As of December 31, 2018, CEMEX Colombia owned two operating cement plants and three mills, having a total annual installed capacity of 4.0 million tons. In addition, through its grinding mills, CEMEX Colombia could produce 0.5 million tons of cement sourced by third parties. In 2018, we replaced 18% of our total fuel consumed in CEMEX Colombia with alternative fuels, and we had an internal electricity generating capacity of approximately 37 MW as of December 31, 2018. We estimate that, as of December 31, 2018, the limestone and clay permitted proven and probable reserves of our operations in Colombia had an average remaining life of approximately 67 and 100 years, respectively, assuming 2014-2018 average annual cement production levels. The operating licenses for quarries in Colombia are renewed every 30 years; assuming renewal of such licenses, we estimate having sufficient limestone reserves for our operations in Colombia for over 200 years assuming 2014-2018 average annual cement production levels. As of December 31, 2018, CEMEX Colombia operated 14 land distribution centers, two mortar plants, 52 ready-mix concrete plants (seven were temporarily inactive) and ten aggregates operations (nine were temporarily inactive). As of that date, CEMEX Colombia also owned 18 limestone quarries.
As of December 31, 2018, CEMEX Panama operated one cement plant in Panama, with an annual installed capacity of 2.1 million tons of cement. As of that date, CEMEX Panama also owned and operated 10 ready-mix concrete plants (one was temporarily inactive), three aggregates quarries (all of which are currently inactive) and four land distribution centers.
As of December 31, 2018, CEMEX Costa Rica operated one cement plant and one grinding mill in Costa Rica, with a total annual installed capacity of 0.9 million tons. As of that date, CEMEX Costa Rica had seven operational ready-mix concrete plants, one aggregates quarry and one land distribution center.
As of December 31, 2018, we leased and operated one fixed cement plant and one grinding mill with a total installed capacity of 0.6 million tons, six ready-mix concrete plants (three were temporarily inactive) and two distribution centers in Nicaragua. Since March 2003, CEMEX Nicaragua has also leased a 100,000 ton milling plant in Managua, which has been used exclusively for pet coke milling.
As of December 31, 2018, CLH indirectly owned 100% of CEMEX Guatemala, our main operating subsidiary in Guatemala. As of December 31, 2018, we owned and operated one cement grinding mill in Guatemala with an installed capacity of 0.5 million tons per year. As of that date, we also owned and operated five land distribution centers, one clinker dome close to the marine terminal in the southern part of the country and three ready-mix concrete plants.
CEMEX LatAm commenced its cement operations in El Salvador in 2011 when it began exporting cement to El Salvador. Our operations in El Salvador consist of a commercial office strategically located in San Salvador, where most of the country's cement demand is located. Our El Salvador's distribution center has a warehouse capacity of 250 metric tons. This commercial office mainly distributes cement produced in Mexico, Costa Rica and Nicaragua.