Unit 3 to be down for some time

By Knight Ridder Tribune


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Sixteen days after an unplanned shutdown, Browns Ferry Unit 3 remained offline and TVA was making no projections on when it would return to service.

"In this instance you had electrical equipment on the generator that is disassembled, being repaired," TVA spokes-man Gil Francis said. "It will be reassembled, and the unit will come back in service. They will do that as quickly as they can, but the No. 1 priority is to do it safely."

When operational, Unit 3 produces 1,155 megawatts of power, enough for about 650,000 homes. Because the unit is down, the Tennessee Valley Authority must find replacement power. "We've got interconnections to the marketplace to buy replacement power if needed, particularly when it's cheaper," Francis said.

"Or we can use other resources, whether it's combustion turbine, other coal plants, hydro plants, Raccoon Mountain. It's such a large system we have that flexibility."

Raccoon Mountain is an energy storage facility near Chattanooga. TVA pumps water to an elevated pool during non-peak hours, then releases the water to generate hydroelectric power during hours of peak demand. Unit 3 automatically shut down Dec. 31 when the main turbine generator received a load reject signal of unknown cause. All safety systems responded properly to the signal. A load reject signal causes the system to "think" that the generator has lost the attached load.

It is similar to the tires of a speeding vehicle losing contact with the road. With the load gone, there is a risk that the engine will overaccelerate, damaging the engine. Similarly, if TVA's safety systems failed, a false load reject signal could cause the turbine and attached generator to speed up to dangerous levels.

The repairs, according to one TVA spokesman, are focused on Unit 3's exciter. The exciter provides a source of direct current to the generator, which allows the generator to produce alternating current electricity. The alternating current electricity connects to the power grid through an output circuit breaker.

Shutdowns during August forced TVA to purchase high-priced power produced by natural gas turbines, but Francis said a January shutdown is unlikely to impact rates.

Power purchases in January are generally less expensive than in August because most systems are not running at full capacity. Francis said TVA does not keep statistics indicating how the length of the Unit 3 outage compares to other unplanned outages in TVA history.

"There is no list of unplanned outages where I can just pull it," he said. "Each outage is different." He said TVA uses unplanned outages to perform maintenance unrelated to the reason for the outage.

"You manage that outage to the best of your ability to take care of all the other issues that are pending," Francis said.

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Hydro One deal to buy Avista receives U.S. antitrust clearance

Hydro One-Avista Acquisition secures U.S. antitrust clearance under Hart-Scott-Rodino, pending approvals from state utility commissions, the FCC, and CFIUS, with prior FERC approval and shareholder vote supporting the cross-border utility merger.

 

Key Points

A $6.7B cross-border utility merger cleared under HSR, still awaiting state, FCC, and CFIUS approvals; FERC approved earlier.

✅ HSR waiting period expired; U.S. antitrust clearance obtained

✅ Approvals pending: state commissions, FCC, and CFIUS

✅ FERC and Avista shareholders have approved the transaction

 

Hydro One Ltd. says it has received antitrust clearance in the United States for its deal to acquire U.S. energy company Avista Corp., even as it sought to redesign customer bills in Ontario.

The Ontario-based utility says the 30-day waiting period under the Hart-Scott-Rodino Antitrust Improvements Act expired Thursday night.

Hydro One announced the friendly deal to acquire Avista last summer, amid customer backlash in some service areas, in an agreement that valued the company at $6.7 billion.

The deal still requires several other approvals, including those from utility commissions in Washington, Idaho, Oregon, Montana and Alaska.

Analysts also warned of political risk for Hydro One during this period, reflecting concerns about provincial influence.

The U.S. Federal Communications Commission must also sign off on the transaction, and although U.S. regulators later rejected the $6.7B takeover following review, clearance is required by the Committee on Foreign Investment in the United States.

The agreement has received approval from the U.S. Federal Energy Regulatory Commission as well as Avista shareholders, and it mirrored other cross-border deals such as Algonquin Power's acquisition of Empire District that closed in the sector.

 

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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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Brenmiller Energy and New York Power Authority Showcase Thermal Storage Success

bGen Thermal Energy Storage stores high-temperature heat in crushed rocks, enabling on-demand steam, hot water, or hot air; integrates renewables, shifts load with off-peak electricity, and decarbonizes campus heating at SUNY Purchase with NYPA.

