the Pickering NGS life extension, contributing to the global transition towards sustainable and secure energy solutions.

 

Related News

View more

A New Era for Churchill Falls: Newfoundland and Labrador Secures Billions in Landmark Deal with Quebec

Churchill Falls NL-Quebec Agreement boosts hydropower revenues, revises power purchase pricing, expands transmission lines, and integrates Indigenous rights, enabling renewable energy growth, domestic supply, exports, and interprovincial collaboration on infrastructure and utility modernization.

 

Key Points

A renegotiated hydropower deal reallocating power and advancing projects with Indigenous benefits in NL and Quebec.

✅ Raises Hydro-Quebec price for Churchill Falls electricity

✅ Increases NL power share for domestic use and exports

✅ Commits joint projects and Indigenous participation safeguards

 

St. John's, Newfoundland and Labrador - In a historic development, Newfoundland and Labrador (NL) and Quebec have reached a tentative agreement over the controversial Churchill Falls hydroelectric project, amid Quebec's electricity ambitions and longstanding regional sensitivities, potentially unlocking hundreds of billions of dollars for the Atlantic province. The deal, announced jointly by Premier Andrew Furey and Quebec Premier François Legault, aims to rectify the decades-long imbalance in the original 1969 contract, which saw NL receive significantly less revenue than Quebec for the province's vast hydropower resources.

The core of the new agreement involves a substantial increase in the price that Hydro-Québec pays for electricity generated at Churchill Falls. This price hike, retroactive to January 1, 2025, is expected to generate billions in additional revenue for NL over the next several decades. The deal also includes provisions for:

  • Increased power allocation for NL: The province will gain a larger share of the electricity generated at Churchill Falls, allowing for increased domestic consumption and potential export opportunities through the sale and trade of power across regional markets.
  • Joint infrastructure development: Both provinces will collaborate on new energy projects, in line with Hydro-Québec's $185-billion plan to reduce fossil fuel reliance, including potential expansions to the Churchill Falls generating station and the development of new transmission lines.
  • Indigenous involvement: The agreement acknowledges the importance of Indigenous rights and seeks to ensure that Indigenous communities in both provinces benefit from the project.

This landmark deal represents a significant victory for NL, which has long argued that the original 1969 contract was grossly unfair. The province has been seeking to renegotiate the terms of the agreement for decades, citing the low price paid for electricity and the significant economic benefits that have accrued to Quebec.

Key Implications:

  • Economic Transformation: The influx of revenue from the new Churchill Falls agreement has the potential to significantly transform the economy of NL, though the legacy of Muskrat Falls costs tempers expectations before plans are finalized. The province can invest in critical infrastructure projects, such as healthcare, education, and transportation, as well as support economic diversification initiatives.
  • Energy Independence: The increased access to electricity will enhance NL's energy security and reduce its reliance on fossil fuels. This shift towards renewable energy aligns with the province's climate change goals, and in the context of Quebec's no-nuclear stance could attract new investment in sustainable industries.
  • Interprovincial Relations: The successful negotiation of this complex agreement demonstrates the potential for constructive collaboration between provinces on major infrastructure projects, as seen in recent NB Power-Hydro-Québec agreements to import more electricity. It sets a precedent for future interprovincial partnerships on issues of shared interest.

Challenges and Considerations:

  • Implementation: The successful implementation of the agreement will require careful planning and coordination between the two provinces.
  • Environmental Impact: The expansion of hydroelectric generation at Churchill Falls must be carefully assessed for its potential environmental impacts, including the effects on local ecosystems and Indigenous communities.
  • Public Consultation: It is crucial that the governments of NL and Quebec engage in meaningful public consultation throughout the implementation process to ensure that the benefits of the agreement are shared equitably across both provinces.

The Churchill Falls agreement marks a turning point in the history of energy development in Canada. It demonstrates the potential for provinces to work together to achieve mutually beneficial outcomes, even as Nova Scotia shifts toward wind and solar after stepping back from the Atlantic Loop, while also addressing historical inequities and ensuring a more equitable distribution of the benefits of natural resources.

 

Related News

View more

Drought, lack of rain means BC Hydro must adapt power generation

BC Hydro drought operations address climate change impacts with hydropower scheduling, reservoir management, water conservation, inflow forecasting, and fish habitat protection across the Lower Mainland and Vancouver Island while maintaining electricity generation from storage facilities.

 

Key Points

BC Hydro drought operations conserve water, protect fish, and sustain hydropower during extended heat and low inflows.

