Solar and wind power curtailments are rising in California


wind and solar power

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CAISO Renewable Curtailments reflect grid balancing under transmission congestion and oversupply, reducing solar and wind output while leveraging WEIM trading, battery storage, and transmission expansion to integrate renewables and stabilize demand-supply.

 

Key Points

CAISO renewable curtailments are reductions in wind and solar output to balance grid amid congestion or oversupply.

✅ Driven mainly by transmission congestion, less by oversupply.

✅ Peaks in spring when demand is low and solar output is high.

✅ Mitigated by WEIM trades, new lines, and battery storage growth.

 

The California Independent System Operator (CAISO), the grid operator for most of the state, is increasingly curtailing solar- and wind-powered electricity generation, as reported in rising curtailments, as it balances supply and demand during the rapid growth of wind and solar power in California.

Grid operators must balance supply and demand to maintain a stable electric system as advances in solar and wind continue to scale. The output of wind and solar generators are reduced either through price signals or rarely, through an order to reduce output, during periods of:

Congestion, when power lines don’t have enough capacity to deliver available energy
Oversupply, when generation exceeds customer electricity demand

In CAISO, curtailment is largely a result of congestion. Congestion-related curtailments have increased significantly since 2019 because California's solar boom has been outpacing upgrades in transmission capacity.

In 2022, CAISO curtailed 2.4 million megawatthours (MWh) of utility-scale wind and solar output, a 63% increase from the amount of electricity curtailed in 2021. As of September, CAISO has curtailed more than 2.3 million MWh of wind and solar output so far this year, even as the US project pipeline is dominated by wind, solar, and batteries.

Solar accounts for almost all of the energy curtailed in CAISO—95% in 2022 and 94% in the first seven months of 2023. CAISO tends to curtail the most solar in the spring when electricity demand is relatively low (because moderate spring temperatures mean less demand for space heating or air conditioning) and solar output is relatively high, although wildfire smoke impacts can reduce available generation during fire season as well.

CAISO has increasingly curtailed renewable generation as renewable capacity has grown in California, and the state has even experienced a near-100% renewables moment on the grid in recent years. In 2014, a combined 9.0 gigawatts (GW) of wind and solar capacity had been built in California. As of July 2023, that number had grown to 17.6 GW. Developers plan to add another 3.0 GW by the end of 2024.

CAISO is exploring and implementing various solutions to its increasing curtailment of renewables, including:

The Western Energy Imbalance Market (WEIM) is a real-time market that allows participants outside of CAISO to buy and sell energy to balance demand and supply. In 2022, more than 10% of total possible curtailments were avoided by trading within the WEIM. A day ahead market is expected to be operational in Spring 2025.

CAISO is expanding transmission capacity to reduce congestion. CAISO’s 2022–23 Transmission Planning Process includes 45 transmission projects to accommodate load growth and a larger share of generation from renewable energy sources.

CAISO is promoting the development of flexible resources that can quickly respond to sudden increases and decreases in demand such as battery storage technologies that are rapidly becoming more affordable. California has 4.9 GW of battery storage, and developers plan to add another 7.6 GW by the end of 2024, according to our survey of recent and planned capacity changes. Renewable generators can charge these batteries with electricity that would otherwise have been curtailed.

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Can the UK grid cope with the extra demand from electric cars?

UK EV Grid Capacity leverages smart charging, V2G, renewable energy, and interconnectors to manage peak demand as adoption grows, with National Grid upgrades, rapid chargers, and efficiency gains enabling a reliable, scalable charging infrastructure nationwide.

 

Key Points

UK EV grid capacity is the power network's readiness to meet EV demand using smart charging, V2G, and upgrades.

✅ Smart charging shifts load to off-peak, cheaper renewable hours

✅ V2G enables EVs to supply power and balance peak demand

✅ National Grid upgrades and interconnectors expand capacity

 

The surge of electric vehicles (EVs) on our roads raises a crucial question: can the UK's electricity grid handle the additional demand? While this is a valid concern, it's important to understand the gradual nature of EV adoption, ongoing grid preparations, and innovative solutions being developed.

A Gradual Shift, Not an Overnight Leap

Firstly, let's dispel the myth of an overnight transition. EV adoption will unfold progressively, driven by factors like affordability and the growing availability of used models. The government's ZEV mandate outlines a clear trajectory, with a gradual rise from 22% EV sales in 2024 to 80% by 2030. This measured approach allows for strategic grid improvements to accommodate the increasing demand.

