Modern HRSG Designs Maximize Combined Cycle Plant Efficiency

Iberdrola SA and Mitsubishi Hitachi Power Systems (MHPS) recently commissioned the El Carmen combined cycle plant, located in Nuevo León, northeast Mexico. Wood supplied the two horizontal heat recovery steam generators (HRSGs) for the plant. The 875-MW combined cycle plant is based on two 300-MW MHPS M501J combustion turbines and is the first plant built in Mexico to sell power directly to industrial customers through its wholesale power market in over 70 years. CFEnergia, a subsidiary of CFER, delivers natural gas to the plant.

Mexico began deregulating its electricity market in 2013 with wholesale trading commencing in 2016. The reforms opened the electricity market to private investors to increase market competition, and to accelerate the expansion and modernization of Mexico’s power generation infrastructure. Until 2013, all facets of the electricity market, from generation to distribution, were the exclusive domain of the state-owned Comisión Federal de Electricidad (CFE), an integrated monopoly, and private participation was limited to the generation of power not intended for public consumption. CFE remains the only provider of retail electricity to consumers. CENCE (Centro Nacional de Control de Energía) operates Mexico’s energy grid as the independent system operator. Private generators gain access to the national grid through an auction of medium- and long-term contracts by CENCE.

A more pressing reason to open the power market to private investment was Mexico’s annual electricity demand had grown an estimated 3% per year since 2000 and is expected to continue to grow for the next decade. This translates into Mexico’s rising economy demanding an additional 70 GW of installed generation through 2033. Mexico expects that an estimated 30 GW of that demand growth will be met by new gas-fired combined cycle power generation facilities. The remainder will be met by various renewable resources. Mexico, as of the end of 2019, had 8.2 GW of gas-fired combined cycle plants in operation.

Spanish power utility Iberdrola subsidiary Iberdrola México is the largest private electricity producer in Mexico with more than $5 billion invested in power generation (fossil fuel-fired and renewable) facilities to date. As of the end of 2019, Iberdrola México had 6,588 MW in commercial service, providing electricity to more than 20 million customers. Of that amount, 5,668 MW correspond to gas-fired combined cycle plants. With another four combined cycle plants set to enter service by the end of 2020, Iberdrola México is on track to add an additional 3,434 MW to its fleet of plants and to surpass the 10,000 MW of installed generation milestone.

Project Overview

The El Carmen combined cycle plant, located in the town of the same name in Nueva León in northeast Mexico close to the Texas border, is one of the newest combined cycle plants added to Iberdrola’s growing fleet of plants (Figure 1). The…