Yes and france depends on other countries for its incapability to quickly vary production. In other words the nuclear fleet of France has a significantly higher capacity factor than the average demand of the french grid because it can push power to other countries. If that did not exist the french nuclear power would be a lot more expensive (uranium is not free!)
Power demands fluctuate as do power generation capabilities. If your generation is inflexible, as nuclear and solar both are at this time (economically speaking right now in this year). You need quick reaction power (e.g. gas peakers) or e.g. pumped hydro.
The funny thing is a wholly nuclear grid needs storage as much as a full solar+wind grid does. Of course in a mixed grid both techs can play to their strengths.
For example in Lazard's 10.0 LCOE analysis solar plus battery is 92 USD per Mwh, while Nuclear starts at $97.
That is smack in the middle of LCOE coal costs!
But the solar, will have a lot less of regulatory and construction uncertainty! And a much smaller financial risk. As 3 years from project start to completion is normal. With most projects being set up in independent financial contracts of about 100mw nameplate to allow cancellation if performance or market do not materialize.
That's temporary. New powerlines to south Germany are being built, a new HVDC line to Norway is under construction.
Additionally we will see a lot of new ways to deal with surplus electricity. Surplus electricity in the North will grow over the next two decades. Power to gas, Power to Heat, etc. will be feasible then.
France has the same problem, but different. Demand varies + production varies. On many weekends they have surplus power from the nuclear plants. In summer and winter nuclear power may not be able to meet demand. In hot summer weeks, the nuclear power plants overheat the rivers. In cold winter weeks, the electrical heating of French consumers creates more demand than nuclear electricity is available. This problem may increase, since France has aging reactors, but new reactors are not coming online - maybe one EPR - but when? 2018? 2020? 2022?
