Fregenal de la Sierra: photovoltaics hybridize with storage batteries

The Regional Ministry of Industry, Energy, Science and Territory of the Junta de Extremadura has opened for public consultation the request to modify the prior administrative authorization of the photovoltaic installation “PS Fregenal de la Sierra”, located in the municipality of Fregenal de la Sierra (Badajoz), in order to incorporate an electrochemical storage module using batteries called “Erg Bess Fregenal”. The announcement, signed on August 31, 2026, is published in the Official Gazette of Extremadura (DOE) number 176, dated September 11, 2026, under file GE-M/17/19 (reference 2026081495).

The request was submitted on March 26, 2026, by Mr. Marco Longoni, representing the company Erg Solar Fregenal de la Sierra, SL, the owner of the installation, with CIF B26550491 and registered office at Paseo de la Castellana 130, 9th floor, Madrid. The project is being processed under Law 24/2013, of December 26, on the Electricity Sector, and Article 125 of Royal Decree 1955/2000, of December 1, which regulates the authorization procedures for electrical energy installations.

Installation Background

The photovoltaic plant “PS Fregenal de la Sierra” has a prior administrative history. On October 30, 2020, the General Directorate of Industry, Energy and Mines issued the resolutions granting the prior administrative authorization (published in DOE number 216, dated November 9, 2020) and the administrative authorization for the construction of the installation and its associated evacuation infrastructures.

Subsequently, on May 16, 2022, the resolution was issued granting the operating authorization to the company Instalación Fotovoltaica Arericsol VIII, SL, currently named Erg Solar Fregenal de la Sierra, SL. Now, the hybridization with the storage system constitutes a modification of the characteristics of the already authorized installation.

Characteristics of the Storage Module

The electrochemical storage module “Erg Bess Fregenal” will be located in Polygon 51, plot 161, of the municipality of Fregenal de la Sierra. Its main technical characteristics are:

• Installed capacity of the storage module: 8,250 kW.
• 8 battery containers, with a capacity of 4,125 kWh each and a total capacity of 33,000 kWh, with a charge/discharge time of 4 hours from full charge.
• 2 inverters with a power of 4,125 kW each (8,250 kW total) and 1 transformer of 8,780 kVA (20/0.69/0.69 kV), plus an auxiliary services transformer of 50 kVA.
• Underground connection line of 20 kV (20 meters, Al RHZ1 3x1x240 mm² conductor) to the sectioning center “CS Erg Bess Fregenal”.
• Sectioning center with four cells, including an auxiliary services transformer of 250 kVA.
• Underground line of 20 kV and 163 meters connecting the sectioning center with the “SET Fregenal” substation, where a new line cell will be installed.

The installation only allows for the accumulation of part of the electrical energy generated at the photovoltaic plant, for the purpose of storing energy from solar generation. The total material execution budget of the project amounts to €4,978,557.99.

Period for allegations and consultation

The project documentation may be examined at the offices of the General Directorate of Industry, Energy and Mines, at Paseo de Roma, s/n, Module D, 1st floor, in Mérida, from 8:00 to 15:00 hours on working days from Monday to Friday. The project, along with the announcement, can also be consulted through the public information website of the department.

Any allegations deemed appropriate must be addressed to the aforementioned body within a period of 30 business days, counting from the day following the publication of the announcement. The announcement is signed by the Director General of Industry, Energy and Mines, Raquel Pastor López.

The hybridization of the photovoltaic plant with battery storage makes “PS Fregenal de la Sierra” an installation capable of better managing its production, accumulating energy during hours of higher solar generation to discharge it when it is most needed. This is a relevant step for the energy transition of the province of Badajoz, combining renewable generation with storage capacity, and opens a period of public participation in which residents and entities may submit allegations before the final resolution.

Source: Official Gazette of Extremadura, number 176, September 11, 2026, section IV (Announcements) (official reference: 2026081495).