As early as the beginning of the 20th century Rudolf Diesel proposed vegetable oil as fuel for his engine. A short time later, before and during World War Two, vegetable oil was examined in "up-to-date" diesel engines. In 1940 first trials with vegetable oil methyl and ethyl esters were carried out in France and, at the same time, scientists in Belgium were using palm oil ethyl ester as a fuel for buses. In 1973, the oil crisis refocused attention on and interest for local energy sources. In recent decades, research concerning and knowledge about the external benefits of renewable raw materials have intensified the efforts for sustainable energy sources. Biodiesel plays a major role in this field because of the world-wide research, development and deployment activities of this sustainable energy source.