Storage system passes 5 million hours operation

By PR Newswire


NFPA 70e Training

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

  • Live Online
  • 6 hours Instructor-led
  • Group Training Available
Regular Price:
$199
Coupon Price:
$149
Reserve Your Seat Today
Ice Energy, a leading provider of advanced energy storage and smart grid solutions to the electric utility industry, announced that its installed base of Ice Bear energy storage systems have successfully recorded more than five million hours of cumulative field run time.

Since 2005, the company and its utility partners have installed and operated Ice Bear distributed energy storage units to shift building energy use from peak to off-peak hours – when electricity generation is cleaner, more efficient and less expensive – across a wide range of climates and geographies throughout the United States and Canada.

Locations include the hot, dry deserts and inland valleys of California, Arizona and Nevada the coastal climates of Hawaii, California and Florida the heat and humidity of Texas, Tennessee and Alabama and the extreme temperature regions of Ontario, Canada, and Northern Colorado.

In logging the five million hours, the systems have been successfully operating on a wide range of commercial, retail, government, and educational facilities with uptime in excess of 99 percent. These include major national retailers, restaurants and fast-food outlets, convenience stores, data centers, libraries, fire and police stations, schools, light commercial and manufacturing facilities, municipal buildings, an airport and even a motion picture studio.

The energy-efficient operation of the Ice Bear system in commercial applications in the field was documented in a recent ASHRAE publication, co-authored by Ice Energy's Robert Willis and Brian Parsonnet.

When aggregated and deployed at scale, Ice Energy's Ice Bear energy storage system represents a sustainable new energy solution equivalent to thousands of megawatts of clean peak power for utilities, enabling them to deliver reliable, competitively priced electric service to their customers in a sustainable, environmentally-sensitive manner.

The company recently announced an agreement with the Southern California Public Power Authority SCPPA to implement a 53 Megawatt energy storage project utilizing Ice Energy technology. The project, which represents the deployment of Ice Bear systems on thousands of locations throughout Southern California, will reduce California's peak electrical demand by as much as 64 Gigawatt hours annually, saving enough on-peak energy to power the equivalent of 10,000 average homes.

Related News

Electric Cooperatives, The Lone Shining Utility Star Of The Texas 2021 Winter Storm

Texas Electric Cooperatives outperformed during Winter Storm Uri, with higher customer satisfaction, equitable rolling blackouts, and stronger grid reliability compared to deregulated markets, according to ERCOT-area survey data of regulated utilities and commercial providers.

 

Key Points

Member-owned utilities in Texas delivering power, noted for reliability and fair outages during Winter Storm Uri.

✅ Member-owned, regulated utilities serving local communities

✅ Rated higher for blackout management and communication

✅ Operate outside deregulated markets; align incentives with users

 

Winter Storm Uri began to hit parts of Texas on February 13, 2021 and its onslaught left close to 4.5 million Texas homes and businesses without power, and many faced power and water disruptions at its peak. By some accounts, the preliminary number of deaths attributed to the storm is nearly 200, and the economic toll for the Lone Star State is estimated to be as high as $295 billion. 

The more than two-thirds of Texans who lost power during this devastating storm were notably more negative than positive in their evaluation of the performance of their local electric utility, mirrored by a rise in electricity complaints statewide, with one exception. That exception are the members of the more than 60 electric cooperatives operating within the Texas Interconnection electrical grid, which, in sharp contrast to the customers of the commercial utilities that provide power to the majority of Texans, gave their local utility a positive evaluation related to its performance during the storm.

In order to study Winter Storm Uri’s impact on Texas, the Hobby School of Public Affairs at the University of Houston conducted an online survey during the first half of March of residents 18 and older who live in the 213 counties (91.5% of the state population) served by the Texas power grid, which is managed by the Electric Reliability Council of Texas (ERCOT). 

