EEBus: Whitepaper
Supported by:
Background:
The Kellendonk EEBus initiative developed from the Federal Government's E-Energy
project. The subject of smart grid is processed by many bodies and actors apart from this
landmark project as well. However, essential aspects of home networking in respect of
Smart Home concepts have not yet been standardised. The Kellendonk initiative took up
this field of action and is mainly targeted at all persons interested in jointly driving
standardisation and prototyping in hardware and software, or striving for product
implementation with high investment safety.
Authors:
Wolfgang Dorst
Til Landwehrmann
Download at:
www.eebus.de
Supported by:
Table of Contents:
CHALLENGES FOR ENERGY MANAGEMENT .............................................................................................. 4
THE EEBUS APPROACH............................................................................................................................ 5
EEBUS AND SMART METERING ............................................................................................................... 9
EEBUS ARCHITECTURE .......................................................................................................................... 10
EEBUS PHYSICAL LAYER......................................................................................................................... 12
THE EEBUS IN STANDARDISATION ......................................................................................................... 13
USING THE EEBUS CONCEPT IN PRODUCTS ............................................................................................ 15
Summary
The EEBus describes a technology for comprehensive networking of devices and load
management between power suppliers, grid operators and end users. For this, it abstracts
many existing protocols in a consistent IPv6/XML format. Furthermore, it defines
mechanisms for automatic load management. The attributes for incentive systems
standardised in international bodies are implemented in the EEBus. They provide the basis
for future business models.
Initial software implementations based on the EEBus are tested in various projects. The
software will be available on the market as of 2012. Expansions of the EEBus approach are
targeted not only at the power-related networking concept, but also at other value-added
services for end customers and service providers in the areas of eHealth, Ambient Assisted
Living and Security.
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Challenges for Energy Management
The increasing development of renewable energies, in particular in the end customer business
low-voltage area, changes the function of energy management. In the past, the power grid had a
balance and a directed, unidirectional load flow could be assumed. Generation mainly took place
in large power plants, and load flows to the consumer were well-predictable. Continuous
monitoring and high degrees of automation were not necessary throughout the distributor
network and at the end customer's.
The continually increasing share of locally generated power makes temporal and regional
balancing of energy generation and energy consumption difficult. The purchaser, mainly
household and agricultural customers, turn into "prosumers", a mixture of consumers and
producers, with the development of local generation plants (Solar, block heat and power plant,
etc.). Smart own consumption even now plays an important role in these groups – not least due
to the existing government aid. The planned distribution of electric mobility will increase this
system change in future. The low-voltage level is facing a challenge. Secure supply requires
changes in the equipment. IKT 1-networked, smart equipment enables the development into a
bidirectional grid.
The need to create a balance in the grid also poses new challenges in the relationship between
end consumer and energy provider. Variable incentives (e.g. load-variable rates) and load
forecasts should ensure reliable power supply in spite of fluctuations in generation. For this,
interaction between the distributor grid operator and end consumer will be required for this. A
high degree of automation, control and data privacy is required to integrate consumers in such
interaction without limitation. Energy Management Gateways2 make this possible. These
gateways are connected to the internet under consideration of high data privacy requirements.
Such IKT-based service platforms provide opportunities for new business models using load
forecasts. Supply-oriented power use should, of course, be implemented aligned with the
consumer demand.
To implement a smart grid system, i.e. a comprehensive, smartly communicating power network,
the actual power grid operation and IKT service platform must be linked. Since this requires
definition of different, previously independent, industry interfaces also characterised by different
technology life cycles in relation to each other, their combination in one comprehensive system
is anything but easy. This situation is additionally made more difficult by strong technology
diversity, in particular in the communications technology area. The EEBus provides a crosstechnology and continually normative solution for this challenge.
1
IKT: Informations- und Kommunikationstechnologie (Information and communications technology)
2
An Energy Management Gateway is a central control unit at the customer's that all devices are connected to. It
can either be an independent device (e.g. Smart Home Gateway, home controller, Home Management Gateway)
or an integrated part of a device (e.g. internet router).