Preparing the Grid for the Future

Grid preparations for the EV revolution have been underway for years. Collaborations between the government, electricity providers, service stations, and charging point developers are ensuring grid coordination across the system. Renewable energy sources like offshore wind farms, combined with new nuclear power and international interconnections, are planned to meet the anticipated 120 terawatt-hour increase in demand. Additionally, improvements in energy efficiency have reduced overall electricity consumption, creating further capacity.

Addressing Peak Demand Challenges

While millions of EVs charging simultaneously might seem like they could challenge power grids, solutions are being implemented to manage peak demand:

1. Smart Charging: This technology allows EVs to charge during off-peak hours when renewable electricity is abundant and cheaper. This not only benefits the grid but also saves owners money. The UK government's EV Smart Charge Points Regulations ensure all new chargers have this functionality.

2. Vehicle-to-Grid (V2G) Technology: This futuristic concept transforms EVs into energy storage units, often described as capacity on wheels, allowing owners to sell their unused battery power back to the grid during peak times. This not only generates income for owners but also helps balance the grid and integrate more renewable energy.

3. Sufficient Grid Capacity: Despite concerns, the grid currently has ample capacity. The highest peak demand in recent years (62GW in 2002) has actually decreased by 16% due to energy efficiency improvements. Even with widespread EV adoption, the expected 10% increase in demand remains well within the grid's capabilities with proper management in place.

National Grid's Commitment:

National Grid and other electric utilities are actively involved in upgrading and expanding the grid to accommodate the clean energy transition. This includes collaborating with distribution networks, government agencies, and industry partners to ensure the necessary infrastructure (wires and connections) is in place for a decarbonized transport network.

Charging Infrastructure: Addressing Anxiety

The existing national grid infrastructure, with its proximity to roads and train networks, provides a significant advantage for EV charging point deployment. National Grid Electricity Distribution is already working on innovative projects to install required infrastructure, such as:

  • Bringing electricity networks closer to motorway service areas for faster and easier connection.
  • Leading projects like the Electric Boulevard (inductive charging) and Electric Nation (V2G charging) to showcase innovative solutions.
  • Participating in the Take Charge project, exploring new ways to facilitate rapid EV charging infrastructure growth.

Government Initiatives:

The UK government's Rapid Charging Fund aims to roll out high-powered, open-access charge points across England, while the Local EV Infrastructure Fund supports local authorities in providing charging solutions for residents without off-street parking, including mobile chargers for added flexibility.

While the rise of EVs presents new challenges, the UK is actively preparing its grid and infrastructure to ensure a smooth transition. With gradual adoption, ongoing preparations, and innovative solutions, the answer to the question Will electric vehicles crash the grid? is a resounding yes. The future of clean transportation is bright, and the grid is ready to power it forward.

 

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BC Hydro electric vehicle fast charging site operational in Lillooet

BC Hydro Lillooet EV fast charging launches a pull-through, DC fast charger hub for electric trucks, trailers, and cars, delivering 50-kW clean hydroelectric power, range-topups, and network expansion across B.C. with reliable public charging.

 

Key Points

A dual 50-kW pull-through DC fast charging site in Lillooet supporting EV charging for larger trucks and trailers.

✅ Dual 50-kW units add ~50 km range in 10 minutes

✅ Pull-through bays fit trucks, trailers, and long-wheelbase EVs

✅ Part of BC Hydro network expansion across B.C.

 

A new BC Hydro electric vehicle fast charging site is now operational in Lillooet with a design that accommodates larger electric trucks and trailers.

'We are working to make it easier for drivers in B.C. to go electric and take advantage of B.C.'s clean, reliable hydroelectricity,' says Bruce Ralston, Minister of Energy, Mines and Low Carbon Innovation. 'Lillooet is a critical junction in BC Hydro's Electric Highway fast charging network and the unique design of this dual station will allow for efficient charging of larger vehicles.'

The Lillooet station opened in early March. It is in the parking lot at Old Mill Plaza at 155 Main Street and includes two 50-kilowatt charging units. Each unit can add 50 kilometres of driving to an average electric vehicle with BC Hydro's faster charging initiatives continuing to improve speeds, in about 10 minutes. The station is one of three in the province that can accommodate large trucks and trailers because of it's 'pull-through' design. The other two are in Powell River and Fraser Lake.

