gave FERC significant new responsibilities, including enforcement of electric transmission reliability standards and the establishment of rate incentives to encourage investment in electricity transmission. Historically, local governments exercised authority over the grid and maintained significant disincentives to actions that would benefit states other than their own. Localities with cheap electricity have a disincentive to encourage making interstate commerce in electricity trading easier, since other regions would be able to compete for that energy and drive up rates. For example, some regulators in Maine refused to address congestion problems because the congestion protects Maine rates. Local constituencies can block or slow permitting by pointing to visual impacts, environmental, and health concerns. In the US, generation is growing four times faster than transmission, but transmission upgrades require the coordination of multiple jurisdictions, complex permitting, and cooperation between a significant portion of the many companies that collectively own the grid. The US national security interest in improving transmission was reflected in the EPAct which gave the Department of Energy the authority to approve transmission if states refused to act. Specialized transmission Grids for railways In some countries where electric locomotives or electric multiple units run on low frequency AC power, separate single phase traction power networks are operated by the railways. Prime examples are countries such as Austria, Germany and Switzerland that utilize AC technology based on 16 2/3 Hz. Norway and Sweden also use this frequency but use conversion from the 50 Hz public supply; Sweden has a 16 2/3 Hz traction grid but only for part of the system. Superconducting cables High-temperature superconductors (HTS) promise to revolutionize power distribution by providing lossless transmission. The development of superconductors with transition temperatures higher than the boiling point of liquid nitrogen has made the concept of superconducting power lines commercially feasible, at least for high-load applications. It has been estimated that waste would be halved using this method, since the necessary refrigeration equipment would consume about half the power saved by the elimination of resistive losses. Companies such as Consolidated Edison and American Superconductor began commercial production of such systems in 2007. Superconducting cables are particularly suited to high load density areas such as the business district of large cities, where purchase of an easement for cables is costly. Single-wire earth return Single-wire earth return (SWER) or single-wire ground return is a single-wire transmission line for supplying single-phase electrical power to remote areas at