Three-quarters of the survey population (75%) live in areas with a deregulated utility market, where a specified transmission and delivery utility by region is responsible for delivering the electricity (purchased from one of a myriad of private companies by the consumer) to homes and businesses. The four main utility providers are Oncor, CenterPoint CNP -2.2%, American Electric Power (AEP) North, and American Electric Power (AEP) Central. 

The other 25% of the survey population live in areas with regulated markets, where a single company is responsible for both delivering the electricity to homes and businesses and serves as the only source from which electricity is purchased. Municipal-owned and operated utilities (e.g., Austin Energy, Bryan Texas Utilities, Burnet Electric Department, Denton Municipal Electric, New Braunfels Utilities, San Antonio’s CPS Energy CMS -2.1%) serve 73% of the regulated market. Electric cooperatives (e.g., Bluebonnet Electric Cooperative, Central Texas Electric Cooperative, Guadalupe Valley Cooperative, Lamb County Electric Cooperative, Pedernales Electricity Cooperative, Wood County Electric Cooperative) serve one-fifth of this market (21%), with private companies accounting for 6% of the regulated market.

The overall distribution of the survey population by electric utility providers is: Oncor (38%), CenterPoint (21%), municipal-owned utilities (18%), AEP Central & AEP North combined (12%), electric cooperatives (6%), other providers in the deregulated market (4%) and other providers in the regulated market (1%). 

There were no noteworthy differences among the 31% of Texans who did not lose power during the winter storm in regard to their evaluations of their local electricity provider or their belief that the power cuts in their locale were carried out in an equitable manner.  

However, among the 69% of Texans who lost power, those served by electric cooperatives in the regulated market and those served by private electric utilities in the deregulated market differed notably regarding their evaluation of the performance of their local electric utility, both in regard to their management of the rolling blackouts, amid debates over market reforms to avoid blackouts, and to their overall performance during the winter storm. Those Texans who lost power and are served by electric cooperatives in a regulated market had a significantly more positive evaluation of the performance of their local electric utility than did those Texans who lost power and are served by a private company in a deregulated electricity market. 

For example, only 24% of Texans served by electric cooperatives had a negative evaluation of their local electric utility’s overall performance during the winter storm, compared to 55%, 56% and 61% of those served by AEP, Oncor and CenterPoint respectively. A slightly smaller proportion of Texans served by electric cooperatives (22%) had a negative evaluation of their local electric utility’s performance managing the rolling blackouts during the winter storm, compared to 58%, 61% and 71% of Texans served by Oncor, AEP and CenterPoint, respectively.

Texans served by electric cooperatives in regulated markets were more likely to agree that the power cuts in their local area were carried out in an equitable manner compared to Texans served by commercial electricity utilities in deregulated markets. More than half (52%) of those served by an electric cooperative agreed that power cuts during the winter storm in their area were carried out in an equitable manner, compared to only 26%, 23% and 23% of those served by Oncor, AEP and CenterPoint respectively

The survey data did not allow us to provide a conclusive explanation as to why the performance during the winter storm by electric cooperatives (and to a much lesser extent municipal utilities) in the regulated markets was viewed more favorably by their customers than was the performance of the private companies in the deregulated markets viewed by their customers. Yet here are three, far from exhaustive, possible explanations.

First, electric cooperatives might have performed better (based on objective empirical metrics) during the winter storm, perhaps because they are more committed to their customers, who are effectively their bosses. .  

Second, members of electric cooperatives may believe their electric utility prioritizes their interests more than do customers of commercial electric utilities and therefore, even if equal empirical performance were the case, are more likely to rate their electric utility in a positive manner than are customers of commercial utilities.  

Third, regulated electric utilities where a single entity is responsible for the commercialization, transmission and distribution of electricity might be better able to respond to the type of challenges presented by the February 2021 winter storm than are deregulated electric utilities where one entity is responsible for commercialization and another is responsible for transmission and distribution, aligning with calls to improve electricity reliability across Texas.

