The success of new technologies that reduce the energy requirements of home automation systems has led to a burgeoning of wireless solutions based on extremely low power devices, including those powered by energy harvested from the environment, for example by light, minute temperature differentials or by the physical power of pressing buttons or switches.
Now, de facto standards in this field have been accepted as the international standard, ISO/IEC 14543-3-10. So, what are the advantages to the home automation industry, and how will it spur growth in home automation?
Without question, the drive to improve energy efficiency and reduce carbon emissions remains high on the agenda of those building home automation systems. Buildings, which account for 40% of our total energy requirements, need to save energy and lower their CO2 output. Sensors and switches are a vital part of the solution. The combination of miniaturised energy harvesting modules with ultra-low power radio technology is the basis for innovative maintenance-free wireless sensors. Energy harvesting wireless technology adds unparalleled flexibility at lowest investment and operational cost.
Interoperability of different end-products based upon energy harvesting technology has been an important success factor for establishment of the technology on the market. For this reason, the industry has long-sought standardisation of communication profiles, ensuring that sensors from one manufacturer can communicate with receiver gateways of another, for example.
However, until recently the industry has had to rely on de facto wireless standards such as those established by EnOcean and deployed through the EnOcean Alliance – a consortium of companies working to further develop and promote self-powered wireless monitoring and control systems for sustainable buildings by formalising the interoperable wireless standard. The EnOcean Alliance has the largest installed base of field-proven wireless building automation networks in the world, all optimised for ultra-lowest power consumption and enabling energy harvesting powered sensor networks.
Now these principles have been enshrined in a new standard, ISO/IEC 14543-3-10, which provides a Wireless Short-Packet (WSP) protocol optimised for energy harvesting -- Architecture and lower layer protocols.
This wireless protocol is especially suitable for energy-harvested devices in the home environment as it is the only standard specifically designed to keep the energy consumption of such sensors and switches extremely low; an order of magnitude lower than alternative standards. It achieves this by transmitting multiple, very short RF transmissions and by selecting radio frequency bands with excellent signal propagation and minimal interference. The result is reliable wireless communication that is energy efficient but not low power, allowing the use of small, cost-effective, maintenance free energy harvesters that can compete with similar battery-powered devices.
A standard standard
In many respects the structure of ISO/IEC 14543-3-10 is identical to most wireless standards where upper layers of the protocol (creating interoperable products) are governed by technology alliances and sit on top of the radio – physical and data link layer defined by an open international standard. This is the case with Bluetooth and IEEE 802.15.1, Wireless HART/ZigBee/RF4CE and IEEE 802.15.4, or WiFi and IEEE 802.11.
Where other wireless standards integrate physical and data link layers and the network layer is integrated in the protocol stacks, in the case of ISO/IEC 14543-3-10 the standard offers physical and data link layer as well as the network layer, with the EnOcean Alliance offering the application level. The EnOcean Alliance creates the application profiles which sit on top of ISO/IEC 14543-3-10 and are defined in order to achieve interoperability between products from different vendors. These application level protocols are referred to as EEPs (EnOcean Equipment Profiles).
Another feature that distinguishes the new standard from other wireless protocols is that there is a rich ecosystem of field-proven devices adhering to the standard. There are already over 850 products in a technological brick or module format operating according to this communication technology. The EnOcean Alliance created in 2008 has 250 members, including over 100 equipment manufacturers.
Standards drive demand and innovation
International standardisation coalesces development around a common technology, while increasing demand for energy harvesting wireless solutions based upon this standard. This will drive developments in lower power sensors and radios and more efficient energy harvesters for various sources of energy. It will expand the market, open it to others and lead to the development of a greater number of interoperable products for building automation. The adoption within the Home and Building Automation sectors will spur adoption in industrial markets such as environmental and cold-chain monitoring, transportation and industrial process control.
There are already a number of solutions and home automation systems that are based upon the standard, for example: WeberHaus, a German-based eco-construction company, has built sustainable homes throughout the UK and Ireland, using self-powered wireless sensor technology. WeberHaus is offering four home automation models that can be combined to match specific self-build specifications and requirements. These include single room and central control of lighting, under-floor heating, blinds and window monitoring, door entry security and central monitoring.
Inherent interoperability provides installers the flexibility to specify the ideal energy-harvesting wireless device for their application, such as: switches to control lighting and shading; occupancy sensors that adjust temperature and turn off lights when a room is not in use; wireless room temperature sensors to minimise energy consumption with maximum comfort. All these examples are complemented by the wide availability of central control software running on a touch panel or PC/notebook, and remote monitoring and control via mobile phone or on the Internet.
Standardisation is helping to drive further innovation by sensor manufacturers. Hoppe, a manufacturer of window hardware, designed a self powered window handle that draws energy from the action of turning the handle. The signal is used to trigger alarm systems or climate control systems to cut back on heating to save energy.
German company Kieback&Peter has developed a miniature wireless actuator which utilises the thermal energy of a heating system as its energy source. When combined with an intelligent energy management system and an integrated thermostat, the actuator is completely energy-independent. The self-powered actuator operates like a traditional radiator valve, combining the radiator’s thermostatic head and motorised actuator. As with a thermostat valve, the user sets the desired room temperature by turning the thermostatic head with the numbers 1-5. The integrated thermostat then regulates the room temperature to match the setting. If the room is unoccupied or windows are opened to allow fresh air in, the actuator automatically adjusts to a lower setpoint.
##IMAGE_4_R##Standardisation reinforces the advantages
Innovations like this make home automation systems easier than ever to install. Whether for retrofit or new construction, maintenance free wireless sensors and switches enable automation installers to save cost and time, reduce on-going maintenance, and eliminate disruption or building downtime.
It removes the requirement for dry linings, fast fix box and wall penetration. There are fewer problems coordinating with other trades, finishes and installation can be scheduled completely independently of first-fix activities. With no control cabling to be installed, there is no disruption to wall installations and the potential requirement of RCD protection of lighting circuits is eliminated.
Cable installation is simplified to a ‘radial’ point to point format, with the Consumer Unit acting as an ‘intelligent hub’ through the use of DIN mounted multi-channel receivers and limits hard wired field terminations.
Last minute client changes are readily accommodated and there is considerably more flexibility in positioning switches anywhere in the house. Finally, the wireless technology is inherently safer for installers and users alike, and is better able to meet the safety requirements of bathrooms and lavatory installations.
From design, through specification to installation, the new ultra-low power wireless standard gives the home automation industry unparalleled flexibility at lowest investment and operational cost.