| Answer | Crossword Clue |
|---|---|
| CLEAN | Like renewable energy |
| SOLAR | Like some renewable energy |
| SOLAR | Renewable energy |
| WIND | Renewable energy source |
| ECOL | Renewable energy subj. |
| ECO | Renewable-energy prefix |
| BIOMASS | Renewable energy source |
| SOLAR | Renewable energy type |
| SOLAR | Kind of renewable energy |
| SOLAR | Renewable kind of energy |
| SOLAR | Renewable energy option, for a few billion more years anyway |
