Winter power will be reliable: NERC

California Renewable Energy Curtailment highlights grid congestion, midday solar peaks, limited battery storage, and market constraints, with WEIM participation and demand response programs proposed to balance supply-demand and reduce wasted solar and wind generation.

Key Points

It is the deliberate reduction of solar and wind output when grid limits or low demand prevent full integration.

✅ Grid congestion restricts transmission capacity

✅ Midday solar peaks exceed demand, causing surplus

✅ Storage, WEIM, and demand response mitigate curtailment

California has long been a leader in renewable energy adoption, achieving a near-100% renewable milestone in recent years, particularly in solar and wind power. However, as the state continues to expand its renewable energy capacity, it faces a growing challenge: the curtailment of excess solar and wind energy. Curtailment refers to the deliberate reduction of power output from renewable sources when the supply exceeds demand or when the grid cannot accommodate the additional electricity.

Increasing Curtailment Trends

Recent data from the U.S. Energy Information Administration (EIA) highlights a concerning upward trend in curtailments in California. In 2024, the state curtailed a total of 3,102 gigawatt-hours (GWh) of electricity generated from solar and wind sources, surpassing the 2023 total of 2,660 GWh. This represents a 32.4% increase from the previous year. Specifically, 2,892 GWh were from solar, and 210 GWh were from wind, marking increases of 31.2% and 51.1%, respectively, compared to the first nine months of 2023.

Causes of Increased Curtailment

Several factors contribute to the rising levels of curtailment:

1. Grid Congestion: California's transmission infrastructure has struggled to keep pace with the rapid growth of renewable energy sources. This congestion limits the ability to transport electricity from generation sites to demand centers, leading to curtailment.
   
   

2. Midday Solar Peaks: Amid California's solar boom, solar energy production typically peaks during the midday when electricity demand is lower. This mismatch between supply and demand results in excess energy that cannot be utilized, necessitating curtailment.
   
   

3. Limited Energy Storage: While battery storage technologies are advancing, California's current storage capacity is insufficient to absorb and store excess renewable energy for later use. This limitation exacerbates curtailment issues.
   
   

4. Regulatory and Market Constraints: Existing market structures and regulatory frameworks may not fully accommodate the rapid influx of renewable energy, leading to inefficiencies and increased curtailment.

Economic and Environmental Implications

Curtailment has significant economic and environmental consequences. For renewable energy producers, curtailed energy represents lost revenue and undermines the economic viability of new projects. Environmentally, curtailment means that clean, renewable energy is wasted, and the grid may rely more heavily on fossil fuels to meet demand, counteracting the benefits of renewable energy adoption.

Mitigation Strategies

To address the rising curtailment levels, California is exploring several strategies aligned with broader decarbonization goals across the U.S.:

• Grid Modernization: Investing in and upgrading transmission infrastructure to alleviate congestion and improve the integration of renewable energy sources.
  
  

• Energy Storage Expansion: Increasing the deployment of battery storage systems to store excess energy during peak production times and release it during periods of high demand.
  
  

• Market Reforms: Participating in the Western Energy Imbalance Market (WEIM), a real-time energy market that allows for the balancing of supply and demand across a broader region, helping to reduce curtailment.
  
  

• Demand Response Programs: Implementing programs that encourage consumers to adjust their energy usage patterns, such as shifting electricity use to times when renewable energy is abundant.

Looking Ahead

As California continues to expand its renewable energy capacity, addressing curtailment will be crucial to ensuring the effectiveness and sustainability of its energy transition. By investing in grid infrastructure, energy storage, and market reforms, the state can reduce curtailment levels and make better use of its renewable energy resources, while managing challenges like wildfire smoke impacts on solar output. These efforts will not only enhance the economic viability of renewable energy projects but also contribute to California's 100% clean energy targets by maximizing the use of clean energy and reducing reliance on fossil fuels.

While California's renewable energy sector faces challenges related to curtailment, proactive measures and strategic investments can mitigate these issues, as scientists continue to improve solar and wind power through innovation, paving the way for a more sustainable and efficient energy future.

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Enbridge Alberta CCS Project targets carbon capture and storage in Alberta, capturing emissions from industrial emitters to advance net-zero goals, leveraging carbon pricing, regulatory support, and a hub model despite a key partner's exit.

