Although macro-level analyses of EU policy outputs are common, few empirical studies have measured the long-run evolution of the Union’s energy policy sector. This article provides an overview of European energy legislation to show past sectoral developmental trends, current characteristics and potential future directions. During this period, EU energy policy has evolved sequentially to encompass multiple sectors, including coal, nuclear energy, oil and gas production, energy conservation, market harmonisation and climate change concerns. Moreover, by measuring the velocity of legislative output as an indicator of policy activity, the overall picture is one of gradual incremental growth centred broadly on several episodes of shallow, delayed action punctuated equilibrium that has resulted in an uneven mixture of national and supranational decision-making. Expansion is perhaps set to continue along a similar path as a common EU climate–energy policy emerges, although some constraints are evident.