California has set ambitious goals to reduce greenhouse gas emissions through both the addition of renewable energy generation sources and the electrification of transportation. But these concurrent initiatives have raised questions about how the grid will accommodate the additional resources and coordinate demand.
Three policies are in place to advance the state’s clean energy efforts.
- Governor Jerry Brown’s Zero-Emissions Mandate (ZEV) requires the deployment of 1.5 million zero-emissions vehicles by 2025.
- The Renewable Portfolio Standards (RPS) obliges California power producers to ensure that 33% of grid energy comes from renewable generation by 2020 and 50% by 2030.
- To ensure grid stability given the intermittency of renewable energy generation, California has also instated an energy storage mandate, requiring the installation of 1.3 GW of stationary storage by the end of 2024.
A new study published in Environmental Research Letters reveals that there may be a synergistic opportunity within these three initiatives. The team of researchers, led by Jonathan Coignard, Samveg Saxena, et al. found that electric vehicles (EVs) could support the grid in managing the demand curve by storing energy when production is high and charging during low-demand hours.
The team came to this conclusion by quantifying the potential for EVs to support the grid. First, researchers studied the California Independent System Operator (CAISO) 2014 historical and 2021 forecast daily net loads to identify the most salient issues within the duck curve. Then, they calculated the impact of the projected addition of 1.5 million EVs.
They determined that vehicle connectivity to the grid, and specifically controlled charging, would have a profoundly positive impact on the projected demand curve since grid-integrated vehicles can time the charging cycle to moderate peaks and valleys in the net-load curve. With regard to over-generation issues, the study found that almost 5 GW of renewables curtailment can be avoided with a combination of vehicles featuring one-way and two-way charging—significantly more than the 1.3 GW mandated stationary storage would offer.
“By displacing the need for construction of new stationary grid storage, EVs can provide a dual benefit of decarbonizing transportation while lowering the capital costs for widespread renewables integration,” the study’s authors explain. “These benefits are not limited to California but are applicable worldwide whenever EVs and renewables generation become widespread.”
What are your thoughts? Do you think that California’s Energy Storage Mandate can be accomplished through the controlled charging of electric vehicles?