Abstract
The transition to low-emission energy matrices, driven by the climate emergency and international decarbonization demands, has increased the prominence of sustainable hydrogen in Brazilian public policies. However, the legal framework recently established by Law No. 14,948/2024, by consolidating the Special Regime for Low-Carbon Hydrogen (Rehidro) and vetoing the creation of a direct tax credit program, has reignited debates about the legal limits of tax incentives and the effectiveness of national energy policy. The tension between the incentive models – tax suspension versus the granting of credits – highlights constitutional conflicts related to equality, fiscal efficiency, and legal certainty for investments in clean technologies. This article critically analyzes the legal foundations of the tax instruments provided for in the low-emission hydrogen legal framework, investigating their compliance with the constitutional principles of economic order, environmental justice, and the promotional role of the State. The research adopts a qualitative approach, based on a literature review, normative analysis, and systematic interpretation of the constitutional text. It was found that the current regulatory framework lacks strategic coherence and legal certainty, which could compromise Brazil's role in the global energy transition. It is concluded that improving fiscal policy for the sector requires the development of an efficient, equitable legal framework aligned with sustainable development objectives.