Locational information for AD service provision

It is necessary to have information structured in an appropriate way about the location of the AD service or more precisely the location in the network of the consumers who will contribute to the provision of an AD product through the flexibility of their loads. This is necessary:

We note that the energy payback tolerance could be an extension of the service delivery envelope. Moreover, if energy payback is explicitly considered in the product delivery, it may happen prior to the “main” product delivery (e.g. by charging thermal or chemical storage) as well as partly before and partly after.

ADDRESS Technical and Commercial Conceptual Architectures - Core document ADD-WP1-T1.5-DEL-EDF-D1.1-Technical_and_Commercial_Architectures

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- not only for the provision of topology-dependent services: for instance, in case of a local service on the grid, only the consumers in the area of concern can contribute to the service. So they should be clearly identified in the aggregator databases and in the requests sent to it;

- but also for the verification of technical feasibility that will be carried out by the DSO and/or TSO. This technical verification is discussed in Section 2.4.2.

At present, no unique way of defining and structuring the exchanges of locational information about AD services has been adopted. Different possibilities have been thought of and are presented below and discussed in more detail in Appendix E. The choice of one or another possibility depends on the country, its network structure, the tools and data management systems of the DSO/TSO. This topic will be further studied in the project, in WP3 which deals with developments for the DSO and TSO and the grid operation.

Locational information at distribution level

For the reasons explained above, there must be a way that an aggregator knows the link between each of the consumers in its portfolio and the area of the distribution network to which they belong. The position level in the distribution network tree will need to be a compromise between too detailed information which may be difficult to understand and to use for the aggregator and useful information for the DSO operation purposes.

The DSO knows to which network node each of the consumers in its area is connected, so it should be responsible for providing locational information to the aggregator. In addition, this information can change over time even if frequent changes are not usual. So when the DSO updates network topology information, aggregators should be notified automatically or by other means of such changes.

The following possibilities may be thought of for sharing consumers location information.

1) An approach could be to link the customers to the transformer to which they are connected. The transformer is hardly changed and it is directly linked with a distribution level in a radial network. 2) A similar approach is to use a code for each consumer. This way the DSO could send to the

aggregator the list of consumers along with their code. In this case the aggregator does not need to be notified about changes in topology since it will be the work of the DSO to map network areas to consumer identifiers.

3) Another possibility could be to link the consumer to some kind of geographical information. In this case the geographical information should be more specific since distribution network nodes cover smaller geographical areas. Information such as neighbourhoods or even street related data could be enough for this purpose.

4) Finally, a fourth possibility is to divide each LV line into different Load Areas composed of several consumers whose loads are equivalent from the electrical point of view. A Load Area may be extended to a LV feeder or to a MV/LV substation as a whole in case of fragmentation in smaller areas brings no benefits. The same approach applies on the MV network, which, similarly to LV network, could be divided into several Load Areas grouping MV consumers. In such a case, if fragmentation brings no benefits to AD services exploitation, Load Area may be designed to encompass entire MV feeders or MV/LV substations.

Aggregators, in turn, group customers in their portfolio according to the Load Areas settled by DSO and are notified at any update. Any consumer may be unambiguously identified within the belonging load area by means of an unchangeable unique key (e.g. the point of delivery ID).

ADDRESS Technical and Commercial Conceptual Architectures - Core document ADD-WP1-T1.5-DEL-EDF-D1.1-Technical_and_Commercial_Architectures

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Locational information at transmission level

The following alternatives for providing locational information from the TSO perspective are briefly described below:

1) One possibility could be to associate each consumer with a “transmission network node identifier” that identifies unambiguously the transmission node at which the consumer is connected. This information could be published by the DSOs and updated according to changes in network topology.

2) As an extension of 4th approach at the distribution level above, it can be envisaged that DSOs collect Load Areas into Macro (greater) Load Areas, tailored according to TSOs point of view (e.g. a HV/MV substation as a whole). Macro Load Areas must be communicated to the TSO and updated on every change. The group of Load Areas forming each Macro Load Area must be communicated to the Aggregators and updated on every change. Thereby, with this approach, TSOs and aggregators can communicate using Macro Load Areas.

3) Like for method 3 at the distribution level above, another possibility could be to assign each consumer to a well-defined geographical area, such as a postal code, city or administrative region. In this case the aggregator does not need any supplementary information since it knows beforehand the geographical region to which each of its consumers belongs to.

This is simpler in the sense that there is no need for updating the information. The work of mapping geographical areas to network nodes where the AD service is required or provided could be carried out by the TSO that would need information from the DSO regarding how the geographical areas are connected to transmission network nodes.

However this 3rd possibility is also more inaccurate than the above mentioned ones.