The European Union is particularly rich in variations of different delivery mechanisms for increasing the use of renewable energy. The requirements of liberalisation in continental Europe, the re-regulation of the UK's gas and electricity sectors in 2000 and ongoing environmental commitments has meant the establishment of a new generation of mechanisms following on from early prototypes. This paper analyses two new mechanisms in detail: the England and Wales RO (Renewables Obligation) and the German EEG (Erneuerbare Energien Gesetz), with a particular focus on how they reduce risk for generators. Assuming that risk reduction is an important way to make a support mechanism effective in promoting deployment, the analysis will look at three different kinds of risk, namely, price, volume and balancing risk. It is argued that the German EEG is more effective at increasing the share of renewables than the England and Wales RO because it reduces risk for RES generators more effectively. (c) 2004 Elsevier Ltd. All rights reserved.