Key Points

A proposed Alberta carbon capture hub by Enbridge to store industrial emissions and support net-zero targets.

✅ Seeks emitters across power, oil and gas, and heavy industry

✅ Backed by carbon pricing, regulation, and net-zero mandates

✅ Faces high capex, storage risk, and anchor-tenant uncertainty

Enbridge Inc., a Canadian energy giant, is digging its heels in on its proposed carbon capture and storage (CCS) project in Alberta. This comes despite the recent withdrawal of Capital Power, a major potential emitter that was expected to utilize the CCS technology. Enbridge maintains the project remains viable, but questions linger about its future viability without a cornerstone anchor.

The CCS project, envisioned as a major carbon capture hub in Alberta, aimed to capture emissions from industrial facilities and permanently store them underground. This technology has the potential to play a significant role in reducing greenhouse gas emissions and mitigating the effects of climate change, alongside grid solutions like bridging the Alberta-B.C. electricity gap that can complement decarbonization efforts.

Capital Power's decision to shelve its $2.4 billion Genesee Generating Station project, which was designed to integrate with the CCS hub, threw a wrench into Enbridge's plans. The Genesee project was expected to be a key source of emissions for capture and storage, and its status is being weighed as Ottawa advances the federal coal plan to phase out unabated coal.

Enbridge, however, remains optimistic. The company cites ongoing discussions with other potential emitters interested in utilizing the CCS technology, amid new funding signals such as the U.S. DOE's $110M for CCUS that highlight momentum. They believe the project holds significant value despite Capital Power's departure.

"We are confident in the long-term viability of the project and continue to actively engage with potential customers," said Enbridge spokesperson Rachel Giroux. "Carbon capture and storage is a critical technology for achieving net-zero emissions, and we believe there is a strong business case for our CCS project."

Enbridge's confidence hinges on several factors. Firstly, they believe there is a growing appetite for CCS technology amongst industrial facilities facing increasing pressure to reduce their carbon footprint. Regulations and carbon pricing mechanisms, including new U.S. EPA power plant rules that test CCS readiness, could further incentivize companies to adopt CCS solutions.

Secondly, Enbridge highlights the potential for capturing emissions from not just power plants but also from other industrial sectors like oil and gas production and clean hydrogen projects in Canada, where reforming processes can generate CO2. This broader application could significantly increase the captured carbon volume and strengthen the project's economic viability.

However, skepticism remains. Critics point to the high upfront costs associated with CCS development and the nascent stage of the technology. They argue that without a guaranteed stream of captured emissions, the project might not be financially sound. Additionally, the long-term safety and effectiveness of large-scale carbon storage solutions remain under scrutiny.

The success of Enbridge's CCS project hinges on attracting new emitters. Replacing Capital Power's contribution will be a significant challenge. Enbridge will need to demonstrate the project's economic viability and navigate the complex regulatory landscape surrounding CCS technology.

The Alberta government's position on CCS is crucial. While the government has expressed support for the technology, the level of financial and regulatory incentives offered will significantly impact investor confidence, especially as the IEA net-zero outlook underscores Canada's need for much more electricity. A clear and stable policy framework will be essential for attracting emitters to the project.

The future of Enbridge's CCS project remains uncertain. Capital Power's withdrawal is a setback, but Enbridge's continued commitment suggests they believe the technology holds promise. Whether they can find enough emitters to justify the project's development will be a critical test. The outcome will have significant implications for the future of CCS technology in Alberta and Canada's broader efforts to achieve net-zero emissions, including Canada-Germany clean energy cooperation that seeks to scale low-carbon fuels.

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Cerro Dominador CSP Plant delivers 110MW concentrated solar power in Chile's Atacama Desert, with 10,600 heliostats, 17.5-hour molten salt storage, and 24/7 dispatchable energy; built by Acciona and Abengoa within a 210MW complex.

Key Points

A 110MW CSP solar-thermal plant in Chile with heliostats and 17.5h molten salt storage, delivering 24/7 dispatchable clean power.

✅ 110MW CSP with 17.5h molten salt for 24/7 dispatch

✅ 10,600 heliostats; part of a 210MW hybrid CSP+PV complex

✅ Built by Acciona and Abengoa; first of its kind in LatAm

A consortium formed by Spanish groups Abengoa and Acciona, as Spain's renewable sector expands with Enel's 90MW wind build activity, has signed a contract to complete the construction of the 110MW Cerro Dominador concentrated solar power (CSP) plant in Chile.

