How California’s Solar Ambitions Led to an Unexpected Energy Surplus

By: Sam Watanuki | Published: Jul 08, 2024

California has long been a leader in solar energy adoption.

The state’s commitment to clean energy is evident, but this rapid adoption has led to an unexpected challenge: generating more solar energy than it can handle at times.

Understanding the "Duck Curve"

The “duck curve” is a term used to describe the times when solar production exceeds demand. This usually occurs on sunny days during the spring when electricity demand is low.

An orange sun seen behind palm trees during sunset.

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The curve is most pronounced during these periods, causing an oversupply of solar energy.

Elliot Mainzer's Insight

Elliot Mainzer, CEO of California’s Independent System Operator (ISO), explains that in spring, when electricity demand is low, California produces more solar energy than it can use.

A photograph of sun rays

Source: Wikimedia

Mainzer highlights that the state sometimes exports excess energy to other Western states but also has to curtail it during extreme conditions.

Renewable Energy Curtailment

According to ISO data, renewable energy curtailment has skyrocketed in recent years.

solar panels against backdrop of sky and trees

Source: Freepik

In 2024 alone, nearly 2.6 million megawatt-hours of renewable energy were wasted due to oversupply and transmission congestion. This amount could power all the homes in San Francisco for a year.

The Need for Transmission Lines

Mainzer advocates for adding more transmission lines to better distribute the excess energy throughout California.

Many electric wires seen connected to towers underneath a blue sky.

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He emphasizes that without adequate transmission infrastructure, new solar projects and other renewable resources become stranded, unable to deliver energy to customers.

Governor Newsom's Battery Push

Governor Gavin Newsom’s administration is pushing to add more batteries to store excess energy for use during peak demand times.

Gavin Newsom looking downwards next to media crowd

Source: Andrew Harnik/Getty Images

Batteries can help capture the surplus solar energy generated during the day and make it available when it’s needed most, such as during the evening.


Controversial Incentive Cuts

The California Public Utilities Commission has taken a controversial approach by cutting financial incentives for homeowners who are wanting to install solar panels.

A close-up of many solar panels on green grass in the daytime.

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This move has led to a significant drop in residential solar installations and job losses in the solar industry.


Impact on Solar Businesses

Ed Murray, president of the California Solar and Storage Association, has seen his business suffer due to the incentive cuts.

A photograph of the sun during a hot day

Source: Wikimedia

Since the changes, residential solar installations have reportedly dropped by 66% in the first quarter of 2024 compared to the same period in 2022, resulting in the loss of 17,000 green jobs statewide.


Financial Challenges for Homeowners

To make solar cost-effective with the new incentives, homeowners now need to install batteries, which can add $10,000 to $20,000 or more to the cost.

A row of different colored houses. Behind the houses are high-rise buildings.

Source: Kae Ng/Unsplash

This has deterred many from adopting solar, as they either can’t afford the additional expense or find it not cost-effective.


Equity Concerns

Supporters of the incentive changes argue that the shift to solar can raise energy costs for those who don’t have it or can’t afford it.

Multi-colored houses on a street. Cars are parked outside the houses.

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However, Murray disputes this, noting that most of his clients have modest incomes and often finance their installations through loans.


National Implications

Murray warns that other states are watching California and may follow suit with similar incentive changes.

A general view of Solar Panels. Solar panels use the photovoltaic effect to convert light into an electrical current, on May19, 2024, in Sydney, Australia

Source: Steve Christo - Corbis/Corbis via Getty Images

This could potentially hurt the solar industry nationwide, as states like Florida, Arizona, and Massachusetts consider adopting similar rules.


California's Clean Energy Vision

Despite the challenges, California remains committed to its clean energy goals. The state aims to achieve 100% clean energy by 2045.

A photograph of the Los Angeles skyline during the daytime/Gavin Newsom is pictured with his thumb up in California

Source: Wikimedia/Justin Sullivan/Getty Images

Governor Newsom emphasizes that California’s solar production has increased nearly twentyfold over the past decade, powering millions of homes with clean energy.