Calling the wireless race results too early?

Calling the wireless race too early?

By Bill Lydon - Contributing Editor
In my recent AHR 2009 report, I noted, "ZigBee looks on track to become the major standard.” Graham Martin, Chairman & CEO of the EnOcean Alliance, suggested that I was calling the race too early.  In fairness, and in the spirit of understanding, I decided to interview Graham about EnOcean technology.
EnOcean is certainly an interesting technology that I first encountered at the Frankfurt Light and Buildings Fair in 2004. I was walking past the EnOcean booth when a gentleman handed me a very thin rocker switch and asked me to push it. When I did, lights turned on in the EnOcean booth and I asked, how small is the battery in the switch? He explained there were no batteries required.
EnOcean GmbH (
EnOcean GmbH is the company which is the originator of the patented self-powered wireless technology. Headquartered in Oberhaching near Munich, the company manufactures and markets maintenance-free wireless sensor solutions for use in buildings and industrial installations. EnOcean solutions are based on miniaturized energy converters, ultra-low-power electronic circuitry and reliable wireless. Combining these elements enables EnOcean and its product partners to offer batteryless sensor systems. EnOcean GmbH was founded in 2001 as a spin-off from Siemens AG. Investors in the company include:
EnOcean Alliance (
The EnOcean Alliance is a consortium of companies dedicated to the advancement of self-powered interoperable wireless control systems. 
Interview with Graham Martin, Chairman & CEO of EnOcean Alliance
Graham Martin is a veteran of the electronics industry with more than 25 years of experience in analog and RF solutions. Before joining EnOcean, he held various engineering and marketing posts in the USA and Europe. Most recently he was responsible for business development at wireless sensor networks specialist Chipcon. At the same time, he was president of Figure8Wireless and vice chairman of ZigBee Alliance.  Martin studied in the USA and Britain, and graduated in physics at Edinburgh University, Scotland.  You can contact Graham Martin at [email protected].
Bill:  What are the basics of the EnOcean technology?
Graham: EnOcean invented and patented energy harvesting wireless sensors in the 1990s. EnOcean technology enables wireless sensors and switches that require no batteries and therefore no maintenance. The sensors are powered by energy harvesting such as linear motion, light or thermal differences. The technology is widely deployed in buildings and industrial sites.
 EnOcean Core Technologies
Bill: What are the distance limits for the EnOcean technology?
Graham: In free-field, the signals will travel up to 1,000 feet. In a building environment this will be reduced depending on the structure and materials – in the tens of thousands of deployments already performed we are seeing typical ranges of 30 to 100 feet range.
Bill: Is EnOcean a mesh based system or point to point?
Graham: It can be both. Typically the deployments have been point to point or point to multi-point within a room, home or office area, then hooking up to a central unit in the house or to the building backbone such as LON Works, BACnet, KNX/EIB or TCP/IP. It is also possible to do signal repeating or simple mesh networking – but in practice most building professionals do not request nor require this.
Bill: How is the EnOcean radio technology different than ZigBee?
Graham: EnOcean radio technology is the only low-power wireless technology that can be powered by energy harvesting, removing the need for tedious, expensive and environmentally unfriendly battery maintenance. Other low-power wireless solutions, such as ZigBee nodes, require typically 30 to 100 times more power than EnOcean nodes, requiring batteries or even cables to power them – with my experience in the field, given the choice, nobody wants to have batteries to maintain in a building.
Bill: How susceptible are EnOcean devices to interference from WLANs, Bluetooth, Microwave ovens and other devices?
Graham: WLANs, Bluetooth, microwave ovens and ZigBee all use the extremely crowded 2,4GHz band and therefore have to deal with interference and often latency issues as well as power hungry frequency agility or hopping. EnOcean functions in the virtually interference free license free 315MHz band in North America which is used basically only for car keys and some tire pressure systems with very low duty cycles.
Bill: Are EnOcean products really maintenance free?
Graham: Yes. EnOcean products will work typically for decades without any maintenance. For example, EnOcean light-switch modules have been tested to over 50,000 switching cycles – typically 25 to 35 years of normal use – whilst conventional light switches are typically tested to 40,000 switching cycles.
Bill: How much energy is required to operate your products?
Graham: All the energy required by the sensors and switches is harvested from motion, light or thermal sources.   EnOcean solar based modules, such as in thermostats, require only 80nA (nanoamp) in sleep mode – meaning that the products can still function many days even in total darkness.   EnOcean light-switch modules use only the minuscule amount of energy created for a few milliseconds after pressing – otherwise they require no energy.
Bill: What standards does EnOcean meet?
Graham: EnOcean, with tens of thousands of buildings already deployed with interoperable products from multiple manufacturers, is already the practical wireless standard for sustainable buildings. Anybody can use the technology. Currently this proven technology is being formally standardized and opened through the IEC.
Bill: Is there a certification of EnOcean products to insure compatibility? How do products become certified?
Graham: EnOcean is such a simple and robust protocol that there is no need for expensive and complicated certification procedures. Our over 100 members currently self-certify their interoperable products according to the regulations set down by our Technical Working Group within the EnOcean Alliance. Under the IEC standard, I expect that this proven self-certification can continue.
Bill: How many fully interoperable products are available today?
Graham: Well over 300 fully interoperable products from over 100 different manufacturers are available off the shelve today.
EnOcean Thermostat and Receiver
Bill: How many buildings have been deployed using EnOcean technologies? How long has the technology been deployed?
