Green power storage size to triple by 2030

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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Methane Hydrate CO2 Sequestration uses carbon capture and nitrogen injection to swap gases in seafloor hydrates along the Gulf of Mexico, releasing methane for electricity while storing CO2, according to new simulation research.

Key Points

A method injecting CO2 and nitrogen into hydrates to store CO2 while releasing methane for power.

✅ Nitrogen aids CO2-methane swap in hydrate cages, speeding sequestration

✅ Gulf Coast proximity to emitters lowers transport and power costs

✅ Revenue from methane electricity could offset carbon capture

The world is quickly realizing it may need to actively pull carbon dioxide out of the atmosphere to stave off the ill effects of climate change. Scientists and engineers have proposed various carbon capture techniques, but most would be extremely expensive—without generating any revenue. No one wants to foot the bill.

One method explored in the past decade might now be a step closer to becoming practical, as a result of a new computer simulation study. The process would involve pumping airborne CO2 down into methane hydrates—large deposits of icy water and methane right under the seafloor, beneath water 500 to 1,000 feet deep—where the gas would be permanently stored, or sequestered. The incoming CO2 would push out the methane, which would be piped to the surface and burned to generate electricity, whether sold locally or via exporters like Hydro-Que9bec to help defray costs, to power the sequestration operation or to bring in revenue to pay for it.

Many methane hydrate deposits exist along the Gulf of Mexico shore and other coastlines. Large power plants and industrial facilities that emit CO2 also line the Gulf Coast, where EPA power plant rules could shape deployment, so one option would be to capture the gas directly from nearby smokestacks, keeping it out of the atmosphere to begin with. And the plants and industries themselves could provide a ready market for the electricity generated.

A methane hydrate is a deposit of frozen, latticelike water molecules. The loose network has many empty, molecular-size pores, or “cages,” that can trap methane molecules rising through cracks in the rock below. The computer simulation shows that pushing out the methane with CO2 is greatly enhanced if a high concentration of nitrogen is also injected, and that the gas swap is a two-step process. (Nitrogen is readily available anywhere, because it makes up 78 percent of the earth’s atmosphere.) In one step the nitrogen enters the cages; this destabilizes the trapped methane, which escapes the cages. In a separate step, the nitrogen helps CO2 crystallize in the emptied cages. The disturbed system “tries to reach a new equilibrium; the balance goes to more CO2 and less methane,” says Kris Darnell, who led the study, published June 27 in the journal Water Resources Research. Darnell recently joined the petroleum engineering software company Novi Labs as a data scientist, after receiving his Ph.D. in geoscience from the University of Texas, where the study was done.

A group of labs, universities and companies had tested the technique in a limited feasibility trial in 2012 on Alaska’s North Slope, where methane hydrates form in sandstone under deep permafrost. They sent CO2 and nitrogen down a pipe into the hydrate. Some CO2 ended up being stored, and some methane was released up the same pipe. That is as far as the experiment was intended to go. “It’s good that Kris [Darnell] could make headway” from that experience, says Ray Boswell at the U.S. Department of Energy’s National Energy Technology Laboratory, who was one of the Alaska experiment leaders but was not involved in the new study. The new simulation also showed that the swap of CO2 for methane is likely to be much more extensive—and to happen quicker—if CO2 enters at one end of a hydrate deposit and methane is collected at a distant end.

The technique is somewhat similar in concept to one investigated in the early 2010s by Steven Bryant and others at the University of Texas. In addition to numerous methane hydrate deposits, the Gulf Coast has large pools of hot, salty brine in sedimentary rock under the coastline. In this system, pumps would send CO2 down into one end of a deposit, which would force brine into a pipe that is placed at the other end and leads back to the surface. There the hot brine would flow through a heat exchanger, where heat could be extracted and used for industrial processes or to generate electricity, supporting projects such as electrified LNG in some markets. The upwelling brine also contains some methane that could be siphoned off and burned. The CO2 dissolves into the underground brine, becomes dense and sinks further belowground, where it theoretically remains.

Either system faces big practical challenges, and building shared CO2 storage hubs to aggregate captured gas is still evolving. One is creating a concentrated flow of CO2; the gas makes up only .04 percent of air, and roughly 10 percent of the smokestack emission from a typical power plant or industrial facility. If an efficient methane hydrate or brine system requires an input that is 90 percent CO2, for example, concentrating the gas will require an enormous amount of energy—making the process very expensive. “But if you only need a 50 percent concentration, that could be more attractive,” says Bryant, who is now a professor of chemical and petroleum engineering at the University of Calgary. “You have to reduce the [CO2] capture cost.”

