Solar and wind power curtailments are rising in California


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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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Why a green recovery goes far deeper than wind energy

Scotland Green Recovery Strategy centers on renewable energy, onshore wind, energy efficiency, battery storage, hydrogen, and electric vehicles, alongside public transport and digital infrastructure, local manufacturing, and grid flexibility to decarbonize industry and communities.

 

Key Points

A plan to cut emissions by scaling renewables, efficiency, storage, and infrastructure for resilient, low-carbon growth.

✅ Prioritize energy efficiency retrofits in homes and workplaces

✅ Invest in battery storage, hydrogen, and EV charging networks

✅ Support local manufacturing and circular economy supply chains

 

THE “green recovery” joins the growing list of Covid-era political maxims, while green energy investment could drive recovery, suggesting a bright and environmentally sustainable post-pandemic future lies ahead.

The Prime Minister once again alluded to it recently when he expressed his ambition to see the UK become the “world leader in clean wind energy”. In his typically bombastic style, Boris Johnson declared that everything from our kettles to electric vehicles, with offshore wind energy central to that vision, will be powered by “breezes that blow around these islands” by the next decade.

These comments create a misleading impression about how we can achieve a green recovery, particularly as Covid-19 hit renewables and exposed systemic challenges. While wind turbines have a key role to play, they are just one part of a comprehensive solution requiring a far more in-depth focus on how and why we use energy. We must concentrate our efforts and resources on reducing our overall consumption and increasing energy capture.

This includes making significant energy efficiency improvements to the buildings where we live and work and grasping the lessons of lockdown, including proposals for a fossil fuel lockdown to accelerate climate action, to ensure we operate in a more effective and less environmentally-damaging fashion. Do we really want to return to a world where people commute daily half way across the country for work or fly to New York for a two-hour meeting?

Businesses will need to adapt to new ways of operating outwith the traditional nine-to-five working week to reduce congestion and pollution levels. To make this possible requires Government investment in critical areas such as public transport and digital infrastructure, alongside more pylons to strengthen the grid, across all parts of Scotland to decentralise the economy and enable more people to live and work outside the main cities.

A Government-supported green recovery must rest on making it financially viable for businesses to manufacture here to reduce our reliance on imported goods. This includes processing recycleable materials here rather than shipping them abroad. It also means using locally generated energy to support local jobs and industry. We miss a trick if Scotland simply becomes a power generator for the rest of the UK.

MOVING transport from fossil fuels to renewable fuels will require a step-change that also requires support across all levels. The increased use of electric vehicles and hydrogen fuel cells are all encouraging developments, but these will rely on investment in infrastructure throughout the country if we’re to achieve significant benefits to our environment and our economy.

This brings us to the role of onshore wind power; still the cheapest form of renewable energy, and a sector marked by wind growth despite Covid-19 around the world today. Repowering existing sites with newer and more efficient turbines will certainly increase capacity rapidly, but we must also invest into development projects that will further enhance the capacity and efficiency of existing equipment. This includes improving on the current practice of the National Grid paying operators to switch off wind turbines when excess electricity is produced and instead developing new and innovative means to capture this energy. Government-primed investment into battery storage could help ensure we achieve and further reduce our reliance on traditional, non-sustainable sources.

We need a level playing field so that all forms of energy are judged on their lifetime cost in terms of emissions as well as construction and decommissioning costs to ensure fiscal incentives are applied on a fairer basis.

Turning the maxim of a green recovery into reality will require more than extra wind turbines, and the UK's wind lessons underscore the importance of policy and scale. We need a significant investment and commitment from business and government to limit existing emissions and ensure we capture and use energy more efficiently.

Andy Drane is projects partner and head of renewables at law firm Davidson Chalmers Stewart.

 

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Requests for Proposal launched for purchase of clean electricity in Alberta

Canada Clean Electricity Procurement advances federal operations with renewable energy in Alberta, leveraging RECs, competitive sourcing, Indigenous participation, and grid decarbonization to cut greenhouse gas emissions and stimulate new clean power infrastructure.

 

Key Points

A plan to procure clean power and RECs, cutting emissions in Alberta and attributing use where renewables are absent.

✅ RFPs to source new clean electricity in Alberta

✅ RECs from net new Canadian renewable generation

✅ Mandatory Indigenous participation via equity or set-asides

 

Public Services and Procurement Canada (PSPC) is taking concrete steps to meet the Government of Canada's commitment in the Greening Government Strategy to reduce greenhouse gas emissions from federal government buildings, vehicle fleets and other operations, aligning with broader vehicle electrification trends across Canada.

The Honourable Anita Anand, Minister of Public Services and Procurement, announced the Government of Canada has launched Requests for Proposal to buy new clean electricity in the province of Alberta, which is moving ahead with the retirement of coal power to clean its grid, to power federal operations there.

As well, Canada will purchase Renewable Energy Certificates (REC) from new clean energy generation in Canada. This will enable Canada to attribute its energy consumption as clean in regions where new clean renewable sources are not yet available. The Government of Canada is excited about this opportunity to stimulate net new Canadian clean electricity generation through the procurement of RECs and complementary power purchase agreements that secure long-term supply for federal demand.