Graham: There are tens of thousands of buildings already successfully deployed – offices, schools, hospitals, public buildings, hotels, retail, industrial sites and of course residential. The first large scale deployment was the Bosch-Siemens Headquarters in Munich, Germany in 2003. Other large scale deployments include SAP Headquarters, IBM Headquarters, the 55 floor Space and Crystal Towers and Uniqa Tower. Some of our most recent North American deployments include the Olympic Village in Vancouver and the IKEA North American Warehouse.
Bill: How would you contrast this with the statements that ZigBee ( is widely deployed?
Graham:  According to the ZigBee Alliance web site there are less than 20 ZigBee Compliant Interoperable End Products available today and there are no references to any wide-scale deployment of these products in buildings. EnOcean technology is successfully deployed in tens of thousands of buildings.
I was at the ISH Show last week – the world’s largest show for HVAC systems and bathroom fittings with over 200,000 visitors and thousands of exhibitors. There were dozens of companies showing solutions with EnOcean based products– I couldn’t find any ZigBee compliant interoperable end-products at the show nor could I find a ZigBee Alliance booth.
It is often very difficult to separate hype from facts, but I think these facts speak for themselves.
Editor's Note: ISH was held in Frankfurt Germany and is advertised as, “The Bathroom Experience, Building, Energy, Air-conditioning Technology, Renewable Energies” trade fair.
Bill: What have been the proven energy savings?
Graham: We have multiple case studies in North America, Europe and Middle East showing between 20% and 60% of actual savings in lighting and HVAC energy in buildings such as schools, hospitals and offices – significantly saving costs and helping to reduce carbon footprints. Obviously there are also significant savings during installation. In one 55 storey building office tower (Space Tower) recently deployed, they saved over 20 miles of cable – that’s a lot of copper and PVC savings as well as man years of installation time and rework time.
EnOcean SmartSpaceControl Kit
  • Room controller (Thinks for itself and dims or turns off lights according to the amount of natural light available and/or occupancy status)
  • Self-powered Wireless Photo/Light Sensor
  • Self-powered Wireless Occupancy Sensor
  • Self-powered Wireless Light Switch
Bill: Are EnOcean or ZigBee an industry Standard?
Graham: The radio which ZigBee uses to communicate its data is based on the IEEE Standard 802.15.4.  ZigBee is a very complicated networking software stack using this radio and is not controlled by any standardization body – therefore allowing the creation of dozens or even hundreds of non-interoperable proprietary versions thereof. EnOcean technology is currently undergoing standardization within the IEC which will ensure the user of continued product interoperability.
Bill: You commented to me that there is confusion about the interoperability of ZigBee devices. Can you describe the present interoperability issues of ZigBee?
Graham: "ZigBee Based", "Designed for ZigBee", "ZigBee Ready", "manufacture specific ZigBee", "uses ZigBee Technology" and similar designations all mean that they are all not multi-vendor interoperable ZigBee.  They are mostly proprietary versions often using some parts of the ZigBee networking stack. According to the ZigBee Alliance, the BACnet version of ZigBee under development is also not fully interoperable with the Smart Energy version of ZigBee recently announced. I think there needs to be more clarification of this confusion and non-interoperability of all of these various versions.
Bill: How does EnOcean interoperability differ?
Graham: EnOcean created the technology together with building professionals, end-users and product OEMs, listening to their needs and practical requirements. The result is a simple to use, short and robust protocol which is easy to install and use.   There are thousands of buildings already deployed using different interoperable products from multiple manufacturers. This demonstrates that EnOcean has true multi-vendor interoperability.  
Bill: There is discussion of Battery-less ZigBee. How would you contrast this to EnOcean?
Graham: EnOcean invented and patented batteryless wireless sensors in the 1990s and in the meantime deployed it in more than 10,000 buildings and within our Alliance received multiple additional patents in this field. Twelve years after the first patents were granted, many people in the industry realized this piece of genius, jumped onto the idea and started to develop their battery-less wireless technology – one of whom is ZigBee. Independent of the IP rights issues the product manufacturers will face, the wireless technologists will also have to come up with a practical technical solution - which could actually be the bigger challenge. Most so-called low-power wireless nodes require typically around 30 to 100 times the energy of an EnOcean node. An example is the latest of the multiple ZigBee stacks - ZigBee Pro. It has frequency agility to deal with WLAN interference - which increases the energy requirements significantly - making many applications practically speaking impossible.
Bill: How do you see the need for batteries in ZigBee impacting acceptance?
Graham: No building owner wants hundreds or thousands of batteries to have to maintain.   Even in energy efficient residential installations there are dozens of sensors and switches – making tedious battery maintenance also a non-starter. Therefore I think trials taking place today of most ZigBee Compliant End Products therefore will actually use power cables to power the nodes. Maybe "wired, wireless" would be more appropriate term for these installations.
Bill: What is the EnOcean vision of wireless sensors?
Graham: Buildings use 40% of our total energy requirements and there is now a global awareness to reduce our energy consumption. With intelligent building automation systems, energy savings of over 30% can easily be achieved. These systems require sensors and whether it is a retrofit of an existing building or a new building, wireless and batteryless sensors are the ideal solution. There are tens of millions of energy inefficient buildings requiring such retrofit and I believe most new buildings will also be thinking “green” so I see the demand for such wireless and batteryless sensors exploding over the next few years.
Bill’s Comments
Wireless is a hot topic in all markets and there is a great deal of technology that has been and continues to be developed. Batteries have been an issue in the many roundtables and other discussion over the last few years. EnOcean certainly addresses the battery issue. It appears that today all types of wireless products are being adopted in many forms simply based on the compelling return on investment based on the elimination of wires.
I am interesting in comments on the good, bad, and ugly from users and system integrators regarding the application of wireless. 
Please provide your comments: [email protected]