Storage is addressed at that modeling site. In particular, a mix of energy storage technologies appears to be very useful (not just batteries). A key is to note that a simple cycle turbine power plant is 5% of the capital cost of a nuclear plant per kW. So, if we had to totally back up the grid with hydrogen-burning turbines that could, in a rare pinch, supply 100% of the demand, it still would be cheap compared to supplying that same power with nuclear power plants.