 

Key Points

A rock-based TES system storing heat to deliver steam, hot water, or hot air using renewables or off-peak power.

✅ Uses crushed rocks to store high-temperature heat

✅ Cuts about 550 metric tons CO2 annually at SUNY Purchase

✅ Integrates renewables and off-peak electricity with NYPA

 

Brenmiller Energy Ltd. (NASDAQ: BNRG), in collaboration with the New York Power Authority (NYPA), a utility pursuing grid software modernization to improve reliability, has successfully deployed its first bGen™ thermal energy storage (TES) system in the United States at the State University of New York (SUNY) Purchase College. This milestone project, valued at $2.5 million, underscores the growing role of TES in advancing sustainable energy solutions.

Innovative TES Technology

The bGen™ system utilizes crushed rocks to store high-temperature heat, which can be harnessed to generate steam, hot air, or hot water on demand. This approach allows for the efficient use of excess renewable energy or off-peak electricity, and parallels microreactor storage advances that broaden thermal options, providing a reliable and cost-effective means of meeting heating needs. At SUNY Purchase College, the bGen™ system is designed to supply nearly 100% of the heating requirements for the Physical Education Building.

Environmental Impact

The implementation of the bGen™ system is expected to eliminate approximately 550 metric tons of greenhouse gas emissions annually. This reduction aligns with New York State's ambitious climate goals, including a 40% reduction in greenhouse gas emissions by 2030, even as transmission constraints can limit cross-border imports. The project also demonstrates the potential of TES to support the state's transition to a cleaner and more resilient energy system.

Collaborative Effort

The successful deployment of the bGen™ system at SUNY Purchase College is the result of a collaborative effort between Brenmiller Energy and NYPA. The project was partially funded by a grant from the Israel-U.S. Binational Industrial Research and Development (BIRD) Foundation. This partnership highlights the importance of international cooperation in advancing innovative energy technologies, as seen in OPG-TVA nuclear collaboration efforts across North America.

Future Prospects

The successful installation and operation of the bGen™ system at SUNY Purchase College serve as a model for broader adoption of TES technology in institutional settings, as OPG's SMR commitment signals parallel low-carbon investment across the region. Brenmiller Energy and NYPA plan to share the project's findings through a webinar hosted by the Renewable Thermal Collaborative on May 19, 2025. This initiative aims to promote the scalability and replicability of TES solutions across New York State and beyond.

As the demand for sustainable energy solutions continues to grow, the successful deployment of the bGen™ system at SUNY Purchase College marks a significant step forward in the integration of TES technology into the U.S. energy landscape, while projects like Pickering B refurbishment underscore parallel clean power investments. The project not only demonstrates the feasibility of TES but also sets a precedent for future initiatives aimed at reducing carbon emissions and enhancing energy efficiency.

Brenmiller Energy's commitment to innovation and sustainability positions the company as a key player in the evolving energy sector. With continued support from partners like NYPA and the BIRD Foundation, and as jurisdictions advance first SMR deployments in North America, Brenmiller Energy is poised to expand the reach of its TES solutions, contributing to a more sustainable and resilient energy future.

 

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Europe Stores Electricity in Natural Gas Pipes

Power-to-gas converts surplus renewable electricity into green hydrogen or synthetic methane via electrolysis and methanation, enabling seasonal energy storage, grid balancing, hydrogen injection into gas pipelines, and decarbonization of heat, transport, and industry.

 

Key Points

Power-to-gas turns excess renewable power into hydrogen or methane for storage, grid support, and clean fuel.

✅ Enables hydrogen injection into existing natural gas networks

✅ Balances grids and provides seasonal energy storage capacity

✅ Supplies low-carbon fuels for industry, heat, and heavy transport

 

Last month Denmark’s biggest energy firm, Ørsted, said wind farms it is proposing for the North Sea will convert some of their excess power into gas. Electricity flowing in from offshore will feed on-shore electrolysis plants that split water to produce clean-burning hydrogen, with oxygen as a by-product. That would supply a new set of customers who need energy, but not as electricity. And it would take some strain off of Europe’s power grid as it grapples with an ever-increasing share of hard-to-handle EU wind and solar output on the grid.