Another major challenge for the methane hydrate approach is how to collect the freed methane, which could simply seep out of the deposit through numerous cracks and in all directions. “What kind of well [and pipe] structure would you use to grab it?” Bryant asks.

Given these realities, there is little economic incentive today to use methane hydrates for sequestering CO2. But as concentrations rise in the atmosphere and the planet warms further, and as calls for an electric planet intensify, systems that could capture the gas and also provide energy or revenue to run the process might become more viable than techniques that simply pull CO2 from the air and lock it away, offering nothing in return.

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Siwash Creek Hydroelectric Project faces downsizing under a BC Hydro power purchase agreement, with run-of-river generation, high grid interconnection costs, First Nations partnership, and surplus electricity from Site C reshaping clean energy procurement.

Key Points

A downsized run-of-river plant in BC, co-owned by Kanaka Bar and Green Valley, selling power via a BC Hydro PPA.

✅ Approved at 500 kW under a BC Hydro clean-energy program

✅ Grid interconnection initially quoted at $2.1M

✅ Joint venture: Kanaka Bar and Green Valley Power

A small run-of-river hydroelectric project recently selected by B.C. Hydro for a power purchase agreement may no longer be financially viable.

The Siwash Creek project was originally conceived as a two-megawatt power plant by the original proponent Chad Peterson, who holds a 50-per-cent stake through Green Valley Power, with the Kanaka Bar Indian Band holding the other half.

The partners were asked by B.C. Hydro to trim the capacity back to one megawatt, but by the time the Crown corporation announced its approval, it agreed to only half that — 500 kilowatts — under its Standing Order clean-energy program.

“Hydro wanted to charge us $2.1 million to connect to the grid, but then they said they could reduce it if we took a little trim on the project,” said Kanaka Bar Chief Patrick Michell.

The revenue stream for the band and Green Valley Power has been halved to about $250,000 a year. The original cost of running the $3.7-million plant, including financing, was projected to be $273,000 a year, according to the Kanaka Bar economic development plan.

“By our initial forecast, we will have to subsidize the loan for 20 years,” said Michell. “It doesn’t make any sense.”

The Kanaka Band has already invested $450,000 in feasibility, hydrology and engineering studies, with a similar investment from Green Valley.

B.C. Hydro announced it would pursue five purchase agreements last March with five First Nations projects — including Siwash Creek — including hydro, solar and wind energy projects, as two new generating stations were being commissioned at the time. A purchase agreement allows proponents to sell electricity to B.C. Hydro at a set price.

However, at least ten other “shovel-ready” clean energy projects may be doomed while B.C. Hydro completes a review of its own operations and its place in the energy sector, where legal outcomes like the Squamish power project ruling add uncertainty, including B.C.’s future power needs.

With the 1,100-megawatt Site C Dam planned for completion in 2024, and LNG demand cited to justify it, B.C. Hydro now projects it will have a surplus of electricity until the early 2030s.

Even if British Columbians put 300,000 electric vehicles on the road over the next 12 years, amid BC Hydro’s first call for power, they will require only 300 megawatts of new capacity, the company said.

A long-term surplus could effectively halt all small-scale clean energy development, according to Clean Energy B.C., even as Hydro One’s U.S. coal plant remains online in the region.

“(B.C. Hydro) dropped their offer down to 500 kilowatts right around the time they announced their review,” said Michell. “So we filled out the paperwork at 500 kilowatts and (B.C. Hydro) got to make its announcement of five projects.”

In the new few weeks, Kanaka and Green Valley will discuss whether they can move forward with a new financial model or shelve the project, he said.

B.C. Hydro declined to comment on the rationale for downsizing Siwash Creek’s power purchase agreement.

The Kanaka Bar Band successfully operates a 49.9-megawatt run-of-river plant on Kwoiek Creek with partners Innergex Renewable Energy.

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Nova Scotia Power Active Demand Control Tariff lets the utility direct Port Hawkesbury Paper load, enabling demand response, efficiency, and industrial electricity rates, while regulators assess impacts on ratepayers, grid reliability, mill viability, and savings.

Key Points

A four-year tariff letting the utility control the mill load for demand response, efficiency, and lower costs.

✅ Utility can increase or reduce daily consumption at the mill

✅ Projected savings of $10M annually for other ratepayers to 2023

✅ Regulators reviewing cost allocation, monitoring, and viability

Nova Scotia Power is scheduled to appear before government regulators Tuesday morning seeking approval for a unique discount rate for its largest customer.

Under the four-year plan, Nova Scotia Power would control the supply of electricity to Port Hawkesbury Paper, a move referenced in a grid operations report that urges changes, with the right to direct the company to increase or reduce daily consumption throughout the year.