Other explanations for these findings may exist, which in addition to the three posited above, await future empirical verification via new and more comprehensive studies designed specifically to study electric cooperatives, large commercial utilities, and the incentives that these entities face under the regulatory system governing production, commercialization and distribution of electricity, including rulings that some plants are exempt from providing electricity in emergencies under state law. 

Still, opinion about electricity providers during Winter Storm Uri is clear: Texans served by regulated electricity markets, especially by electric cooperatives, were much more satisfied with their providers’ performance than were those in deregulated markets. Throughout its history, Texas has staunchly supported the free market. Could Winter Storm Uri change this propensity, or will attempts to regulate electricity lessen as the memories of the storm’s havoc fades? With a hotter summer predicted to be on the horizon in 2021 and growing awareness of severe heat blackout risks, we may soon get an answer.   

 

Related News

View more

Germany extends nuclear power amid energy crisis

Germany Nuclear Power Extension keeps Isar 2, Neckarwestheim 2, and Emsland running as Olaf Scholz tackles the energy crisis, soaring gas prices, and EU winter demand, prioritizing grid stability amid the Ukraine war.

 

Key Points

A temporary policy keeping three German reactors online to enhance grid stability and national energy security.

✅ Extends Isar 2, Neckarwestheim 2, and Emsland operations

✅ Addresses EU energy crisis and soaring gas prices

✅ Prioritizes grid stability while coal phase-out advances

 

German Chancellor Olaf Scholz has ordered the country's three remaining nuclear power stations to keep operating until mid-April, signalling a nuclear U-turn as the energy crisis sparked by Russia's invasion of Ukraine hurts the economy.

Originally Germany planned to phase out all three by the end of this year, continuing its nuclear phaseout policy at the time.

Mr Scholz's order overruled the Greens in his coalition, who wanted two plants kept on standby, to be used if needed.

Nuclear power provides 6% of Germany's electricity.

The decision to phase it out was taken by former chancellor Angela Merkel after Japan's Fukushima nuclear disaster in 2011.

But gas prices have soared since Russia's invasion of Ukraine in February, which disrupted Russia's huge oil and gas exports to the EU, though some officials argue that nuclear would do little to solve the gas issue in the short term. In August Russia turned off the gas flowing to Germany via the Nord Stream 1 undersea pipeline.

After relying so heavily on Russian gas Germany is now scrambling to maintain sufficient reserves for the winter. The crisis has also prompted it to restart mothballed coal-fired power stations, with coal generating about a third of its electricity currently, though the plan is to phase out coal in the drive for green energy.

Last year Germany got 55% of its gas from Russia, but in the summer that dropped to 35% and it is declining further.

EU leaders consider how to cap gas prices
France sends Germany gas for first time amid crisis
Chancellor Scholz's third coalition partner, the liberal Free Democrats (FDP), welcomed his move to keep nuclear power as part of the mix. The three remaining nuclear plants are Isar 2, Neckarwestheim 2 and Emsland, which were ultimately shut down after the extension.

The Social Democrat (SPD) chancellor also called for ministries to present an "ambitious" law to boost energy efficiency and to put into law a phase-out of coal by 2030, aiming for a coal- and nuclear-free economy among major industrial nations.

Last week climate activist Greta Thunberg said it was a "mistake" for Germany to press on with nuclear decommissioning while resorting to coal again, intensifying debate over a nuclear option for climate goals nationwide.

 

Related News

View more

IEA praises Modi govt for taking electricity to every village; calls India 'star performer'

India Village Electrification hailed by the IEA in World Energy Outlook 2018 showcases rapid energy access progress, universal village power, clean cooking advances via LPG, and Modi-led initiatives, inspiring Indonesia, Bangladesh, and Sub-Saharan Africa.

 

Key Points

A national push to power every Indian village, praised by the IEA for boosting energy access and clean cooking.

✅ Electrified 597,464 villages ahead of schedule in April 2018.

✅ IEA hails India in World Energy Outlook 2018 as star performer.

