New smart grid control decentralizes electricity supply

New smart grid control decentralizes
electricity supply
2 February 2015
collect consumption data centrally and also centrally
coordinate electricity demand and supply. This
makes the electricity supply vulnerable to hacker
attacks and also raises data protection issues –
problems that do not arise with a fully decentral
solution of the Max Planck researchers. Decentral
control also relaxes the need for the complex
design of the vast communications infrastructure
that would be required to connect millions of
electricity meters with the major energy suppliers in
Decentrally organised electricity supply: According to a
study carried out by researchers from the Max Planck
Institute for Dynamics and Self-Organization, electricity
control devices, so-called smart meters, can tailor the
electricity supply from nuclear power plants and wind
farms to the demand from industry and households
based on a self-organised process. The study also takes
into account whether the electricity is available in stored
form, for example in batteries, or whether it has free
storage capacity. Credit: Benjamin Schäfer / MPI for
Dynamics and Self-Organization
To improve the management of fluctuations in the
electricity supplied by solar and wind installations,
the electricity network needs to work more
intelligently in the future. Electricity suppliers aim to
be able to regulate consumption on the basis of
supply with the help of an intelligent electricity
network, a smart grid. Intelligent electricity meters
developed for such a system would be able to
switch electrical devices on and off. Researchers
from the Max Planck Institute for Dynamics and
Self-Organization have now shown that intelligent
electricity meters can match electricity demand and
supply decentrally and on an entirely selforganised basis. Up to now, electricity suppliers
worked on the assumption that they would need to
The use of renewable energy sources is growing
rapidly. For instance, since early 2014, the feed-in
from renewable energy sources has reached over
28 percent of electricity consumption in Germany –
a new, all-time high. However, with the rise of solar
and wind installations, fluctuations in the electricity
network are also on the rise. When a cloud front
covers South Germany, there is an abrupt dip in the
amount of electricity supplied by the solar power
plants. And when a storm approaches, electricity
production in the wind parks increases suddenly
and fluctuates even more than usual. Such
fluctuations do not arise in the traditional electricity
network, as the generators in the coal-fired power
stations and remaining nuclear power stations chug
along regularly day in day out, providing a constant
supply of electricity.
The increasing feed-in fluctuations will have to be
balanced out in the future by simultaneous
variations in electricity consumption. For example,
when the wind and sun provide a lot of energy, the
cooling units in computer centres and warehouses,
and electric car charging stations should be
cranked up; when production dips, they should be
put on stand-by. To achieve this, the energy
suppliers would like to equip their customers in the
future with electricity control devices, so-called
smart meters. These would be installed in
households or company premises and transmit the
data they collect automatically to the energy
supplier. Depending on the available supply of
electricity, household and industrial devices could
then be switched on or off. Customers are more
likely to adopt such systems if they are offered
excess energy at lower prices. To coordinate the
electricity supply and demand, researchers at the
Max Planck Institute for Dynamics and SelfOrganization in Göttingen have introduced a new
concept which focuses on the fully decentral
matching of electricity supply and demand.
Hackers could bring a central supply network to
a standstill
Centrally organized electricity supply: Today, electricity
suppliers would like to operate an intelligent electricity
network that regulates consumption on the basis of the
current supply by transmitting consumption data from
consumers to a central location and coordinating the
demand there with the available electricity supply. They
also want to control the consumption by different
customers centrally. Credit: Benjamin Schäfer / MPI for
Dynamics and Self-Organization
The concepts available today for a future intelligent
electricity network (smart grid) work on the
assumption that the data for all electricity
consumers and generators would be collected
centrally by the energy supplier. However,
according to Benjamin Schäfer, a physicist from the
Max Planck Institute for Dynamics and SelfOrganization, this approach involves various risks:
"This kind of central control is a potential target for
hacker attacks." If someone hacks into the control
centre via the Internet, they could at worst bring the
supply network to a complete standstill. In times of
increasing Internet criminality, this scenario must
be taken seriously. "Moreover, it remains to be
clarified how data protection could be guaranteed if
customer consumption data are constantly being
transmitted to a central location."
For this reason, Benjamin Schäfer, member of
Marc Timme's Research Group, "Network
Dynamics" examined whether central control is
actually essential. The inspiration for the project
was provided by a cooperation partner of the Max
Planck researchers, the managing director of the
Karlsruhe-based company Easy Smart Grid,
Thomas Walter. His company develops system
solutions for the operation of decentral energy
networks – that is electricity networks, in which the
electricity is not provided exclusively by large power
plants and is increasingly supplied by numerous
small generators. As part of this study, Benjamin
Schäfer, together with Marc Timme, his former
colleague Dirk Witthaut and Masters' student Moritz
Matthiae, examined whether, and how, smart
meters installed on customers' premises could
regulate consumption directly and decentrally
without a detour via a central control system.
For this purpose, the physicists developed a
mathematical model in which they simulated the
electricity generators and consumers. They wanted
to find out whether the entire network remains
stable when regulation is carried out decentrally
and no longer involves coordination with the central
energy supplier. Would the network be able to run
itself on a more or less self-organised basis?
Basically, network frequency, i.e. the frequency at
which the alternating current oscillates in the supply
network, is used as a parameter for regulation. It is
defined at 50 Hertz and may only deviate from this
target value as a result of network fluctuations by a
maximum of 0.2 Hertz. If a storm front darkens the
skies over a solar park, for example, or an
aluminium plant starts up its machinery, less
electricity is available the network locally and the
frequency falls slightly. If the sun generates more
electricity again or major electricity consumers are
switched off, more electrical energy is available and
the frequency rises. The electricity suppliers must
take active measures to maintain the frequency of
50 Hertz and avoid faults in the network.
Smart meters can control the electricity
consumption decentrally
Schäfer and his colleagues have now succeeded in
demonstrating that such faults can actually be
balanced out if the electricity control devices
respond directly. The smart meters are thus entirely
capable of using frequency changes as a
parameter and controlling the electricity
consumption of connected electrical devices
themselves. Schäfer overcame a particular
challenge through his analysis: It is known that
many devices have a delayed response to shortterm frequency changes in the network, which
sometimes arise within a period of milliseconds –
for example, a cooling unit has a delayed response
when the compressor has to be switched on or off.
Schäfer wondered how long such a delay can be
and whether it might prevent the direct control of
frequency fluctuations through the smart meters
installed on the consumers' premises.
the major energy suppliers.
More information: "Decentral Smart Grid Control"
2015 New J. Phys. 17 015002 DOI:
Provided by Max Planck Society
His results are very positive. He established that
smart meters do not have to react immediately as
smaller fluctuations often balance themselves out
within a few seconds or fractions of a second. For
larger fluctuations, this kind of delay is actually
useful. Therefore, it is ideal if the smart meters
average out the frequency values over a few
seconds, then intervene, and regulate and adapt
consumption accordingly. This means, of course,
that a sufficient number of smart meters and
electrical devices must always be activated so that
the impact on the electricity network is adequate.
"No previous study analysed in detail whether a
smart grid can actually function without central
control. Our analysis has shown for the first time
that this is possible in principle," says Marc Timme.
A decentral control system of this nature would
offer enormous advantages. In particular, it would
no longer be necessary to build the vast
communications infrastructure that would otherwise
be required to connect millions of smart meters to
APA citation: New smart grid control decentralizes electricity supply (2015, February 2) retrieved 6 February
2015 from
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