The Iberian blackout highlighted the vulnerability of individuals in their daily lives and countries in their fundamental organisation due to energy dependence, underscoring the critical and strategic importance of this sector. Beyond debates about the responsibilities of different generation technologies, which often veer into the politicisation of energy, compelling cases emerge on how to maximise all available resources to achieve competitiveness and greater autonomy in the face of events like the one on 28 April. Fernando Barreiro, Head of Energy Intelligence at Norvento Enerxía, outlined the value of 100% renewable microgrids as a tool for managing local energy resources efficiently and competitively. "A well-designed microgrid enables a building, an industry, or even a community to manage its own energy, harnessing available renewable resources, storing them appropriately, and relying on intelligent backup systems," he explained in a conversation with Strategic Energy Europe. Far from being a mere contingency response, microgrids represent an alternative energy architecture that enhances consumer autonomy, optimises long-term costs, and promotes a decentralised energy model based on technological efficiency and source diversification. A microgrid is an energy system capable of generating, storing, and distributing electricity autonomously, independent of the main transmission grid. Unlike a conventional self-consumption setup, which relies on the grid to function even if it generates its own energy, a microgrid can operate in "island" mode, maintaining its own internal voltage and frequency without needing an external reference. This technical distinction was evident during the blackout, as a conventional self-consumption solar inverter follows the grid"s frequency and voltage, shutting down automatically for safety if the grid fails. "In contrast, a microgrid has its own regulation system: it creates its own local grid, frequency, and voltage.
This allows it to continue operating independently, even if the main system collapses," Barreiro elaborated. Microgrids require three essential components:
- Renewable generation sources (solar, wind, biomass, etc.), sized according to local resources.
- Storage systems (batteries) to manage renewable variability and ensure supply during low-generation periods.
- Backup systems (e.g., biodiesel generators or biomass engines), activated only in extreme cases to maximise supply security.
- Renewable generation: Photovoltaic solar and wind energy, harnessing local natural resources.
- Storage: An advanced electric battery system that stores energy and stabilises supply, sized according to the plant"s daily consumption profile.
- Proprietary power electronics: Converter equipment designed and manufactured by Norvento, managing internal voltage and frequency to ensure the local grid functions even if the main grid fails.
- Backup system: A biomass cogeneration engine (Stirling engine) and a biodiesel generator as an emergency backup, ensuring continuous supply in extreme situations.