Gas-fired power stations are a conceivable means to compensate for the shut-down of nuclear power plants, at least over the mid-term until renewable energy sources can be economically exploited at large scales. According to current policies in Switzerland, any future gas-fired station would have to be free of CO2 emissions, yet a 400 MWel combined-cycle station would produce approximately 0.7 Mt CO2 per year (assuming 360 kg/MWh and 5000 h/year operation). Given that CO2-capture technologies exist, the challenge to enable gas-based electricity production is to demonstrate that such large quantities of CO2 can be safely and permanently stored in the subsurface of Switzerland without felt seismicity, near sites where gas-fired stations could be constructed. Several injection projects around the world have proven that large-scale geological storage can be successfully implemented from the technological standpoint. However, these projects have underscored the fact that technological success is extremely dependent on the specific geological characteristics of the site chosen. In Switzerland, preparatory work has estimated a theoretical storage potential of 2.5 Gt CO2 in the deep saline aquifers beneath the Central Plateau. These aquifers must now be evaluated with respect to practically achievable storage capacities, as well as to viable rates of CO2 injection, magnitude and predicability of induced seismicity, cap-rock integrity and longevity of trapping.