Smart EV Charger Integration

Overview

This project ran across three semesters at Odisee Ghent as part of the Energy Technology programme. The brief was to integrate a smart EV charger into a home energy management system (HEMS) using Home Assistant as the central platform. It was a 12 ECTS project, which meant it carried real weight, and we scored 16 out of 20.

The project covered everything from physical installation of the charging hardware through to the software stack that makes the charger communicate intelligently with the rest of the home’s energy system. The goal was not just a working charger but a charger that responds to grid conditions, solar generation, and household load in a way that makes economic and technical sense.

The Challenge

A standalone EV charger is straightforward. A smart EV charger that integrates with a home energy management system is considerably more interesting. The charger needs to receive commands from the HEMS, report its status back, and respond dynamically to changes in available capacity. If solar generation drops or the household load peaks, the charger should throttle back without losing session state. If there is surplus solar, it should ramp up.

Getting this to work requires understanding the communication stack at every layer: the physical interface between the HEMS and the charger, the protocol used to carry commands and telemetry, and the Home Assistant automation logic that makes decisions.

What I Did

I owned most of the technical side of this project. My teammate handled the documentation and project management, which let me focus on the hardware and integration work.

Charger Installation

Physical installation of the EV charging hardware: mounting, cabling, circuit protection, and commissioning. Working with real hardware and real power levels requires care. A charger rated for 7.4 kW on a 32A circuit is not something you commission carelessly.

Communication Integration

Connecting the charger to Home Assistant required understanding the communication protocol the charger uses to report status and receive commands. This involved configuring the integration on the Home Assistant side, mapping the charger’s data points to entities that the HEMS can act on, and verifying that commands round-tripped correctly.

Energy Management Logic

The interesting part was writing the automation logic in Home Assistant that makes the system actually smart. The rules govern when the charger runs at full power, when it throttles, and when it stops entirely based on grid import, solar production, battery state, and time-of-use tariffs. Getting the logic right, particularly around the edges (what happens when the solar reading drops out, what happens if the charger loses connectivity mid-session) took considerably more iteration than the happy path.

Testing and Validation

Logging the charger’s behaviour across real charging sessions and comparing actual energy flows against the expected behaviour of the automation logic. This is where you find the cases that do not behave the way you thought — the solar reading that drops to zero mid-session and triggers an unintended stop, the session that does not resume cleanly after a connectivity gap. Each one required diagnosing the actual state of the system against what the automation assumed was true, tracing back through the logic to find where the assumption broke down.

Why This Project Matters for Energy Product Engineering

EV charging integration is a genuinely difficult problem at scale. The gap between a charger that works and a charger that works intelligently inside a home energy system touches power electronics, communication protocols, control logic, and the failure modes that only appear in the real world. This project gave me hands-on experience with all of those layers.

The skills it exercised — protocol integration, fleet-aware automation logic, systematic fault isolation from telemetry data, and building systems that degrade gracefully rather than fail hard — map directly to product engineering roles in residential energy. A Powerwall, a Wall Connector, or any energy device at scale faces the same class of problems: the fleet behaves as expected most of the time, and the interesting work is finding and fixing what happens when it does not.

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TODO: add image at public/projects/ev-charger/system-diagram.png (system architecture diagram showing charger, HEMS, solar, and grid connections)

TODO: add image at public/projects/ev-charger/dashboard.png (Home Assistant dashboard showing charger status and energy flows)

TODO: add image at public/projects/ev-charger/install.jpg (photo of installed charger hardware)