| Cover | Apr. 29, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 29, 2021 |
| Entity File Number | 333-203369 |
| Entity Registrant Name | Clearway Energy LLC |
| Entity Central Index Key | 0001637757 |
| Entity Tax Identification Number | 32-0407370 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 300 Carnegie Center |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | Princeton |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 08540 |
| City Area Code | 609 |
| Local Phone Number | 608-1525 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
