Forecast: Sunny with a Chance of Curtailment
A while back, the DOE Solar Energy Technologies Office asked my colleague Wesley Cole to explore the implications of continuing declines in PV (and storage) prices on potential deployment. He led this study, which uses NREL’s ReEDS model and found least-cost expansion scenarios where the U.S. derives up to 55% of annual electricity from solar by 2050. ReEDS is great (and now open access), but it’s still “just” a capacity expansion model, so it doesn’t do chronological simulations and is thus limited in its ability to verify operational feasibility. So Bethany Frew led a follow-on study using a utility-grade dispatch model to look at some of these scenarios and test the usual metrics (dropped load, reserve violations, etc.).
The result: our new paper, which looks at how the system would need to be operated at 55% PV penetration (with lots of storage) across all three U.S. interconnections. While the results align with what we’ve seen on smaller test systems, I think it provides a good perspective of the “new normal” under large-scale solar deployment: massive ramp rates and lots of economic curtailment. We didn’t simulate frequency response, but we had periods with very little synchronous generation (particularly in ERCOT), so this will keep the EEs employed designing grid-forming inverters. And, of course, we saw many hours of zero marginal prices to keep the market design folks busy, too. So, it’s certainly an exciting time to be in the grid integration space, with lots of interesting problems to solve.
W?rtsil? Energy Storage & Optimization
5 年This is exactly what we are seeing across all our projects, and our islands of Graciosa and Bonaire (which have grid forming inverters and the latest advanced GEMS software) are prime examples of where the bigger grids are heading. Economic curtailment is exactly the right approach.
CEO & Co-founder of Starfire Energy
5 年Thanks, Paul. We regularly have people suggest that Starfire Energy can use the curtailed solar at zero cost to make lower cost carbon-free NH3. My take is that (a) you can't plan around curtailment very well, and (b) curtailed electricity will only be free until someone says they want it. Any business undertaking that plans on using zero-cost electricity starts to look like a paying customer once they scale up and actually NEED that electricity. Do you have any thoughts on that?
Senior Vice President, Fundamentals & New Markets at Pattern Energy Group
5 年Paul Denholm would be great to have the same focus for wind power and some combinations of wind and solar with Ryan Wiser - what would these look like operationally on US grids.
Intern Program Manager at National Renewable Energy Laboratory
5 年great title!
Senior Vice President Darlington New Nuclear Project
5 年This is exactly what California is already seeing with even lower levels of solar penetration.