Virtual Conference, February 12, 2021:

Can V2G Alleviate the Duck Curve in California?

The Center for Community Energy (CCE) plans to hold a virtual conference on February 12, 2021, bringing together experts on the potential for putting the extra battery power in electric vehicles back onto the electric grid (Vehicle-to-Grid) in the evening.  This could significantly reduce or even alleviate the so-called “Duck Curve” (see below), the surplus of solar power during the day and the shortage of renewable power during the evening, which greatly increases electric rates during those hours.  It could make it possible to stop using obsolete fossil fuel-powered electric plants in favor of existing cleaner and more efficient technologies.

CCE’s goal is to prepare a consensus document to submit to the Public Utilities Commission as an expert opinion to inform them about the current state-of-the-art in Vehicle-to-Grid (V2G).  If the potential of V2G to alleviate the duck curve is not addressed now it will not get into the resource planning process, which means that antiquated sources of power will continue to pollute for decades to come.  

To give this issue the visibility it deserves, we plan to hold a virtual conference on the topic “Can V2G Alleviate the Duck Curve in California?”  We would bring together (via Zoom) top experts from the US and abroad to make presentations on this topic.  The presentations would be followed by a roundtable discussion at which the moderator would try to bring the participants to a consensus.  A consensus document would be drawn up by the CCE and circulated to the participants until as broad an agreement as possible was achieved.  This consensus document would then be submitted to the PUC, other state agencies, elected officials, media and load-serving entities as an expert opinion that would inform them about the prevailing state-of-the-art in V2G.  (For more details, see background below.)

The “Duck Curve” in California.  Source: California ISO Image used with permission.

Additional information will be coming soon.  In the meantime, please email questions to Jose Torre-Bueno, Executive Director of CCE, or compete the contact form below.


As part of its response to the climate crisis, the state of California has a goal of achieving 60% renewable electricity by 2030 and 100% by 2045.  It has become clear that the main impediment in achieving this goal is the so-called “Duck Curve,” the surplus of solar power during the day and the shortage of renewable power during the evening.  The amount of solar energy the state has been forced to curtail in the middle of the day (because there would be too much power produced relative to demand) has increased for the last several years.  In addition, in order to be assured of evening power the state has been forced to keep in operation several fossil fuel plants that were scheduled for retirement.  It has been suggested that in order to be assured of reliable power availability the state would have to keep essentially the entire fleet of existing natural gas plants on standby through 2050, and/or spend on the order of 40 billion dollars on battery systems to store the excess power that would be produced in the middle of the day.

On the other hand, the state also has a target of 5 million electric vehicles on the road by 2030. It has been pointed out that the combined capacity of the batteries in these vehicles would be far more than would be needed to overcome the duck curve, and most would be parked just when the power was needed.  Vehicle-to-Grid (V2G) electricity distribution has the potential to alleviate or even eliminate the duck curve. 

In 2019, the state legislature passed SB 676 mandating that “the commission shall establish strategies and quantifiable metrics to maximize the use of feasible and cost-effective electric vehicle grid integration by January 1, 2030.”  In response, there is an ongoing rulemaking at the PUC on electric vehicle infrastructure, but the staff report that will form the basis of that rulemaking proposes leaving it to the investor-owned utilities to develop 10-year plans for vehicle electrification infrastructure.  The staff report never mentions V2G as a way to address the duck curve.

The PUC has just launched the next round of resource planning.  The report from the EV infrastructure rulemaking is part of the input to this planning process, but if the potential of V2G to alleviate the duck curve is not addressed in the EV rulemaking it will, in all likelihood, not get into the resource planning process.  Given its high potential cost effectiveness, it is imperative that V2G be given full weight as one of the measures that could be taken to help meet the state’s decarbonization goals.  If not, the state will commit itself to expensive and potentially greenhouse gas producing measures that may not be necessary.

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