The Instituto Costarricense de Electricidad says it is investing $20.5 million to erect 37 towers and build a substation to improve the transmission of electricity between Parrita and Jacó.
The project is expected to be in service by the middle of next year. Work began in 2014.
The new power lines also will include a link to Cañas, said the company.
The work is supposed to improve electrical service along the Pacific coast for the benefit of residents, businesses and tourism operators, said the company.