Because PECS is largely governed by its student members, the selection process gives considerable weight to indications that a student likes to volunteer and take initiative. Candidates self-nominate and are required to prepare a summary description of their research (< 500 words) including its intersections with energy and climate, and to explain how they would contribute to the PECS community. A letter of recommendation from their primary advisor highlighting their qualifications and motivations for joining the group is also required.

PECS membership lasts for two years. Typically, only post-generals Ph.D. students are eligible for participation, but special cases will be considered.