This paper addresses a structural tension that is already visible in bank-based financial systems, including the Russian case. Central bank digital currencies (CBDCs) are presented as instruments capable of increasing payment transparency, enabling programmable and targeted public transfers, and reducing the transaction costs of cross-border green investment flows. At the same time, their introduction may weaken the banking sector’s traditional intermediation role, creating the risk of deposit outflows and balance sheet erosion in commercial banks – the very institutions that still provide long-term credit to the real economy and finance the energy transition. The objective of the study is twofold: first, to assess how specific design features of retail CBDC (a two-tier distribution model through commercial banks, the absence of interest on CBDC holdings, and quantitative limits on individual balances) affect the stability of the banking sector; and second, to evaluate whether such a design can function as an institutional layer for targeted green finance without undermining the bank-based credit channel. Methodologically, the paper relies on an institutional and comparative assessment of three CBDC frameworks: the digital ruble, the e-CNY, and the proposed digital euro. The analysis focuses on channels of financial risk (deposit reallocation away from banks, rapid digital withdrawals by depositors during stress episodes, pressure on banks’ fee and interest margins) and channels of opportunity (programmable disbur- 403 Third International Scientific Conference sement of green subsidies, traceability of ESG-linked financial flows, and emerging cross-border multi-CBDC settlement platforms such as mBridge). The contribution of the paper lies in bringing together two strands of debate that are often treated separately in the literature: the question of financial stability under retail CBDC, and the question of institutional infrastructure for sustainable finance. The paper argues that CBDC can be conceptualised as a potential settlement layer for green finance, provided that its design preserves the ability of commercial banks to act as the primary lenders to long-horizon decarbonisation projects.