The EnOcean wireless standard describes a battery-free technology marketed under the Dolphin and Easyfit brands. Read here how the wireless technology works battery-free and yet completely without cables and wires, which advantages and disadvantages result from it and how safe EnOcean really is.
In order for the many electric helpers and smart products to function in everyday life, they first need energy themselves. They are often powered by batteries that have to be replaced regularly – “green” technology looks different. That’s what EnOcean GmbH thought 15 years ago. With their battery-free wireless modules, they have found an innovative solution with which the smart home always has energy available. Worldwide EnOcean is already used in more than 2,500,000 buildings. The smart radio technology is not only used in new buildings – EnOcean can also be retrofitted for retrofitting or renovation. Since the radio modules step only on command into action, they produce little electrical smog and are suitable from building-biological view very well for kindergartens and hospitals.
In addition, EnOcean is compatible with wired home automation systems and various bus systems. These already use EnOcean technology to supplement their own systems where they themselves are not flexible enough.
EnOcean: origin and history
EnOcean GmbH was founded in 2001 and is a venture of Siemens AG. It is headquartered in Oberhaching in Munich, Germany, and brought the first battery-free wireless modules to market after just one year. This batteryless radio sensor technology forms thereby the basic technology for the radio standard for house automation. The company’s name, EnOcean, is based on the observation that the world is an ocean of unused energy.
In 2008, the EnOcean Alliance was formed, an association of various companies whose goal is to promote the compatibility and cooperation of different systems based on the EnOcean wireless standard. It also aims to establish other automation solutions for sustainable and smart building projects, all of which use the batteryless wireless technology. Compatible products from all areas of building and home automation will thus gradually be developed to offer a complete smart home system in the future. EnOcean also hopes to use wireless technology in miniature switches, tiny wireless temperature sensors and sensor modules in the future. These switches and sensors will then be molded into machine parts to implement smart living in an energy-efficient way in all areas of life.
EnOcean: A promising wireless standard for the Internet of Things
The battery-free wireless sensors enable communication between maintenance-free IoT devices (IoT = Internet of Things) based on various wireless standards such as EnOcean, Zigbee and Bluetooth. The solutions are used in building automation, smart home, LED lighting control, industrial applications and other smart products.
EnOcean is based on the so-called “energy harvesting principle”. Energy is generated from the slightest changes in the environment and used to transmit radio signals. EnOcean uses energy from the environment. For example, when you press a switch with your finger. The resulting piezoelectric effect generates electrical charges on the surface. The built-in, miniaturized energy converters can convert this energy into a radio signal that is transmitted, for example, from the light switch to the central smart home control system or the lighting.
EnOcean’s Dolphin modules and Easyfit products harness energy not only from motion, but also from light and even temperature differences, such as waste heat. EnOcean is also working on tapping energy in the future using rotary and vibration transducers. This would offer entirely new products and possibilities – gas and water meters rotate during operation, for example, and machines as well as people generate vibrations.
EnOcean in the smart home: Free choice of location
Currently, the most common use of EnOcean in the smart home is for switching electrical loads such as switches for room lighting, room air conditioning or remotely switchable sockets. And here, apart from the self-sufficient power supply, there are other tangible advantages. Thanks to smart wireless technology, you can place all the switches where you need them: Be it next to the couch to turn on the TV and hi-fi system or even better as an all-out switch next to the front door. If you want to redesign your home, you can easily remove the screwed-on or glued-on switches.
Can EnOcean be used worldwide?
EnOcean can be used worldwide, because different frequencies are selected depending on the country. In Europe, the frequency of 868 MHz is used and has been defined as an international standard by the IEC since March 2012.
Good to know: For North America, you need modules with 902 MHz according to the FCC/IC specification. In Japan, modules with 928 MHz according to the ARIB specification are suitable.
Application and range of the EnOcean wireless protocol
EnOcean devices are used across systems. For example, it is possible to use BACnet or KNX building control systems and still integrate EnOcean radio-based devices and products in the network using certain gateways.
EnOcean uses the so-called “mesh network topology”. Normally, this means a network in which each node is connected to at least two others. However, there is also the option that the network only has several nodes. The advantage is that it is the most fail-safe and powerful network. However, the complex routing is problematic.
Since EnOcean offers both uni- and bidirectional radio modules, i.e. not all devices can communicate in all directions, it uses the mesh network only in a limited form. The bidirectional devices can take over routing functions and be used as gateways. Occasionally, bidirectional actuators and sensors may also be present. Often, these are also designed as transmitters or receivers, but must obtain their energy from the environment and therefore cannot provide sufficient energy for bidirectional communication.
To ensure successful communication, the so-called EEP (EnOcean Equipment Profiles) are used. These are defined by the EnOcean Alliance and enable systems from different manufacturers to work together seamlessly. However, EnOcean is already planning a general profile with a simplified application layer, so that unnecessary components can be dispensed with.
In every respect EnOcean attaches importance to simplicity. This also applies, for example, to minimizing potential collisions during data transmission. This means that all end points in the wireless network send out data in so-called telegrams. The integrity of these messages is verified by the central system using a checksum. Each telegram occupies only a small time window (about one millisecond). In addition, no interference can occur for Wlan, Dect or PMR systems.
The range in buildings is up to 30 meters. However, this can be improved by WLAN mesh repeaters.
What are the advantages and disadvantages of EnOcean?
The unmistakable advantage of EnOcean technology is that it functions without a battery or cables. This can save up to 40 percent of energy consumption. In addition, almost all devices are maintenance-free and have a long service life. Via gateways, EnOcean can communicate with all existing bus systems such as KNX or BACnet.
Furthermore, the number of sensors is limitless. Who would like to distribute these in the house, does not have to seize to the drill, but can stick the switches and sensors everywhere. This makes EnOcean ideal for renovations in buildings where it is difficult to lay cables. This is also the case, for example, in the Semper Opera House in Dresden, where EnOcean-based products were installed because areas of the building are listed and cabling is prohibited.
Another advantage of EnOcen is the short transmission time of the signals. This makes the wireless standard not only energy-efficient but also low-radiation.
While battery-free wireless modules were a unique selling point of EnOcean in the beginning, more and more competition can now be found. ZigBee, for example, has already recognized the potential. It must be noted, however, that not every technology works with such low power requirements as EnOcean. Adding a harvesting function to ZigBee, for example, might not yield results comparable to EnOcean.
Older EnOcean components still operate unidirectionally. The simple construction of the radio standard can bring a certain safety risk with it. This is because the energy-saving model of one-way communication means that there is no confirmation that data is being received. An increased security standard is only provided by the Dolphin architecture.