Turning clean electricity into energetic gases such as hydrogen or methane is an old idea that is making a comeback as renewable power generation surges and crowds out gas in Europe. That is because gases can be stockpiled within the natural gas distribution system to cover times of weak winds and sunlight. They can also provide concentrated energy to replace fossil fuels for vehicles and industries. Although many U.S. energy experts argue that this “power-to-gas” vision may be prohibitively expensive, some of Europe’s biggest industrial firms are buying in to the idea.

European power equipment manufacturers, anticipating a wave of renewable hydrogen projects such as Ørsted’s, vowed in January that, as countries push for hydrogen-ready power plants across Europe, all of their gas-fired turbines will be certified by next year to run on up to 20 percent hydrogen, which burns faster than methane-rich natural gas. The natural gas distributors, meanwhile, have said they will use hydrogen to help them fully de-carbonize Europe’s gas supplies by 2050.

Converting power to gas is picking up steam in Europe because the region has more consistent and aggressive climate policies and evolving electricity pricing frameworks that support integration. Most U.S. states have goals to clean up some fraction of their electricity supply; coal- and gas-fired plants contribute a little more than a quarter of U.S. greenhouse gas emissions. In contrast, European countries are counting on carbon reductions of 80 percent or more by midcentury—reductions that will require an economywide switch to low-carbon energy.

Cleaning up energy by stripping the carbon out of fossil fuels is costly. So is building massive new grid infrastructure, including transmission lines and huge batteries, amid persistent grid expansion woes in parts of Europe. Power-to-gas may be the cheapest way forward, complementing Germany’s net-zero roadmap to cut electricity costs by a third. “In order to reach the targets for climate protection, we need even more renewable energy. Green hydrogen is perceived as one of the most promising ways to make the energy transition happen,” says Armin Schnettler, head of energy and electronics research at Munich-based electric equipment giant Siemens.

Europe already has more than 45 demonstration projects to improve power-to-gas technologies and their integration with power grids and gas networks. The principal focus has been to make the electrolyzers that convert electricity to hydrogen more efficient, longer-lasting and cheaper to produce.

The projects are also scaling up the various technologies. Early installations converted a few hundred kilowatts of electricity, but manufacturers such as Siemens are now building equipment that can convert 10 megawatts, which would yield enough hydrogen each year to heat around 3,000 homes or fuel 100 buses, according to financial consultancy Ernst & Young.

The improvements have been most dramatic for proton-exchange membrane electrolyzers, which are akin to the fuel cells used in hydrogen vehicles (but optimized to produce hydrogen rather than consume it). The price of proton-exchange electrolyzers has dropped by roughly 40 percent during the past decade, according to a study published in February in Nature Energy. They are also five times more compact than older alkaline electrolysis plants, enabling onsite hydrogen production near gas consumers, and they can vary their power consumption within seconds to operate on fluctuating wind and solar generation.

Many European pilot projects are demonstrating “methanation” equipment that converts hydrogen to methane, too, which can be used as a drop-in replacement for natural gas. Europe’s electrolyzer plants, however, are showing that methanation is not as critical to the power-to-gas vision as advocates long believed. Many electrolyzers are injecting their hydrogen directly into natural gas pipelines—something that U.S. gas firms forbid—and they are doing so without impacting either the gas infrastructure or natural gas consumers.

Europe’s first large-scale hydrogen injection began in eastern Germany in 2013 at a two-megawatt electrolyzer installed by Essen-based power firm E.ON. Germany has since ratcheted up the amount of hydrogen it allows in natural gas lines from an initial 2 percent by volume to 10 percent, in a market where renewables now outpace coal and nuclear in Germany, and other European states have followed suit with their own hydrogen allowances. Christopher Hebling, head of hydrogen technologies at the Freiburg-based Fraunhofer Institute for Solar Energy Systems, predicts that such limits will rise to the 20-percent level anticipated by Europe’s turbine manufacturers.

Moving renewable hydrogen and methane via natural gas pipelines promises to cut the cost of switching to renewable energy. For example, gas networks have storage caverns whose reserves could be tapped to run gas-fired electric generation power plants during periods of low wind and solar output. Hebling notes that Germany’s gas network can store 240 terawatt-hours of energy—roughly 25 times more energy than global power grids can presently store by pumping water uphill to refill hydropower reservoirs. Repurposing gas infrastructure to help the power system could save European consumers 138 billion euros ($156 billion) by 2050, according to Dutch energy consultancy Navigant (formerly Ecofys).

