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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U.S. Electricity Sales Projections Continue to Fall

US Electricity Demand Outlook examines EIA forecasts, GDP decoupling, energy efficiency, electrification, electric vehicles, grid load growth, and weather variability to frame long term demand trends and utility planning scenarios.

 

Key Points

An analysis of EIA projections showing demand decoupling from GDP, with EV adoption and efficiency shaping future grid load.

✅ EIA lowers load growth; demand decouples from GDP.

✅ Efficiency and sector shifts depress kWh sales.

✅ EV adoption could revive load and capacity needs.

 

Electricity producers and distributors are in an unusual business. The product they provide is available to all customers instantaneously, literally at the flip of a switch. But the large amount of equipment, both hardware and software to do this takes years to design, site and install.

From a long range planning perspective, just as important as a good engineering design is an accurate sales projections. For the US electric utility industry the most authoritative electricity demand projec-tions come from the Department of Energy’s Energy Information Administration (EIA). EIA's compre-hensive reports combine econometric analysis with judgment calls on social and economic trends like the adoption rate of new technologies that could affect future electricity demand, things like LED light-ing and battery powered cars, and the rise of renewables overtaking coal in generation.

Before the Great Recession almost a decade ago, the EIA projected annual growth in US electricity production at roughly 1.5 percent per year. After the Great Recession began, the EIA lowered its projections of US electricity consumption growth to below 1 percent. Actual growth has been closer to zero. While the EIA did not antici-pate the last recession or its aftermath, we cannot fault them on that.

After the event, though, the EIA also trimmed its estimates of economic growth. For the 2015-2030 period it now predicts 2.1 percent economic and 0.3 percent electricity growth, down from previously projections of 2.7 percent and 1.3 percent respectively. (See Figures 1 and 2.)



 

Table 1. EIA electric generation projections by year of forecast (kWh billions)

 


 

Table 2. EIA forecast of GDP by year of forecast (billion 2009 $)

Back in 2007, the EIA figured that every one percent increase in economic activity required a 0.48 percent in-crease in electric generation to support it. By 2017, the EIA calculated that a 1 percent growth in economic activity now only required a 0.14 percent increase in electric output. What accounts for such a downgrade or disconnect between electricity usage and economic growth? And what factors might turn the numbers 
around?

First, the US economy lost energy intensive heavy industry like smelting, steel mills and refineries; patterns in China's electricity sector highlight how industrial shifts can reshape power demand. A more service oriented economy (think health care) relies more heavily on the movement of data or information and uses far less power than a manufacturing-oriented economy.

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Second, internet shopping has hurt so-called "brick and mortar" retailers. Despite the departure of heavy industry, in years past a burgeoning US commercial sector increased its demand and usage of electricity to offset the industrial decline. But not anymore. Energy efficiency measures as well as per-haps greater concern about global warming and greenhouse gas emissions and have cut into electricity sales. “Do more with less” has the right ring to it.

But there may be other components to the ongoing decline in electricity usage. Academic studies show that electricity usage seems to increase with income along an S curve, and flattens out after a certain income level. That is, if you earn $1 billion per year you do not (or cannot) use ten times a much electricity as someone earning only $100 million.

But people at typical, middle income levels increase or decrease electricity usage when incomes rise or fall. The squeeze on middle income families was discussed often in the late presidential campaign. In recent decades an increasing percentage of income has gone to a small percentage of the population at the top of the income scale. This trend probably accounts for some weakness in residential sales. This suggests that government policy addressing income inequality would also boost electricity sales.

Population growth affects demand for electricity as well as the economy as a whole. The EIA has made few changes in its projections, showing 0.7 percent per year population growth in 2015- 2030 in both the 2007 and 2017 forecasts. Recent studies, however, have shown a drop in the birth rate to record lows. More troubling, from a national health perspective is that the average age of death may have stopped rising. Those two factors point to lower population growth, especially if the government also restricts immi-gration. Thus, the US may be approaching a period of rather modest population growth.

All of the above factors point to minimal sales growth for electricity producers in the US--perhaps even lower than the seemingly conservative EIA estimates. But the cloud on the horizon has a silver lining in the shape of an electric car. Both the United Kingdom and France have set dates to end of production of automobiles with internal combustion engines. Several European car makers have declared that 20 percent of their output will be electric vehicles by the early 2020s. If we adopt automobiles powered by electricity and not gasoline or diesel, electricity sales would increase by one third. For the power indus-try, electric vehicles represent the next big thing.

