Geothermal energy is mainly used for heating buildings in Iceland, where over 50% of the country's energy comes from geothermal sources. Hot water is piped from kilometers away to heat homes and provide hot tap water. Geothermal energy can also be used to generate electricity. Hundreds of meters of piping are buried underground, where cold water is pumped into injection wells and becomes heated by underground rock. This hot water or steam is then used to power generators and produce electricity. Geothermal energy comes from the natural heat of the earth and can provide both heating and electricity with limited environmental impact.