Cogeneration is broadly defined as the simultaneous production or by combination of electricity and heat.

The prefix “co” in the word “cogeneration” simply means valorifying all modes of use of energy sources, in this case natural gas. Thus, by cogeneration there is produced a supplement of energy with a much of the energy that would be lost in the typical use.

Combining heat with electricity is not a new concept. Since 1978, the US Department of Energy reported that in 1900, 58% of the total electricity produced by industrial plants had been obtained through cogeneration. In Europe however, cogeneration widespread use was much faster. In 1972, according to the statistics of the same department, 16% of the electricity produced in West Germany was cogenerated. In Italy cogenerated electricity was 18%, France 16% and 10% in the Netherlands.

Over time the type of energy cogeneration has been improved in concept and production operations, developing innovative processes and equipment to achieve them. CHP systems are used increasingly more in the northern and eastern Europe, and lately in the US and Canada. Electricity production from cogeneration is approx. 10% in the EU in 2001 (installed capacity), but there are large differences between different countries – from 2 to 60% of electricity production.

The strategy formulated in 1997 by the European Commission has set the goal of doubling by 2010, the use of this technology, reaching a 18% share of CHP in EU electricity production. It is estimated that achieving this goal will result in reducing CO2 emissions by 65 million tons annually.

In Romania, in addition to industrial cogeneration, around the 1960s, massive development of urban buildings created favorable prerequisites for the development of cogeneration in heating. Notably is the fact that Romania ranks 3rd in Europe (after Russia and Poland) in terms of heating network.

Cogeneration is a process that capitalizes every resource to its full potential, which provides economic and energy efficiency while helping protect the environment.

The principle underlying the cogeneration process is quite simple: electricity generation produces heat, the cogeneration system captures and uses this heat to provide hot water, steam, heat for space heating or cooling. From this perspective, conventional production proves to be extremely economic and energy inefficient, only a third of the energy potential of the fuel is converted into usable energy. In this way, significantly increase of the efficiency with cogeneration means lower fuel consumption and reduced emissions compared to conventional production of heat and electricity.

The process of a cogeneration system is the following: A heat engine (steam or gas turbine, internal combustion engine) acts as an electric generator that produces electricity and waste heat (steam, combustion gas and / or liquid cooling) is recovered to produce process steam or heating agents.