The rate proposal is supported by the mill, which says it needs to lower its power bill to keep its operation viable.

The rate went into effect on Jan. 1 on a temporary basis, pending the outcome of a hearing this week before the Nova Scotia Utility and Review Board, amid broader calls for an independent body to lead electricity planning.

The mill accounts for 10 per cent of the provincial electricity load, even as a neighbouring utility pursues more Quebec power for the region, producing glossy paper used in magazines and catalogs.

Nova Scotia Power says controlling how much electricity the mill uses — and when — will allow it to operate the system much more efficiently, as it expands biomass generation initiatives, saving other customers $10 million a year until the rate expires in 2023.

Ceding control 'not an easy decision'
In its opening statement that was filed in advance, Port Hawkesbury Paper said ceding the control of its electrical supply to Nova Scotia Power was "not an easy decision" to make, but the company is confident the arrangement will work.

In September 2019, Nova Scotia Power and the mill jointly applied for an "extra large active demand control tariff," which would provide electricity to the mill for about $61 per megawatt hour, well below the full cost of generating the electricity.

The utility said "fully allocating costs" would result in "prices in excess of $80/MWh ... and [would] not [be] financially viable for the mill."

In its statement, Port Hawkesbury Paper said since the initial filing "there have been greater near term declines in market demand and pricing for PHP's product than was forecast at that time, continuing to put pressure on our business and further highlighting the need to maintain the balance provided for in the new tariff."

Consumer advocate sees 'advantage,' but will challenge
Bill Mahody represents Nova Scotia Power's 400,000 residential customers before the review board. He wants proof the mill will pay enough toward the cost of generating the electricity it uses, amid concerns over biomass use in the province today.

"We filed evidence, as have others involved in the proceeding, that would call into question whether or not the rate design is capturing all of those costs and that will be a significant issue before the board," Mahody said.

Still, he sees value in the proposal.

The proposed new rate went into effect on Jan. 1 on a temporary basis. (The Canadian Press)
"This proposed rate gives Nova Scotia Power the ability to control that sizable Port Hawkesbury Paper load to the advantage of other ratepayers, as the province pursues more wind and solar projects, because Nova Scotia Power would be reducing the costs that other ratepayers are going to face," he said.

Mahody is also calling for a mechanism to monitor whether the mill's position actually improves to the point where it could pay higher rates.

"An awful lot can change during a four-year period, with new tidal power projects underway, and I think the board ought to have the ability to check in on this and make sure that their preferential rate continues to be justified," he said.

Major employer
Port Hawkesbury Paper, owned by Stern Partners in Vancouver, has received discounted power rates since it bought the idled mill in 2012. But the "load retention tariff" as it was called, expired at the end of 2019.

Regulators have accepted Nova Scotia Power's argument that it would cost other customers more if the mill ceased to operate.

The mill said it spends between $235 million and $265 million annually, employing 330 people directly and supporting 500 other jobs indirectly.

The Nova Scotia government pledged $124 million in financial assistance as part of the reopening in 2012.

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Toronto Hydro Storm Outages continue after strong winds and heavy rain, with crews restoring power, clearing debris and downed lines. Safety alerts and real-time updates guide affected neighborhoods via website and social media.

Key Points

Toronto Hydro Storm Outages are weather-related power cuts; crews restore service safely and share public updates.

✅ Crews prioritize areas with severe damage and limited access

✅ Report downed power lines; keep a safe distance

✅ Check website and social media for restoration updates

In the aftermath of a powerful spring storm that swept through Toronto on Tuesday, approximately 400 customers remain without power as of Sunday. The storm, which brought strong winds and heavy rain that caused severe flooding in some areas, led to significant damage across the city, including downed trees and power lines. Toronto Hydro crews have been working tirelessly to restore service, similar to efforts by Sudbury Hydro crews in Northern Ontario, focusing on areas with the most severe damage. While many customers have had their power restored, the remaining outages are concentrated in neighborhoods where access is challenging due to debris and fallen infrastructure.

Toronto Hydro has assured residents that restoration efforts are ongoing and that they are prioritizing safety and efficiency, in step with recovery from damaging storms in Ontario across the province. The utility company has urged residents to report any downed power lines and to avoid approaching them, as they may still be live and dangerous, and notes that utilities sometimes rely on mutual aid deployments to speed restoration in large-scale events. Additionally, Toronto Hydro has been providing updates through their website and social media channels, keeping the public informed about the status of power restoration in affected areas.