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The EEBus Approach
In the commercial and residential areas, devices of different manufacturers, with different field
bus or interface protocols are usually used instead of complex "single source" systems.
Furthermore, the devices are often installed or replaced at different times. The EEBus is a
middle-ware to support integration of the heterogeneous device infrastructures distributed
throughout the building. The EEBus is a kind of interpreter between the protocols of the different
devices and technologies, ensuring up-to-date, smooth, transparent and secure communication
between the power supply and the smart consumer.
Individual links between the data points of such protocols on a user level cannot solve this task.
The missing rules (defined, e.g. in standards) would in this case always enable only proprietary
– i.e. not generally valid and not expansible - implementation.
The EEBus as an integration platform generates this possibility for general application and thus
the transparency and structure for device couplings. Therefore, the respective bodies consider
mapping between the different protocols in standardisation as well. The EEbus has only a single
adapter for every connected protocol type. Ideally, implementation of the EEBus should not
require any changes to the device field buses to be integrated due to the parallel standardisation
efforts.
Additionally, the EEBus creates a consistent abstraction of energy characteristics of various
devices across the different field buses. It warrants complete transaction safety of load
management in spite of different message and communications protocols at the device
interfaces. Only a single, standardised EEBus interface in XML format is visible from the outside,
i.e. from the power supply to the consumer. Only this enables transmission of incentive values
between the power supplier and consumer and reconciliation of consumption and demand
between the parties involved.
On the inside (machine-consumer), the EEBus expands established interface standards by
necessary signal and control functions for communication in a smart grid. Exchange or
supplementation of end devices is easy because new devices can be "connected" with their
standardised interfaces. The parallel standardisation efforts of the EEBus thus enable a solution
concept comprehensively based on standards!
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On figure 1: standardised incentive value – estimated consumption
The EEBus supporters actively contribute to international standardisation of incentive
models. Incentives are to achieve a balance between power generation and
consumption. For example, lower power prices at times with a power surplus should be
an incentive for the consumer to consume power. The XML data model defined for this is
designed CIM3-compliantly in the EEBus. At the same time, the EEBus returns a load
estimate for the consumer to the system.
On figure 2: consistent abstraction of consumer energy characteristics
The EEBus initiative also deals with standardised integration of common building
automation systems to IP-based grids of the power suppliers. The different devices are
connected to the smart grid and can be controlled in a system-compliant manner by the
incentives. Thus, an Energy Management Gateway with EEBus is a connection between
the outside (power supplier) and building (smart consumer). Through the internet, the
EEBus creates an access to the world of power suppliers for the currently mainly non-IPcapable world of building automation. The EEBus makes it possible to target any device
as a (virtual) IP-device, including individual addresses. Applications the end user installs
on his gateway can implement different local services or connection to different services
online. Devices are centrally registered with all their properties at the gateway through
the EEBus and thus gain full access to the EEBus network information if the user wishes
and explicitly clears this function.
3
CIM (Common Information Model) Standard: IEC 61970
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Background: Differentiation from proprietary systems
There are currently many systems with similar approaches on the market. However, such systems only use
the approach of forming device categories that can be abstracted (data models) from the individual devices
and linking them on a proprietary application level. Every provider of this kind of system therefore has its own
abstracted language with the power producer.
In contrast to this, the EEBus offers a consistently standardised solution. The EEBus also contains simpler
forms of load management.
On figure 3: expansion of the existing communications standards
While current networking technologies like ZigBee or KNX know what energy efficiency
is, the implementation within the standardised profiles is usually rudimentary or
proprietary. Usually, it is only based on existing specifications. (Usually), no expansions
for the often-standardised specifications are provided for new application cases. This
makes generally phrased load management nearly impossible.
The consistent technical definition and mainly similar implementation of the terms of "load
management", "metering", "pricing model or "incentive model"4, however, are essential
components for the definition of a comprehensively working Smart Home.5 Only more
consistent systems and a continuous expansion within the respective underlying
protocols ensures future-capability of a network approach.
The new data models resulting from this should be able to characterise devices regarding
their energy properties, as well as their possible use in load management (demand
response) more precisely. Consistent standards, e.g. for load management, make it
easier for device producers (e.g. producers of washing machines, heat pumps, etc.) to
describe their products to even participate in a smart grid.