Together, these contracts will help to ensure Canada is reducing its greenhouse gas footprint by approximately 133 kilotonnes or 56% of total real property emissions in Alberta. Additionally, the contracts will displace approximately 41 kilotonnes of greenhouse gas emissions from electricity use in the rest of Canada, supporting progress toward 2035 clean electricity goals even as challenges remain.

Through these open, fair and transparent competitive procurement processes, PSPC will be a key purchaser of clean electricity and will support the growth of new clean electricity and renewable power infrastructure, such as recent turbine investments in Manitoba that expand capacity.

The Government of Canada's Clean Electricity Initiative plans to use 100% clean electricity by 2022, where available, in alignment with evolving net-zero electricity regulations that shape supply choices, to reduce greenhouse gas emissions and stimulate growth in clean renewable power infrastructure. PSPC has applied the goals of the Government of Canada's Clean Electricity Initiative to its specific requirement for net new clean electricity generation to power federal operations in Alberta.  

These procurements will support economic opportunities for Indigenous businesses by encouraging participation in the move towards clean energy, seen in provincial shifts toward clean power in Ontario that broaden markets. Each Request for Proposal incorporates mandatory requirements for Indigenous participation through equity holdings or set-asides under the Procurement Strategy for Aboriginal Business.

 

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Subsea project to bring renewable power from Scotland to England awarded $1.8bn

Eastern Green Link 1 is a 190km HVDC subsea electricity superhighway linking Scotland to northern England, delivering renewable energy, boosting grid capacity, and enhancing energy security for National Grid and Scottish Power.

 

Key Points

A 190km HVDC subsea link sending Scottish renewables to northern England, boosting grid capacity and UK energy security.

✅ 190km HVDC subsea route from East Lothian to County Durham

✅ Cables by Prysmian; converter stations by GE Vernova, Mytilineos

✅ Powers the equivalent of 2 million UK households

 

One of Britain’s biggest power grid projects has awarded contracts worth £1.8bn for a 190km subsea electricity superhighway, akin to a hydropower line to New York in scale, to bring renewable power from Scotland to the north of England.

National Grid and Scottish Power, following a recent 2GW substation commissioning, plan to begin building the “transformative” £2.5bn high-voltage power line along the east coast of the country from East Lothian to County Durham from 2025.

The Eastern Green Link 1 (EGL1) project is one of Britain’s largest grid upgrade projects in generations and has been designed to carry enough clean electricity to power the equivalent of 2 million households.

The UK is under pressure to deliver a power grid overhaul, including moves to fast-track grid connections nationwide, as it prepares to double its demand for electricity by 2040 as part of a plan to cut the use of gas and other fossil fuels.

The International Energy Agency has forecast that 600,000km of electric lines will need to be either added or upgraded across the UK by the end of the next decade to meet its climate targets, amid a global race to secure supplies of high voltage cabling and other electrical infrastructure components and to explore superconducting cables to cut losses.

The EGL1 project has awarded Prysmian Group, an international cable maker, the contract to deliver nearly 400km of power cable. The contract to supply two HVDC technology converter stations, one at each end of the cable, has been awarded to GE Vernova and Mytilineos.

The upgrades are expected to cost tens of billions of pounds, according to National Grid, which faces plans for an independent system operator overseeing Great Britain’s electricity market. The FTSE 100 energy company has warned that five times as many pylons and underground lines need to be constructed by the end of the decade than in the past 30 years, and four times more undersea cables laid than there are at present.

Britain’s power grid upgrades are also expected to emerge as an important battleground in the general election. The next government will need to balance the strong local opposition to new grid infrastructure across rural areas of the UK against the climate and economic benefits of the work.

Research undertaken by National Grid has found there will be an estimated 400,000 jobs created by 2050 due to the work needed to rewire Britain’s grid, a trend mirrored by recent cross-border transmission approvals in North America, including about 150,000 jobs anticipated in Scotland and the north of England.

Peter Roper, the project director for EGL1, said the super-cable would be “a transformative project for the UK, enhancing security of supply and helping to connect and transport green power for all customers”.

He added: “These contract announcements are big wins for the supply chain and another important milestone as we build the new network infrastructure to help the UK meet its net zero and energy security ambitions.

 

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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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Ontario to Reintroduce Renewable Energy Projects 5 Years After Cancellations

Ontario Renewable Energy Procurement 2024 will see the IESO secure wind, solar, and hydro power to meet rising electricity demand, support transit electrification, bolster grid reliability, and serve manufacturing growth across the province.

 

Key Points

A provincial IESO initiative to add 2,000 MW of clean power and plan 3,000 MW more to meet rising demand.

✅ IESO to procure 2,000 MW from wind, solar, hydro

✅ Exploring 3,000 MW via upgrades and expansions

✅ Demand growth ~2% yearly; electrification and industry

 

After the Ford government terminated renewable energy contracts five years ago, despite warnings about wind project cancellation costs that year, Ontario's electricity operator, the Independent Electricity System Operator (IESO), is now planning to once again incorporate wind and solar initiatives to address the province's increasing power demands.

