This paper presents a stochastic optimization approach to the feasibility study for power lines, taking into account market conditions. To validate the proposed stochastic approach, an economic comparison of several power line design alternatives has been done, considering technical issues as well. The final evaluation and analysis was based on the results obtained by applying both approaches: the deterministic (classical) method and the stochastic one. Both methods are used for power line design including optimum selection of the main parameters of the line such as tower height, type and coordinates, conductor type and cross-section, line fittings etc. The optimization problem is formulated as minimization of the total annual operating and construction costs. The solution task is realized in MATLAB software by using the Monte Carlo method as well as in the overhead power line automation design system PLS-CADD.