Energy supply in Sri Lanka is mainly based on three primary resources, namely, biomass, petroleum and hydroelectricity. In 2004, hydro-electricity production in the country accounted for 706.9 kTOE (thousand tonnes of oil equivalent) while the biomass-based energy supply was 4,494.4 kTOE. Approximately 4,304.2 kTOE was provided by imported crude oil and finished petroleum products such as diesel and liquefied petroleum gas (LPG). Additionally, the non-conventional resources (mainly wind) provided 3.5 kTOE of primary energy, giving an aggregate primary energy supply of approximately 9,509.1 kTOE. The 2004 primary energy contributions to national energy supply were 47.3% from biomass, 45.3% from crude oil and petroleum products and 7.4% from hydroelectricity. The use of non-conventional energy resources in Sri Lanka is of a relatively smaller scale and therefore its contribution is presently of low significance in the macro energy picture.