That's not really true. The grid has worked just fine for decades. We also do have "good" means of storing electrical energy, they're not as economical as just running at sufficient capacity and managing the grid properly.
Texas had blackouts due to extreme cold as recently as 2011. The findings from the investigation after that event were ignored and we are now seeing a repeat of it exactly 10 years later. It has not worked "just fine" for decades.