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Flexibility and demand: a distribution systems operator’s perspective - Joost Gottmer, EU affairs, EDSO for<br />
Smart Grids<br />
3 WHICH ACTORS NEED FLEXIBILITY ACTIVITIES?<br />
Generally, flexibility is needed by the market and by the system operators for three<br />
reasons:<br />
Market players (like the BRP) for portfolio optimisation processes;<br />
TSO for balancing processes (TSO only buyer). TSOs purchase system services from<br />
market parties (aggregators, generators) – (can buy up (generation) or down (demand<br />
response);<br />
DSO for congestion management and voltage control processes (DSO only buyer).<br />
DSO is like the TSO a single buying counterpart (can buy up (generation) or down<br />
(demand response).<br />
DSOs must ensure that quality of service and security of supply is maintained at all<br />
times. Therefore, flexibility services for network operators will help them to keep the<br />
lights on when the grid is pushed to its limits. This is different than for market players<br />
that refer to activities performed with commercial interests in mind, and competing<br />
actions for offering the best service to customers.<br />
4 WHAT SYSTEM FLEXIBILITY SERVICES MAY BE PROCURED BY<br />
DSOS?<br />
DSOs could use flexibility services for a range of DSO activities including planning,<br />
connection, access and operation. Three characteristics of grid users providing flexibility<br />
are key for distribution networks: location, firmness and power. The lower in voltage the<br />
electricity infrastructure is, the lower the possibilities in terms of providers and location<br />
of flexibility. This considered, the chosen mechanism should be the most cost-efficient<br />
from a system point of view.<br />
DSOs should be able to make the most of system flexibility services such as:<br />
• Congestion management: This will be needed to maximise the existing capacity<br />
in distribution grids for DERs, while ensuring a high level of security and quality of<br />
supply. Flexibility from DERs and consumers would help to optimise networks in<br />
the most cost-efficient way and to solve local grid constraints. DSOs could<br />
postpone network reinforcement until it becomes more cost-effective than<br />
procuring services from DERs.<br />
• Voltage control: European draft network codes forbid or limit the ability of DSOs<br />
to export reactive power to transmission grids. Injections of active power due to<br />
DERs is likely to provoke deviations from voltage limits, causing system<br />
imbalances. But, if used in a smart way with monitoring and coordination tools,<br />
distributed generation could help to control voltage and manage network losses.<br />
The table below proposes a list of system flexibility services that could be procured by<br />
DSOs or TSOs. This classification is not exhaustive: the list could vary from one country<br />
to another depending on regulatory arrangements, network operator needs and the<br />
Revue E Tijdschrift – 131 ste jaargang/131 e année – n° 1-2-3-4-<strong>2<strong>01</strong>5</strong> (publication mars/publicatie maart 2<strong>01</strong>7)<br />
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