Solar and wind power are now cheaper than fossil fuels but are intermittent. The extra supply-side variability implies growing benefits of using real-time retail pricing (RTP). We evaluate the potential gains of RTP using a model that jointly solves investment, supply, storage, and demand to obtain a chronologically detailed dynamic equilibrium for the island of Oahu, Hawai'i. We find that, holding demand assumptions fixed, RTP reduces costs in high-renewable systems by roughly 6 to 12 times as much as in fossil systems, markedly lowering the cost of clean energy integration.