The energy requirements for storing one ton of co2 are many many times higher than the energy gained from generating one ton of co2 (by oil, gas, coal or biofuel).

So each MWh spent "storing co2" would be ten times more efficient if used to offset oil extraction to get one MWh less out in the first place.

This is wasteful greenwashing. If it wasn't, we'd have broken physics on the level of making perpetual motion machines.