Net metering has been around since the early 1980s when solar panels were expensive and few people had them. But the dynamics changed drastically when states began passing renewable portfolio standards (RPS) that required predetermined percentages of electricity be generated from renewable sources—some even specified which sources are part the mix and how much of the resource was required. For example, in my home state of New Mexico, the Diversification Rule requires that 1.5% of the RPS must be met by “distributed generation” (read: rooftop solar). Arizona requires 30% of the RPS be derived from “distributed energy technologies” (once again, rooftop solar).