350 PART | III Smart Infrastructure, Smart Prices, Smart Devices regulators may not find utility smart grid proposals compelling in terms of direct, near-term benefits to customers. These issues are explored further in the section below on regulatory treatment of smart grid deployment proposals. REGULATORY REVIEW EXPERIENCE WITH SMART GRID DEPLOYMENT PROPOSALS Smart grid technologies present a set of new challenges to regulators in making decisions regarding smart grid investments. U.S. electricity systems have largely operated at high reliability levels at the transmission level, though distribution system reliability varies. But as long as "the lights stay on" and rates remain rela- tively low, it can be difficult for policymakers to understand how smart grid tech- nologies can improve the value of electricity systems. It can also be challenging to understand the incremental value of smart grid investments, as they are often implemented in stages, with each stage requiring regulatory approval. But many smart grid benefits come from the combined and cumulative effects of a portfolio of smart grid technologies over time. The Illinois Commerce Commission summarized this conundrum recently (ISSGC, 2010): The issue of smart grid cost recovery has been a matter of controversy and litigation for