Hybrid Solar Plant Campo Arañuelo III

The Campo Arañuelo III hybrid solar plant, promoted by Iberdrola España, is a solar installation of almost 40 MWp of installed power located in the municipality of Romangordo (Cáceres, Extremadura) and commissioned in 2021. It was pioneering in Spain as the first national photovoltaic project to incorporate a lithium battery storage system for solar panels, with batteries of 3 MW power and 9 MWh capacity, which facilitates greater integration of renewable energy into the grid and contributes to system stability.

The main access to the installation is from the N-5 road at kilometer 199, near the roundabout accessing the A-5 at exit 200.

The installation is divided into 11 solar fields with two transformer center configurations:

• Type 1 fields: CT01, CT04, CT05, CT06, CT07, CT08, CT09, CT10 and CT11, each with two inverters of ~1.637 MVA and a transformer of 3 280 kVA (0.630/30 kV).

• Type 2 fields: CT02 and CT03, each with one inverter of ~1.637 MVA and a transformer of 1 640 kVA (0.630/30 kV).

In addition, it has 2 DC-DC converters of 1,500 kW and 2 storage containers with a capacity of 4.5575 MWh. In the storage area, the inverters are grouped in groups of 2 forming the “Inverter Station”. For battery delivery, each battery container of 4.5575 MWh capacity is associated with each DC-DC converter, via direct current cabling.

The plant is controlled by a central supervision system for power delivery to the point of connection (POI), managing the 28 MW nominal photovoltaic and 3 MW nominal battery to optimize delivery. Together with the photovoltaic and battery hybridization of Puertollano II, as of October 2025, they are among the only operating plants that incorporate batteries for solar panels.

The battery is intended to shift solar production and improve operational flexibility. As of December 2025, its purchase programming unit has not been formally established in Red Eléctrica or in OMIE, so it is not yet used for price arbitrage strategies (buying energy when it is cheap, and selling when it is expensive).

It is part of the Campo Arañuelo complex, together with the Arañuelo I and II plants, which together have an installed capacity of 143 MWp and a total investment of 80 million euros, generating clean energy equivalent to the consumption of approximately 65,000 homes per year and avoiding the emission of about 41,000 tons of CO₂ annually, according to Iberdrola.