Cemig and Alsol Energia Renováveis initiated last Friday (15) the operation of the first large scale energy storage system next to a photovoltaic power plant, with a maximum power of 1.26 MVA and storage capacity of 1.36 MWh, in Uberlândia, in the Triângulo Mineiro. It is expected that the first tests in the electrical network will be done in the third week of February.

This equipment is part of a research and development project with a total investment of R $ 22.7 million - R $ 17.5 million invested by Cemig and R $ 5.2 million by Alsol, a company accelerated by the Algar group, which is the creator and executor of the project.

According to Alécio de Melo Oliveira, manager of the Cemig solar power plant project, "this system was acquired from the Chinese company BYD and its technology is lithium ion, which provides greater storage capacity," he says.

In the coming months, another two storage systems with acid lead batteries, totaling 225 kWh of power, will be installed in the plant. These equipments, provided by the Brazilian company PHB, have modified inverters and switching systems that will allow to define what better strategy of injection of energy in the network in specific situations, if it comes from the photovoltaic plant or the batteries of the storage system.

The 400 kWp (kilowatt-peak) photovoltaic power plant combined with the different energy storage systems will have a capacity of 1.58 MWh, with a generation potential of approximately 640,000 kWh / year, sufficient energy to supply at least 350 homes with average consumption of 150 kWh / month, for one year.

The plant is located at Alsol's headquarters in the District Industrial District, in Uberlândia (MG), and was inaugurated last year with 300 kW. Since then, Alsol has increased the system power by 33%, reaching 400kW.

Gustavo Malagoli, president of the company and coordinator of the project, says that this is an essential phase for the development of the project. "Now we are going to put into operation, on a large scale, the storage that we were already testing in prototype. The success of this connection will be a milestone for the energy sector in the country and, consequently, for consumers, "he explains. The energy generated in this plant will be used by several companies in the region.

Pioneer plant in Brazil

Currently, the photovoltaic plants in operation in Brazil supply power to the grid only during the day, suspending the supply at the moment the system is most in demand.

With this new configuration, this logic is inverted, since it allows the storage during the day with the presence of the sun and, after 18 hours, considered the peak time, it is possible to inject in the network 1 MW for one hour and sock. Another example would be to inject 0.79 MW for two hours or 0.53 MW for three hours.

According to the superintendent of Technology, Innovation and Energy Efficiency of Cemig, Carlos Renato França Maciel, the project represents Cemig's constant search for innovation and brings advances to the electric sector.

"One of the purposes of the plant is the development of a new business model, from hybrid plants that combine photovoltaic generation and storage systems with consumer units, which guarantees the quality of energy distribution, especially at times of greater demand "He explains.

According to Maciel, "the quality of energy delivered will be improved, increasing the profitability of the company, since fewer disconnections should occur. There is also the expectation of reducing losses in feeders and transformers during peak hours, which influences the quality of service, "he points out.

The Research and Development (R & D) project was proposed by Companhia Energética de Minas Gerais (Cemig) and approved by the National Electric Energy Agency (Aneel) in April last year. The execution is the responsibility of Alsol, together with the Federal University of Paraíba (UFPB) and the Federal Institute of Rio Grande do Norte (IFRN).

About Alsol Energias Renováveis 

Alsol is a 100% Brazilian company, accelerated by the Algar group since 2015, specializing in distributed generation using different renewable sources. Responsible for the 1st photovoltaic installation included in Aneel's compensation system in Brazil (REN482 / 2012). Currently has more than 500 projects in operation. There are approximately 25 MWp of photovoltaic systems in operation and another 15 MWp in installation, in addition to 2.0 MW of biogas. It is present in 11 Brazilian states, generating clean and distributed energy.