A Monte Carlo model has been constructed to describe the energization and energy degradation of low-energy protons in an H2 atmosphere in the presence of parallel electric field. The energy spectrum of Ly α collision events is employed to determine the volume emission rate (VER) of H Ly α emissions. Numerical experiments have been performed to study the effect of initial proton energy, electric field, neutral number density, initial pitch angle, and cutoff limit on H Ly α VER. The present study demonstrates that energization of solar EUV-generated low-energy protons by parallel electric fields is incapable of producing optically thin Ly α emissions on Uranus through direct collision with H2. However, nonthermal H atoms, produced through acceleration of protons in parallel electric fields, play an important role in enhancing the Ly α intensity through resonant scattering of solar Ly α flux: resulting emissions are consistent with the broadening of the Ly α line observ