Founded in 1998, Panama's state transmission company Empresa de Transmisión Eléctrica S.A. (Etesa) operates high voltage power lines. With offices in Panama City, Etesa holds the extendable concession for high voltage transmission until 2025 granted by local public services regulator Asep. Its transmission system is formed by ten stretches of 230kV power lines that run from hydro plant Bayano to substation Progreso on the Costa Rican border and two 115kV lines linking thermo plant Bahía Las Minas to substation Panama I and substation Caldera to hydro plants Estrella and Los Valles. In 2014 it issued its first call for tenders for solar generation projects. In 2016 Etesa called for tenders to supply electricity to power distributors for the period 2017-2020 drawing the interest of 17 companies. In addition, the company provides technical studies to identify hydro and geothermal development opportunities in the country.