Solar Power related words

2. a device converting solar radiation into electricity
5. dead plant and animal material suitable for using as fuel
7. a building with sails or vanes that turn in the wind and generate power
8. more important than anything else; main
9. something that you have arranged in case your main plans, equipment, etc. go wrong:
11. heating or cooling a medium to use the energy when needed later
13. less important than related things
14. to provide something that is wanted or needed
16. something that depends on the current weather to work
18. a place, person, or thing from which something comes or can be obtained

1. existing in limited quantities that cannot be replaced after they have all been used
3. fuels, such as gas, coal, and oil, that were formed underground from plant and animal remains millions of years ago
4. substances that can be used and easily replaced
6. a device storing electricity converted from solar radiation
10. able to produce electricity from light, or relating to the process of doing this
12. to reduce something in size or amount, especially supplies of energy, money
15. a flat section in the shape of a rectangle that is part of or fits into something larger
17. the act of sending out gas, heat, light, etc