The consortium received notice to proceed to build the solar-thermal plant, which is part of the 210MW Cerro Dominador solar complex.

Under the contract, Acciona, which has 51% stake in the consortium and recently launched a 280 MW Alberta wind farm, will be responsible for building the plant while Abengoa will act as the technological partner.

Expected to be the first of its kind in Latin America upon completion, the plant is owned by Cerro Dominador, which in turn is owned by funds managed by EIG Global Energy Partners.

The project will add to a Abengoa-built 100MW PV plant, comparable to California solar projects in scope, which was commissioned in February 2018, to form a 210MW combined CSP and PV complex.

Spread across an area of 146 hectares, the project will feature 10,600 heliostats and will have capacity to generate clean and dispatachable energy for 24 hours a day using its 17.5 hours of molten salt storage technology, a field complemented by battery storage advances.

Expected to prevent 640,000 tons of CO2 emission, the plant is located in the commune of María Elena, in the Atacama Desert, in the Antofagasta Region.

“In total, the complex will avoid 870,000 tons of carbon dioxide emissions into the atmosphere every year and, in parallel with Enel's 450 MW U.S. wind operations, will deliver clean energy through 15-year energy purchase agreements with distribution companies, signed in 2014.

“The construction of the solarthermal plant of Cerro Dominador will have an important impact on local development, with the creation of more than 1,000 jobs in the area during its construction peak, and that will be priority for the neighbors of the communes of the region,” Acciona said in a statement.

The Cerro Dominador plant represents Acciona’s fifth solar thermal plant being built outside of Spain. The firm has constructed 10 solarthermal plants with total installed capacity of 624MW.

Acciona has been operating in Chile since 1993. The company, through its Infrastructure division, executed various construction projects for highways, hospitals, hydroelectric plants and infrastructures for the mining sector.

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India Coal Supply Rationing redirects shipments from high-inventory power plants to stations facing shortages as electricity demand surges, inventories fall, and outages persist; Coal India, NTPC imports, and smaller mines bolster domestic supply.

Key Points

A temporary policy redirecting coal from high-stock plants to shortage-hit plants amid rising demand

✅ Shipments halted 1 week to plants with >14 days coal stock

✅ Smaller mines asked to raise output; NTPC to import 270,000 tons

✅ Outages at Adani and Tata Mundra units pressure domestic supply

India will ration coal supplies to power plants with high inventories to direct more shipments to stations battling shortages, even as shortages ease in some regions, as surging demand outstrips production.

Supplies to plants with more than two weeks’ coal inventory will be halted for a week, a team headed by federal Coal Secretary Alok Kumar decided on Saturday, the Power Ministry said in a statement. The government has also requested smaller mines to raise output to supplement shipments from state miner Coal India Ltd., and is taking steps to get nuclear back on track to diversify the energy mix.

A jump in electricity consumption spurred by a reviving economy and an extended summer, after an earlier steep demand decline in India, is driving demand for coal, which helps produce about 70% of the nation’s electricity. The surge in demand complicates India’s clean-energy transition efforts amid solar supply headwinds that cloud near-term alternatives, and may bolster arguments favoring the country’s dependence on coal to fuel economic growth.

“There’s no doubt India will continue to need coal for stable power for years,” said Rupesh Sankhe, vice president at Elara Capital India Pvt. in Mumbai. “Plants that meet environmental standards and are able to produce power efficiently will see utilization rising, but I doubt we’re going to have many new coal plants.”  

Coal stockpiles at the country’s power plants had fallen to 14.7 million tons as of Aug. 24, tumbling 62% from a year earlier, according to the latest data from the Central Electricity Authority. More than 88 gigawatts of generation plants, about half the capacity monitored by the power ministry, had inventories of six days or less as of that date, the data show. Power demand jumped 10.5% in July from a year earlier, even as global electricity use dipped 15% during the pandemic, according to the government.
Outages at some large plants that run on imported coal have increased the burden on those that burn domestic supplies, aiding shortfalls.

Adani Power Ltd. had almost 2 gigawatts of capacity in outage at its Mundra plant in Gujarat at the start of the week, while Tata Power Co. Ltd. had shut 80% of its 4-gigawatt plant in the same town for maintenance, power ministry data show.

