| Naics index | Naics index description |
|---|---|
| 221118 | Electric power generation, tidal |
| 221118 | Power generation, tidal electric |
| 221121 | Electric power control |
| 221121 | Electric power transmission systems |
| 221121 | Transmission of electric power |
| 221122 | Distribution of electric power |
| 221122 | Electric power brokers |
| 221122 | Electric power distribution systems |
| 221210 | Blue gas, carbureted, distribution |
| 221210 | Coke oven gas distribution |