Power-to-Gas can contribute with valuable balancing power and seasonal storage capacity to future power systems. In Portugal, forecasts for 2020 show significant excess of renewable energy generation that can be transformed by power-to-gas technology and fed into the natural gas infrastructure. This work suggests an innovative approach to assess future power-togas integration potentials at the national level, focusing on wind power. Following a geographical distance analysis, a first economical estimation of future energy transformation costs is made with the help of Levelized Costs of Energy (LCOE).