NTPC Ltd., the largest power generator, will import the 270,000 tons of coal it left out from contracts placed earlier to mitigate the fuel shortage, reflecting higher imported coal volumes this fiscal, the power ministry said in a separate statement.

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Ukraine-ENTSO-E Grid Synchronization links Ukraine and Moldova to the European grid via secure interconnection, matching frequency for stability, resilience, and energy security, enabling cross-border support, islanding recovery, and coordinated load balancing during wartime disruptions.

Key Points

Rapid alignment of Ukraine and Moldova into the European grid to enable secure interconnection and system stability.

✅ Matches 50 Hz frequency across interconnected systems

✅ Enables cross-border support and electricity trading

✅ Improves resilience, stability, and energy security

On February 24 Ukraine’s electric grid operator disconnected the country’s power system from the larger Russian-operated network to which it had always been linked. The long-planned disconnection was meant to be a 72-hour trial proving that Ukraine could operate on its own and to protect electricity supply before winter as contingencies were tested. The test was a requirement for eventually linking with the European grid, which Ukraine had been working toward since 2017. But four hours after the exercise started, Russia invaded.

Ukraine’s connection to Europe—which was not supposed to occur until 2023—became urgent, and engineers aimed to safely achieve it in just a matter of weeks. On March 16 they reached the key milestone of synchronizing the two systems. It was “a year’s work in two weeks,” according to a statement by Kadri Simson, the European Union commissioner for energy. That is unusual in this field. “For [power grid operators] to move this quickly and with such agility is unprecedented,” says Paul Deane, an energy policy researcher at the University College Cork in Ireland. “No power system has ever synchronized this quickly before.”

Ukraine initiated the process of joining Europe’s grid in 2005 and began working toward that goal in earnest in 2017, as did Moldova. It was part of an ongoing effort to align with Europe, as seen in the Baltic states’ disconnection from the Russian grid, and decrease reliance on Russia, which had repeatedly threatened Ukraine’s sovereignty. “Ukraine simply wanted to decouple from Russian dominance in every sense of the word, and the grid is part of that,” says Suriya Jayanti, an Eastern European policy expert and former U.S. diplomat who served as energy chief at the U.S. embassy in Kyiv from 2018 to 2020.

After the late February trial period, Ukrenergo, the Ukrainian grid operator, had intended to temporarily rejoin the system that powers Russia and Belarus. But the Russian invasion made that untenable. “That left Ukraine in isolation mode, which would be incredibly dangerous from a power supply perspective,” Jayanti says. “It means that there’s nowhere for Ukraine to import electricity from. It’s an orphan.” That was a particularly precarious situation given Russian attacks on key energy infrastructure such as the Zaporizhzhia nuclear power plant and ongoing strikes on Ukraine’s power grid that posed continuing risks. (According to Jayanti, Ukraine’s grid was ultimately able to run alone for as long as it did because power demand dropped by about a third as Ukrainians fled the country.)

Three days after the invasion, Ukrenergo sent a letter to the European Network of Transmission System Operators for Electricity (ENTSO-E) requesting authorization to connect to the European grid early. Moldelectrica, the Moldovan operator, made the same request the following day. While European operators wanted to support Ukraine, they had to protect their own grids, amid renewed focus on protecting the U.S. power grid from Russian hacking, so the emergency connection process had to be done carefully. “Utilities and system operators are notoriously risk-averse because the job is to keep the lights on, to keep everyone safe,” says Laura Mehigan, an energy researcher at University College Cork.

An electric grid is a network of power-generating sources and transmission infrastructure that produces electricity and carries it from places such as power plants, wind farms and solar arrays to houses, hospitals and public transit systems. “You can’t just experiment with a power system and hope that it works,” Deane says. Getting power where it is it needed when it is needed is an intricate process, and there is little room for error, as incidents involving Russian hackers targeting U.S. utilities have highlighted for operators worldwide.

Crucial to this mission is grid interconnection. Linked systems can share electricity across vast areas, often using HVDC technology, so that a surplus of energy generated in one location can meet demand in another. “More interconnection means we can move power around more quickly, more efficiently, more cost effectively and take advantage of low-carbon or zero-carbon power sources,” says James Glynn, a senior research scholar at the Center on Global Energy Policy at Columbia University. But connecting these massive networks with many moving parts is no small order.