'As the primary fuel supplier for electric vehicles, we are building out more charging stations to ensure we can accommodate the volume and variety of electric vehicles that will be on B.C. roads in the coming years,' says Chris O'Riley, President and CEO of BC Hydro. 'BC Hydro will add 325 charging units to its network at 145 sites, and is piloting vehicle-to-grid technology to support grid flexibility within the next five years.'

Transportation accounts for about 40 per cent of greenhouse gas emissions in B.C. In September, BC Hydro revealed its Electrification Plan, with initiatives to encourage B.C. residents, businesses and industries to switch to hydroelectricity from fossil fuels to help reduce carbon emissions, alongside investments in clean hydrogen development to further decarbonize. The plan encourages switching from gas-powered cars to electric vehicles and is supported by provincial EV charger rebates for homes and workplaces.

BC Hydro's provincewide fast charging network currently includes, as part of B.C.'s expanding EV leadership across the province, 110 fast charging units at 76 sites in communities throughout B.C. The chargers are funded in a partnership with the Province of B.C. and Natural Resources Canada.

 

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'Consumer Reports' finds electric cars really do save money in the long run

Electric Vehicle Ownership Costs include lower maintenance, repair, and fuel expenses; Consumer Reports shows BEV and PHEV TCO beats ICE over 200,000 miles, with per-mile savings compounding through electricity prices and reduced service.

 

Key Points

Lifetime EV expenses, typically lower than ICE, due to cheaper electricity, reduced maintenance, and fewer repairs.

✅ BEV: $0.012/mi to 50k; $0.028/mi after; vs ICE up to $0.06/mi

✅ PHEV: $0.021/mi to 50k; $0.031/mi after; still below ICE

✅ Savings increase over 200k miles from fuel and service reductions

 

Electric vehicles are a relatively new technology, and the EV age is arriving ahead of schedule today. Even though we technically saw the first battery-powered vehicles more than 100 years ago, they haven’t really become viable transportation in the modern world until recently, and they are greener than ever in all 50 states as the grid improves.

As viable as they may now be, however, it still seems they’re unarguably more expensive than their conventional internal-combustion counterparts, prompting many to ask whether it’s time to buy an electric car today. Well, until now.

Lower maintenence costs and the lower price of electricity versus gasoline (see the typical cost to charge an electric vehicle in most regions) actually make electric cars much cheaper in the long run, despite their often higher purchase price, according to a new survey by Consumer Reports. The information was collected using annual reliability surveys conducted by CR in 2019 and 2020.

In the first 50,000 miles (80,500 km), battery electric vehicles cost just US$0.012 per mile for maintenence and repairs, while plug-in hybrid models bump that number up to USD$0.021. Compare these numbers to the typical USD$0.028 cost for internal combustion vehicles, and it becomes clear the more you drive, the more you will save, and across the U.S. plug-ins logged 19 billion electric miles in 2021 to prove the point. After 50,000 miles, the costs for BEV and PHEV vehicles is US$0.028 and US$0.031 respectively, while ICE vehicles jump to US$0.06 per mile.

To put it more practically, if you chose to buy a Model 3 instead of a BMW 330i, you’d see a total US$17,600 in savings over the lifetime of the vehicle, aligning with evidence that EVs are better for the planet and your budget as well, based on average driving. In the SUV sector, buying a Tesla Model Y instead of a Lexus crossover would save US$13,400 (provided the former’s roof doesn’t fly off) and buying a Nissan Leaf over a Honda Civic would save US$6,000 over the lifetime of the vehicles.

CR defines the vehicle’s “lifetime” as 200,000 miles (320,000 km). Ergo the final caveat: while it sounds like driving electric means big savings, you might only see those returns after quite a long period of ownership, though some forecasts suggest that within a decade adoption will be nearly universal for many drivers.

 

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US: In 2021, Plug-Ins Traveled 19 Billion Miles On Electricity

US Plug-in EV Miles 2021 highlight BEV and PHEV growth, DOE and Argonne data, 19.1 billion electric miles, 6.1 TWh consumed, gasoline savings, rising market share, and battery capacity deployed across the US light-duty fleet.

 

Key Points

They represent 19.1 billion electric miles by US BEVs and PHEVs in 2021, consuming 6.1 TWh of electricity.

✅ 700 million gallons gasoline avoided in 2021

✅ $1.3 billion fuel cost savings estimated

✅ Cumulative 68 billion EV miles since 2010

 

Plug-in electric cars are gradually increasing their market share in the US (reaching about 4% in 2021), which starts to make an impact even as the U.S. EV market share saw a brief dip in Q1 2024.

