Exhibit 1
JOINT FILING AGREEMENT
Each of the undersigned hereby agrees that this statement on Schedule 13D is being filed with the Securities and Exchange Commission on behalf of each of the undersigned pursuant to Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended.
Dated: December 9, 2015
| TOTAL S.A. | ||
| By: | /s/ Humbert de Wendel | |
| Name: Humbert de Wendel | ||
| Title: Treasurer | ||
| TOTAL ENERGIES NOUVELLES ACTIVITÉS USA | ||
| By: | /s/ Marc de Lataillade | |
| Name: Marc de Lataillade | ||
| Title: Managing Director | ||