One of the primary challenges of interconnecting grids is synchronizing them, which is what Ukrenergo, Moldelectrica and ENTSO-E accomplished last week. Synchronization is essential for sharing electricity. The task involves aligning the frequencies of every energy-generation facility in the connecting systems. Frequency is like the heartbeat of the electric grid. Across Europe, energy-generating turbines spin 50 times per second in near-perfect unison, and when disputes disrupt that balance, slow clocks across Europe can result, reminding operators of the stakes. For Ukraine and Moldova to join in, their systems had to be adjusted to match that rhythm. “We can’t stop the power system for an hour and then try to synchronize,” Deane says. “This has to be done while the system is operating.” It is like jumping onto a moving train or a spinning ride at the playground: the train or ride is not stopping, so you had better time the jump perfectly.

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2019 Global CO2 Emissions stayed flat, IEA reports, as renewable energy growth, wind and solar deployment, nuclear output, and coal-to-gas switching in advanced economies offset increases elsewhere, supporting climate goals and clean energy transitions.

Key Points

33 gigatonnes, unchanged YoY, as advanced economies cut power emissions via renewables, gas, and nuclear.

✅ IEA reports emissions flat at 33 Gt despite 2.9% GDP growth

✅ Advanced economies cut power-sector CO2 via wind, solar, gas

✅ Nuclear restarts and mild weather aided reductions

Despite widespread expectations of another increase, global energy-related CO2 emissions stopped growing in 2019, according to International Energy Agency (IEA) data released today. After two years of growth, global emissions were unchanged at 33 gigatonnes in 2019, a notable marker in the global energy transition narrative even as the world economy expanded by 2.9%.

This was primarily due to declining emissions from electricity generation in advanced economies, thanks to the expanding role of renewable sources (mainly wind and solar across many markets), fuel switching from coal to natural gas, and higher nuclear power generation, the Paris-based organisation says in the report.

"We now need to work hard to make sure that 2019 is remembered as a definitive peak in global emissions, not just another pause in growth," said Fatih Birol, the IEA's executive director. "We have the energy technologies to do this, and we have to make use of them all."

Higher nuclear power generation in advanced economies, particularly in Japan and South Korea, avoided over 50 Mt of CO2 emissions. Other factors included milder weather in several countries, and slower economic growth in some emerging markets. In China, emissions rose but were tempered by slower economic growth and higher output from low-carbon sources of electricity. Renewables continued to expand in China, and 2019 was also the first full year of operation for seven large-scale nuclear reactors in the country.

A significant decrease in emissions in advanced economies in 2019 offset continued growth elsewhere. The USA recorded the largest emissions decline on a country basis, with a fall of 140 million tonnes, or 2.9%. US emissions are now down by almost 1 gigatonne from their peak in 2000. Emissions in the European Union fell by 160 million tonnes, or 5%, in 2019 driven by reductions in the power sector as electricity producers move away from coal in the generation mix. Japan’s emissions fell by 45 million tonnes, or around 4%, the fastest pace of decline since 2009, as output from recently restarted nuclear reactors increased.

Emissions in the rest of the world grew by close to 400 million tonnes in 2019, with almost 80% of the increase coming from countries in Asia where coal-fired power generation continued to rise, and in Australia emissions rose 2% due to electricity and transport. Coal-fired power generation in advanced economies declined by nearly 15%, reflecting a sharp fall in coal-fired electricity across multiple markets, as a result of growth in renewables, coal-to-gas switching, a rise in nuclear power and weaker electricity demand.

The IEA will publish a World Energy Outlook Special Report in June that will map out how to cut global energy-related carbon emissions by one-third by 2030 and put the world on track for longer-term climate goals, a pathway that, in Canada, will require more electricity to hit net-zero. It will also hold an IEA Clean Energy Transitions Summit in Paris on 9 July, bringing together key government ministers, CEOs, investors and other major stakeholders.

Birol will discuss the results published today tomorrow at an IEA Speaker Series event at its headquarters with energy and climate ministers from Poland, which hosted COP24 in Katowice; Spain, which hosted COP25 in Madrid; and the UK, which will host COP26 in Glasgow this year, as greenhouse gas concentrations continue to break records worldwide.

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