California’s ambitious pursuit of clean energy has encountered an unexpected challenge: at times, the state generates more solar energy than it can manage, resulting in significant energy waste. This situation, referred to as the “duck curve,” occurs when solar production exceeds demand, typically on sunny spring days when energy consumption is lower. The “duck curve” describes the pattern where the “belly” of the curve shows excess solar energy production during midday.

Elliot Mainzer, CEO of California’s Independent System Operator (ISO), which oversees 80% of the state’s electricity flow, explained that during periods of low electricity demand and high solar production, California often produces more energy than it can use. The state relies on its extensive transmission connectivity to export excess energy to other Western states. However, in extreme cases, this surplus energy must be curtailed.

Data from the Independent System Operator reveals a dramatic rise in curtailed renewable energy due to oversupply and congestion. So far this year, California has lost nearly 2.6 million megawatt-hours of renewable energy, enough to power all homes in San Francisco for a year.

To mitigate this issue, Mainzer advocates for expanding transmission lines to improve the distribution of electricity throughout the state. He emphasized the importance of having the necessary infrastructure to deliver energy from new solar, battery, or wind projects to customers, avoiding the risk of these projects becoming isolated and underutilized.

Governor Gavin Newsom’s administration is also pushing for increased battery storage to capture excess energy for use during peak demand periods. However, a controversial decision by the California Public Utilities Commission to cut financial incentives for homeowners installing solar panels has had significant repercussions.

The revised incentive structure, known as net metering, has led to a sharp decline in residential solar installations. According to the California Solar and Storage Association, installations dropped by 66% in the first quarter of 2024 compared to the same period in 2022. The association estimates that since the change, 17,000 green jobs have been lost statewide.

Ed Murray, president of the California Solar and Storage Association and operator of Aztec Solar near Sacramento, expressed concerns that the new rules have made solar installations less attractive and cost-effective. As a result, his business has suffered, and he has had to lay off employees. To make solar installations cost-effective under the new incentives, homeowners now need to invest in battery systems, which can add $10,000 to $20,000 or more to the cost.

Governor Newsom defended the state’s policies, highlighting California’s leadership in solar production. He pointed out that this year, the state has had nearly 100 days where clean energy exceeded 100% of demand for part of the day. Supporters of the new incentives argue that the previous net metering system unfairly raised energy costs for non-solar customers.

Public Utilities Commission member John Reynolds stated in 2022 that while net metering had been successful, it had become too costly for non-solar customers and needed reform. Murray disputes this claim, noting that most of his clients earn annual salaries of $50,000 to $60,000 and often finance their solar installations through loans. He warns that other states may follow California’s lead, potentially stalling solar adoption nationwide.

California’s path to 100% clean energy by 2045 faces significant hurdles. Addressing infrastructure and economic challenges is crucial for the state to maintain its leadership in renewable energy and achieve its environmental goals.