Energy policy in the European Union (EU) is driven by the objective to transition to an affordable, reliable, and low carbon energy system. To achieve this objective, the EU has explicitly stated targets for greenhouse reduction, shares of renewable energy sources (RES), and energy efficiency improvements for 2020 and 2030. In this paper, we focus on the drivers, barriers and enablers to achieving the EU's RES targets (20% by 2020 and 27% by 2030). Effective energy policies play a key role in the deployment of RES technologies. In order to design effective policies, a clear understanding of past trends and projections for future deployment is required. In this paper, we first analyse the past deployment of RES technologies for electricity supply (RES-E) in selected EU Member States. This highlights the key drivers, barriers, and enablers for deployment of RES in the past. In a second step, we conduct a meta-analysis of projections for RES-E shares from multiple well-established studies. Such an analysis will help in supporting the design of more effective energy policies and successfully achieving the EU's energy targets.