The seaside Encina Power Station, a Carlsbad landmark since the 1950s, has officially been retired to prepare for demolition.

Owner NRG Energy Inc. switched off the old plant at 11:59 p.m. Dec. 11 and turned on its replacement. The new, smaller, more efficient “peaker” facility can be fired up in 10 minutes to meet local demand.

Removal of the old plant could take up to three years. After that, the prime piece of coastal real estate will be ready for something new.

A luxury hotel, restaurants and a shopping center are possibilities under the Carlsbad General Plan, though nothing’s certain yet. Some smaller pieces of the property will be turned over to the city to remain as parks or open space.