- Long-range (generally, DC) power transmission lines. China is investing heavily here.
- Similarly, inter-grid connections. See https://en.wikipedia.org/wiki/Tres_Amigas_SuperStation - Superconductors!
- Diversified renewables. Solar works on the stifling windless summer days; wind works on those nasty drifting snow winter nights.
- Dispatched demand. For example, industrial facilities can be incentified to shut down power-hungry processes on days with less available electricity, in exchange for cheaper electricity on other days.
- Of course, 'peaker' natural gas turbines. A surprising number of gas power plants are used less than 10% of the time...