Grand canonical Monte Carlo simulations are performed to evaluate the hydrogen-storage capacity of the recently discovered hydrogen hydrates of the sH type, at 274 K and up to 500 MPa. First, the pure H-2 hydrate is investigated in order to determine the upper limit of H-2 content in sH hydrates. It is found that the storage capacity of the hypothetical pure H-2 hydrate could reach 3.6 wt % at 500 MPa. Depending on pressure, the large cavity of this hydrate can accommodate up to eight H-2 molecules, while the small and medium ones are singly occupied even at pressures as high as 500 MPa. Next, the binary H-2-methylcyclohexane sH hydrate is examined. In this case, the small and medium cavities are again singly occupied, resulting in a maximum H-2 uptake of 1.4 wt %. Finally, the results from simulations on pure H-2 and binary hydrates are utilized to investigate the potential of H-2 storage in sH hydrates where the promoter molecules occupy the medium instead of the large cavities.