sentences:  The Svartsengi power plant and the Nesjavellir power plant produce both electricity and hot water for heating purposes.The move from oil-based heating to geothermal heating saved Iceland an estimated total of US $8.2 billion from 1970 to 2000 and lowered the release of carbon dioxide emissions by 37%.It would have taken 646,000 tons of oil to heat Iceland's homes in 2003.