The power supply and the energy supply will not have a single solution. It is analogous to the levels of caching in a Von Neumann cpu. L1 will capacitors, L2 batteries, bulk storage is pumped hydro and other GWh energy stores.

The duck curve is a smoke screen and should only exist for a region that doesn't have solar to the west of it. Those solar farms in CA should be feeding users a timezone over to the east.

Any source can then feed into those stores, wind, solar, hydro.

If your power solution is involves hydrocarbons, it should be a closed cycle.