The famous California power grid "duck curve" has intensified into a "canyon curve"-Shenzhen ZH Energy Storage - Zhonghe LDES VRFB - Vanadium Flow Battery Stacks - Sulfur Iron Electrolyte - PBI Non-fluorinated Ion Exchange Membrane

The famous California power grid "duck curve" has intensified into a "canyon curve"

Classification：Industrial News

- Author：ZH Energy

- Release time：May-15-2023

【 Summary 】More than a decade ago, the famous California power grid net load "duck curve" led the global energy community to pay attention to energy storage demand, hoping to use energy storage to smooth the duc

More than a decade ago, the famous California power grid net load "duck curve" led the global energy community to pay attention to energy storage demand, hoping to use energy storage to smooth the duck curve. However, more than a decade later today, the duck curve has intensified into a "canyon curve".

The Duck Curve - first introduced by the California State Grid and named after its resemblance to a duck shape - displays the difference between the net demand for electricity throughout the day and the net demand for renewable energy sources such as solar energy, defined as the net load of the grid. The duck curve reflects the challenges posed by the increasing photovoltaic installation, resulting in a decrease in net demand during the day (duck belly), a sharp increase at sunset (duck neck), a deeper belly, and a steeper and longer neck every year.

Since then, the power industry has been working hard to improve the operation of the power grid under the duck curve, as the belly can lead to excessive power generation and renewable energy curtailment, while the neck can provide power supply institutions with very high output response speed. More flexible power supply capabilities are crucial for addressing these challenges.

Net load chart of California power grid as of April 24, 2023
Recently, the daytime net load of the California power grid has reached zero or become negative. The canyon is getting deeper, which means that there are fewer conventional power generation facilities that need to be activated during the day, and then the conventional power generation capacity that needs to be activated rapidly increases as the sun sets. Therefore, power generation companies need to activate power generation resources that cannot be quickly ramped up before sunset, in order to provide all loads after sunset, which can cause a considerable amount of resource waste. As the canyon walls become steeper, energy companies need to deploy more responsive power generation resources.

This morning, when the net load curve dropped to the canyon, it was mainly achieved by reducing natural gas power generation, transitioning from imported electricity to exported electricity, and charging the energy storage system. In order to climb out of the canyon in the evening, some natural gas generators must remain online, even at the bottom of the canyon, to prevent sudden weather changes. When the sun sets, in order to fully climb to the top of the canyon, it is necessary to increase natural gas power generation, shift exports to electricity imports, release additional hydroelectric power from the reservoir, and use its energy storage system to charge at the bottom of the canyon.

In the future, other tools will be needed to fill the canyon and climb steep cliffs. These tools include: time of use electricity prices and other plans to encourage daytime electricity consumption, other forms of energy storage technologies (thermal, mechanical, chemical, etc.), and new technologies such as hydrogen production that can be used in conjunction with photovoltaics.

California Power Grid Net Load Forecast for the Next 7 Days