Optimizing energy and regulation services for energy communities with uncertain PV and demand: A bilevel adaptive robust approach

This paper develops an adaptive robust optimization (ARO) model for the optimal market participation of energy communities (ECs) under demand and photovoltaic (PV) uncertainty. The model jointly considers the day-ahead (DA) energy market, real-time regulation market, grid trading, and the operation of shared resources such as a community battery energy storage system (BESS). In the DA stage, operational costs are minimized by scheduling local generation, storage, and internal energy exchanges while respecting technical and market constraints. The framework prioritizes the use of local resources to enhance self-sufficiency and reduce reliance on the external grid. In the regulation stage, the model extends DA decisions by enabling the BESS to provide both up- and down-regulation services. These actions are coordinated with the EC's prior DA commitments to ensure feasibility under dual imbalance pricing and to avoid penalties. Uncertainty in demand and PV generation is addressed through a robust optimization approach. The problem is structured as a min–max–min model: the outer minimization determines DA decisions, the maximization captures worst-case realizations of uncertain demand and PV generation, and the inner minimization optimizes real-time regulation responses. This formulation guarantees feasibility against all admissible uncertainty scenarios within a defined budget of uncertainty, ensuring resilient and reliable EC operation. To improve tractability, the min–max–min problem is reformulated as a min–max problem using strong duality theory and solved through a decomposition method. Simulation studies on a 250-member EC validate the model, achieving a daily cost of €631.64 with 5666.46 kWh of demand met internally and up to 1052.64 kW of up-regulation via the BESS, even under worst-case uncertainty (budget of uncertainty = 6). Prioritizing local resources reduces grid dependence by 77% compared to market-driven strategies while preserving regulation revenue (€127.17). The results demonstrate that the proposed ARO framework reduces operational costs, enhances flexibility, and strengthens EC resilience to market volatility and renewable variability.