Geothermal energy

2. a building with glass sides and a glass roof for growing plants in
5. to make a hole in something
8. disadvantage
9. a place, person or thing that you get something from
11. deplete
12. the hot gas that water changes into when it boils
13. a deep hole in the ground from which people obtain water
15. that is replaced naturally or controlled carefully and can therefore be used without the risk of using it all up
17. very hot liquid rock found below the earth’s surface
18. the quality of being hot

1. the most important or central part of something
3. involving the use of natural products and energy in a way that does not harm the environment
4. building or group of buildings where electricity is produced
6. to control and use the force or strength of something to produce power or to achieve something
7. the parts of a dead animal or a plant that have become hard and turned into rock
8. run out
10. kept to use later
14. to become less powerful
16. a natural spring that sometimes sends hot water or steam up into the air