Technical Regulation for the entry into commercial operation of renewable generation

The previous blog post described the technical requirements that a renewable generation plant has to meet in order to connect to the grid according to the new grid connection codes, and introduced the Supervision Technical Standard [1] (hereinafter NTS) as a key element for the evaluation of these technical requirements. This article analyses this standard in detail and highlights the importance of the complementary simulations defined in it.

Origin and entry into force of technical regulations

The NTS has been developed by Red Eléctrica de España and the Association of Electricity Companies (AELEC) in order to establish how each of the technical requirements applicable to a generation plant for its connection to the grid must be assessed and certified. It will come into force once the proposed Royal Decree [2] and Ministerial Order [3] developed by the Ministry for Ecological Transition (MITECO) for the national implementation of the European grid connection codes (Regulation (EU) 2016/631 [4]) have been approved.

Certificate of plant compliance

In order to obtain the Final Operational Notification (FON) and, therefore, be able to start commercial operation of a generation plant, it is necessary to submit the plant’s certificate of conformity or MGE (Modulo de Generación de Electricidad), which certifies that the plant complies with the technical requirements of the grid connection codes.

To obtain this certificate of conformity of the plant, it is necessary to follow the indications of the NTS to evaluate and certify compliance with each of the applicable technical requirements. Therefore, it is important to know this standard in detail.

Technical requirements assessment procedure

The NTS defines the following two methods for assessing and certifying compliance with the different applicable technical requirements:

• By performing the tests and simulations described in the NTS for each of the requirements, at plant level. These tests and simulations must be carried out by an accredited entity.
• Through the certificates of the plant equipment, supplemented by additional simulations. It is not necessary to be accredited to carry out these complementary simulations.

The validation process through equipment certification and complementary simulations has clear advantages over the test and simulation process, so it is expected to be the procedure most used by developers when certifying their renewable generation plants. The equipment certificates would be provided by the manufacturer and the developer would only have to carry out or subcontract the complementary simulations.

Therefore, the supplementary simulations defined in the NTS will become very important in the coming years as the vast majority of developers who want to connect a new generation plant to the grid will opt to perform these supplementary simulations to certify the plant’s compliance with the requirements of the grid connection codes.

Figure 1 lists the technical requirements to be assessed in a renewable generation plant according to the NTS, indicating to the right of the requirement the procedure to be followed to assess compliance (test, simulation, certificate or complementary simulation) and the type of plant for which each of the requirements applies. In addition, those requirements that can be certified through complementary simulations, as a complement to the equipment certificates, are highlighted in bold blue. As analysed in the previous blog post, the plant type or significance is a function of the installed power and the voltage at the connection point.

What additional simulations do I have to do to connect my power plant to the grid?

As indicated in Figure 1, developers of new renewable generation plants will need to perform additional simulations to certify compliance with five technical requirements, three of them for power-frequency regulation and two of them for reactive power. Of these five requirements, the reactive power capacity requirement (5.7) will be assessed from static simulations, while the remaining four requirements (5.1, 5.2, 5.3 and 5.8) will be assessed from dynamic simulations.

Any of these complementary simulations can be carried out using electrical simulation software such as PSS/E or DigSilent Power Factory. In the next article we will discuss in more detail the main electrical simulation programs currently used to run the complementary simulations of the NTS.

What happens until the NTS comes into effect?

During the transitional process until the Government approves the proposed Royal Decree [2] and Ministerial Order [3], a ‘conditional’ Definitive Operational Notification will be issued and, once the aforementioned regulations have been approved, the delivery of the plant’s certificate of conformity will be required within a period of 12 months (with the possibility of extending it for another 12 months) for the issuing of the Definitive Operational Notification.

Norvento helps our clients to meet the requirements of the NTS or any of the higher level regulations in the process of monitoring the compliance of renewable generators to obtain the permit for their entry into commercial operation.

References

• Diario Oficial de la Unión Europea, Reglamento (UE) 2016/631 de la Comisión de 14 de abril de 2016 que establece un Código de red sobre requisitos de conexión de generadores a la red, abril 2016