EN 
PT_BR 
A recurring question in the photovoltaic market is whether zero grid solar energy projects need to be approved. To answer this question, the Solar Channel talked to Pedro Dante, partner in the energy and infrastructure area of Lefosse Lawyers.
According to him, as it is a new topic, There is no standard on whether or not specific approval is necessary of the zero grid system.
“There are few distributors that have updated their regulations to include specific provisions on the topic, and each interested party must monitor the evolution of the regulations to keep up with the evolution of the topic”, he explained.
Zero grid systems do not qualify as micro or mini DG
With regard to zero grid solar energy projects, it is worth clarifying, initially, that this involves energy generation without the respective injection into the distributor's local grid. That is, it is a system that is not connected to the distributor's network.
Despite Law No. 14,300/2022 and Normative Resolution No. 1,000/2021 not dealing with zero grid systems, ANEEL (National Electric Energy Agency) issued Official Letter No. 149/2022 – SRD/ANEEL, dated 8 June 2022, which considers and ratifies that zero grid systems do not inject energy into the grid.
Therefore, they do not participate in the Electricity Compensation System, and, consequently, do not qualify as distributed micro or minigeneration, under the terms of Law No. 14,300/2022.
“Furthermore, if the installed power is up to 5 MW, the system will be characterized as a reduced capacity generating plant, that is, the granting of the granting power is not necessary to be implemented (under the terms of Normative Resolutions 875 and 876/2021) ”, reported Dante.
According to the lawyer, the existence of such plants smaller than 5 MW (as long as they are not intended for distributed generation), even if not connected to the distributor's system, must be communicated to ANEEL for registration purposes (simplified registration), as provided in the Law No. 9,074/1995.
“That said, given that zero grid solar energy generation systems are not characterized as distributed generation under the terms of Law No. 14,300/2022, there must be subsequent communication to ANEEL about the implementation of the system”, he pointed out.
What is this communication like?
The specialist highlighted the provisions of Official Letter No. 149/2022, in which, to proceed with the connection of the zero grid system at the facilities of the consumer unit, the interested party must contact the local distributor, so that, upon analysis of the distributor, it is guaranteed that there will be no injection of energy into the network and that no disturbances or damage will be caused to the electrical system or to people.
If there is an injection of energy by default, which results in technical and security problems for the network, or even for other consumers, the distributor may demand:
- Reimbursement of compensation related to data;
- Installation of corrective equipment;
- Payment of the works necessary to correct the disturbance(s) that occurred, and even suspend the energy supply, in accordance with the provisions of articles 44 and 355 of ANEEL Normative Resolution No. 1,000/2021.
Is there a well-defined form or procedure?
Regarding communication to ANEEL for registration purposes, which occurs after the installation of the zero grid system, it is carried out in the granting authority's system, by filling out the online form available on the Regulatory Agency website.
Zero grid technical requirements that the concessionaire observes
Regarding the requirements that are observed by the electricity distribution concessionaire, the partner in the energy and infrastructure area of Lefosse Advogados highlighted the adequacy of the project to the norms and technical construction standards, guidelines and specific requirements of the local distributor, that is, to the procedures and protections applicable to enterprises.
Thus, among the requirements that must be observed is the installation and construction of various equipment and facilities, as long as they are required in the distributor's technical standards, set out in art. 30 of REN nº 1,000/2021, such as:
- Energy input standard, so that it is possible to perform the reading from the public road or from free and unrestricted access to the distributor, according to the distributor's technical standard;
- Boxes, frames, panels or cubicles intended for the installation of meters, measuring transformers and other distributor devices, necessary for the measurement and protection of these installations;
- Compartment intended for the installation of transformation and protection equipment;
- Protective equipment and grounding systems, observing the requirements for each type of input standard specified in the distributor's technical standards.
“The standards of ABNT (Brazilian Association of Technical Standards) and the standards of the competent official bodies must also be considered, as far as applicable and do not contradict the regulations of the Regulatory Agency, as listed in art. 29 of REN No. 1,000/2021”, he added.
In the case of zero grid with batteries, are there any impediments?
According to Pedro Dante, regarding the energy storage system, if it is a solar plant with reserve batteries whereby the electrical energy stored in the battery comes from the photovoltaic source or other sources, it is emphasized that the standards regulatory/legislative provisions do not provide for any impediments to this modality. “In other words, there are no differences in regulatory treatment if the zero grid system contains batteries in our view.”
Are zero grid inverters defined in Inmetro Ordinance 140?
The answer is yes. Inmetro (National Institute of Metrology, Quality and Technology) published, on March 30, 2022, in the DOU (Official Gazette of the Union), the Ordinance 140/2022 - O regulation for photovoltaic equipment sold in Brazil.
Among the main innovations are, precisely, on-grid inverters with batteries (hybrids), “and most hybrids on the national market have the zero export function attached. Therefore, zero grid inverters are defined in Ordinance 140”, said engineer Geraldo Silveira, a specialist in photovoltaic systems.
Below is the excerpt from the Ordinance that shows the defined equipment:
