Least-Cost Firm PV Power Generation: Dynamic Curtailment vs. Inverter-Limited Curtailment:

Overbuilding and dynamic curtailment are increasingly acknowledged as central to cost-optimally transforming intermittent PV and wind resources into firm power resources. While this strategy is not currently monetizable, firm power generation will be a prerequisite at ultra-high renewable penetration when demand will have to be met 24/365 without reliance on underlying dispatchable generation.A distinct overbuilding/curtailment strategy is increasingly implemented today: inverter-limited curtailment. This strategy can take advantage of some existing remuneration systems.In this article, we compare the effectiveness of the two strategies to deliver firm power generation at least cost. We consider the extreme case of PV meeting demand with 100% certainty using two MISO’s load balancing areas (#4 and #10) as experimental support. We show that, while both strategies can achieve firm power generation at a lower cost than curtailment avoidance would, dynamic curtailment is far more cost-effective than inverter-limited curtailment. Importantly, we also show that optimally combining both strategies can further reduce firm power generation cost.