RET_2015-01-02-03-04_Flipbook

Flexibility and demand: a distribution systems operator’s perspective - Joost Gottmer, EU affairs, EDSO for
Smart Grids
3 WHICH ACTORS NEED FLEXIBILITY ACTIVITIES?
Generally, flexibility is needed by the market and by the system operators for three
reasons:
Market players (like the BRP) for portfolio optimisation processes;
TSO for balancing processes (TSO only buyer). TSOs purchase system services from
market parties (aggregators, generators) – (can buy up (generation) or down (demand
response);
DSO for congestion management and voltage control processes (DSO only buyer).
DSO is like the TSO a single buying counterpart (can buy up (generation) or down
(demand response).
DSOs must ensure that quality of service and security of supply is maintained at all
times. Therefore, flexibility services for network operators will help them to keep the
lights on when the grid is pushed to its limits. This is different than for market players
that refer to activities performed with commercial interests in mind, and competing
actions for offering the best service to customers.
4 WHAT SYSTEM FLEXIBILITY SERVICES MAY BE PROCURED BY
DSOS?
DSOs could use flexibility services for a range of DSO activities including planning,
connection, access and operation. Three characteristics of grid users providing flexibility
are key for distribution networks: location, firmness and power. The lower in voltage the
electricity infrastructure is, the lower the possibilities in terms of providers and location
of flexibility. This considered, the chosen mechanism should be the most cost-efficient
from a system point of view.
DSOs should be able to make the most of system flexibility services such as:
• Congestion management: This will be needed to maximise the existing capacity
in distribution grids for DERs, while ensuring a high level of security and quality of
supply. Flexibility from DERs and consumers would help to optimise networks in
the most cost-efficient way and to solve local grid constraints. DSOs could
postpone network reinforcement until it becomes more cost-effective than
procuring services from DERs.
• Voltage control: European draft network codes forbid or limit the ability of DSOs
to export reactive power to transmission grids. Injections of active power due to
DERs is likely to provoke deviations from voltage limits, causing system
imbalances. But, if used in a smart way with monitoring and coordination tools,
distributed generation could help to control voltage and manage network losses.
The table below proposes a list of system flexibility services that could be procured by
DSOs or TSOs. This classification is not exhaustive: the list could vary from one country
to another depending on regulatory arrangements, network operator needs and the
Revue E Tijdschrift – 131 ste jaargang/131 e année – n° 1-2-3-4-2015 (publication mars/publicatie maart 2017)
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