Eventually, Musk has said he hopes Tesla will produce 20 million vehicles a year as the demand for electric vehicles increases. Higher adoption of EVs is expected to drive electric grid demand, but Musk seemed to downplay the ability of plug-in vehicles to provide some services to the grid or to power homes.
Questions about V2G usefulness
“Vehicle-to-grid sounds good but I think actually has a much lower utility than people think,” Musk said. “Very few people would actually use vehicle-to-grid” capabilities, he said, in part because cars are not plugged in constantly.
“I think it’s going to be better for people’s freedom of action to have a Powerwall and a car separate,” Musk said, referring to the Tesla’s residential stationary storage product. Combine a local battery with solar generation and “you basically become your own utility,” he said.
Future generations of Tesla’s power electronics will enable V2G capabilities in North America, according to Tesla Senior Vice President of Powertrain and Energy Engineering Drew Baglino, who also spoke at the event. But additional hardware would be required to allow cars to back up a home’s electric supply.
Future cars “will at least be able to do bi-directional energy flows for the purposes of energy market participation, but even for that it’s important to remember that your car isn’t plugged in 24-7 so it’s kind of unpredictable,” said Baglino. “It will have a value but it’s not the same as a stationary battery pack.”
“Despite the large quantity of EVs coming online over the next decade, the jury is still out to what extent EVs in a V2G role will play a major role in the future grid,” said Roger Lueken, senior associate at The Brattle Group.
“Elon noted that EVs are a much less reliable grid asset than utility-scale batteries, as they’re not always plugged in,” Lueken said in an email. “Vehicle-to-grid charging also requires customers to participate and be willing to have the utility or other third party access their car’s battery.”
Improvements to stationary storage, also
Tesla’s new EV battery design and production aspirations may not have immediate impacts for utilities, but that could change in the future according to Hanjiro Ambrose, a researcher at the University of California, Davis.
“There’s a clear path to success but there’s a lot of work between here and there,” Ambrose said. For now, he said EVs will be primarily used for grid regulation and services, as the cost remains high. But V2G potential “gets more promising by the day,” as a new generation of batteries could be more robust and dynamically managed to minimize degradation.
“We’re still going to see batteries really need to be able to take advantage of market structure,” said Ambrose. “They need to be able to stack value in some way to take advantage of the capacity they can provide to the grid.”
There was some news out of Tesla’s Battery Day event related to larger applications, according James Frith, head of energy storage at BloombergNEF.
“The interesting take away for stationary storage is that Musk highlighted that Tesla would use lithium iron phosphate (LFP) based batteries for stationary applications, as energy density is less of an issue,” Frith said in an email. “This makes sense particularly as we move to a period where stationary storage is used more for ‘energy shifting’ rather than frequency regulation.”
Energy shifting — charging from the grid when power prices are low or renewables are being curtailed, and then discharging when prices are higher — is an application more suited to LFP chemistry, said Frith, “which provides a longer cycle life, lower raw material cost and fewer potential raw material supply constraints.”
New California grid rules open door to V2G charging
California has approved changes to grid connection rules that will open the door for the interconnection of electric vehicles with two-way charging capabilities to the grid.
The changes to Rule 21 by the California Public Utilities Commission (CUPC) will pave the way for the faster deployment of distributed energy resources (DER) including solar and behind-the-meter batteries, but more importantly in the case of electric vehicles, to allow for bidirectional vehicle-to-grid charging.
When California was hit by a series of rolling blackouts across the grid in August, renewable energy critics and jumped on board, blaming solar and wind resources in much the same way the Australian media did in the case of South Australia’s 2018 blackouts.
Although neither, as Ketan Joshi points out on Renew Economy, were actually caused by renewables, transforming rules for the interconnection of distributed energy resources solar rooftop and electric vehicles can help introduce more flexibility in the grid to avoid blackouts in the first place.
As with Australia’s ANU V2G trial in collaboration with Nissan, V2G trials are being conducted in California such as this Nuvve Corp trial with local utility San Diego Gas & Electric (SDG&E).
However, until now, broad integration of V2G chargers has been held back by a lack of standardisation.
The changes made by the CPUC to Rule 21, which governs what kind of DERs may interconnect with California’s electricity grid, clears a way forward to standardise technical requirements.
The CPUC’s approved revisions of Rule 21 notes that the California energy commission established that “flexible electric vehicle charging could reduce the amount of renewable generation and energy storage selected to meet 2030 greenhouse gas planning targets”.
It defines three types of vehicle-to-grid integrations including V1G (one-way managed or “smart” charging), V2G AC and V2G DC (both referring to bidirectional charging systems).
While it does not consider V2G to be applicable to Rule 21, it notes that to date, interconnections of V2G systems have been done on a case-by-case basis.
The new rules allow bi-directional ev chargers to be interconnected to the grid as long as the operator gains utility permission.
California has a gigawatt hours worth of EV chargers, and as Greentech Media notes, “enabling them to export EV battery capacity, rather than simply stop charging, could make them an even more valuable grid resource.”
To be able to be used for V2G charging, EV charging equipment must comply with technical requirements before being approved for interconnection with the grid.
This includes ensuring that all V2G capable chargers to be used for DC interconnection comply with technical requirements to ensure uni-directional charging only as a default mode.
Only after gaining permission from the utility can EV chargers then be switched into bidirectional mode.
Bridie Schmidt Bridie Schmidt is lead reporter for The Driven, sister site of Renew Economy. She specialises in writing about new technology and has been writing about electric vehicles for two years. She has a keen interest in the role that zero emissions transport has to play in sustainability and is co-organiser of the Northern Rivers Electric Vehicle Forum.