Intermittency just mean that we cant switch society over to it wholesale. -
CCS is a daft idea, because a coal fired plant with ccs is going to be at even more expensive and difficult to build than a nuclear powerplant, and the potential failure modes make chernobyl look harmless - imagine what happens if the geological storage ruptures after 15 years of operation? - Everything above the storage point will chocke to death.
So its simply worse than nuclear plant in every possible way. and to top it off, we dont know how to actually build them. Replacing replacing coalfired plants with reactors will be cheaper and safer both..

1. You don't balance intermittency by running balancing power plants at full power.

2. Coal power plants are NOT used for balance: just like nuclear, they aren't well suited for variable power output. It's gas, oil, hydro (and pumped storage) that can be used for this.

3. That intermittency would be a problem for baseload provision comes from an antiquated and over-simplifying notion of power provision, helped by having only two categories ("base load" and "peak load") in the English language.
   
   It would be closer to reality to divide power provision in three (as is done in German): "base load" consisting of plants running at full capacity, a "medium load" providing scheduled variable power; and finally a "peak load" compensating unplanned positive and negativew spikes in generation and demand on short order.
   
   Now, what is the second of these for? In the pre-windpower system, it is usually said to compensate the well-known periodic daily change in demand. However, it does another thing too: when a big baseload plant is stopped for maintenance, or stops because of an accident, the medium load plants also compensate for this foreseeable variability in baseload production.
   
   Now, what if we introduce intermittent wind power into the system? Well, wind power output, especially if there are lots of wind farms in the system, can be predicted. Thus, in fact, in Denmark or North Germany, the bulk of the variability of wind power production can be fed into the schedule of the "medium load" plants! While only the deviations from that need to be compensated by the peak load plants. Thus, in effect, wind power is base load.

4. What's more, if you think about the above, neither coal nor nuclear is able to replace medium and peak load plants that use other fossil fuels. (This is true even for nuclear France, where some of the balancing is 'done' by exporting the surplus to Italy, Spain and the Netherlands.) That whole argument (whether used for nuclear, or, less frequently, CCS) is bollocks.