A cemig (Companhia Energética de Minas Gerais) expects a growing de 73% of installed capacity em GD projects (distributed generation) in its concession area in 2023.
The distributor projects that the modality will reach 3,91 GW by December this year and sur the mark of 7,69 GW by the end of 2029, with a great predominance of the photovoltaic source.
As information were shared by ONS (National Electrical System Operator) in technical note released this Tuesday (25).
The study was carried out after exchanging information with Cemig and studies carried out by EPE (Energy research company).
Despite the growth expected from the source, the document ready that the increase expressive of access requests from new generators would be causing impacts on transformers of the basic border network Taj northern regions and Mining Triangle.
In the first region mentioned, the ONS claims that the transformers in Pirapora 2, Três Marias, Jaíba and Paracatu 4 would already have a load greater than their operational capacity.
Os results of this technical note are not impediments to connecting projects from GD, but they constitute an additional element of for the distributors’ decisions in the analysis of access in its concession area, according to the ONS.
Check out the complete ONS technical note by clicking here.
Q&A
Since the beginning of the year, the State of Minas Gerais has been the stage for a series of discussions involving DG, especially photovoltaic systems.
In recent months, Cemig has received complaints involving the non-approval of projects on the grounds that there would be no more space for flow in the network, as reported by the Canal Solar.
Cemig stops projects and causes losses to companies in the solar sector
At the beginning of this second semester, the company once again became the center of discussions in the sector, after starting to approve requests for the connection and expansion of DG photovoltaic systems with the condition that the injection of power into the grid would only occur from 19pm to 5am, during a period in which there is no longer any sunlight.
O Canal Solar spoke with one of the integrators impacted by the decision, who said that it all started when he filed a request to expand the system of one of his clients in December last year.
At the time, Cemig reported network exhaustion and did not allow the system to be expanded. Not satisfied with the response, the integrator filed a complaint and the distributor deemed it valid, returning the project for analysis.
The professional reported to the Canal Solar who, after this, received a response from the distributor informing that the impact that its application would cause on the concessionaire's network meant that its request was sent to the ONS (National Electric System Operator) and that, soon, it would be given a response.
After a long period of waiting, he received approval to expand the system. To his surprise, the distributor issued an opinion on access without works, but with the condition that the energy generated by his client's system would only be injected during the night, between 19pm and 5am.
Furthermore, Cemig's response said that the integrator would still have to present the appropriate technical solution that would guarantee power generation only at the times mentioned, as shown below in the document sent by Cemig to the integrator in question:
What does Cemig say?
Sought by Canal Solar, Cemig reported that due to the number of connected plants, the concessionaire's distribution system would be impacted with a reversal of power flow in substation transformers and feeder circuit breakers.
“To eliminate this type of occurrence, Normative Resolution No. 1000/2021, from Aneel, determines that the distributor carry out studies of the options set out in paragraph 1 of article 73. In some cases, the technically viable option with the lowest overall cost is the injection at a pre-established time”, highlighted Cemig.
The distributor also stated that the most common technical solution for this type of connection, in the case of a photovoltaic source, involves the installation of battery storage systems in order to “allow control of the levels and times of power injection into the distribution network” .
“The converters must meet the technical requirements established in ABNT NBR 16149 and must have an anti-roofing system, as established in ABNT NBR IEC 62116”, concluded the company.
Answers of 6
I see a great opportunity to maintain the levels of the dam reservoirs. Reduce generation at the dam and increase consumption of solar energy, thus preserving the infrastructure limit. Would this be technically and economically viable?
THIS IS AN EXCELLENT OPPORTUNITY FOR IMPLEMENTING ELECTRIC MOBILITY WITH A ROBUST PROGRAM FOR CREATING SUPPLY INFRASTRUCTURE ACROSS THE COUNTRY.
THE REPLACEMENT OF COMBUSTION VEHICLES (CARS, BUSES & TRUCKS) BY HYBRIDS AND 100% ELECTRIC VEHICLES REQUIRES THE CREATION OF THIS INFRASTRUCTURE!
THE SAVINGS PROVIDED TO CONSUMERS BY SWITCHING FROM A COMBUSTION SYSTEM TO AN ELECTRIC ONE SHOULD PROMOTE STRONG GROWTH IN THE INDUSTRY CONVERTING THE CURRENT FLEET FROM COMBUSTION TO ELECTRICITY.
THE BIG ADVANTAGE IS THE USE OF CLEAN ENERGY.
PHOTOVOLTAIC AND WIND ENERGY ARE WELCOME!
THIS WILL ALSO HELP IN ACHIEVING AND EVEN EXCEEDING ENVIRONMENTAL OBJECTIVES.
THEREFORE WIND AND PHOTOVOLTAGE ENERGY SHOULD BE ENCOURAGED.
Once again, they raise a red flag, a pink and yellow flag... they say it's due to the water crisis. Now that there's no way to drain the excess energy.
If they have a bidirectional meter, why not a bidirectional transformer as well? This way, the energy will circulate in reverse gear to the hydroelectric plants, automatically turning off the turbines that are idle and keeping our “Minas Sea” always full to compensate for the impact of when it was created and which left many families desperate at the time.
The question I have is, are they creating difficulties, or is this really a problem to block the injection?
They turned GD in Minas Gerais into an energy trade, a connection budget trade (access report) and to circumvent this, they are selling the CNPJ of the holder of the connection budget.
In addition to these items, technical managers present false declarations of loads to be consumed.
Companies and RT reported that GD would end after January 06th, causing a fervor in requests, most of which were not for clients who wanted to have their own compensation system, but rather businesspeople looking for access opinions to be sold.
There is a failure on Cemig's part in not having planned the future scenario, but it does not exempt the "smart" ones from wanting to be greedy and overload the network in a short space of time.
It can be seen from the ONS technical note that the lack of capacity began in areas that did not have as much load to transport energy, that is, DG installations in rural areas.
If I understand the article correctly, Cemig is forcing DGs to install battery banks to control the injection of energy produced into their networks?
If that is the case, we will have a considerable increase in new projects, and certainly, making most of them economically unfeasible.