Alfen
Smart EV Charging and Energy Storage for the Netherlands and Europe
Alfen (Almere, Netherlands) is a leading Dutch EV charging and energy storage company — Eve Single Pro-line is the standard for Dutch commercial and semi-public charging. OCPP 2.0.1 and local Modbus TCP integration make Alfen the preferred choice for smart building KNX-connected EV infrastructure.
Role in our panels
How we use Alfen
Eve Single Pro-line 22 kW three-phase: IP54, cable-attached or socket, RFID, OCPP 1.6J and 2.0.1. Modbus TCP on port 502, unit ID 1. Registers (float32, FC3): 300-301 (charge state: 0=A/available, 1=B1, 2=B2, 3=C1/charging, 4=C2, 5=D), 316-317 (charge current setpoint, A), 320-321 (actual charge current L1, A), 322-323 (L2), 324-325 (L3), 344-345 (active power total, W), 374-375 (session energy, Wh). Dynamic load management: KNX Modbus gateway reads grid meter (Eastron SDM630) total power every 10s. Available headroom = contract limit (25A) minus base load current. KNX logic writes headroom to Alfen registers 316-317 (charge current setpoint) — charger automatically reduces rate when building load peaks. Multiple chargers: Alfen SCU (Smart Charging Unit) manages up to 100 Eve chargers with internal load balancing — KNX only needs to communicate with SCU Modbus master via single gateway connection. Alfen ACE energy storage: 100-500 kWh Li-ion, Modbus TCP registers for SOC (%), charge/discharge power (W), state (idle/charging/discharging). KNX integrates ACE same pattern as EV charger.
Alfen Eve chargers connect via Modbus TCP — KNX reads active power and charge state, and writes charge current setpoint for dynamic load management based on grid meter headroom.
Used in these project types
Alfen products
Key components we install
Eve Single Pro-line 22 kW
22 kW three-phase commercial EV charger with IP54, RFID, OCPP 1.6J/2.0.1, and Modbus TCP on port 502. Unit ID 1. Float32 registers for charge state (300-301), current setpoint (316-317), active power (344-345), and session energy (374-375). Standard for Dutch commercial car parks and office buildings.
Eve Double Pro-line 2×22 kW
Dual-port 22 kW per side three-phase commercial charger. Two independent Modbus TCP unit IDs (1 and 2) on same IP address — gateway connects twice to same IP for independent load management of each socket. RFID, OCPP 2.0.1, IP54.
ICU Eve Series 11 kW
11 kW single or three-phase residential wallbox. OCPP 1.6J, Modbus TCP, Wi-Fi or Ethernet. Compact design for home garage installation. KNX integration via Modbus TCP same register map as Eve Pro-line for residential PV self-consumption charging automation.
ACE 100 kWh energy storage
100 kWh Li-ion battery energy storage system (BESS). Modbus TCP registers for SOC (%), charge/discharge power (W), and state (idle/charging/discharging). KNX integrates ACE alongside Eve chargers for combined peak shaving and EV load management from single KNX Modbus gateway.
Alfen FAQ
What is the Alfen Eve Modbus TCP register for charge power?
Registers 344-345 (float32, W, FC3). Unit ID 1. These two consecutive 16-bit registers form a 32-bit float value for total active power in watts across all three phases. Read with FC3 for 2 registers and interpret as IEEE 754 float32 big-endian.
How many chargers per KNX Modbus gateway?
Each Eve charger has its own Modbus TCP address (IP). A gateway with 10 TCP connections handles 10 chargers simultaneously. For larger installations, use Alfen SCU (Smart Charging Unit) as a single Modbus aggregator — KNX communicates with SCU only, and SCU manages up to 100 Eve chargers internally.
OCPP or Modbus TCP for KNX integration?
Modbus TCP is simpler for PLC/KNX gateway integration — direct register reads and writes without an OCPP broker. OCPP is preferred when using Home Assistant or IP-Symcon as middleware, or when a charge point management system (CPMS) is required for billing and user management.
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