Tariff sandboxes as a tool for modernizing the tariff structure of the Brazilian power sector

The Brazilian electricity tariff structure, rooted in legislation from 1968, is undergoing a critical review to address modern technological and regulatory challenges. Traditionally based on a monomial volumetric model, the tariff structure for low-voltage consumers does not adequately reflect the variability in energy generation and distribution costs. Rapid advances in decentralized renewable energy sources, such as solar and wind power, and the growing importance of sustainability have underscored the need for a more dynamic and inclusive pricing model. The introduction of regulatory sandbox environments by the Brazilian Electricity Regulatory Agency (ANEEL) has enabled pilot projects to test innovative tariff modalities. These initiatives involve diverse stakeholders, including energy distributors, consumer councils, and civil society, aiming to align tariff structures with technological advances, consumer behavior, and sustainability goals. The governance project for these sandboxes integrates phases of planning, public consultations, research, and monitoring, fostering a comprehensive evaluation of new models like time-of-use, fixed tariffs, and prepaid schemes. Preliminary results emphasize the importance of transparent communication and consumer education to ensure acceptance and adaptability. This study highlights the potential of experimental environments to inform regulatory modernization, promoting energy efficiency and equitable access while supporting Brazil's energy transition commitments.