The energy evolution in Oradea City after 1918 took place in the difficult circumstances of Romania affected by two world wars and by a financial crisis in interwar period 1929-1933. Thus, in the years following 1918, economic development of Romania was slow, with a peak in 1938. Low-power energy installations, generally smaller than 1 MWe / unit, have supplied electricity to the towns and local industry. After 1950, a large number of hydro and thermal power plants were built in Romania, which have been interconnected in the National Energy System, providing electricity and heat to the industrial and dweling expansion. The paper presents some aspects of the energy field achievements in Oradea, registered after 1918 until 1945, especially with regard to the cogeneration thermal power plants built in this city in the 1960s – 1970s. Cogeneration thermal plant achieved in Oradea has had an installed power capacities of 355 MWe, which has a significant contribution to the economic and social development of the city, but as we saw, the return to democracy in Romania after 1990 meant stopping and dismantling a great part of the industrial units, this thermal plant needed to be closed, as a result of the sharp decreasing of the heat consumption, mainly after 2005-2010. In Oradea, an up to date 47 MWe and 51 MWt gas turbine cogeneration plant was established from non-reimbursable European funds, that supplies the city with thermal energy beginning by the winter 2016/2017.