Are Integration Costs and Tariffs Based on Cost-Causation?

Integration cost analysis has progressed significantly over the past ten years. There is also a much better understanding of the cost drivers among the system stakeholders. This paper examines how wind and solar integration studies have evolved, what analysis techniques work, what common mistakes are still made, and what and why calculating integration costs is such a difficult problem thatshould be undertaken carefully, if at all. The many complex interactions among components of the power system and assumptions regarding the base case have important influences on integration cost estimates, and raise questions about whether integration cost components can be correctly untangled. We discuss many of these concerns and implications, shedding some light on the difficulties involvedin measuring and interpreting integration cost estimates.