Relationships between regulated players

Good coordination is needed between the TSO and the DSO. For this purpose, taking in consideration that:

- the DSO has the knowledge of the distribution network and of the actual configuration of the consumers Point Of Delivery (POD8) and

- the DSO has the responsibility for ensuring the distribution network security and technical quality

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

Revision 1.0

of supply.

The DSO has to be informed of any TSO request for AD services to the market, which could have impacts on the distribution system operation. It has then to evaluate if the request is not contradictory with previous ones and if it is technically compatible with the distribution network operation.

Similarly, taking in consideration that the TSO is in charge of the security, energy balancing and frequency control of the whole power system, it should be informed of any DSO request for AD services, which could have impact on the electricity system operation (and also on the transmission grid).

So, it is necessary to define a clear mechanism and criteria to establish the priority of different actions. Obviously, the DSO cannot stop/delay feasible TSO requests, in the same way that the TSO cannot stop/delay feasible DSO requests.

Commercial relationship

From the commercial point of view, there might be some services such as voltage and reactive power control which might have a high topology dependency and for which alternatives to AD services can be provided by DSOs. The TSO could request first to the DSO who then decides the most efficient way of providing the services by using AD or other means (condenser batteries, tap changers etc.). Then, if AD services are required, the DSO could request them to aggregators based in the specific location(s) where they are needed through demand flexibility requests. The regulatory framework should establish in these cases which actor is responsible for doing what and what is the hierarchy of request to follow when a certain service is required by an actor.

However, it must be ensured that this “coordination” between the TSO and the DSO does not introduce any bias in the market and does not raise any barriers for any deregulated players to provide services.

Technical relationship

Depending on the technical relationships between aggregators, DSOs and TSOs, different possibilities exist:

- A possible approach could be that the aggregator is the actor who sends AD service information to be validated first by the DSO and secondly by the TSO. In this case there is no need of a direct relation between the TSO and the DSO for technical validation purposes, because the aggregators directly send all the information to the DSO and the TSO and directly receive from them all validations. For this purpose, the aggregator needs to know both how to aggregate his consumers at distribution network level and at transmission network level (if it must be provided with enough topology information), so it should be able to do this two step validation.

- Another possibility is that the information for technical validation is sent aggregated at distribution network level by the aggregator to the DSO, who aggregates all the activities by all the aggregators, and then the DSO sends the corresponding information aggregated at the transmission network level to the TSO. The results of the technical validation then follow the reverse path: from TSO to DSO first and from DSO to aggregators in second. This is the procedure adopted, in the ADDRESS project, for AD service provided to deregulated players.

- If the market structure is such that the service buyer is the player which aggregates the situation, the above two possibilities could be also used with the difference that in this case, the buyer is the actor in charge of sending AD service information to the DSO and/or the TSO providing that it has

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

Revision 1.0

enough information for aggregating demand actions.

This is the procedure adopted, in the ADDRESS project, for AD services provided to regulated players, with the exception that in this case the buyer of the service is either the DSO or the TSO and it will be in charge of sending the required information to the TSO or the DSO (depending on the case). The buyer of the service will inform the aggregator of the result of the technical verification.

Sharing of topology related information

As discussed in 2.2.3, a relationship will probably be needed if the geographical area or macro load area approaches are considered for specifying the area to which AD services affects the transmission network. In this case, the DSO should inform the TSO about the impact of those geographical or load areas on the transmission network nodes.

Inefficiency of services requests

When a TSO and a DSO need a service in the same area it could be more efficient to establish coordination between them in order to adapt the request. In solving this issue of possible inefficiencies, the regulatory framework should define clear rules and make clear what the responsibilities of each of the regulated players are.

Incoherent services requests

The case of the DSO and TSO contracting the exactly the same service or conflicting services with an aggregator should not happen because both regulated players will perform the corresponding validation and will be aware about the services contracted by each other. If the aggregator does not accept any service request implying AD resources which are already involved in some other service pending from technical verification, these kind of problems could be avoided.

The DSO that knows the details of the operation should detect incoherencies between service requests and notify the aggregator and the TSO about them.