Planning for Reliability with Variable Renewables: Brazil’s Diagnostic and Pathways for ELCC Implementation

Based on international experience—particularly in U.S. power markets—the paper shows that

ELCC is a mature framework for capacity accreditation under high renewable penetration. In the Brazilian context, a simplified ELCC simulation is applied ex post to the generation expansion trajectory defined by the Investment Decision Model (MDI) in the PDE 2034. The results show that rapid capacity growth does not translate proportionally into firm capacity, revealing increasing firming requirements not captured by energy-based planning. This paper positions ELCC not as an isolated analytical tool, but as a structuring element of a broader reform of technical and economic signals, aimed at realigning long-term planning, market incentives, and reliability outcomes under high renewable penetration.

Finally, building on nationwide Short-Circuit Ratio (SCR) diagnostics and Australian experience, the paper proposes a harmonized framework in which ELCC signals energy reliability and probabilistic SCR capture electrical robustness. In this framework, ancillary services are explicitly valued, ensuring that costs are borne by agents that increase system stress while reliability-enhancing resources are remunerated