For all the pilot plants and promise, renewable hydrogen presently supplies a tiny fraction of Europe’s gas. And, globally, around 4 percent of hydrogen is supplied via electrolysis, with the bulk refined from fossil fuels, according to the International Renewable Energy Agency.

Power-to-gas is catching up, however. According to the February Nature Energy study, renewable hydrogen already pays for itself in some niche applications, and further electrolyzer improvements will progressively extend its market. “If costs continue to decline as they have done in recent years, power-to-gas will become competitive at large scale within the next decade,” says study co-author Gunther Glenk, an economist at the Technical University of Munich.

Glenk says power-to-gas could scale up faster if governments guaranteed premium prices for renewable hydrogen and methane, as they did to mainstream solar and wind power.

Tim Calver, an energy storage researcher turned consultant and Ernst & Young’s executive director in London, agrees that European governments need to step up their support for power-to-gas projects and markets. Calver calls the scale of funding to date, “not proportionate to the challenge that we face on long-term decarbonization and the potential role of hydrogen.”

 

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Why Fort Frances wants to build an integrated microgrid to deliver its electricity

Fort Frances Microgrid aims to boost reliability in Ontario with grid-connected and island modes, Siemens feasibility study, renewable energy integration, EV charging expansion, and resilience modeled after First Nations projects and regional biomass initiatives.

 

Key Points

A community microgrid in Fort Frances enabling grid and island modes to improve reliability and integrate renewables.

✅ Siemens-led feasibility via FedNor funding

✅ Grid-connected or islanded for outage resilience

✅ Integrates renewables, EV charging, and industry growth

 

When the power goes out in Fort Frances, Ont., the community may be left in the dark for hours.

The hydro system's unreliability — caused by its location on the provincial power grid — has prompted the town to seek a creative solution: its own self-contained electricity grid with its own source of power, known as a microgrid. 

Located more than 340 kilometres west of Thunder Bay, Ont., on the border of Minnesota, near the Great Northern Transmission Line corridor, Fort Frances gets its power from a single supply point on Ontario's grid. 

"Sometimes, it's inevitable that we have to have like a six- to eight-hour power outage while equipment is being worked on, and that is no longer acceptable to many of our customers," said Joerg Ruppenstein, president and chief executive officer of Fort Frances Power Corporation.

While Ontario's electrical grid serves the entire province, and national efforts explore macrogrids, a microgrid is contained within a community. Fort Frances hopes to develop an integrated, community-based electric microgrid system that can operate in two modes:

  • Grid-connected mode, which means it's connected to the provincial grid and informed by western grid planning approaches
  • Island mode, which means it's disconnected from the provincial grid and operates independently

The ability to switch between modes allows flexibility. If a storm knocks down a line, the community will still have power.

The town has been given grant funding from the Federal Economic Development Agency for Northern Ontario (FedNor), echoing smart grid funding in Sault Ste. Marie initiatives, for the project. On Monday night, council voted to grant a request for proposal to Siemens Canada Limited to conduct a feasibility study into a microgrid system.

The study, anticipated to be completed by the end of 2023 or early 2024, will assess what an integrated community-based microgrid system could look like in the town of just over 7,000 people, said Faisal Anwar, chief administrative officer of Fort Frances. A timeline for construction will be determined after that. 

The community is still reeling from the closure of the Resolute Forest Products pulp and paper mill in 2014 and faces a declining population, said Ruppenstein. It's hoped the microgrid system will help attract new industry to replace those lost workers and jobs, drawing on Manitoba's hydro experience as a model.

This gives the town a competitive advantage.

"If we were conceivably to attract a larger industrial player that would consume a considerable amount of energy, it would result in reduced rates for everyone…we're the only utility really in Ontario that can offer that model," Ruppenstein said.

The project can also incorporate renewable energy like solar or wind power, as seen in B.C.'s clean energy shift efforts, into the microgrid system, and support the growth of electric vehicles, he said. Many residents fill their gas tanks in Minnesota because it's cheaper, but Fort Frances has the potential to become a hub for electric vehicle charging.

A few remote First Nations have recently switched to microgrid systems fuelled by green energy, including Gull Bay First Nation and Fort Severn First Nation. These are communities that have historically relied on diesel fuel either flown in, which is incredibly expensive, or transported via ice roads, which are seeing shorter seasons each year.