✅ LPG connections surge via Ujjwala, aiding clean cooking access.

 

The global energy watchdog International Energy Agency (IEA) has called India's electrification of every village the greatest success story of 2018. In its latest report, World Energy Outlook 2018, the IEA has called India a "star performer" in terms of achieving the big milestone of the providing power to each village. "In particular, one of the greatest success stories in access to energy in 2018 was India completing the electrification of all of its villages," said the IEA. It added that countries like Indonesia and Bangladesh have also achieved the commendable electrification rate of 95% (up from 50% in 2000), and 80% (up from 20% in 2000), respectively, even as Europe's electrification push continues as part of broader transitions.

This 643-page report by the IEA says over 120 million people worldwide gained access to electricity in 2017 and charts growth in the electric car market as part of broader energy trends. For the first time ever, the total number of people without access fell below 1 billion, it said.  The mega plan of providing electricity to 597,464 villages in India was announced by Prime Minister Narendra Modi during his Independence Day speech in 2015. On April 28, 2018, PM Modi confirmed that India had achieved its goal ahead of schedule. "This is one of the greatest achievements in the history of energy," said the IEA.

Praising the Narendra Modi government for making efforts towards lighting up every village in India, the agency said: "Since 2000 around half a billion people have gained access to electricity in India, with political effort over the last five years significantly accelerating progress."

India's achievement of providing universal household electricity access will improve the lives of over 230 million people, said the IEA, even as analyses like a Swedfund report debate some poverty outcomes in electrified areas. For a start, electric lighting makes the use of candles, kerosene and other polluting fuels for lighting redundant, not only saving money (and providing more light) but also seriously improving health, it said.

Though the global energy agency has called India "a success story", and a "bright spot for energy access", it says huge challenges remain in other regions of the world where over 670 million people still live without electricity access. "90% of these people are concentrated in sub-Saharan Africa, with countries such as Nigeria facing severe shortages," said the report.

Seven decades after independence and nearly three decades after India's economic liberalisation, the Modi government achieved the historic milestone of giving power to every single village of India, 12 days ahead of the deadline set by PM Modi. Leisang in Manipur became the last village to be connected to the grid, while a Delhi energy storage project explores ways to balance supply and demand.

The agency also praised India for tackling a related problem: access to clean cooking facilities. "While an estimated 780 million people in India rely on biomass for cooking, progress is emerging, as India is one of the few countries in the world targeting this "blind spot" of energy policy," it said.

Around 36 million LPG connections have been made since Prime Minister Modi and Minister for Petroleum and Natural Gas, Dharmendra Pradhan, launched the Pradhan Mantri Ujjwala Yojana scheme in May 2016 to provide free connections to families living below the poverty line. In India, around 50 million free LPG stoves and initial refills have been provided to poor households via this scheme since 2015. The government has set a target of providing LPG connections to 80 million households by 2020.

 

Related News

View more

Attacks on power substations are growing. Why is the electric grid so hard to protect?

Power Grid Attacks surge across substations and transmission lines, straining critical infrastructure as DHS and FBI cite vandalism, domestic extremists, and cybersecurity risks impacting resilience, outages, and grid reliability nationwide.

 

Key Points

Power Grid Attacks are deliberate strikes on substations and lines to disrupt power and weaken grid reliability.

✅ Physical attacks rose across multiple states and utilities.

✅ DHS and FBI warn of threats to critical infrastructure.

✅ Substation security and grid resilience upgrades urged.

 

Even before Christmas Day attacks on power substations in five states in the Pacific Northwest and Southeast, similar incidents of attacks, vandalism and suspicious activity were on the rise.

Federal energy reports through August – the most recent available – show an increase in physical attacks at electrical facilities across the nation this year, continuing a trend seen since 2017.

At least 108 human-related events were reported during the first eight months of 2022, compared with 99 in all of 2021 and 97 in 2020. More than a dozen cases of vandalism have been reported since September.

