1. sun/ effective/ source/ power 2. it/ be /cheap 3. it/ be/ clean 4. it/ not cause/ pollution 5. solar panels/ be installed/ roof/ house/ receive/ energy/ the sun 6.it/ can/ store/ a number of days 7. it/ be used/ cloudy days 8. solar energy/ provide / enough power/ world's population 9. we/ save / natural resources/ use / solar energy/ instead/ gas , oil and coal 10. there for lot countries/ world / already / use / solar energy