U.S. UTILITIES see great potential in the use of remote-controlled drones to do the often-dangerous work of inspecting power lines and transmission towers, but strict regulations have so far slowed adoption of the technology.

The remote-controlled devices make the work of linemen safer, more efficient and less expensive, according to the Electric Power Research Institute, which last month put on a three-day workshop to help nearly a dozen utilities choose the best machines for the job. Miniature helicopter-like drones, some equipped with cameras and other sensors, conducted demonstration inspections of transmission lines at a hydroelectric plant in New York's Catskill Mountains.

Utilities spend millions of dollars inspecting power lines, which are often in hard-to-reach places. The industry has been interested in the potential use of drones for years, but has been slower than European companies to adopt the technology because of U.S. regulatory restrictions.

Although hobbyists can fly drones without certification, the Federal Aviation Administration requires special certification for commercial users. There are numerous conditions and limitations.