Oil was discovered in Lithuania in the 1950s, but only a few wells operate, and all that do are located in the western part of the country. It is estimated that the Baltic Sea shelf and the western region of Lithuania hold commercially viable amounts of oil, but if exploited this oil would satisfy only about 20 percent of Lithuania's annual need for petroleum products for the next twenty years. Lithuania has a large amount of thermal energy along the Baltic Sea coast which could be used to heat hundreds of thousands of homes, as is done in Iceland.