California’s ambitious climate targets require a growing share of new passenger cars, trucks, and SUVs sold in the state to meet zero-emission vehicle standards, with a sales target of 100% by 2035. A study commissioned by Assembly Bill (AB) 2127 Second Electric Vehicle Charging Infrastructure Assessment examined the infrastructure needs to support targets in 2030 and 2035. The main findings indicate the state needs orders of magnitude more charging infrastructure than currently available.
The primary EV adoption scenario analyzed in the report (i.e., AATE3) projects a need for over a million public and shared private chargers (including about 33,000 direct-current fast chargers) to serve the estimated 7.1 million light-duty plug-in electric vehicles (EVs) in 2030. The number required will increase to over two million in 2035 to support 15.2 million EVs. As shown in the dynamic chart below, the majority of chargers deployed are not in public but instead privately owned and accessed at single-family homes.
In a state where 95.81% of all residential land area is zoned single-family-only, and 58% of households in California live in detached single-family homes, it is no surprise that a staggering number of private residential EV chargers exist. Furthermore, early EV adopters in California are more likely to live in single-family homes (79%), as these households are more likely to have the ability to install charging equipment and afford EVs.
The peer-to-peer EV charger sharing solution
If these chargers are accessible in one’s driveway or carport and sit unused most of the week, what if owners could rent charging access to those in need of nearby charging? A web-based platform could facilitate matching potential hosts and renters based on schedule availability, prices, and location (i.e., how far renters are willing to travel).
The peer-to-peer EV charger sharing solution illustrates the transaction process, showcasing interactions between the renter, the host, and the platform, including enrollment, verification of charging sessions, and payment processing.
Note: P2P-EVSE stands for peer-to-peer electric vehicle supply equipment.
Survey results
We developed a web-based survey to understand how peer-to-peer electric vehicle (EV) charger sharing might work. We recruited California plug-in EV households to complete it, which resulted in over 350 complete and clean responses. Fewer than a quarter of households have heard of this new charging solution, suggesting that companies like Buzze, Co Charger, and EVmatch are not reaching most EV households.
We asked households to identify the potential benefits and risks of this charging solution for them as potential hosts and renters, and what host protections should be prioritized in this platform. Potential hosts are motivated by rental income, followed by helping other EV drivers get convenient and available near-home charging. But they worry the most about having an unreliable charger if the equipment is damaged, being liable for damaged equipment, and renters injuring themselves on their property. Potential renters are motivated to have convenient and nearby charging, cheaper charging than at public stations, and more charging station options. Likewise, they are concerned about charger unreliability at these new locations, being liable for damage to their EV from faulty equipment, and not being able to find a peer-to-peer charger when needed.
All households stated their likelihood of becoming a host or renter on a 5-point Likert-type scale, which we converted to a binary response (1 = Likely, 0 = Unlikely). We estimated separate binary logistic regression equations for host and renter responses with and without attitudinal factors. We found two exciting interaction effects for both hosts and renters.
Firstly, we see a landlord effect on the likelihood of being a host on this platform. Households that own detached houses are 2.28 to 2.15 times more likely to host. However, if you’re a renter in a detached home, you’re less likely to become a host! Secondly, we observe a Tesla effect on the likelihood of being a renter on this platform. Respondents who are not White or Asian American are more likely to become renters (2.78 to 4.08 times more likely), possibly because these same residents are more likely to live in neighborhoods with limited public charging stations. However, this disadvantage effect is tempered, but not overcome, by operating a Tesla. In other words, either having a Tesla or Tesla continuing to open its extensive public fast-charging network to non-Teslas will play a role in peer-to-peer EV charging sharing demand.
If California is serious about its ambitious zero-emission vehicle goals, it will likely fall short in installing public charging stations. Perhaps the state should work to incentivize households with private residential chargers to share them with their neighbors. Maybe then we can (1) serve this unmet public charging demand and (2) increase EV adoption by providing near-home charging access to households who can’t reasonably install home charging equipment.
Our new paper, published in Transportation Research Part D: Transport and Environment, provides this and more exciting information.
This study was made possible with the generous support of the Samueli Foundation. The authors would also like to thank the anonymous respondents who completed our web-based survey.