Energy Harvesting: How EnOcean Devices Generate Power
EnOcean pushbuttons use the piezoelectric effect: pressing a button generates enough energy for a radio telegram. Temperature sensors and room controllers typically tap solar energy via a micro cell, even diffuse office light is sufficient for continuous operation.
Free-field transmission range is up to 300 m (ISO 14543-3). In buildings with concrete and metal structures, 30–50 m per "hop" is realistic. Repeaters extend range but add approximately 30 ms latency per stage.
The radio telegram is 1–14 bytes short and transmitted on 315 MHz (Americas), 868 MHz (Europe) or 928 MHz (Japan). In Europe, 868 MHz is the standard; a duty cycle of max. 1% is permitted, sufficient for switching and status telegrams.
EnOcean-KNX Gateway: Integration and Use Cases
The gateway receives EnOcean radio telegrams and converts them into KNX telegrams. Each EnOcean transmitter has a unique 32-bit ID (EnOcean ID) that the gateway uses to identify it and assign it to the correct KNX CO. Configuration is done via ETS plugin or the gateway's web interface.
Typical EnOcean-KNX applications: retrofit wall switches without cables or duct work (ideal for refurbishment), window/door contacts for after-the-fact alarm integration, temperature sensors for individual rooms without cabling effort.
EnOcean devices are not compatible with KNX-RF, these are two separate wireless standards. KNX-RF uses the same physical layer as KNX-TP but wirelessly; EnOcean is a standalone ecosystem integrated into KNX via a gateway.
Key Facts
- No battery, no cable: energy from button press, light or heat
- Range 30–50 m in buildings, up to 300 m in open field
- 868 MHz in Europe, max. 1% duty cycle
- EnOcean ID: unique 32-bit device identifier
- Not compatible with KNX-RF, integration only via gateway