It is widely appreciated that renewable sources of energy are desirable. In particular, in recent years the development of biodiesel has been encouraged in order to find a replacement for fossil fuels in internal combustion engines. Typically, such biodiesel is based on triacylglycerols of vegetable origin. Animal fat, due to its different chemical composition and production process presents additional challenges when attempted to be used as a source of fuel. Most known methods require extensive processing of naturally occurring fats in order for them to be usable in conventional engines. According to the present invention, there is provided a method of oxidizing organic fats within an internal combustion engine to generate power by applying a first electrical charge to an oxidizer (e.g. air) and applying a second electrical charge to the organic fat opposite in polarity to the first electrical charge. In this way, constituents of the organic fat to be oxidized are attracted to the oxidizer, in preference to an interior surface of the combustion chamber. Thus, carbonization of the interior surface of the combustion chamber is reduced, as material contributing to carbonization is retained within exhaust gas.