Because of their large size, rapid growth, and palatability, tilapia cichlids are the focus of major farming efforts, specifically various species of "Oreochromis", "Sarotherodon", and "Coptodon" (all were formerly in the namesake genus "Tilapia"). Like other large fish, they are a good source of protein and popular among artisanal and commercial fisheries. Most such fisheries were originally found in Africa, but outdoor fish farms in tropical countries, such as Papua New Guinea, the Philippines, and Indonesia, are underway in freshwater lakes. In temperate zone localities, tilapiine farming operations require energy to warm the water to tropical temperatures. One method uses waste heat from factories and power stations.