We don’t pretend to know how electric car sales will progress. But assume vehicle turnover rates re-main at the current 7 percent per year and electric cars account for 5 percent of sales in the first five years (as op-posed to 1 percent now), 20 percent in the next five years and 50 percent in the third five year period. Wildly optimistic assumptions? Maybe. By 2030, electric cars would constitute 28 percent of the vehicle fleet. They would add about 10 percent to kilowatt hour sales by that date, assuming that battery efficiencies do not improved by then. Those added sales would require increased electric generation output, with low-emissions sources expected to cover almost all the growth globally. They would also raise long term growth rates for 2015-2030 from the present 0.3 percent to 1.0 percent. The slow upturn in demand should give the electric companies time to gear up so to speak.

In the meantime, weather will continue to play a big role in electricity consumption. Record heat-induced demand peaks are being set here in the US even as surging global demand puts power systems under strain worldwide.

Can we discern a pattern in weather conditions 15 years out? Maybe we can, but that is one topic we don’t expect a government agency to tackle in public right now. Meantime, weather will affect sales more than anything else and we cannot predict the weather. Or can we?

 

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Report: Duke Energy to release climate report under investor pressure

Duke Energy zero-coal 2050 plan outlines a decarbonized energy mix, aligning with Paris goals, cutting greenhouse gas emissions, driven by investor pressure, shifting to natural gas, extending nuclear power, and phasing out coal.

 

Key Points

An investor-driven scenario to end coal by 2050, shift to natural gas, extend nuclear plants, and manage climate risk.

✅ Eliminates coal from the generation mix by 2050

✅ Prioritizes natural gas transitions without CCS breakthroughs

✅ Extends nuclear plant licenses to limit carbon emissions

 

One of America’s largest utility companies, Duke Energy, is set to release a report later this month that sketches a drastically changed electricity mix in a carbon-constrained future.

The big picture: Duke is the latest energy company to commit to releasing a report about climate change in response to investor pressure, echoing shifts such as Europe's oil majors going electric across the sector, conveyed by non-binding but symbolically important shareholder resolutions. Duke provides electricity to more than seven million customers in the Carolinas, the Midwest and Florida.

Gritty details: The report is expected to find that coal, currently 33% of Duke’s mix, gone entirely from its portfolio by 2050 in a future scenario where the world has taken steps to cut greenhouse gas emissions, and where global coal-fired electricity use is falling markedly, to a level consistent with keeping global temperatures from rising two degrees Celsius. That’s the big ambition of the 2015 Paris climate deal, but the current commitments aren’t close to reaching that.

What they're saying: “What’s difficult about this is we are trying to overlay what we understand currently about technology,” Lynn Good, Duke CEO, told Axios in an interview on the sidelines of a major energy conference here.

She went on to say that this scenario of zero coal by 2050 doesn’t assume any breakthroughs in technology that captures carbon emissions from coal-fired power plants. “We don’t see that technology today, and we need to make economic decisions to get those units moving and replacing them with natural gas.”

Good also stressed the benefits of its several nuclear power plants, highlighting the role of sustaining U.S. nuclear power in decarbonization, which emit no carbon emissions. She said Duke isn’t considering investing in new nuclear plants, but plans to seek federal relicensing of current plants.

“If I turn them off, the resource that would replace them today is natural gas, so carbon will go up,” Good said. “Our objective is to continue to keep those plants as long as possible.”

What’s next: A spokesman said the other details of their 2050 scenario estimates will be available when the report is officially released by month’s end.

Axios reports that Duke Energy will release a report later this month that detail the utility's efforts to mitigate climate change risks and plan carbon-free electricity investments across its operations. The report includes a scenario that eliminates coal entirely from the company's power mix by 2050. Coal currently makes up about a third of Duke's generation.

Duke CEO Lynn Good told the news outlet the scenario ending coal-fired generation assumes no technological advances in emissions capture, seemingly leaving open the possibility.

Last year, a report by the Union of Concerned Scientists concluded one in four of the remaining operating coal-fired plants in the U.S. are slated for closure or conversion to natural gas, amid falling power-sector carbon emissions across the country. Duke's report is expected to be released by the end of the month.

Duke's report on its carbon plans comes at the behest of shareholders, a trend utility companies have seen growing among investors who are increasingly concerned about companies' sustainability and their financial exposure to climate policy.

Last year, a majority of shareholders of Pennsylvania utility PPL Corp. called on company management to publish a report on how climate change policies and technological innovations will affect the company's bottom line. Almost 60% of shareholders voted in favor of the non-binding proposal.

