During the past five years there has been a growing trend in the states to adopt legislation for the siting of power facilities. To date, 25 states have enacted new legislation that provides for regulation of the siting of thermal power plants and transmission lines. Many other states have such requirements under consideration. The most definite trend in recent state laws is the requirement for preconstruction certification for new fossil and nuclear generating plant sites, as well as for transmission line routes. In all the 25 states, environmental protection was mandated as a fundamental policy, requiring environmental issues to be part of the considerations made by the certifying agency. Furthermore, the trend to consolidate the certification process is indicated by the fact that the majority of states, 17 of 25, have a “one-stop licensing” provision for siting power facilities. Consolidating the licensing process increases regulatory effectiveness and decreases licensing delay. Since there is the need for expediting the certification process as well as public interest in protecting environmental values in power facility siting, we can expect more states to enact similar siting and certification laws, regardless of the success of federal activity on power plant siting legislation.