The attacks have prompted a flurry of calls to better protect the nation's power grid, with a renewed focus on protecting the U.S. power grid across sectors, but experts have warned for more than three decades that stepped-up protection was needed.

Attacks on power stations on the rise 
Twice this year, the Department of Homeland Security warned "a heightened threat environment" remains for the nation, including its critical infrastructure amid reports of suspected Russian breaches of power plant systems. 

At least 20 actual physical attacks were reported, compared with six in all of 2021. 
Suspicious-activity reports jumped three years ago, nearly doubling in 2020 to 32 events. In the first eight months of this year, 34 suspicious incidents were reported.
Total human-related incidents – including vandalism, suspicious activity and cyber events such as Russian hackers and U.S. utilities in recent years – are on track to be the highest since the reports started showing such activity in 2011.


Attacks reported in at least 5 states
Since September, attacks or potential attacks have been reported on at least 18 additional substations and one power plant in Florida, Oregon, Washington and the Carolinas. Several involved firearms.

  • In Florida: Six "intrusion events" occurred at Duke Energy substations in September, resulting in at least one brief power outage, according to the News Nation television network, which cited a report the utility sent to the Energy Department. Duke Energy spokesperson Ana Gibbs confirmed a related arrest, but the company declined to comment further.
  • In Oregon and Washington state: Substations were attacked at least six times in November and December, with firearms used in some cases, local news outlets reported. On Christmas Day, four additional substations were vandalized in Washington State, cutting power to more than 14,000 customers.
  • In North Carolina: A substation in Maysville was vandalized on Nov. 11. On Dec. 3, shootings that authorities called a "targeted attack" damaged two power substations in Moore County, leaving tens of thousands without power amid freezing temperatures.
  • In South Carolina: Days later, gunfire was reported near a hydropower plant, but police said the shooting was a "random act."

It's not yet clear whether any of the attacks were coordinated. After the North Carolina attacks, a coordinating council between the electric power industry and the federal government ordered a security evaluation.


FBI mum on its investigations
The FBI is looking into some of the attacks, including cyber intrusions where hackers accessed control rooms in past cases, but it hasn't said how many it's investigating or where. 

Shelley Lynch, a spokesperson for the FBI's Charlotte field office, confirmed the bureau was investigating the North Carolina attack. The Kershaw County Sheriff's Office reported the FBI was looking into the South Carolina incident.

Utilities in Oregon and Washington told news outlets they were cooperating with the FBI, but spokespeople for the agency's Seattle and Portland field offices said they couldn't confirm or deny an investigation.

Could domestic extremists be involved?
In January, the Department of Homeland Security said domestic extremists had been developing "credible, specific plans" since at least 2020, including a Neo-Nazi plot against power stations detailed in a federal complaint, and would continue to "encourage physical attacks against electrical infrastructure."

In February, three men who ascribed to white supremacy and Neo-Nazism pleaded guilty to federal crimes related to a scheme to attack the grid with rifles.

In a news release, Timothy Langan, assistant director of the FBI’s Counterterrorism Division, said the defendants "wanted to attack regional power substations and expected the damage would lead to economic distress and civil unrest."

 

Why is the power grid so hard to protect?
Industry experts, federal officials and others have warned in one report after another since at least 1990 that the power grid was at risk, and a recent grid vulnerability report card highlights dangerous weak points, said Granger Morgan, an engineering professor at Carnegie Mellon University who chaired three National Academies of Sciences reports.

The reports urged state and federal agencies to collaborate to make the system more resilient to attacks and natural disasters such as hurricanes and storms. 

"The system is inherently vulnerable, with the U.S. grid experiencing more blackouts than other developed nations in one study. It's spread all across the countryside," which makes the lines and substations easy targets, Morgan said. The grid includes more than 7,300 power plants, 160,000 miles of high-voltage power lines and 55,000 transmission substations.

