Renault Plug Inn : Designing Trust in a Revolutionary Business Model

Challenge

How do you create trust between strangers in a peer-to-peer economy when there's no connected infrastructure to rely on?

From 2022 to 2024, I led the complete 0-to-1 UX design for this challenge: all user flows, interaction design, and functional framework. For this case study, I'll focus on the Charging experience, where real-world testing revealed unexpected insights.

Note: Interfaces were translated from French to English for this case study. Translated copy may not reflect microcopy best practices.

Meet our users

Clara (Host)

Wants to monetize unused charging equipment but fears privacy invasion and time commitment

Paul (Driver)

Needs reliable charging but worries about vehicle safety and access complexity

The Charging Experience

Based on user research insights, I designed trust-building mechanisms that addressed specific anxieties from both user types:

Reassuring Drivers

Visual transparency for decision-making

Drivers needed to assess compatibility of the charging point with their vehicle to book a charging session. To meet this requirement, hosts were required to provide high-quality photos of charging equipment, parking space, and clear access instructions.

Snippet of the Search flow within the Driver experience. Map view showing charging stations with power ratings and prices, followed by charging stations cards displaying key informations, then detailed station page with compatibility details and the host profile. This progression moves users from quick comparison to trust-building, addressing key research insights about range anxiety and safety concerns.

Damage liability protection

To prevent damage disputes, drivers had to complete a mandatory photo documentation of parking space condition and charging equipment state upon arrival and departure.

Reassuring Hosts

Privacy and security concerns

To address these concerns, we implemented user verification with vehicle details and license plates and reminder notifications of arrival times.

Snippet of the booking flow: drivers were suggested to verify their identity before sending a booking request. On the Host side, requests from verified drivers were highlighted and hosts could disallow automatic bookings from unverified accounts.

Community accountability

We built bidirectional ratings with strategic reminders to ensure participation, defining specific criteria based on user insights that would build meaningful community trust over time.

Rating flows for both Driver and Host experiences. Each rates the other on research-backed criteria: drivers evaluate charging quality, hosts evaluate punctuality and equipment care. Both rate communication (or lack thereof) — the main source of anxiety.

Validation Methodology: Beyond Screen Testing

Phase 1: Controlled Environment

We tested a functional POC with 5 users in our agency private parking to uncover real-world constraints. Users were recruited through a user testing agency and were given instructions by email equivalent to the ones that would have been provided through the app.

Key discoveries

• While users had no trouble accessing the designated parking spot autonomously, they ignored check-in prompts, focusing on completing the physical charging task
• The check-in flow didn't match natural behavior (park → plug → check-in flow, and not check-in flow → park → plug)

Follow-up fixes

• Reordered photo sequence to match natural behavior
• Added multiple reminder touchpoints and tutorial guidance

Phase 2: Real-World Experiment

A few months after the release, we rented EVs and booked charging slots to test the experience in real conditions. Most charging points were located in residential areas, typically in hosts’ garage or private parking spot.

Key discoveries

• Physical constraint insight

  Once parked, drivers are limited to a few kilometers radius on foot, severely restricting their activity options during charging sessions. This amplified the notion drivers would primarily book charging points near locations where they already planned extended stays, limiting the platform's utility for residential areas devoid of amenities.

• Social friction insight

  While one charging point offered autonomous access, the others required host assistance (eg. parking badges, manual access). This created uncomfortable dependency where drivers felt they were interrupting on hosts' personal spaces to access their vehicle.

• Service ownership gap

  In 3 cases out of 4, the host account holder wasn't the person managing the actual charging session. Reason given was that the parking spot needed to be available for drivers to come and charge, meaning, the EV car owner, and likely person who signed up on the service, would be away. This wasn’t a new information, as we had heard this insight several times in interviews, but so far we hadn’t gained feedback on what it would entail in practice. When spouses or family members handled the interaction, they lacked knowledge of the app functionality and booking details. This created confusion, additional friction, and awkward explanations between strangers who were already navigating an unfamiliar social interaction.

Plot twist : while working to improve Trust, we discovered a deeper issue

the (real) Challenge

How do you redesign a service when the fundamental infrastructure model creates user friction?

We had successfully solved the trust challenge, but our real-world testing revealed that the residential peer-to-peer model only functioned under highly specific conditions: autonomous access and extended-stay-worthy locations. These criteria naturally limited the addressable user base, indicating that UX optimization alone couldn't scale the service to mass adoption. The fundamental service structure needed to change.

Strategic Response

These insights directly informed two strategic responses:

• Rethink the charging discovery experience to better match real user journey patterns

• Expand to professional hosts (hotels, restaurants, businesses where extended stays are natural)

The platform pivot addressed the social and dependency issues, while the roadplanner integrated fast charging options into planned trip flows rather than treating it as an isolated transaction. An onboard (ie. car OS) was also in discussion to give more visibility to Plug Inn charging points to Renault EV car owners.

Impacts

Platform Success

• 75,000+ downloads in first weeks
• 1,000+ charging points within launch period
• 4.2/5 Play Store, 4.1/5 App Store

Industry Recognition

• Cannes Lions, 2023: Winner of the grand prize in Creative Strategy and 3 awards in Mobile and Service Design
• Fast Company’s World Changing Ideas, 2024: Winner in Transportation category and finalist in Apps Category
• Clio Awards, 2024: Grand Winner in Creative Business Transformation