NEW YORK & BOGOTÁ, Colombia--(BUSINESS WIRE)--The Dominican Republic's diversification of the country's energy matrix away from more expensive liquid fuels will lower the marginal cost of electricity but not affect the ratings of major Dominican private electric generators (GENCOs), Fitch Ratings says. The government's plan adds cheaper new coal capacity and sets the stage for a renegotiation of private electricity generators' power purchase agreements (PPAs) that expire between 2016 and 2018,