Nuclear Flexibility in the Iberian Electricity Market

A. Algora Tussy, F.A. Campos, L.J. Fernández, L.A. Herrero, E. Centeno

Summary:

This paper assesses the operational value of nuclear flexibility in the Iberian electricity market using an hourly mixed-integer quadratic dispatch model. Nuclear flexibility is represented through reduced-power operating bands, minimum maneuver duration, a prior full-load requirement, and an annual cycle budget. A summer-week case and a full-year 2030 case show that nuclear modulation mainly supports renewable integration. In the annual case, renewable curtailment falls by 12.5%, operating costs decrease by about 21 M€, and zero-price hours decline, while average prices remain nearly unchanged. The results identify curtailment reduction, rather than a significant average-price decrease, as the main system benefit of nuclear flexibility.

Spanish layman's summary:

Se evalúa la flexibilidad nuclear en MIBEL mediante un modelo horario de despacho. En 2030, reduce los vertidos renovables un 12,5 % y el coste anual unos 21 M€, con escaso efecto sobre el precio medio.

English layman's summary:

Nuclear flexibility in MIBEL is assessed with an hourly dispatch model. In the 2030 case, it cuts renewable curtailment by 12.5% and annual operating costs by about 21 M€, with little effect on average prices.

Keywords: Keywords: nuclear flexibility; economic dispatch; mixed-integer quadratic programming; renewable curtailment; MIBEL.

Registration date: 02-oct-2026