The Spanish energy sector faces three main challenges: competitiveness (low-cost supply, especially to energy-intensive sectors), security of supply (through diversification of sources, and exploration and eventual exploitation of domestic resources) and growth, following heavy investment in infrastructure, in a context of stagnating demand. To better understand the challenges, several drivers or contextual factors are analysed: global energy markets, trends in the global economy, decarbonisation, shale gas revolution in the USA, Energy Union in the EU, Energy Transition in Germany, distributed generation and transport. On the basis of the above, the paper concludes with some reflections and suggestions.