Ivory Egg Blog Archive

EnOcean, the inventor of energy harvesting wireless sensor networks, manufactures self-powered radio modules and energy harvesters that enable OEMs to develop wireless sensors & switches for new and retrofit BAS (Building Automation Systems).

Their battery-less radio modules convert ambient solar, thermal and motion energy into useable electrical energy that powers building network communications. These “peel-n-stick” devices reduce the time, cost and occupant disruption of energy conservation retrofits; and provide unparalleled flexibility in new construction. The company is a spinoff of Siemens AG and U.S. operations are based in Boston, Mass.

The EnOcean technology is a proprietary environment not yet set out for international, European or national standardisation. However, EnOcean GmbH ist offering its technology and licenses for the patented features under license with the EnOcean Alliance framework. The concept was developed to enable e.g. battery-free switches for building equipment. The economical perspective let Siemens decide to spin the operation out of the company combine. Actual shareholders are not disclosed.

EnOcean Technology

EnOcean has developed a technology that is based on the energetically efficient exploitation of applied slight mechanical excitation and other potentials from the ambiance using the principles of energy harvesting. In order to transform such energy fluctuations into usable electrical energy, electromagnetic, piezogenerators, solar cells, thermocouples, and other energy converters are used.

The EnOcean products (such as sensors and radio switches) need no battery and are engineered to operate maintenance-free. The signals from these sensors and switches can be transmitted wireless over a distance of up to 300 meters. Early designs from the company used piezo generators, later replaced with electromagnetic energy sources to reduce the operating pressure (7 newtons), and increase the service life to 50,000 operations.

The most pervasive example of a product making use of a proprietary RF protocol is a battery-free wireless light switch. This product has gone to market with the competitive advantage that it saves time and material not to install wires between the switch and e.g. a light effector. It also saves switched circuits as the switching is performed locally at the load itself when enhanced with a local switch on permanent supply.

Packets of data are transmitted at 120 kbit/s with the packet being 14 bytes long with a four byte data payload. RF energy is only transmitted for the 1’s on the data, reducing the amount of power required. Three packets are sent at pseudo-random intervals reducing the possibility of packet collisions. Push switches also transmit a further three data packets on release of the switch push-button, enabling other features such as light dimming to be implemented.

The EnOcean technology may be used also for wireless mesh networking (proprietary mesh protocol).

Switch signals and sensor information are transmitted – interference from other signals is no threat. Every device has a unique 32-bit serial number, so local ambiguity is avoided by ‘training’ a receiver to its specific transmitters. The transmission frequency used for the devices is 868.3 MHz.

Application Examples

One application of the technology is an audience voting system developed by EnOcean’s UK distributor. Each member of the audience is given a four-button remote with an EnOcean transmitter, and the signals are decoded by a receiver connected to a PC. This avoids the need to manage batteries in many remote handsets, and each handset is uniquely identified, so the ‘quizmaster’ or presenter can see each individual answer from each member of the audience.

EnOcean Company

EnOcean GmbH is a spin-off company of Siemens AG founded in 2001, that is venture funded. It is a German company headquartered in Oberhaching, near Munich, which currently employs 35 staff. It is a technology supplier of self-powered modules (transmitters, receivers, transceivers, energy converter) to companies (e.g. Siemens, Distech Controls, Zumtobel, Omnio, Osram, Wieland Electric, Peha, Thermokon, Wago, Herga), which develop and manufacture products used in building automation (light, shading, hvac), industrial automation, and automotive industry (replacement of the conventional battery in tyre pressure sensors).

The company has won awards for the technology and company performance, e.g. the Bavarian Innovation Prize 2002 for its globally unique technology, the award “Technology Pioneer 2006″ by the renowned World Economic Forum and the award BuildingGreen Top-10 Product for 2007. The standard switch modules produced by EnOcean employ electro-magnetic generation techniques.

EnOcean Alliance

A group of companies across Europe and North America (e.g. Omnio, Thermokon, Masco, MK Electric, Distech Controls and EnOcean) formed the EnOcean Alliance in April 2008 as a non-profit, mutual benefit corporation which has the formal purpose of initially developing the specifications for the interoperability of the sensor profiles for the wireless products operating in unlicensed frequency bands and subsequently to apply for ratification as an international standard at the appropriate standardization committee, and of helping to bring about the existence of a broad range of interoperable wireless monitoring and controlling products for use in and around residential, commercial and industrial buildings.

EnOcean Licensees

EnOcean technologies also appear in other products such as ‘Navatis’ from Herga. In July 2007, the company announced technology to allow transmitters to be powered from Peltier devices with a minimum of 2 degrees Celsius temperature difference on each side of a 15 mm square Peltier panel. In November 2007, MK Electric, the largest manufacturer of consumer electrical fitments in the UK, adopted EnOcean technology for a new range of wireless switches.

To find out more, please visit EnOcean-Alliance.org.