One could reach 100% renewable energy in your scheme by adding one more source of renewable — water: hydroelectric.
Create a two-level reservoir system of lakes.
Use the periods of excess energy to pump the water from the lower to the upper lake of each pair.
During the periods of low/no wind, etc. produce hydroelectricity as the water flows from upper to lower lake of each pair.
True, except the trend in this country is to remove dams ... for the environment.
Except that the energy expended in pumping water uphill is always greater than the energy generated by the water flowing back downhill.
That’s already been done for conventional power (pumped hydro power) and is being developed further for use with renewable and renamed “water battery”.
https://www.hydroreview.com/hydro-industry-news/a-water-battery-it-could-happen-soon/