Carbon credit systems have emerged as tools to incentivize emission reductions and support the transition to clean energy. Reliable carbon-credit certification depends on mechanisms that connect real and measured renewable-energy production with verifiable emission-reduction records. Although blockchain and IoT technologies have been applied to emission monitoring and trading, existing work provides limited support for certification processes, especially for small and medium-scale renewable installations. This paper introduces an architecture for a blockchain-based carbon-credit certification system that integrates real-time energy data collection, edge-level aggregation, and secure on-chain storage using a permissioned blockchain with smart contracts. The architecture integrates IoT sensing, edge aggregation, and blockchain storage to collect, validate, and record smart-meter data. Unlike approaches focused on trading mechanisms, the proposed system is aligned with European legislation and voluntary carbon-market standards, clarifying the practical requirements and constraints that apply to photovoltaic operators. The resulting architecture provides a structured pathway for generating verifiable carbon credit records and supporting third-party verification.