LANCASTER TWP — Alternative energy sources are not just for power generating companies. They also are beginning to show up on residential properties, including one in the township.

The township supervisors Wednesday night approved a residential wind turbine that will assist a township homeowner with his electrical power consumption.

The 60-foot tall, 12-foot diameter, monopole wind turbine will be built on property owned by Frank Brewster at 128 Stone Church Road.

Township ordinances allow wind turbines on residentially-zoned property with more than 5 acres, and a turbine cannot exceed 150 feet in height.

Brewster owns 120 acres.

Contractors representing Brewster said the turbine, the size of a small airplane propeller, would not make any audible noise.

The number of residential wind turbines has grown steadily in the past decade, according to the American Wind Energy Association, a nonprofit advocacy group in Washington, D.C.

In 2007, the wind turbine market grew 14 percent.

Residential turbines are much smaller than turbines used for power company use such as can be seen off the Pennsylvania Turnpike at the Somerset Wind Farm and the new turbines being constructed off Route 22 near Altoona.

Residential turbines are typically 33 to 100 feet tall, with outputs of two to 10 kilowatts. They cost between $12,000 and $55,000.

It is estimated by industry experts that an investment in a residential wind turbine will break even over the 20-year life of the turbine, depending on electrical rates.