The EEBus offers power suppliers, meter providers and application developers a standardised
XML format that can still be flexibly adjusted to the respective needs. For example, this XMLinterface facilitates distribution of price information or maintenance messages, coordinated load
management or structured presentation of available smart grid devices at the consumer's.
4
Price is not the only differentiating criterion for the end consumer
5
Smart Home describes solutions in the private living area that use devices, systems and technologies to provide
more energy efficiency, comfort, efficiency, flexibility and safety. Technically, the aspects of building automation are
achieved with bus systems (by cable, power-line or radio).
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The EEBus thus also acts as a kind of data turntable for communications protocols and
integrates field and building automation (mainly non-IP-based) into the IP-world:
Background: data communication with the power supplier
Protocols for concrete physical connection of this kind of gateway to a backed system are not necessarily prescribed
by the EEBus. They can be provided by the respective telecommunications and/or power service provider that
connects the gateway to the network.
The EEBus does not mainly define data exchange (since it depends on transmission channel), but the backed-system
data format
At this time, it offers a standardised web-service interface via SOAP over HTTP(s).
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EEBus and Smart Metering
Transmission of an incentive value to the household alone does not require any Smart Meter.
However, an incentive value remains mainly ineffective economically if the customer is not
provided with a calculation for the rate relevant for invoicing at this time. Therefore, a loadmanagement-capable "smart consumer concept" sends an incentive value to the energy
management application and a new rate to the Smart Meter at the same time. One facility, e.g.
the power provider, therefore sends two data packages. Typically, two separate network
connections are intended for this as well. No physical connection is needed between them.
The EEBus take over networking of household devices and runs on the household's energy
management gateway with the energy management. This gateway is connected to the energy
management world (e.g. for reception of the incentive value for a 24 hour power price forecast)
through the internet (e.g. via the regular DSL channel). In contrast to this, access to the metering
world for rate information will be through a dedicated network according to the power provider's
calibration rights. For this, the system must comply with the safety requirements of the BSI
protection profile.
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Only if the energy management application receives information on binding time flags and actual
power prices in spite of this data-privacy separation of the network accesses, the incentive value
can be linked to settlement-relevant consumption as a control figure for the household devices
connected to the EEBus.
The EEBus data models therefore include the metering data for current standards6 and are
generally suitable for mapping such links.
The data determined according to calibration law under compliance with data integrity thus can
generally be forwarded to the energy management application through the EEBus by the meter
gateway if the corresponding security mechanisms are in place. No BSI protection profiles7 have
been developed – yet – for the area of energy management gateways.
EEBus Architecture
The EEBus uses the generally known, widely used and secured Qt Framework for its basic
functions (e.g. for Multi-threading, XML- Parsing). That makes it possible to use the EEBus stack
on several platforms like Linux, Windows, MAC or Symbian.
6
ZigBee SE1.0 and SE2.0; KNX RF pursuant to Open Metering specification, EDL21 pursuant to FNN specification
7
Processing and linking of person-related consumption data in the smart meter as well as possible negative effects
on energy supply place great demands on data protection and IT-security. For this reason, the Federal Ministry of
Economics and Technology (BMWi) commissioned the Federal Office for Information Security (BSI) in September
2010 to develop a protective profile for smart meters. This Protection Profile defines the security objectives and
corresponding requirements for a Gateway which is the central communication component of such a Smart
Metering System.
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EEBus Physical Layer
The transfer between the worlds of power supply and building automation is provided in two
layers: (1) the physical layer, taking up the heterogeneous interfaces of the building devices via
the respective hardware and software adapters and (2) the abstractions layer that maps the
devices in the building in their diversity in a consistent and standardised fashion for the outside
power provider via the internet.
If the EEBus is to create a solution for existing infrastructures as well, this consequently requires
different physical interfaces. Communication between the refrigerator in the kitchen, the heat
pump in the basement, PV plant on the roof and the smart meter can only be "warranted" by
wire-bound communications routes; reinforced concrete ceilings, for example, cause high radio
dampening. Power-line – a power-grid-modulated communication – is suitable in this context
because its infrastructure is available in every single building. Nevertheless, the recent past
shows increased interest in radio technologies on the market that are, among others,
characterised by high spatial flexibility.
