Dr. Milan Prodanović

Significant political and economic efforts have been undertaken within the European Union to mitigate the effects of climate change. In alignment with adopted directives, several member states have developed national strategies and prospective studies. One of the most ambitious initiatives is Spain’s National Energy and Climate Plan (NECP), which outlines a substantial reduction in CO₂ and other emissions within the energy sector. This talk will address the main challenges associated with the decarbonisation of electricity networks, as well as explore potential technical and market-based solutions. The discussion will begin with an overview of the specific topology of the electricity network in the Iberian Peninsula and its interconnections. This will be followed by an analysis of trends in energy demand and a mapping of renewable energy resources. Finally, the current regulatory framework and the conditions of the energy and service markets will be introduced. Decarbonisation entails the large-scale integration of renewable energy sources (RES) into the power grid. In Spain, this transition primarily involves wind generation in the northwest and photovoltaic (PV) sources in the central and southern regions. Additionally, there are plans for floating offshore wind farms in both the Atlantic and Mediterranean areas. Simultaneously, many conventional coal and gas-fired power plants are being decommissioned. This transformation gives rise to several key challenges: How can RES variability be managed to meet demand? Where should the power grid be reinforced? How can the loss of synchronous generation be compensated? How can service quality be maintained? What market mechanisms and regulatory frameworks are needed? And how should excess generation capacity be handled? To address the loss of synchronous generation—particularly the associated reduction of inertia and voltage stability margins—various technical solutions have been proposed. Power converters used with renewable energy sources and battery systems offer advanced functionalities, such as Grid-Forming capability. Additionally, converters in static compensators, when paired with energy storage, are expected to deliver essential network services. A more traditional alternative involves the deployment of synchronous condensers. The implementation of these solutions is closely linked with the evolution of regulatory frameworks and the development of new service markets. Moreover, advanced planning tools are needed to identify the most cost-effective strategies—whether they are mandated by Grid Codes or capable of competing in emerging service markets. This presentation will explore techno-economic-environmental tools designed to support the transformation of the electricity network in the context of decarbonisation. In particular, it will assess the impact on various aspects of network stability and critically evaluate potential solutions. Different control topologies for power converters will be examined and critically compared, both in terms of their ability to provide grid services and their compliance with evolving Grid Codes.

Keywords: decarbonisation, renewable energy sources, Converter-Interfaced-Generation, new grid services