The vote, reportedly a first for the power sector, followed a similar decision by shareholders of Occidental Petroleum, which was supported by about 66% of shareholders.

Duke's Good told Axios that right now the utility does not see the coal technology on the horizon that would keep it operating plants. “We don't see that technology today, and we need to make economic decisions to get those units moving and replacing them with natural gas," Good said. However, it does not mean the utility is making near-term efforts to erase coal from its power mix. However, some utilities are taking those steps as they prepare for en energy landscape with more carbon regulations.

In addition to the 25% of coal plants heading for closure or conversion, the UCS report also said that another 17% of the nation’s operating coal plants are uneconomic compared with natural gas-fired generation, and could face retirement soon. But there is plenty of ongoing research into "clean coal" possibilities, and the federal government has expressed an interest in smaller, modular coal units.

 

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Over 30% of Global Electricity from Renewables

Global Renewable Electricity Milestone signals solar, wind, hydro, and geothermal surpass 30% of power generation, driven by falling costs, battery storage, smart grids, and ambitious policy targets that strengthen energy security and decarbonization.

 

Key Points

It marks renewables exceeding 30% of global power, enabled by cheaper tech, storage, and strong policy.

✅ Costs of solar and wind fall, boosting competitiveness

✅ Storage and smart grids improve reliability and flexibility

✅ Policies target decarbonization while ensuring just transition

 

A recent report by the energy think tank Ember marks a significant milestone in the global energy transition. For the first time ever, according to their analysis, renewable energy sources like solar, wind, hydro, and geothermal now account for more than 30% of the world's electricity generation, a milestone echoed by wind and solar growth globally. This achievement signifies a pivotal shift towards a cleaner and more sustainable energy future.

The report attributes this growth to several key factors. Firstly, the cost of renewable energy technologies like solar panels and wind turbines has plummeted in recent years, making them increasingly competitive with traditional fossil fuels. Secondly, advancements in battery storage technology are facilitating the integration of variable renewable sources like solar and wind into the grid, addressing concerns about reliability. Thirdly, a growing number of countries are implementing ambitious renewable energy targets and policies, driven by environmental concerns and the desire for energy security.

The rise of renewables is not uniform across the globe. Europe leads the pack, with the European Union generating a staggering 44% of its electricity from renewable sources in 2023. Countries like Denmark, Germany, and Spain are at the forefront of this clean energy revolution. Developing nations are also starting to embrace renewables, driven by factors like falling technology costs and the need for affordable electricity access.

However, challenges remain. Fossil fuels still dominate the global energy mix, accounting for roughly two-thirds of electricity generation. Integrating a higher proportion of variable renewables into the grid necessitates robust storage solutions and smart grid technologies. Additionally, the transition away from fossil fuels needs to be managed carefully to ensure a just and equitable outcome for workers in the coal, oil, and gas sectors.

Despite these challenges, the report by Ember paints an optimistic picture. The rapid growth of renewables demonstrates their increasing viability and underscores the global commitment to a cleaner energy future, and in the United States, for example, renewables are projected to reach one-fourth of U.S. electricity generation, reinforcing this trajectory. The report also highlights the economic benefits of renewables, with new jobs created in the clean energy sector and reduced reliance on volatile fossil fuel prices.

Looking ahead, continued technological advancements, supportive government policies, and increased investment in renewable energy infrastructure are all crucial for further growth, with scenarios such as BNEF's 2050 outlook suggesting wind and solar could provide half of electricity, underscoring the importance of sustained effort. Furthermore, international cooperation is essential to ensure a smooth and equitable global energy transition. Developed nations can play a vital role by sharing technology and expertise with developing countries.

The 30% milestone is a significant step forward, but it's just the beginning. As the world strives to combat climate change and ensure energy security for future generations, renewables are poised to play a central role in powering a sustainable future, with wind and solar surpassing coal in the U.S. offering a clear signal of the shift. The report by Ember serves as a powerful reminder that a clean energy future is not just a dream, but a rapidly unfolding reality.

 

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Mines found at Ukraine's Zaporizhzhia nuclear plant, UN watchdog says

Zaporizhzhia Nuclear Plant Mines reported by IAEA at the Russian-occupied site: anti-personnel devices in a buffer zone, restricted areas; access limits to reactor rooftops and turbine halls heighten nuclear safety and security concerns in Ukraine.

 

Key Points

IAEA reports anti-personnel mines at Russian-held Zaporizhzhia, raising nuclear safety risks in buffer zones.

