The Biofuel Obligation Scheme was introduced in July 2010 as the primary means to meet the target of at least 10% renewable energy in transport by 2020, which was mandated by the 2009 Renewable Energy Directive. The scheme works by obligating road transport fuel suppliers to bring a certain amount of biofuel, currently 6% by volume of total transport fuel sales, to the market. This has seen increased amounts of biofuel used in Ireland since the scheme was introduced and, in 2012, when the obligation was 4% by volume, approximately 128 million litres of biofuels were placed on the Irish market.