✅ Proactive reservoir releases protect downstream salmon spawning.

✅ Reduced flows at Puntledge, Coquitlam, and Ruskin/Stave facilities.

✅ System relies on northern storage to maintain electricity supply.

 

BC Hydro is adjusting its operating plans around power generation as extended heat and little forecast rain continue to impact the province, a report says.

“Unpredictable weather patterns related to climate change are expected to continue in the years ahead and BC Hydro is constantly adapting to these evolving conditions, especially after events such as record demand in 2021 that tested the grid,” said the report, titled “Casting drought: How climate change is contributing to uncertain weather and how BC Hydro’s generation system is adapting.”

The study said there is no concern with BC Hydro being able to continue to deliver power through the drought because there is enough water at its larger facilities, even as issues like crypto mining electricity use draw scrutiny from observers.

Still, it said, with no meaningful precipitation in the forecast, its smaller facilities in the Lower Mainland and on Vancouver Island will continue to see record low or near record low inflows for this time of the year.

“In the Lower Mainland, inflows since the beginning of September are ranked in the bottom three compared to historical records,” the report said.

The report said the hydroelectric system is directly impacted by variations in weather and the record-setting, unseasonably dry and warm weather this fall highlights the impacts of climate change, while demand patterns can be counterintuitive, as electricity use even increased during Earth Hour 2018 in some areas, hinting at challenges to come.

It noted symptoms of climate change include increased frequency of extreme events like drought and intense storms, and rapid glacial melt.

“With the extremely hot and dry conditions, BC Hydro has been taking proactive steps at many of our South Coast facilities for months to conserve water to protect the downstream fish habit,” spokesperson Mora Scott said. “We began holding back water in July and August at some facilities anticipating the dry conditions to help ensure we would have water storage for the later summer and early fall salmon spawning.”

Scott said BC Hydro’s reservoirs play an important role in managing these difficult conditions by using storage and planning releases to provide protection to downstream river flows. The reservoirs are, in effect, a battery waiting to be used for power.

While the dry conditions have had an impact on BC Hydro’s watersheds, several unregulated natural river systems — not related to BC Hydro — have fared worse, with rivers drying up and thousands of fish killed, the report said.

BC Hydro is currently seeing the most significant impacts on operations at Puntledge and Campbell River on Vancouver Island as well as Coquitlam and Ruskin/Stave in the Lower Mainland.

To help manage water levels on Vancouver Island, BC Hydro reduced Puntledge River flows by one-third last week and on the Lower Mainland reduced flows at Coquitlam by one-third and Ruskin/Stave by one quarter.

However, the utility company said, there are no concerns about continued power delivery.

“British Columbians benefit from BC Hydro’s integrated, provincial electricity system, which helps send power across the province, including to Vancouver Island, and programs like the winter payment plan support customers during colder months,” staff said.

Most of the electricity generated and used in B.C. is produced by larger facilities in the north and southeast of the province — and while water levels in those areas are below normal levels, there is enough water to meet the province’s power needs, even as additions like Site C's electricity remain a subject of debate among observers.

The Glacier Media investigation found a quarter of BC Hydro's power comes from the Mica, Revelstoke and Hugh Keenleyside dams on the Columbia River. Some 29% comes from dams in the Peace region, including the under-construction Site C project that has faced cost overruns. At certain points of the year, those reservoirs are reliant on glacier water.

Still, BC Hydro remains optimistic.

Forecasts are currently showing little rain in the near-term; however, historically, precipitation and inflows show up by the end of October. If that does not happen, BC Hydro said it would continue to closely track weather and inflow forecasts to adapt its operations to protect fish, while regional cooperation such as bridging with Alberta remains part of broader policy discussions.

Among things BC Hydro said it is doing to adapt are:

Continuously working to improve its weather and inflow forecasting;
Expanding its hydroclimate monitoring technology, including custom-made solutions that have been designed in-house, as well as upgrading snow survey stations to automated, real-time snow and climate stations, and;
Investing in capital projects — like spillway gate replacements — that will increase resiliency of the system to climate change.

 

Related News

View more

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.

 

Related News

View more

Sign Up for Electricity Forum’s Newsletter

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

Electricity Today T&D Magazine Subscribe for FREE

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

Download the 2025 Electrical Training Catalog

Explore 50+ live, expert-led electrical training courses –

  • Interactive
  • Flexible
  • CEU-cerified