Due to the multiple demands like: cost-efficient vs. robust transmission; basement-to-living-areacommunication vs. inner room communication; radio vs. power-line, a networking concept must
be able to map just as diverse a range of interfaces in the physical layer. The EEBus already has
many solutions for both ratio and power-line applications. In the radio area, communication is
implemented within a meshed 2.4 GHz network (ZigBee) and in the frequency range of 868 MHz
(KNX-RF). In the power-line area, it focuses on the Cenelec B-Band, the only narrow-band
standardised in Europe and free for use in addition to the narrower C-Band. Both the standard
KNX PL 110 and the expansion KNX PL 110+8, which is currently being standardised, can be
actively integrated in a smart home through the EEBus. Several Ethernet media types (RJ 45,
WLAN) are also part of the solution. The EEBus therefore integrates all of the currently most
important networking technologies. It will see continuous expansion in this area in future. Due to
its architecture, all bus systems can, by principle, be integrated into it.
8
KNX PL 110+ describes a further development of the KNX PL 110. In contrast to the existing FSK modulation, the
KNX PL 110+ solution is based on OFDM modulation; however, it excludes the two FSK carriers to warrant
complete interoperability and downwards compatibility. The OFDM modulation procedure enables a data rate
increased by up to 20 times. The new medium is currently being standardised.
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The EEBus in Standardisation
Smart appliances that permit the required control and provide the necessary information form a
central part of a "smart consumption concept". As home networking protocols, technologies like
KNX have achieved high market penetration in particular in Europe. North America currently is
performing a large-scale launch of ZigBee devices, supported by national projects.
Background: Does the EEBus compete with current standards?
No! The EEBus does not constitute a new bus; it merely expands present technologies by the functions
relevant for smart grid. From the power suppliers' point of view, a household is presented as EEBus; from the
device's point of view, however, it will still be, e.g., a KNX device.
The EEBus concept expends the present standardised device networking protocols by smart
grid functions only. In addition to the requirements from smart grid and smart home application
cases, mainly the requirement criteria of the device industry are included. Expansions will be
according to the considerations of the European smart grid mandate M/490 and additionally
represent the relevant components of the German standardisation roadmap E-Energy / Smart
Grid.
Independently from the networking protocols present in the building, the standardised EEBus
makes it possible to record energy characteristics for the devices in the household as far as
possible and to use them for different types of control and visualisation.
The Kellendonk initiative is active in the standardisation and association bodies to define new
profiles together with the EEBus. As a result, the devices that are part of the building network
can be presented consistently to the outside in their diversity. This is particularly important for
power suppliers that usually are unable and unwilling to deal with the consumer's specific
infrastructure. At the same time, every standard-compliant device will in future automatically
become a potential smart home – and thus smart grid - participant with a device interface
integrated in the EEBus.
Background: Cooperation with established standards:
The KNX Organisation was one of the founders of a comprehensive alliance for smart energy solutions for
technology-neutral interoperability of Smart Energy customer profiles in 2010. In the scope of this alliance, it
was determined that the EEBus maps and supports the KNX protocol for future energy management services
to work independently of the devices. The EEBus initiative is contributing to the KNX organisation's
standardisation work for expansion of the globally open standards for house and building system technology
(ISO/IEC 14543-3). KNX in turn supports the EEBus standardisation set for consistent energy management
functions.
A similar cooperation with the ZigBee organisation is currently being implemented.
Active cooperation with uPnP is targeted, too, and already driven via partners from the areas of
telecommunications and home entertainment.
With consistent abstraction of the individual protocols in the neutral, standardised XML data
structure, the EEBus warrants interoperability between IP (e.g. 6LoWPAN and WLAN) with nonIP networks (e.g. KNX, ZigBee). The EEBus will also integrate uPnP to warrant consistent
mapping from TCP/IP-based systems. The EEBus modularity permits integration of other device
protocols in addition to KNX, ZigBee and UPnP. Generally, it is not expected that all
manufacturers convert their previous transfer technologies to a consistent, ideally IP-based,
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technology within the next 5 years. The EEBus even now describes a possible solution to
implement this change early with a connecting middle-ware concept between IP and non-IP
buses to contribute to homogenisation.
