High energy efficiency goals demand flexible automation systems
for a variety of buildings over several areas.
Global challenges in energy generation and consumption motivates govern- ments worldwide to set ambitious goals
for increased energy efficiency, which results in
a fast growing need for energy-efficient buildings.
Therefore, innovative, sustainable technologies
that can be easily installed, especially in retrofit
projects, are a necessity if the governments’ ambitious objectives are to be realized.
Buildings consume more than 40 percent of
primary energy. Over a trillion dollars in energy
savings opportunities are available in the U.S., but
in order to realize these savings, state and local
programs need to become involved by financing
efficiency measures – offering programs such as
repayment on utility bills or property tax bills.
Such measures, including the support of efficient
technologies to increase energy productivity
across the economy, are part of the Energy 2030
plan of the Alliance Commission on National
Energy Efficiency Policy, with U.S. government
objectives to cut energy waste in buildings and
homes in half.
Energy harvesting wireless technology becomes
more attractive for OEMs as a basis technology for
products and solutions that contribute to a building’s efficient energy management. The wireless
modules gain their power from the surrounding
environment. In the process, an electrodynamic
energy converter uses mechanical motion or a
miniaturized solar module generating energy
from light. Combining a peltier element with a
DC/DC ultra-low-voltage converter taps heat as
an energy source. Even the smallest amounts of
harvested energy are sufficient to transmit a wireless signal. The addition of a capacitor can ensure
adequate power storage to bridge intervals when
no energy can be harvested.
Energy harvesting technology enables batteryless automation devices and systems to make
buildings more energy-efficient based on sustainable, resource-saving technologies that eliminate
the need for batteries. This makes the difference
for OEMs when deciding on wireless technologies, as at the end of their lifetime, batteries are,
and remain, hazardous waste and need to be
carefully (and expensively) disposed. In addition,
batteries contradict the sustainability and “green”
aspect that intelligent control systems offer buildings when making them more energy efficient.
No Compromise in
Energy harvesting wireless devices are
low energy, but not low power. For optimal
RF effectiveness, the radio protocol uses
315 MHz and 902 MHz frequency bands
in the US. The sub1 GHZ radio waves have
twice the range of 2. 4 GHz signals for the
same energy budget, and better penetration within buildings. As a reference point,
duplicating the energy harvesting wireless
system at 2. 4 GHz system requires about
four times more receiver nodes to cover the
same area. RF reliability is assured because
wireless signals are just 0.7 milliseconds in
duration and are transmitted multiple times
for redundancy. The range of energy harvesting
wireless sensors is about 900 ft in an open field
and up to 90 ft inside buildings.
In comparison to 315 MHz, the 902 MHz
modules allow for integration into very small
product enclosures due to short antenna length.
Interference from co-located devices such as light
ballasts and LED drivers are at a minimum. These
enable an effective, robust wireless platform for
applications in the building automation sector,
smart home solutions, consumer appliances, or
The Link to Networks
The interconnection of a system’s sensors and
relay receivers with a central control to an adaptive network must be intelligent. Therefore, there
is an increasing demand to incorporate batteryless,
wireless devices into networks based on several
different communication standards such as WiFi,
GSM, Ethernet/IP, BACnet, LON, KNX, DALI,
etc. Previously, OEMs had to develop individual
software solutions, transferring energy harvesting
wireless signals into the requested communication protocol. This challenge is now overcome by
EnOcean Link, the first middleware for energy
harvesting wireless networks.
EnOcean Link converts the bits and bytes of
an EnOcean telegram directly into data values. In
doing so, the middleware automatically takes into
account the specifications of the EnOcean proto-
col stack and the EnOcean Equipment Profiles
(EEPs) of the EnOcean Alliance, as well as
encryption mechanisms. All wireless applications
can have a ready-made key to the wireless energy
harvesting world. Since the software interprets all
data, it also ensures the interoperability of equip-
ment from different manufacturers.