The IESO, responsible for managing the provincial power supply, is set to secure 2,000 megawatts of electricity from clean sources, which include wind, solar, and hydro power, as wind power competitiveness increases across Canada. Additionally, the IESO is exploring the possibilities of reacquiring, upgrading, or expanding existing facilities to generate an additional 3,000 MW of electricity in the future.

These new power procurement efforts in Ontario aim to meet the rising energy demand driven by transit electrification and large-scale manufacturing projects, even as national renewable growth projections were scaled back after Ontario scrapped its clean energy program, which are expected to exert greater pressure on the provincial grid.

The IESO projects a consistent growth in demand of approximately two percent per year over the next two decades. This growth has prompted the Ford government, amid debate over Ontario's electricity future in the province, to take proactive measures to prevent potential blackouts or disruptions for both residential and commercial consumers.

This renewed commitment to renewable energy represents a significant policy shift for Premier Doug Ford, reflecting his new stance on wind power over time, who had previously voiced strong opposition to wind turbines and pledged to dismantle all windmills in the province. In 2018, shortly after taking office, the government terminated 750 renewable energy contracts that had been signed by the previous Liberal government, incurring fees of $230 million for taxpayers.

At the time, the government cited reasons such as surplus electricity supply and increased costs for ratepayers as grounds for contract cancellations. Premier Ford expressed pride in the decision, echoing a proud of cancelling contracts stance, claiming that it saved taxpayers $790 million and eliminated what he viewed as detrimental wind turbines that had negatively impacted the province's energy landscape for 15 years.

The Ontario government's new wind and solar energy procurement initiatives are scheduled to commence in 2024, following a court ruling on a Cornwall wind farm that spotlighted cancellation decisions.

 

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Sales Of Electric Cars Top 20% In California, Led By Tesla

California EV Sales 2023 show rising BEV market share, strong Tesla Model Y and Model 3 demand, hybrid growth, and ICE decline, per CNCDA Q3 data, underscoring California auto trends and ZEV policy momentum.

 

Key Points

BEVs hit 21.5% YTD in 2023 (22.3% in Q3); 35.4% with hybrids, as ICE share fell and Tesla led the California market.

✅ BEVs 21.5% YTD; 22.3% in Q3 per CNCDA data

✅ Tesla Model Y, Model 3 dominate; 62.9% BEV share

✅ ICE share down to 64.6%; hybrids lift to 35.4% YTD

 

The California New Car Dealers Association (CNCDA) reported on November 1, 2023, that sales of battery electric cars accounted for 21.5% of new car sales in the Golden State during the first 9 months of the year and 22.3% in the third quarter. At the end of Q3 in 2022, sales of electric cars stood at 16.4%. In 2021, that number was 9.1%. So, despite all the weeping and wailing and gnashing of teeth lately about green new car wreck warnings in some coverage, the news is pretty good, at least in California.

When hybrid and hydrogen fuel cell vehicles are included in the calculations, the figure jumps up 35.4% for all vehicles sold year to date in California. Not surprisingly this means EVs still trail gas cars in the state, with the CNCDA reporting ICE market share (including gasoline and diesel vehicles) was 64.6% so far this year, down from 71.6% in 2022 and 88.4% in 2018.

California is known as the vanguard for automotive trends in the country, with shifts in preferences and government policy eventually spreading to the rest of the country. While the state’s share of electric cars exceeds one fifth of all vehicles sold year to date, the figure for the US as a whole stands at 7.4%, with EV sales momentum into 2024 continuing nationwide. California has banned the sale of gas-powered vehicles starting in 2035, and its push toward electrification will require a much bigger grid to support charging, although the steady increase in the sale of electric cars suggests that ban may never need to be implemented as people embrace the EV revolution.

Not surprisingly, when digging deeper into the sales data, the Tesla Model Y and Model 3 dominate sales in the state’s electric car market this year, at 103,398 and 66,698 respectively. Tesla’s overall market share of battery electric car sales is at 62.9%. In fact, the Tesla Model Y is the top selling vehicle overall in California, followed by the Model 3, the Toyota RAV4 (40,622), and the Toyota Camry (39,293).

While that is good news for Tesla, its overall market share has slipped from 71.8% year to date last year at this time. Competing models from brands like Chevrolet, BMW, Mercedes, Hyundai, Volkswagen, and Kia have been slowly eating into Tesla’s market share. Overall, in California, Toyota is the sales king with 15% of sales, even as the state leads in EV charging deployment statewide, followed by Tesla at 13.5%. In the second quarter, Tesla narrowly edged out Toyota for top sales in the state before sales swung back in Toyota’s favor in the third quarter.

That being said, Tesla’s sales in the state climbed by 38.5% year to date, while Toyota’s actually shrank by 0.7%. Time will tell if Tesla’s popularity with the state’s car buyers improves and it can overtake Toyota for the 2023 crown, even as U.S. EV market share dipped in early 2024, or if other EV makers can offer better products at better prices and lure California customers who want to purchase electric cars away from the Tesla brand. Certainly, no company can expect to have two thirds of the market to itself forever.

 

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