The Perception That PV Curtailment is “Waste” Can Have Major Effects on Resource Planning

While it is generally understood within the technical PV community that intentional PV curtailment is a tool used to achieve a cost-optimized highly-renewable grid, this is less well known by environmentalists and regulators that participate in the process to approve future generation assets. This paper will describe recent discussions at the Colorado Public Utilities Commission and decisions in which a proposed cap on curtailment at 5% may have had a significant effect in rejecting the addition of significant renewables in a resource plan targeting 80% renewables by 2027. Economic arguments are complicated by Power Purchase Agreements that buy power that has been subsidized through production tax credits. This increases the apparent costs of curtailments by requiring reimbursement for foregone tax credits.