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EV depot charging planner · Schneider Electric

Charging 60 buses overnight on a grid connection built for 20.

A web planner for overnight charging of electric buses and vans at depots. Every vehicle is ready by its departure time, without going over the site's grid limit.

Role
Digital Product Lead
Company
Schneider Electric
Timeline
2021 to 2022
Team
1 designer, 1 PM, 5 engineers, 1 optimisation engineer
Platforms
Web app, Email and SMS alerts

1The grid limit is always on screen

2Risk shown the evening before, with the reason

3Each row ends at the vehicle's departure time

6.2% → 0.8%

Vehicles not ready at departure

−31%

Peak grid load at pilot depots

€41k

Peak fees avoided per depot per year

12 → 2 min

Morning check by the depot manager

The problem

Fleet operators were electrifying faster than their grid connections could grow. Depot managers planned overnight charging in spreadsheets, and every morning a few vehicles weren't charged enough to run their route.

What I did

This was my first project as Digital Product Lead. I shaped the product strategy, designed a schedule built around departure times and the grid limit, and designed the alerts and rescheduling for when a charger fails at 1 a.m.

What changed

At three pilot depots, vehicles that weren't ready at departure dropped from 6.2% to 0.8%, peak load fell by 31%, and the morning check went from twelve minutes to two.

01 · Context

The real limit was the grid connection.

In 2021, public transport companies and delivery fleets across Europe were switching to electric vehicles fast. A depot that used to park 60 diesel buses now needed to charge 60 batteries overnight, often on a grid connection sized for a much smaller load. Upgrading the connection could take two years.

So the real job wasn't charging. It was deciding which vehicle charges when, on which charger and at what power, so every one is ready for its morning route and the depot never goes over its limit.

Charge everything on arrivalSmart schedule Grid limit 1.2 MW
0 MW1 MW1 MW2 MW2 MW
18:0020:0022:0000:0002:0004:0006:00
Fig. 1One night at a bus depot in Amsterdam. Charging everything on arrival crosses the grid limit for four hours.

02 · Problem

Spreadsheets, guesswork and buses stuck at the depot.

Depot managers planned with a spreadsheet and experience. When the evening was busy, they staggered charging by hand. When a charger failed overnight, nobody knew until the morning, when a bus with 40% battery couldn't start a 120 km route.

1Buses arrive
2Plan the night
3Overnight
4Morning check
5Departures
Feeling
What they do
Note arrival and battery levels
Assign chargers in a spreadsheet
Nothing, unless someone calls
Walk the depot, check screens
Swap vehicles that aren't ready
What hurts
Data in three systems
Can't see the grid limit
Faults go unnoticed
12 minutes, every morning
Late routes, angry dispatch
Fig. 2A depot manager's night before the planner.

The question we worked on

How might we make sure every vehicle is ready by its departure, without anyone having to stay up all night watching the chargers?

03 · Research

Nights at the depot.

I visited four depots, including two overnight shifts, interviewed nine depot managers and dispatchers, and worked with our optimisation engineer to understand what the scheduling algorithm could and couldn't promise.

Insight 1

Departure time is the only deadline that matters

Depot managers don't think in chargers. They think in routes leaving at 05:50. The plan had to be organised around departures.

“I don't care when it charges. I care that bus 36 leaves at ten to six.”

MartijnDepot manager, Amsterdam
Insight 2

The grid limit was invisible

Nobody at the depot could see how close they were to the limit. They found out from the monthly peak-fee invoice.

“We only learn we went over when finance calls.”

LotteFleet operations lead
Insight 3

Trust needs a reason

Managers overrode the algorithm whenever they didn't understand it. When a plan showed why a bus charged later, they left it alone.

“If it tells me why, fine. If not, I'll do it myself.”

RachidDepot manager, Rotterdam

04 · Process

Showing an algorithm's plan to a person.

Option ARejected

List of chargers with status

How charger software usually looks. It hid the two things that mattered: departures and the grid limit.

Option BTested

Map of the depot

Useful for finding a vehicle on site. Useless for understanding the night.

Option CChosen

Timeline per vehicle with the grid limit on top

One row per vehicle, departures as flags, and the depot's load drawn against its limit above it.

Fig. 3Three ways to show the night, tested with depot managers.
Month 024681012
Depot research
Strategy and scope
Schedule view
Alerts and rescheduling
Pilot, 3 depots
Commercial launch
◆ Scope agreed◆ Pilot◆ Launch
Fig. 4September 2021 to September 2022.

05 · Design decisions

Departures and the grid limit, always visible.

The grid limit is always on screen

Above the schedule, a load chart shows the depot's planned power use for the night against its limit. When the plan is close to the limit, the line turns amber. Managers could finally see the constraint the algorithm was working with.

Fig. 5The capacity view, with the cost of charging everything at once next to the smart schedule.

Every vehicle row ends in its departure

Each vehicle has a row with its charging sessions and a flag at its departure time. If the plan can't reach the needed charge by then, the row is marked at risk with the reason, the evening before, while there's still time to act.

Fig. 6Vehicle detail. Bus 4127 needs 85% by 05:50 and is marked as a priority vehicle.

When a charger fails at 1 a.m., the plan fixes itself

If a charger stops, the planner proposes a new schedule within a minute and texts the on-call person only if a departure is at risk. For the common case, the alert says the problem and the fix in one message, and one tap approves it.

Fig. 7A charger fault and the automatic reschedule proposal.

Alerts only when a departure is at risk

Early versions alerted on every charger event. In the first pilot week, one depot manager got 47 messages in a night and turned them off. We changed the rule: only alert a person when something will affect a departure and the system can't solve it alone.

Handled

No message

Charger restarted, plan unchanged.

Rescheduled

Summary in the morning

Bus 4127 moved to C-09, still ready on time.

Needs approval

SMS with one-tap approve

Reschedule delays two vehicles by 10 minutes.

At risk

Phone call

Bus 36 can't reach 85% by 05:50 on any charger.

Fig. 8Alert levels after the first pilot week. Messages per night dropped from 47 to an average of 0.6.

06 · Outcome

Every bus out on time, on the same grid connection.

Before the planner Pilot, 4 monthsLower is better
Vehicles not ready at departure
6.2%
0.8%(-87%)
Peak load, share of grid limit
142%
98%(-31%)
Morning check
12 min
2 min(-83%)
Fig. 9Results across the three pilot depots.

“I check one screen with my coffee and I know the morning will be fine.”

MartijnDepot manager, Amsterdam

“We postponed the grid upgrade by at least two years.”

LotteFleet operations lead
Fig. 10From the pilot review.

07 · Reflection

What I learned.

My first project as a lead taught me that the job of the interface is to make an algorithm's reasoning visible. Managers didn't need to understand optimisation. They needed to see the limit, the departures and the reason a bus charges later.

I'd design alerts with the night shift from day one. The 47-message night was avoidable.

Tools on this project

Figma, Principle, D3 prototypes, Jira, Confluence

Names of the people quoted have been changed to protect their privacy.

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