The 40 MW Arañuelo III PV plant is now up and running. This is the first large-scale PV plant in Spain to incorporate an energy storage system, comprising in this case a 3 MW/9 MWh battery system. This PV plant with batteries is part of the Campo Arañuelo photovoltaic complex developed by Iberdrola in the district of Almaraz in Extremadura and formed by the Arañuelo I, II and III solar plants, with a total installed capacity of 143 MW.
Ingeteam was the technology partner selected by Iberdrola to equip the Campo Arañuelo solar complex. In the case of Arañuelo plants I and II, the supply was the usual one for a PV plant: PV inverters, transformer stations, PPC (power plant controller) system and commissioning. The novelty of the project relates to Arañuelo III given that, in addition to all the above, Ingeteam also completed the turnkey supply of the energy storage system. In other words, Ingeteam supplied the lithium-ion batteries, the integration of the batteries in the 45-foot containers, the converters, the SCADA monitoring system, the civil work, the field assembly of the storage system and its subsequent commissioning.
Furthermore, Ingeteam was also responsible for the supply of the digital protection and control system for the Arañuelo III substation. The scope of supply included the systems responsible for the protection and control of the line delivering power to the grid from the plant, the 30/132kV step-up transformer, the collector circuits and the connection circuit for the energy storage system, providing the renewable energy control centre (CORE) with real-time information and access to any of the elements.
A new battery converter
As well as being the first large-scale solar plant in Spain to incorporate batteries, this project offers a further novel feature with the inclusion of the battery storage system within the PV plant as a distributed system with a DC-Coupling configuration. In this mode, the batteries are installed within the solar array and the battery converters share the DC connection with the PV inverters, offering the following key technical advantages:
- Possibility of utilizing the extra power from the solar panels that is not used in the peak production hours (Clipping Recapture).
- This makes it possible to minimize the losses by charging the batteries from the PV array, given that the connection between the panels and the batteries only passes through the DC/DC converter. The discharge is also more efficient, due to the fact that no power transformer is required, in contrast to the AC connected solution.
This novel technique to create a hybrid PV generation system with battery energy storage, was made possible thanks to the development by Ingeteam of a new battery converter: the DC-DC series of the INGECON SUN STORAGE Power family. This converter is coupled to the DC input of a PV inverter, thereby obtaining in practice a hybrid central inverter with a direct coupling to the solar panels and batteries alike and with a single AC output that is coupled to the LV/MV transformer.
The Campo Arañuelo complex is already producing clean energy to supply a population equivalent to 65,000 homes a year and will prevent the release into the atmosphere of 41,000 tons of CO2 each year.
Scope of supply for the Campo Arañuelo PV complex
- 29 power stations fitted with all the necessary equipment to inject medium voltage power: LV/MV transformer, medium voltage switchgear, auxiliary services transformer and auxiliary services switchgear.
- 72 units of the INGECON® SUN 1640TL B630 solar inverter with a rated power output of 1.64 MW.
- Two units of the INGECON® SUN STORAGE Power DC-DC battery inverter with a rated power output of 1.5 MW, for Arañuelo III.
- Two 45-foot, fully integrated battery containers, each for 1.5MW / 4.5MWh, for Arañuelo III.
- Three INGECON® SUN Plant Controller systems.
- Hybrid plant controller (solar + batteries) for Arañuelo III.
- SCADA monitoring system for Arañuelo III.
- Civil work and assembly of the storage system at Arañuelo III.
- Commissioning of the three photovoltaic plants and also the storage system at Arañuelo III.
- Digital system for the control and protection of the Arañuelo III substation.