Interconnection standards specify the technical and procedural process by which an electric customer connects an electricity-generating system to the grid. Interconnection standards include the technical, contractual, metering, and rate arrangements that system owners and utilities must abide by. Standards for systems interconnected at the distribution level are typically adopted by state public utility commissions, while the Federal Energy Regulatory Commission (FERC) has adopted standards for systems interconnected at the transmission level. Not all states have adopted interconnection standards, and some states? standards apply only to investor-owned utilities -- not to municipal utilities or electric cooperatives.