✅ IAEA observes mines in buffer zone at occupied site

✅ Restricted areas; no roof or turbine hall access granted

✅ Safety systems unaffected, but staff under pressure

 

The United Nations atomic watchdog said it saw anti-personnel mines at the site of Ukraine's Zaporizhzhia nuclear power plant which is occupied by Russian forces.

Europe's largest nuclear facility fell to Russian forces shortly after the invasion of Ukraine in February last year, as Moscow later sought to build power lines to reactivate it amid ongoing control of the area. Kyiv and Moscow have since accused each other of planning an incident at the site.

On July 23 International Atomic Energy Agency (IAEA) experts "saw some mines located in a buffer zone between the site's internal and external perimeter barriers," agency chief Rafael Grossi said in a statement on Monday.

The statement did not say how many mines the team had seen.

The devices were in "restricted areas" that operating plant personnel cannot access, Mr Grossi said, adding the IAEA's initial assessment was that any detonation "should not affect the site's nuclear safety and security systems".

Laying explosives at the site was "inconsistent with the IAEA safety standards and nuclear security guidance" and, amid controversial proposals on Ukraine's nuclear plants that have circulated internationally, created additional psychological pressure on staff, he added.

Ukrainians in Nikopol are out of water and within Russia's firing line. But Zaporizhzhia nuclear power plant could pose the biggest threat, even as Ukraine has resumed electricity exports to regional grids.

Last week the IAEA said its experts had carried out inspections at the plant, without "observing" the presence of any mines, although they had not been given access to the rooftops of the reactor buildings, while a possible agreement to curb attacks on plants was being discussed.

The IAEA had still not been given access to the roofs of the reactor buildings and their turbine halls, its latest statement said, even as a proposal to control Ukraine's nuclear plants drew scrutiny.

After falling into Russian hands, Europe's biggest power plant was targeted by gunfire and has been severed from the grid several times, raising nuclear risk warnings from the IAEA and others.

The six reactor units, which before the war produced around a fifth of Ukraine's electricity, have been shut down for months, prompting interest in wind power development as a harder-to-disrupt source.

 

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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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TransAlta Poised to Finalize Alberta Data Centre Agreement in 2025 

TransAlta Alberta Data Centre integrates AI, cloud computing, and renewable energy, tackling electricity demand, grid capacity, decarbonization, and energy storage with clean power, cooling efficiency, and PPA-backed supply for hyperscale workloads.

 

Key Points

TransAlta Alberta Data Centre is a planned AI facility powered mostly by renewables to meet high electricity demand.

✅ Targets partner exclusivity mid-year; ops 18-24 months post-contract.

✅ Supplies ~90% power via TransAlta; balance from market.

✅ Anchors $3.5B clean energy growth and storage in Alberta.

 

TransAlta Corp., one of Alberta’s leading power producers, is moving toward finalizing agreements with partners to establish a data centre in the province, aligned with AI data center grid integration efforts nationally, aiming to have definitive contracts signed before the end of the year.

CEO John Kousinioris stated during an analyst conference that the company seeks to secure exclusivity with key partners by mid-year, with detailed design plans and final agreements expected by late 2025. Once the contracts are signed, the data centre is anticipated to be operational within 18 to 24 months, a horizon mirrored by Medicine Hat AI grid upgrades initiatives that aim to modernize local systems.

Data centres, which are critical for high-tech industries such as artificial intelligence, consume large amounts of electricity to run and cool servers, a trend reflected in U.S. utility power challenges reporting, underscoring the scale of energy demand. In this context, TransAlta plans to supply around 90% of its partner's energy needs for the facility, with the remainder coming from the broader electricity market.

Alberta has identified data centres as a strategic priority, aiming to see $100 billion in AI-related data centre construction over the next five years. However, the rapid growth of this sector presents challenges for the region’s energy infrastructure. Electricity demand from data centres has already outpaced the available capacity in Alberta’s power grid, intensifying discussions about a western Canadian electricity grid to improve regional reliability, potentially impacting the province’s decarbonization goals.

To address these challenges, TransAlta has adopted a renewable energy investment strategy. The company announced a $3.5 billion growth plan focused primarily on clean electricity generation and storage, as British Columbia's clean energy shift advances across the region, through 2028. By then, more than two-thirds of TransAlta’s earnings are expected to come from renewable power generation, supporting progress toward a net-zero electricity grid by 2050 nationally.

The collaboration between TransAlta and data centre developers represents an opportunity to balance growing energy demand with sustainability goals. By integrating renewable energy generation into data centre operations and broader macrogrid investments, Alberta could move toward a cleaner and more resilient energy future.

 

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