The Los Azufres III (75MW) Expansion Project in the Los Azufres Geothermal Field, Mexico

Abstract

In 1982 commercial exploitation of The Los Azufres geothermal field, Mexico, began with the installation and commissioning of the first 5 backpressure turbine generator units, 5 MW each, and was increased until reaching an installed capacity of 188 MW with the addition of 4 units of 25 MW each in 2003. The field contains fourteen units distributed as follows: 5 in the southern part fed by the steam of 18 producing wells, 2 units of binary cycle using residual brine and 7 units in the northern fed by the steam of 22 wells. Of these, seven are backpressure of 5 MW capacity each, and with specific consumption averaging 13.7 t/h-MW. Three are located in the south and four in the north. This paper presents the Los Azufres Project III (75MW), which aims to achieve greater efficiency in the utilization of geothermal resources for power generation. This allows the replacement of 7 backpressure units, with a high specific consumption and close to fulfilling their lifetime, for two to condensation, of lower specific consumption, one of 50 MW, located in the north and another 25 MW in the south. This reduces the fuel economy of 13.7 to 7.2 t / h-MW (47.4%). Without the withdrawal of 7 units, the installed capacity would have increased from 188 MW to 228 MW, without drilling new wells. Based on the foregoing, it is proposed to develop a geothermal project of 75 MW, sustainably and in harmony with the requirements of energy for economic and social development in the region by 2012, replacing backpressure plants by other more efficient condensation plants. It defines the basic criteria for drawing up the feasibility study, basic engineering Los Azufres III Project and the Environmental Impact Statement.