In today's energy mix, gas is an immediately available, storable energy that is supported by a very large distribution network. It is possible to completely replace fossil gas with 100% renewable gas by 2050. However, the quality of biogas is much more fluctuating than that of fossil gases and "power to gas". Radiolysis (degradation by ionising radiation) of impurities could be a method of choice to carry out this purification in a simple way, or even to propose alternative storage methods by functionalising the biomethane.