Nudges and Money in Green Discharging: Vehicle-to-Grid (V2G) Response for Renewable Energy

Last registered on September 29, 2025
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Pre-Trial

Trial Information

General Information

Title
Nudges and Money in Green Discharging: Vehicle-to-Grid (V2G) Response for Renewable Energy
RCT ID
AEARCTR-0016875
Initial registration date
September 24, 2025

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
September 29, 2025, 10:41 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country
China
Region
Liyang, Jiangsu

Primary Investigator

Name
Jin Di Zheng
Affiliation
Huazhong University of Science and Technology
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2025-09-22
End date
2025-09-28
Keywords
Behavior, Environment & Energy, Governance
Additional Keywords
v2g, green charging, electric vehicle
JEL code(s)
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract
In a previous demand response trial (AEARCTR-0016549), we measured the effects of different behavioral and economic incentives -- either it is a nudge, or monetary incentives, or time-flexibility to respond -- on charging behavior among electric vehicle users. Earlier this month (September, 2025), the National Development and Reform Commission of China launched a campaign encouraging the practice of vehicle-to-grid practices so as to smooth the demand for electricity in cities, eg., too many charging in the peak hours and too few in the valley.
To complete the map of demand response, either it is charging behavior or discharging of renewable energy supply, we conduct a randomized controlled trial (RCT) at solar-powered EV charging stations, in collaboration with the same EV service provider in Liyang, China. Participants are randomly assigned to one of four arms: (i) an information-only nudge emphasizing environmental benefits, (ii) a monetary incentive, or (iii) a monetary incentive with a flexible time window, and (iv) a control group with no intervention. Discharging behavior is measured using administrative transaction data, and treatment effects are estimated through a difference-in-differences framework.
External Link(s)

Registration Citation

Citation
Zheng, Jin Di. 2025. "Nudges and Money in Green Discharging: Vehicle-to-Grid (V2G) Response for Renewable Energy ." AEA RCT Registry. September 29. https://doi.org/10.1257/rct.16875-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Participants are randomly assigned to one of four arms:
(i) an information-only nudge emphasizing environmental benefits,
(ii) a monetary incentive,
(iii) a monetary incentive with a flexible time window,
(iv) a control group with no intervention.
Intervention (Hidden)
Arm 1 is the information nudge treatment in which an SMS invitation to discharge at a designated PV-storage-charging station on a specific date. The message will emphasize the environmental benefits of the charging behavior and their contributions to the local sustainability goals.

Arm 2 focus on a monetary incentive in cash, of 4 RMB/kWh, if they manage to charge their cars on a given date, for instance, Sep 25 exact.

Arm 3 focus on a monetary incentive in cash with flexible discharging time, of 4 RMB/kWh, if they manage to charge their cars on a given date. They can discharge on any day from Sep 26 -- Sep 28.

Arm 4 is a control treatment where no SMS are sent.
Intervention Start Date
2025-09-25
Intervention End Date
2025-09-28

Primary Outcomes

Primary Outcomes (end points)
Discharging electricity (kWh)
Primary Outcomes (explanation)
Discharging behavior is measured using administrative transaction data, and treatment effects are estimated through a difference-in-differences framework.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Participants are randomly assigned to one of four arms:
(i) an information-only nudge emphasizing environmental benefits, inviting them to discharge on Day 0, Day +1, Day +2, or Day +3.
(ii) a monetary incentive, inviting them to discharge on Day 0, Day +1, Day +2, or Day +3.
(iii) a monetary incentive with a flexible time window, from Day +1 to Day +3.
(iv) a control group with no intervention.
Experimental Design Details
Randomization Method
coin flip
Randomization Unit
individual user
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
0
Sample size: planned number of observations
1000 users
Sample size (or number of clusters) by treatment arms
400 users in arm 1. 400 users in arm 2. 200 users in arm 3.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Nanjing Audit University
IRB Approval Date
2025-09-22
IRB Approval Number
N/A
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials