Yes we need more long time energy storage. It helps to balance the energy grid and it helps for days when not enough energy is produced. Batteries aren’t really the answer, but pumping water uphill might be.

Many places actually do pump water uphill into reservoir lakes for hydroelectric dams. In that case it is a form of energy storage, a literal water battery.

Unfortunately, it’s not always a feasible option. For instance, in the great planes there’s not much of an uphill to pump the water to.