Of the bacterial isolates found in the Arctic that are able to degrade PCBs, none used compounds such as 2-chlorobiphenyl, 3-chlorobiphenyl, camphor, citronellol, cymene, dehydroabietic acid, limonene, methanol, n-hexadecane, pentachlorophenol, phenol, or pinene as primary growth substrates (Master and Mohn 1998).
In the 20th century, demand for electricity led to the consideration of geothermal power as a generating source. Prince Piero Ginori Conti tested the first geothermal power generator on 4 July 1904, at the same Larderello dry steam field where geothermal acid extraction began. It successfully lit four light bulbs. Later, in 1911, the world's first commercial geothermal power plant was built there.
Countries generating more than 15 percent of their electricity from geothermal sources include El Salvador, Kenya, the Philippines, Iceland and Costa Rica. Geothermal power is considered to be a sustainable, renewable source of energy because the heat extraction is small compared with the Earth's heat content.eothermal electricity is electricity generated by geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations.