As part of Boston’s most aggressive effort to reduce energy consumption, the city is launching a two-month pilot program dubbed Lights Out Boston, a move that will save about 25 percent in energy used for lighting, Boston.com reports.

The program will see 34 Boston skyscrapers, from Back Bay to the South Boston waterfront, extinguishing the lights above their 30th floors between 11 p.m. and 5 a.m., under the request of Mayor Thomas Menino.

Some of the city’s largest landlords are voluntarily participating in the program, such as CB Richard Ellis, Boston Properties, and Broadway Partners Real Estate Services.

The Planet also saved big with a lights-out program, reducing its yearly energy consumption by more than 1.4 million kilowatt hours which delivered an annual cost savings of almost $140,000.

Last year, Yahoo and PG&E donated more than 100,000 compact fluorescent light bulbs as part of an energy conservation campaign organized by Lights Out San Francisco.