Among the many ocean energy technologies under development, the tidal turbine farm has been proposed as an environmentally friendly ocean energy converter application. Although the technology and capital costs of ocean energy turbines are understood, the economics of operating a gang of turbines as an energy farm has yet to be analyzed. In this paper, a planning, operation and maintenance model for tidal turbine farms is proposed. The system is modeled using life-cycle assessment, incorporating a variety of time-dependent variables. Model components include farm construction and planning, operation strategy, regular maintenance, and emergency maintenance. Preliminary numerical simulation results are shown in a case study for a potential site.