The Department of Energy (DOE)’s Vehicle Technologies Office highlights in its latest weekly report that in 2021, plug-ins traveled some 19.1 billion miles (31 billion km) on electricity - all miles traveled in BEVs and the EV mode portion of miles traveled in PHEVs, underscoring grid impacts that could challenge state power grids as adoption grows.

This estimated distance of 19 billion miles is noticeably higher than in 2020 (nearly 13 billion miles), which indicates how quickly the electrification of driving progresses, with U.S. EV sales continuing to soar into 2024. BEVs noted a 57% year-over-year increase in EV miles, while PHEVs by 24% last year (mostly proportionally to sales increase).

According to Argonne National Laboratory's Assessment of Light-Duty Plug-in Electric Vehicles in the United States, 2010–2021, the cumulative distance covered by plug-in electric cars in the US (through December 2021) amounted to 68 billion miles (109 billion miles).

U.S. Department of Transportation, Federal Highway Administration, December 2021 Traffic Volume Trends, 2022.

The report estimates that over 2.1 million plug-in electric cars have been sold in the US through December 2021 (about 1.3 million all-electric and 0.8 million plug-in hybrids), equipped with a total of more than 110 GWh of batteries, even as EV sales remain behind gas cars in overall market share.

It's also estimated that 19.1 billion electric miles traveled in 2021 reduced the national gasoline consumption by 700 million gallons of gasoline or 0.54%.

On the other hand, plug-ins consumed some 6.1 terawatt-hours of electricity (6.1 TWh is 6,100 GWh), which sounds like almost 320 Wh/mile (200 Wh/km), aligning with projections that EVs could drive a rise in U.S. electricity demand over time.

The difference between the fuel cost and energy cost in 2021 is estimated at $1.3 billion, with Consumer Reports findings further supporting the total cost advantages.

Cumulatively, 68 billion electric miles since 2010 is worth about 2.5 billion gallons of gasoline. So, the cumulative savings already is several billion dollars.

Those are pretty amazing numbers and let's just imagine that electric cars are just starting to sell in high volume, a trend that mirrors global market growth seen over the past decade. Every year those numbers will be improving, thus tremendously changing the world that we know today.

 

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Stalled spending on electrical grids slows rollout of renewable energy

IEA Grid Expansion Warning highlights stalled investment in power lines and transmission infrastructure, risking renewable energy rollout for solar, wind, EVs, and heat pumps, and jeopardizing climate targets under the Paris Agreement amid connection bottlenecks.

 

Key Points

IEA alert urging grid investment to expand transmission, connect renewables, and keep 1.5 C climate goals on track.

✅ 80 million km of lines needed by 2040, per IEA

✅ Investment must double to $600B annually by 2030

✅ Permitting delays stall major cross-border projects

 

Stalled spending on electrical grids worldwide is slowing the rollout of renewable energy and could put efforts to limit climate change at risk if millions of miles of power lines are not added or refurbished in the next few years, the International Energy Agency said.

The Paris-based organization said in the report Tuesday that the capacity to connect to and transmit electricity is not keeping pace with the rapid growth of clean energy technologies such as solar and wind power, electric cars and heat pumps being deployed to move away from fossil fuels, a gap reflected in why the U.S. grid isn't 100% renewable today.

IEA Executive Director Fatih Birol told The Associated Press in an interview that there is a long line of renewable projects waiting for the green light to connect to the grid, including UK renewable backlog worth billions. The stalled projects could generate 1,500 gigawatts of power, or five times the amount of solar and wind capacity that was added worldwide last year, he said.

“It’s like you are manufacturing a very efficient, very speedy, very handsome car — but you forget to build the roads for it,” Birol said.

If spending on grids stayed at current levels, the chance of holding the global increase in average temperature to 1.5 degrees Celsius above pre-industrial levels — the goal set by the 2015 Paris climate accords — “is going to be diminished substantially,” he said.

The IEA assessment of electricity grids around the globe found that achieving the climate goals set by the world’s governments would require adding or refurbishing 80 million kilometers (50 million miles) of power lines by 2040 — an amount equal to the existing global grid in less than two decades.

Annual investment has been stagnant but needs to double to more than $600 billion a year by 2030, the agency said, with U.S. grid overhaul efforts aiming to accelerate upgrades.

It’s not uncommon for a single high-voltage overhead power line to take five to 13 years to get approved through bureaucracy in advanced economies, while lead times are significantly shorter in China and India, according to the IEA, though a new federal rule seeks to boost transmission planning.

