The subnational level embodied by regions and cities presents unique challenges for energy policy. Large metropolitan areas tend to be consumers rather than producers of energy, with two of the most critical sectors being transport and residential. The Madrid region in Spain – one of Europe’s most significant urban areas – represents such a phenomenon. The Long-Range Energy Alternatives Planning System (LEAP) modelling approach has been applied to Madrid for long-term sustainable energy planning. This paper presents the model, a business-as-usual projection and two alternate scenarios to 2050. The results show that by applying measures to decarbonize the transport and residential sectors, significant reductions in energy demand are possible.