The storm's impact has also led to disruptions in other services, and power outages in London disrupted morning routines for thousands earlier in the week. Some public transportation routes experienced delays due to debris on tracks, and several schools in the affected areas were temporarily closed. City officials are coordinating with various agencies to address these issues and ensure that services return to normal as quickly as possible, even as Quebec contends with widespread power outages after severe windstorms.

Residents are advised to stay updated on the situation through official channels and to exercise caution when traveling in storm-affected areas. Toronto Hydro continues to work diligently to restore power to all customers and appreciates the public's patience during this challenging time, a challenge echoed when Texas utilities struggled to restore power during Hurricane Harvey.

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Ontario Pickering Nuclear Closure will shift supply to natural gas, raising emissions as the electricity grid manages nuclear refurbishment, IESO planning, clean power imports, and new wind, solar, and storage to support electrification.

Key Points

Ontario will close Pickering and rely on natural gas, increasing emissions while other nuclear units are refurbished.

✅ 14% of Ontario electricity supplied by Pickering now

✅ Natural gas use rises; grid emissions projected up 375%

✅ IESO warns gas phaseout by 2030 risks blackouts, costs

The Ontario government will not reconsider plans to close the Pickering nuclear station and instead stop-gap the consequent electricity shortfall with natural gas-generated power in a move that will, as an analysis of Ontario's grid shows, hike the province’s greenhouse gas emissions substantially in the coming years.

In a report released this week, a nuclear advocacy group urged Ontario to refurbish the aging facility east of Toronto, which is set to be shuttered in phases in 2024 and 2025, prompting debate over a clean energy plan after Pickering as the closure nears. The closure of Pickering, which provides 14 per cent of the province’s annual electricity supply, comes at the same time as Ontario’s other two nuclear stations are undergoing refurbishment and operating at reduced capacity.

Canadians for Nuclear Energy, which is largely funded by power workers' unions, argued closing the 50-year-old facility will result in job losses, emissions increases, heightened reliance on imported natural gas and an electricity supply gap across Ontario.

But Palmer Lockridge, spokesperson for the provincial energy minister, said further extending Pickering’s lifespan isn’t on the table.

“As previously announced in 2020, our government is supporting Ontario Power Generation’s plan to safely extend the life of the Pickering Nuclear Generating Station through the end of 2025,” said Lockridge in an emailed response to questions.

“Going forward, we are ensuring a reliable, affordable and clean electricity system for decades to come. That’s why we put a plan in place that ensures we are prepared for the emerging energy needs following the closure of Pickering, and as a result of our government’s success in growing and electrifying the province’s economy.”

The Progressive Conservative government under Premier Doug Ford has invested heavily in electrification, sinking billions into electric vehicle and battery manufacturing and industries like steel-making to retool plants to run on electricity rather than coal, and exploring new large-scale nuclear plants to bolster baseload supply.

Natural gas now provides about seven per cent of the province’s energy, a piece of the pie that will rise significantly as nuclear energy dwindles. Emissions from Ontario’s electricity grid, which is currently one of the world’s cleanest with 94 per cent zero-emission power generation, are projected to rise a whopping 375 per cent as the province turns increasingly to natural gas generation. Those increases will effectively undo a third of the hard-won emissions reductions the province achieved by phasing out coal-fired power generation.

The Independent Electricity System Operator (IESO), which manages Ontario’s grid, studied whether the province could phase out natural gas generation by 2030 and concluded that “would result in blackouts and hinder electrification” and increase average residential electricity costs by $100 per month.

The Ontario Clean Air Alliance, however, obtained draft documents from the electricity operator that showed it had studied, but not released publicly, other scenarios that involved phasing out natural gas without energy shortfalls, price hikes or increases in emissions.

The Ontario government will not reconsider plans to close the Pickering nuclear station and instead stop-gap the consequent electricity shortfall facing Ontario with natural gas-generated power in a move that will hike the province’s greenhouse gas emissions.

One model suggested increasing carbon taxes and imports of clean energy from other provinces could keep blackouts, costs and emissions at bay, while another involved increasing energy efficiency, wind generation and storage.

“By banning gas-fired electricity exports to the U.S., importing all the Quebec water power we can with the existing transmission lines and investing in energy efficiency and wind and solar and storage — do all those things and you can phase out gas-fired power and lower our bills,” said Jack Gibbons, chair of the Ontario Clean Air Alliance.

The IESO has argued in response that the study of those scenarios was not complete and did not include many of the challenges associated with phasing out natural gas plants.

Ontario Energy Minister Todd Smith asked the IESO to develop “an achievable pathway to zero-emissions in the electricity sector and evaluate a moratorium on new-build natural gas generation stations,” said his spokesperson. That report, an early look at halting gas power, is expected in November.

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