The report cited the South Link transmission project to carry wind power from northern to southern Germany. First planned in 2014, it was delayed after political opposition to an overhead line meant it was buried instead, while more pylons in Scotland are being urged to keep the lights on, industry says. Completion is expected in 2028 instead of 2022.

Other important projects that have been held up: the 400-kilometer (250-mile) Bay of Biscay connector between Spain and France, now expected for 2028 instead of 2025, and the SunZia high-voltage line to bring wind power from New Mexico to Arizona and California, while Pacific Northwest goals are hindered by grid limits. Construction started only last month after years of delays.

On the East Coast, the Avangrid line to bring hydropower from Canada to New England was interrupted in 2021 following a referendum in Maine, as New England's solar growth is also creating tension over who pays for grid upgrades. A court overturned the statewide vote rejecting the project in April.

 

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Bus depot bid to be UK's largest electric vehicle charging hub

First Glasgow Electric Buses will transform the Caledonia depot with 160 charging points, zero-emission operations, grid upgrades, and rapid charging, supported by Transport Scotland funding and Alexander Dennis manufacturing for cleaner urban routes by 2023.

 

Key Points

Electric single-deckers at Caledonia depot with 160 chargers and upgrades, delivering zero-emission service by 2023

✅ 160 charging points; 4-hour rapid recharge capability

✅ Grid upgrades to power a fleet equal to a 10,000-person town

✅ Supported by Transport Scotland; built by Alexander Dennis

 

First Bus will install 160 charging points and replace half its fleet with electric buses at its Caledonia depot in Glasgow.

The programme is expected to be completed in 2023, similar to Metro Vancouver's battery-electric rollout milestones, with the first 22 buses arriving by autumn.

Charging the full fleet will use the same electricity as it takes to power a town of 10,000 people.

The scale of the project means changes are needed to the power grid, a challenge highlighted in global e-bus adoption analysis, to accommodate the extra demand.

First Glasgow managing director Andrew Jarvis told BBC Scotland: "We've got to play our part in society in changing how we all live and work. A big part of that is emissions from vehicles.

"Transport is stubbornly high in terms of emissions and bus companies need to play their part, and are playing their part, in that zero emission journey."

First Bus currently operates 337 buses out of its largest depot with another four sites across Glasgow.

The new buses will be built by Alexander Dennis at its manufacturing sites in Falkirk and Scarborough.

The transition requires a £35.6m investment by First with electric buses costing almost double the £225,000 bill for a single decker running on diesel.

But the company says maintenance and running costs, as seen in St. Albert's electric fleet results, are then much lower.

The buses can run on urban routes for 16 hours, similar to Edmonton's first e-bus performance, and be rapidly recharged in just four hours.

This is a big investment which the company wouldn't be able to achieve on its own.

Government grants only cover 75% of the difference between the price of a diesel and an electric bus, similar to support for B.C. electric school buses programmes, so it's still a good bit more expensive for them.

But they know they have to do it as a social responsibility, and large-scale initiatives like US school bus conversions show the direction of travel, and because the requirements for using Low Emissions Zones are likely to become stricter.

The SNP manifesto committed to electrifying half of Scotland's 4,000 or so buses within two years.

Some are questioning whether that's even achievable in the timescale, though TTC's large e-bus fleet offers lessons, given the electricity grid changes that would be necessary for charging.

But it's a commitment that environmental groups will certainly hold them to.

Transport Scotland is providing £28.1m of funding to First Bus as part of the Scottish government's commitment to electrify half of Scotland's buses in the first two years of the parliamentary term.

Net Zero Secretary Michael Matheson said: "It's absolute critical that we decarbonise our transport system and what we have set out are very ambitious plans of how we go about doing that.

"We've set out a target to make sure that we decarbonise as many of the bus fleets across Scotland as possible, at least half of it over the course of the next couple of years, and we'll set out our plans later on this year of how we'll drive that forward."

Transport is the single biggest source of greenhouse gas emissions in Scotland which are responsible for accelerating climate change.

In 2018 the sector was responsible for 31% of the country's net emissions.

Electric bus
First Glasgow has been trialling two electric buses since January 2020.

Driver Sally Smillie said they had gone down well with passengers because they were much quieter than diesel buses.

She added: "In the beginning it was strange for them not hearing them coming but they adapt very easily and they check now.

"It's a lot more comfortable. You're not feeling a gear change and the braking's smoother. I think they're great buses to drive."

 

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