Compliant fuel gas storage tank includes a housing having an outer wall enclosing the interior. The first and the bottom wall and the second bottom wall are spaced apart in a direction along a vertical axis, side walls extending between of said bottom wall and has spaced apart in a direction along the horizontal axis, and end walls above among said bottom wall extending between the side walls of which are spaced in a direction along the longitudinal axis. Internal walls divide the interior and stretches in a direction between the ends of the wall and between the wall of the bottom, is spaced in a direction along the horizontal axis. The inner wall forms a through-channel spaced apart in an elongated, horizontal orientation extending in the longitudinal direction between said end walls. Gas storage material is disposed within the channel, the gas permeability along the flow guide is at least one of the channel and extends beyond the gas storage material.