One challenge is that there's no single entity whose responsibilities span the entire system, Morgan said. And the risks are only increasing as the grid expands to include renewable energy sources such as solar and wind, he said. 

 

Related News

View more

FPL Proposes Significant Rate Hikes Over Four Years

FPL Rate Increase Proposal 2026-2029 outlines $9B base-rate hikes as Florida grows, citing residential demand, grid infrastructure investments, energy mix diversification, and Florida PSC review impacting customer bills, reliability, and fuel price volatility mitigation.

 

Key Points

A $9B base-rate plan FPL filed with the Florida PSC to fund growth, grid upgrades, and energy diversification through 2029.

✅ Adds 275k since 2021; +335k customers projected by 2029.

✅ Monthly bills rise to about $157 by 2029, up ~22% total.

✅ Investments in poles, wires, transformers, substations, renewables.

 

Florida Power & Light (FPL), the state's largest utility provider, has submitted a proposal to the Florida Public Service Commission (PSC) seeking a substantial increase in customer base rates over the next four years, amid ongoing scrutiny, including a recent hurricane surcharge controversy that heightened public attention.

Rationale Behind the Rate Increase

FPL's request is primarily influenced by Florida's robust population growth. Since 2021, the utility has added about 275,000 customers and projects an additional 335,000 by the end of 2029. This surge necessitates significant investments in transmission and distribution infrastructure, including poles, wires, transformers, and substations, to maintain reliable service. Moreover, FPL aims to diversify its energy mix to shield customers from fuel price volatility, even as the state declined federal solar incentives that could influence renewable adoption, ensuring a stable and sustainable power supply.

Impact on Customer Bills

If approved, the proposed rate increases would affect residential customers as follows:

  • 2026: An estimated increase of $11.52 per month, raising the typical bill to $145.66.

  • 2027: An additional $6.05 per month, bringing the bill to $151.71.

  • 2028: A further increase of $3.64 per month, totaling $155.35.

  • 2029: An extra $2.06 per month, resulting in a final bill of $157.41.

These adjustments represent a cumulative increase of approximately 22% over the four-year period, while in other regions some customers face sharper spikes, such as Pennsylvania's winter price increases this season.

Comparison with Previous Rate Hikes

This proposal follows a series of rate increases approved in recent years, as California electricity bills have soared and prompted calls for action in that state. For instance, Tampa Electric Co. (TECO) received approval for rate hikes totaling $287.9 million in 2025, with additional increases planned for 2026 and 2027. Consumer groups have expressed intentions to challenge these rate hikes, indicating a trend of growing scrutiny over utility rate adjustments.

Regulatory Review Process

The PSC is scheduled to review FPL's rate increase proposal in the coming months. A staff recommendation is expected by March 14, 2025, with a final decision anticipated at a commission conference on March 20, 2025. This process allows for public input and thorough evaluation of the proposed rate changes, while elsewhere some utilities anticipate stabilization, such as PG&E's 2025 outlook in California.

Customer and Consumer Advocacy Responses

The proposed rate hikes have elicited concerns from consumer advocacy groups. Organizations like Food & Water Watch have criticized the scale of the increase, labeling it as the largest rate hike request in U.S. history, amid mixed signals such as Gulf Power's one-time 40% bill decrease earlier this year. They argue that such substantial increases could place undue financial strain on households, especially those with fixed incomes.

Additionally, the Florida Public Service Commission has faced challenges in approving rate hikes for other utilities, such as TECO, and a recent Florida court decision on electricity monopolies that may influence the policy landscape, with consumer groups planning to appeal these decisions. This backdrop of heightened scrutiny suggests that FPL's proposal will undergo rigorous examination.

As Florida continues to experience rapid growth, balancing the need for infrastructure development and reliable energy services with the financial impact on consumers remains a critical challenge. The PSC's forthcoming decisions will play a pivotal role in shaping the state's energy landscape, influencing both the economy and the daily lives of Floridians.

 

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

Live Online & In-person Group Training

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

Request For Quotation

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