Natural Resources Minister Jonathan Wilkinson was in Thunder Bay, Ont., to announce $35 million for a biomass generation facility in Whitesand First Nation, complementing federal funding for the Manitoba-Saskatchewan transmission line elsewhere in the region.

 

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'Transformative change': Wind-generated electricity starting to outpace coal in Alberta

Alberta wind power surpasses coal as AESO reports record renewable energy feeding the grid, with natural gas conversions, solar growth, energy storage, and decarbonization momentum lowering carbon intensity across Alberta's electricity system.

 

Key Points

AESO data shows wind surpassing coal in Alberta, driven by coal retirements, gas conversions, and growing renewables.

✅ AESO reports wind output above coal several times this week

✅ Coal units retire or convert to natural gas, boosting renewables

✅ Carbon intensity falls; storage and solar improve grid reliability

 

Marking a significant shift in Alberta energy history, wind generation trends provided more power to the province's energy grid than coal several times this week.

According to data from the Alberta Energy System Operator (AESO) released this week, wind generation units contributed more energy to the grid than coal at times for several days. On Friday afternoon, wind farms contributed more than 1,700 megawatts of power to the grid, compared to around 1,260 megawatts from coal stations.

"The grid is going through a period of transformative change when we look at the generation fleet, specifically as it relates to the coal assets in the province," Mike Deising, AESO spokesperson, told CTV News in an interview.

The shift in electricity generation comes as more coal plants come offline in Alberta, or transition to cleaner energy through natural gas generation, including the last of TransAlta's units at the Keephills Plant west of Edmonton.

Only three coal generation stations remain online in the province, at the Genesee plant southwest of Edmonton, as the coal phase-out timeline advances. Less available coal power, means renewable energy like wind and solar make up a greater portion of the grid.

 

EVOLUTION OF THE GRID
"Our grid is changing, and it's evolving," Deising said, adding that more units have converted to natural gas and companies are making significant investments into solar and wind energy.

For energy analyst Kevin Birn with IHS Markit, that trend is only going to continue.

"What we've seen for the last 24 to 36 months is a dramatic acceleration in ambition, policy, and projects globally around cleaner forms of energy or lower carbon forms of energy," Birn said.

Birn, who is also chief analyst of Canadian Oil Markets, added that not only has the public appetite for cleaner energy helped fuel the shift, but technological advancements have made renewables like wind and solar more cost-efficient.

"Alberta was traditionally heavily coal-reliant," he said. "(Now) western Canada has quite a diverse energy base."


LESS CARBON-INTENSIVE
According to Birn, the shift in energy production marks a significant reduction in carbon emissions as Alberta progresses toward its last coal plant closure milestone.

Ten years ago, IHS Markit estimates that Alberta's grid contributed about 900 kilograms of carbon dioxide equivalent per megawatt-hour of energy generation.

"That (figure is) really representing the dominance and role of coal in that grid," Birn said.

Current estimates show that figure is closer to 600 kilograms of CO2 equivalent.

"That means the power you and I are using is less carbon-intensive," Birn said, adding that figure will continue to fall over the next couple of years.


RENEWABLES HERE TO STAY
While many debate whether Alberta's energy is getting clean enough fast enough, Birn believes change is coming.

"It's been a half-decade of incredible price volatility in the oil market which had really dominated this sector and region," the analyst said.

"When I think of the future, I see the power sector building on large-scale renewables, which means decarbonization, and that provides an opportunity for those tech companies looking for clean energy places to land facilities."

Coal and natural gas are considered baseline assets by the AESO, where generation capacity does not shift dramatically, though some utilities report declining coal returns in other markets.

"Wind is a variable resource. It will generate when the wind is blowing, and it obviously won't when the wind is not," Deising said. "Wind and solar can ramp quickly, but they can drop off quite quickly, and we have to be prepared.

"We factor that into our daily planning and assessments," he added. "We follow those trends and know where the renewables are going to show up on the system, how many renewables are going to show up."

Deising says one wind plant in Alberta currently has an energy storage capacity to preserve renewably generated electricity during summer demand records and peak hours as needed. As the technology becomes more affordable, he expects more plants to follow suit.

"As a system operator, our job is to make sure as (the grid) is evolving we can continue to provide reliable power to Albertans at every moment every day," Deising said. "We just have to watch the system more carefully." 

 

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