Background: IP-based protocols
Currently, device interfaces and their corresponding data transfer can be implemented much more costefficiently with the mentioned building automation systems KNX or ZigBee then transmission by WLAN (IEEE
802.11) connection would be. In respect of power consumption considerations for data transmission, the
building automation systems named also currently offer a much better alternative then direct integration of IP
technologies.
This could change with 6LoWPAN; however, market introduction is not nearly as advanced yet as in the area
of building automation systems. For example, 6LoWPAN still has the problem that they cannot be directly
integrated into a WLAN structure so that the user needs a gateway to connect the 6LoWPAN world to his
home network for devices from both worlds to communicate. Accordingly, "seamless integration" is far from
achieved.
6LoWPAN integration with a selection of IP-based sensor/actor protocols (e.g. DPWS) into the EEBus is
striven for and under preparation.
The objective is using comprehensive standardisation also on the level of the currently existing
standards to enable complete, cross-section, smart homes with consistent addresses.
Background: Timeline EEBus and Standardisation
2011:
Initial tests for EEBus software in various field tests.
9
Introduction of a national VDE application rule for the area of Home and Building
as a basis for international standard drafts.
2011 - 2012:
Amendments of the specifications and data models in the underlying
international protocols; in cooperation with the respective organisations and
committees.
2012:
Pursuant to Smart Grid Mandate 490: Definition of the reference architecture and initial
standard drafts.
"At the end of 2012, the reference architecture and a first set of standards
(including newly delivered technical specifications) will be available”
9
For more information on the application rule, see: http://www.dke.de/de/std/Pubs/Seiten/default.aspx
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Using the EEBus Concept in Products
The EEBus requires a system platform consisting of hardware and associated operating system.
The Energy Management Gateway is a suitable central component in the scope of house
automation. Typical system requirements for this gateway with EEBus are the microprocessor
category ARM9 at at least 375 MHz and 64 MB Flash and 128 MB RAM memory. The supported
operating systems are Linux, Mac OS and Windows, with Android possibly following soon.
There are many good reasons for standardisation and prototyping. The EEBus is suitable as an
abstraction interface for the world of energy management in the commercial and private areas.
This interface can be used by energy efficiency service providers to offer consistent services for
very different devices in the scope of building automation. These building devices can be
equipped with different technologies for local networking in the building. They can be connected
to the EEBus and then communicate with each other within their technology – or even across
technologies with future expansions. For example, KNX displays can be implemented to display
the measured data of a ZigBee meter. For Universal Plug and Play (uPnP), all devices
connected to the EEBus can be presented as uPnP devices independently of their networking
technology. Furthermore, the Energy Management Gateway can run central applications, e.g. to
implement coordinated load management that can be optimised according to different
parameters (e.g. forcing a smooth load curve or preferred consumption of the self-produced
solar power). Additionally, a power supplier can connect to this Energy Management Gateway
via the internet to provide value-added information on the power price (e.g. determination of the
solar power share, etc.).
In addition to these smart grid-driven use cases, the EEBus will, in future, cover all areas of
home automation and thus enable cross-bus home automation use cases in the areas of comfort
and safety. Furthermore, the approach can be expanded by other subjects like e-Healthapplications and Ambient Assisted Living. Finally, all of these different sections require a joint,
consistent and standardised path into the house. The requirements to information safety, data
protection and hardware will be comparable and very likely connected to a joint gateway. Use of
the EEBus middle-ware that will then already be present for energy management will thus
enable development of other business models for the respective market participants.
Based on the EEBus-approach, which is currently going through standardisation, Kellendonk is
currently developing and testing EEBus software that will then be provided on the market.
Application software developments by customer order or integration support is offered for service
providers, developers and product manufacturers. Co-operations in the hardware business also
enable active participation in the Smart Home future market via OEM-EEBus products.
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