Screening and Valuing Local Flexibility as a Non-Wires Alternative: A Topology-, Contingency-, and Resource-Deliverability Framework Under Lithuanian Distribution Regulation

Distribution flexibility can be overvalued when priced before network-side alternatives and resource deliverability are screened. This study develops a three-gate appraisal framework for local flexibility as a non-wires alternative (NWA): network incrementality, resource deliverability, and conditional economic value. The framework is demonstrated on the IEEE 33-bus benchmark using the observed Lithuanian 2025 hourly load shape and the 2026 Energy Distribution Operator (DSO) flexibility product as well as the Lithuanian National Energy Regulatory Council (VERT) context; it is not an actual Lithuanian feeder model. At the year-3 stress point, the normal topology violates the 0.95 p.u. analytical threshold, but the screened connected-radial topology space contains a compliant configuration, so paid flexibility has no incremental value in that benchmark state if an equivalent configuration is operationally permissible. In contrast, the Zone-C L22 contingency remains non-compliant after topology-only screening and leaves a 222.1 kW local residual requirement at buses 23–24. With a 20% controllable-demand bound, 106.1 kW of firm injection remains necessary, showing that an electrical support requirement may map to demand response, firm injection, or a hybrid portfolio. Economic eligibility then depends on the genuinely deferrable share of reinforcement. The contribution is the ordered stopping logic that separates electrical need, physical deliverability, and attributable economic value.