Hat tip to PV Magazine:

• B. Frew, W. Cole, P. Denholm, W. Frazier, N. Vincent, R. Margolis, “Sunny with a Chance of Curtailment: Operating the US Grid with very high levels of solar photovoltaics“, (open access) iScience, 21, 22 November 2019, Pages 436-447.
• J. Weaver, “Designing for and monetizing curtailed solar power“, PV Magazine, May 2019.
• V. Gevorgian, “Highly accurate method for real-time active power reserve estimation for utility-scale photovoltaic power plants“, NREL, 2019.

Highlights of Frew, Cole, Denholm, Frazier, Vincent, Margolis

• Load and operating reserves can be met in US grid with up to 55% PV with storage
• Power system must rapidly transition between synchronous and inverter-based generation
• Significant curtailment is seen, with hours of >40% economic curtailment
• Hours with very low energy prices become more frequent, up to 36% of hours

Summary

With rapid declines in solar photovoltaic (PV) and energy storage costs, futures with PV penetrations approaching or exceeding 50% of total annual US generation are becoming conceivable. The operational merits of such a national-scale system have not been evaluated sufficiently. Here, we analyze in detail the operational impacts of a future US power system with very high annual levels of PV (>50%) with storage. We show that load and operating reserve requirements can be met for all hours while considering key generator operational constraints. Storage plays an active role in maintaining the balance of supply and demand during sunset hours. Under the highest PV penetration scenario, hours with >90% PV penetration are relatively common, which require rapid transitions between predominately conventional synchronous generation and mostly inverter-based generation. We observe hours with almost 400 GW (over 40%) of economic curtailment and frequent (up to 36%) hours with very low energy prices.

(Emphasis added in the above.)

Highlights.