Comment by hvb2
> You can do find in a day with battery but you can’t really produce a lot in the summer and use in winter.
Batteries aren't the only storage. The better options in my opinion are the places where you can use the landscape to your advantage. Pump a lake full when there's too much power and let it drain when there's too little.
Also in a connected grid setup, the sun always shines somewhere though that does come with potentially huge transmission losses from distance
You need a reliable source for energy. Pumped storage is not. They are mostly good for dealing with the fluctuations of energy supply and demand. It crucially requires water to operate. You can't do much when there's a drought. Also, did some googling. The world’s largest pumped‑hydro storage plant (Fengning, China) stores nearly 40 GWh, delivering 3.6 GW for about 10.8 hours when full. Thats not even a day.
There are really three options for reliable baseload: coal, gas, nuclear. Pick your poison.